bluuebunny/crossref_metadata_2025_split huggingface dataset:
Structural signature of SCA3: From presymptomatic to late disease stages
Authors: Rezende Thiago Junqueira Ribeiro , de Paiva Jean Levi Ribeiro , Martinez Alberto Rolim Muro , Lopes‐Cendes Iscia , Pedroso José Luiz , Barsottini Orlando Graziani Povoas , Cendes Fernando , França Marcondes C. 
Published: July 2018

ObjectiveMachado–Joseph disease (SCA3/MJD) is the most frequent spinocerebellar ataxia worldwide and characterized by brainstem, basal ganglia, and cerebellar damage. However, little is known about the natural history of the disease. This motivated us to determine the extension and progression of central nervous system involvement in SCA3/MJD using multimodal magnetic resonance imaging (MRI)‐based analyses in a large cohort of patients (n = 79) and presymptomatic subjects (n = 12).MethodsAll subjects underwent MRI in a 3T device to assess gray and white matter. To evaluate the cerebral and cerebellar cortices, we used measures from FreeSurfer and SUIT. T1‐multiatlas assessed deep gray matter. Diffusion tensor imaging multiatlas was used to investigate cerebral white matter (WM) and SpineSeg to assess the cervical spinal cord.ResultsThere was widespread WM and cerebellar damage, in contrast to the restricted motor cortex involvement when all patients are compared to age‐ and sex‐matched controls. Presymtomatic patients showed WM microstructural abnormalities mainly in the cerebellar and cerebral peduncles and volumetric reduction of midbrain, spinal cord, and substantia nigra. To assess the disease progression, we divided patients into four subgroups defined by time from ataxia onset. There was a clear pattern of evolving structural compromise, starting in infratentorial structures and progressing up to the cerebral cortex.ConclusionStructural damage in SCA3/MJD begins in the spinal cord, cerebellar peduncles, as well as substantia nigra and progresses to cerebral areas in the long term. These structural differences reveal some insights into the pathogenesis of SCA3/MJD and suggest a staging scheme to map the progression of the disease. Ann Neurol 2018;84:401–408
NHC‐Catalyzed Electrophilic Trifluoromethylation: Efficient Synthesis of γ‐Trifluoromethyl α,β‐Unsaturated Esters
Authors: Yang Wen , Ma Dengke , Zhou Yu , Dong Xiuqin , Lin Zhenyang , Sun Jianwei 
Published: July 2018

AbstractDescribed herein is a highly regioselective and efficient N‐heterocyclic‐carbene‐catalyzed γ‐trifluoromethylation of vinylogous enolates. Control experiments and DFT calculations provided important insight into the reaction mechanism.
Synthesis of a Structure‐Definite α‐Cyclodextrin‐Based Macromolecular [3]Rotaxane Using a Size‐Complementary Method
Authors: Akae Yosuke , Sogawa Hiromitsu , Takata Toshikazu 
Published: July 2018

AbstractThe challenging synthesis of an α‐cyclodextrin (CD)‐based macromolecular rotaxane with definite structure was fulfilled using a size‐complementary method. A new peracetylated (PAc) α‐CD‐based size‐complementary [3]rotaxane was prepared and its thermal dissociation kinetics studied. The de‐slippage mechanism was found to be different from that of the native α‐CD‐based system. PAcα‐CD‐based size‐complementary [3]rotaxanes were employed as initiators for a ring‐opening polymerization of ϵ‐caprolactone to obtain the macromolecular [3]rotaxanes. Detailed investigation of component dissociation showed the highly movable character of the wheel on the polymer main chain. A general method for controlling the movement of wheels in rotaxane frameworks, even in polymer systems, was established. This will enable the development of new supramolecular architectures and molecular machines.
The Hydrazine–O2 Redox Couple as a Platform for Organocatalytic Oxidation: Benzo[c]cinnoline‐Catalyzed Oxidation of Alkyl Halides to Aldehydes
Authors: Stone Ilana B. , Jermaks Janis , MacMillan Samantha N. , Lambert Tristan H. 
Published: July 2018

AbstractAn organocatalytic oxidation platform that capitalizes on the capacity of hydrazines to undergo rapid autoxidation to diazenes is described. Commercially available benzo[c]cinnoline is shown to catalyze the oxidation of alkyl halides to aldehydes in a novel mechanistic paradigm involving nucleophilic attack, prototropic shift, and hydrolysis. The hydrolysis and reoxidation events occur readily with only adventitious oxygen and water. A survey of the scope of viable substrates is shown along with mechanistic and computational studies that give insight into this mode of catalysis.
A semantic network model for measuring engagement and performance in online learning platforms
Authors: Lim Sunghoon , Tucker Conrad S. , Jablokow Kathryn , Pursel Bart 
Published: July 2018

AbstractDue to the increasing global availability of the internet, online learning platforms such as Massive Open Online Courses (MOOCs), have become a new paradigm for distance learning in engineering education. While interactions between instructors and students are readily observable in a physical classroom environment, monitoring student engagement is challenging in MOOCs. Monitoring student engagement and measuring its impact on student performance are important for MOOC instructors, who are focused on improving the quality of their courses. The authors of this work present a semantic network model for measuring the different word associations between instructors and students in order to measure student engagement in MOOCs. Correlation analysis is then performed for identifying how student engagement in MOOCs affect student performance. Real‐world MOOC transcripts and MOOC discussion forum data are used to evaluate the effectiveness of this research.
Molecular Tweezers with Additional Recognition Sites
Authors: Heid Christian , Sowislok Andrea , Schaller Torsten , Niemeyer Felix , Klärner Frank‐Gerrit , Schrader Thomas 
Published: July 2018

AbstractA new synthetic access to molecular tweezers with one or two aliphatic phosphate ester groups in the central benzene spacer‐unit is presented. Alkynyl ester groups offer the prospect to attach additional functional units by click chemistry and greatly broaden the scope of these tools for chemical biology. We present two alternative strategies: the trichloroacetonitrile method involves activation of only one OH group of each phosphoric acid substituent by way of trichloroacetimidate intermediates and subsequent introduction of an aliphatic ester alcohol moiety. The method is versatile, robust and combines simple workup with high yields. Mono‐ and disubstituted novel host structures are thus accessible in a convenient way. Alternatively, the phosphoramidite strategy activates the hydroquinone precursor by way of phosphoramidite intermediates and couples the desired ester alcohols followed by mild oxidation to the desired phosphate esters. Each step of the synthesis is carried out at very mild conditions and allows to combine sensitive host candidates and recognition elements. After neutralization of the phosphoric acids to water‐soluble tri‐ and tetra‐anions the cavities of the new tweezer derivatives are open to bind lysine and arginine as well as peptidic guests. The concept of introducing clickable alkynyl phosphates to free OH groups may be transferred to other major macrocyclic host classes to introduce additional recognition elements, biomolecules or fluorescence labels.
Alkali Metals‐Based Energetic Coordination Polymers as Promising Primary Explosives: Crystal Structures, Energetic Properties, and Environmental Impact
Authors: Sun Qi , Liu Yang , Li Xin , Lu Ming , Lin Qiuhan 
Published: July 2018

AbstractCoordination polymers (CPs) consisting of alkali metals (Na, K, Rb, and Cs) and a powerful nitrogen‐ and oxygen‐rich energetic ligand (4,4′‐bis(dinitromethyl)‐3,3′‐bisnitramide‐methylene‐furazanate, DBMF2−) were developed. Molecular structures of these CPs, confirmed by single‐crystal X‐ray diffraction analysis, indicated that the same ligand takes on a U‐shaped state for Na and an N‐shaped state for K, Rb, and Cs. Explosion tests demonstrated that both Na2DBMF and K2DBMF efficiently detonated the secondary explosive RDX. This indicates that they are both effective primary explosives. K2DBMF exhibits better calculated detonation performance (D: 8227 m s−1; P: 32.5 GPa) than the primary explosive Pb(N3)2. In addition, toxicity tests and evaluation of their decomposition products reveal their low impact on the environment. Both experimental results and theoretical analyses indicate that the combination of alkali metals and a powerful energetic ligand can stimulate the development of primary explosives.
Hydrogen‐Bonded Donor–Acceptor Arrays at the Solution–Graphite Interface
Authors: Velpula Gangamallaiah , Li Mengmeng , Hu Yunbin , Zagranyarski Yulian , Pisula Wojciech , Müllen Klaus , Mali Kunal S. , De Feyter Steven 
Published: July 2018

AbstractControlling the nanoscale morphology of organic thin films represents a critical challenge in the fabrication of organic (opto)electronic devices. The morphology of the (multicomponent) thin films in turn depends on the mutual orientation of the molecular components and their supramolecular packing on the surface. Here, it is shown how the surface co‐assembly of electron‐donating and ‐accepting building blocks can be controlled via (supra)molecular design. Hexa‐peri‐hexabenzocoronene (HBC) derivatives with multiple hydrogen‐bonding (H‐bonding) sites were synthesized and their co‐assembly with alkyl‐substituted perylene tetracarboxy diimide (PDI) was studied using scanning tunneling microscopy (STM) at the solution–graphite interface. STM data shows that electron‐rich HBCs co‐assemble laterally with electron deficient PDIs via preprogrammed H‐bonding sites with high fidelity. The surface stoichiometry of the two components could be readily tuned by changing the number of H‐bonding sites on the HBC derivatives via organic synthesis. This model study highlights the utility of (supra)molecular design in co‐assembly of building blocks relevant for organic electronics.
Metal‐Organic Layers Catalyze Photoreactions without Pore Size and Diffusion Limitations
Authors: Xu Ruoyu , Drake Tasha , Lan Guangxu , Lin Wenbin 
Published: July 2018

AbstractMetal‐organic frameworks (MOFs) have emerged as promising single‐site solid catalysts for organic reactions. However, MOF catalysts suffer from pore size limitation and slow diffusion, which are detrimental for photoreactions. Metal‐organic layers (MOLs) have unique ultrathin 2D monolayer structures and overcome pore size and diffusion limitations. Here, the synthesis of photoactive Zr‐RuBPY MOL based on Zr‐oxo clusters and [Ru(bpy)3]2+‐containing linkers is reported as well as its application in photocatalytic [2+2] cyclizations of enones and Meerwein addition reactions between aryl diazonium salts, styrenes, and nitriles.
Extensive somatosensory and motor corticospinal sprouting occurs following a central dorsal column lesion in monkeys
Authors: Fisher Karen M. , Lilak Alayna , Garner Joseph , Darian‐Smith Corinna 
Published: July 2018

AbstractThe corticospinal tract (CST) forms the major descending pathway mediating voluntary hand movements in primates, and originates from ∼nine cortical subdivisions in the macaque. While the terminals of spared motor CST axons are known to sprout locally within the cord in response to spinal injury, little is known about the response of the other CST subcomponents. We previously reported that following a cervical dorsal root lesion (DRL), the primary somatosensory (S1) CST terminal projection retracts to 60% of its original terminal domain, while the primary motor (M1) projection remains robust (Darian‐Smith et al., J. Neurosci., 2013). In contrast, when a dorsal column lesion (DCL) is added to the DRL, the S1 CST, in addition to the M1 CST, extends its terminal projections bilaterally and caudally, well beyond normal range (Darian‐Smith et al., J. Neurosci., 2014). Are these dramatic responses linked entirely to the inclusion of a CNS injury (i.e., DCL), or do the two components summate or interact? We addressed this directly, by comparing data from monkeys that received a unilateral DCL alone, with those that received either a DRL or a combined DRL/DCL. Approximately 4 months post‐lesion, the S1 hand region was mapped electrophysiologically, and anterograde tracers were injected bilaterally into the region deprived of normal input, to assess spinal terminal labeling. Using multifactorial analyses, we show that following a DCL alone (i.e., cuneate fasciculus lesion), the S1 and M1 CSTs also sprout significantly and bilaterally beyond normal range, with a termination pattern suggesting some interaction between the peripheral and central lesions.
Generic algorithms for scheduling applications on heterogeneous platforms
Authors: Amaris Marcos , Lucarelli Giorgio , Mommessin Clément , Trystram Denis 
Published: July 2018

SummaryWe study the problem of executing an application represented by a precedence task graph on a parallel machine composed of standard computing cores and accelerators. Both off‐line and on‐line settings are addressed by proposing generic scheduling approaches. In the first case, we establish strong lower bounds on the worst‐case performance of a known approach based on Linear Programming and replace the greedy List Scheduling policy used in this approach by a better task ordering. Although this modification leads to the same approximability guarantees, it performs much better in practice. We also extend this algorithm to more types of computing units, achieving an approximation ratio which depends on the number of different types. In the on‐line case, tasks arrive in any order which respects the precedence relations and the scheduler has to take irrevocable decisions about their allocation and execution. We propose the first on‐line scheduling algorithm taking into account precedences, which is based on adequate rules for selecting the type of processor where to allocate the tasks. Finally, all the previous algorithms have been experimented on a large number of simulations built on actual libraries, assessing their good practical behavior with respect to the state‐of‐the‐art solutions and baseline algorithms.
Working alliance and outcome effectiveness in videoconferencing psychotherapy: A systematic review and noninferiority meta‐analysis
Authors: Norwood Carl , Moghaddam Nima G. , Malins Sam , Sabin‐Farrell Rachel 
Published: July 2018

AbstractVideoconferencing psychotherapy (VCP)—the remote delivery of psychotherapy via secure video link—is an innovative way of delivering psychotherapy, which has the potential to overcome many of the regularly cited barriers to accessing psychological treatment. However, some debate exists as to whether an adequate working alliance can be formed between therapist and client, when therapy is delivered through such a medium. The presented article is a systematic literature review and two meta‐analyses aimed at answering the questions: Is working alliance actually poorer in VCP? And is outcome equivalence possible between VCP and face‐to‐face delivery? Twelve studies were identified which met inclusion/exclusion criteria, all of which demonstrated good working alliance and outcome for VCP. Meta‐analyses showed that working alliance in VCP was inferior to face‐to‐face delivery (standardized mean difference [SMD] = −0.30; 95% confidence interval [CI] [−0.67, 0.07], p = 0.11; with the lower bound of the CI extending beyond the noninferiority margin [−0.50]), but that target symptom reduction was noninferior (SMD = −0.03; 95% CI [−0.45, 0.40], p = 0.90; CI within the noninferiority margin [0.50]). These results are discussed and directions for future research recommended.
Effects and mechanisms of cold atmospheric plasma on skin wound healing of rats
Authors: Zhang Jun‐Ping , Guo Ling , Chen Qi‐Liang , Zhang Ke‐Ying , Wang Tian , An Guang‐Zhou , Zhang Xiao‐Fei , Li He‐Ping , Ding Gui‐Rong 
Published: July 2018

Cold atmospheric plasma (CAP) has been reported as a novel potential way to promote skin wound healing. The aim of this study was to explore the effects of an atmospheric‐pressure plasma generated in helium gas through dielectric barrier discharge on skin wound healing in rats and its mechanism. A total of 44 adult male Sprague–Dawley rats were divided into the CAP group and the control group after a full‐thickness skin wound model was established. The animals in the CAP group received CAP treatment (driving frequency 17 kHz, root‐mean‐square [rms] values of the discharge voltage 1.33 kV, rms values of the discharge current 10.7 mA, helium flow rate 11 slpm [standard litres per minute]) for 1 min. After that, the size of the healed area of the wound, morphological changes in the wound, wound neovascularization, collagen deposition, and the level of inflammatory factors were recorded. The results showed that compared to that of the control group, the size of the wound area in the CAP group significantly decreased, the contraction and re‐epithelialization of the wounds were obviously speeded up, and the protein level of smooth muscle actin markedly increased. However, the levels of collagen type I A2, collagen type III, and the deposition of collagen bundles did not change. In addition, it was found that the level of inflammatory factors (such as tumour necrosis factor and interleukin‐1β) significantly increased at 24 hr after the creation of the wound. These results suggest that CAP treatment in this condition could promote skin wound healing by accelerating the contraction, re‐epithelialization, neovascularization, and inflammatory response.
Modeling and performance analysis of VI‐CRA: A congestion control algorithm for vehicular networks
Authors: Verma Poonam , Singh Neeta , Sharma Mohit 
Published: July 2018

SummaryThis study proposes a Vehicle ID‐based CAM Rate Adaptation (VI‐CRA) algorithm for beacon messages in the vehicular network. Foremost, an improved vehicle ID–based analytical model is proposed at the MAC layer of vehicular network. The model weighs the random back‐off number chosen by vehicles participating in the back‐off process, with the vehicle ID incorporated in their respective CAMs. This eventually leads to the selection of a vehicle ID–based random back‐off number, minimizing the probability of collision due to same back‐off number selection. It is worth noting that the improved analytical model outperforms the existing works in terms of average packet delay since only one fourth of the contention window size is used throughout the simulation. To enhance the performance of the analytical model, the paper incorporates a congestion control algorithm, by adapting the rate of CAM broadcast over the control channel. The algorithm is designed considering a wide range of scenarios, ranging from nonsaturated to extremely saturated network (in terms of collision probability) and sparsely distributed to teemed network (in terms of vehicular density). For better analyses of simulation results, the algorithm is applied over different vehicle ID–based back‐off numbers. Simulation results for all the back‐off numbers show that vehicle ID–based CAM rate adaptation algorithm performs better than the traditional fixed CAM rate IEEE 802.11p, even at high vehicular density.
Decaying trees improve nesting opportunities for cavity‐nesting birds in temperate and boreal forests: A meta‐analysis and implications for retention forestry
Authors: Gutzat Fabian , Dormann Carsten F. 
Published: July 2018

AbstractMany studies have dealt with the habitat requirements of cavity‐nesting birds, but there is no meta‐analysis on the subject and individual study results remain vague or contradictory. We conducted a meta‐analysis to increase the available evidence for nest‐site selection of cavity‐nesting birds. Literature was searched in Web of Science and Google Scholar and included studies that provide data on the habitat requirements of cavity‐nesting birds in temperate and boreal forests of varying naturalness. To compare nest and non‐nest‐tree characteristics, the following data were collected from the literature: diameter at breast height (DBH) and its standard deviation (SD), sample size of trees with and without active nest, amount of nest and available trees described as dead or with a broken crown, and amount of nest and available trees that were lacking these characteristics. Further collected data included bird species nesting in the cavities and nest‐building type (nonexcavator/excavator), forest type (coniferous/deciduous/mixed), biome (temperate/boreal), and naturalness (managed/natural). From these data, three effect sizes were calculated that describe potential nest trees in terms ofDBH, vital status (dead/alive), and crown status (broken/intact). These tree characteristics can be easily recognized by foresters. The results show that on average large‐diameter trees, dead trees, and trees with broken crowns were selected for nesting. The magnitude of this effect varied depending primarily on bird species and the explanatory variables forest type and naturalness. Biome had lowest influence (indicated by ΔAIC). We conclude that diameter at breast height, vitality, and crown status can be used as tree characteristics for the selection of trees that should be retained in selectively harvested forests.
Annual flower strips support pollinators and potentially enhance red clover seed yield
Authors: Rundlöf Maj , Lundin Ola , Bommarco Riccardo 
Published: July 2018

AbstractEcological intensification provides opportunity to increase agricultural productivity while minimizing negative environmental impacts, by supporting ecosystem services such as crop pollination and biological pest control. For this we need to develop targeted management solutions that provide critical resources to service‐providing organisms at the right time and place. We tested whether annual strips of early flowering phacelia Phacelia tanacetifolia support pollinators and natural enemies of seed weevils Protapion spp., by attracting and offering nectar and pollen before the crop flowers. This was expected to increase yield of red clover Trifolium pratense seed. We monitored insect pollinators, pests, natural enemies and seed yields in a total of 50 clover fields along a landscape heterogeneity gradient, over 2 years and across two regions in southern Sweden. About half of the fields were sown with flower strips of 125–2,000 m2. The clover fields were pollinated by 60% bumble bees Bombus spp. and 40% honey bees Apis mellifera. The clover seed yield was negatively associated with weevil density, but was unrelated to bee species richness and density. Flower strips enhanced bumble bees species richness in the clover fields, with the strongest influence in heterogeneous landscapes. There were few detectable differences between crop fields with and without flower strips. However, long‐tongued bumble bees were redistributed toward field interiors and during phacelia bloom honey bees toward field edges. Clover seed yield also increased with increasing size of the flower strip. We conclude that annual flower strips of early flower resources can support bumble bee species richness and, if sufficiently large, possibly also increase crop yields. However, clover seed yield was mainly limited by weevil infestation, which was not influenced by the annual flower strips. A future goal should be to design targeted measures for pest control.