bluuebunny/crossref_metadata_2025 huggingface dataset:
Avaliação pré-operatória da força muscular respiratória, da função pulmonar e da capacidade funcional de pacientes submetidos a ressecção pulmonar
Authors: Baltieri Letícia , Passos Ana Isabela Morsch , Galhardo Fernanda Diório Masi , Roceto Lígia Dos Santos , Toro Ivan Felizardo Contrera
Published: May 2015

Introdução: As neoplasias pulmonares podem causar deterioração na função pulmonar e capacidade funcional, prejudicando a evolução do paciente após cirurgia de ressecção. Objetivo: Avaliar a força muscular respiratória, a função pulmonar e a capacidade funcional de pacientes no pré-operatório de ressecção pulmonar por neoplasia, comparar aos valores de normalidade e por estadiamento. Métodos: Foram incluídos pacientes na faixa etária de 30 a 80 anos com diagnóstico de neoplasia de pulmão que aguardavam cirurgia de ressecção pulmonar. A avaliação pré-operatória incluiu medida de força muscular respiratória por manovacuometria, função pulmonar por espirometria e capacidade funcional pelo teste de caminhada dos seis minutos (TC6). Os valores obtidos foram comparados aos valores preditos pela literatura e comparados os estadiamentos inicial e avançado. Resultados: Foram avaliados 59 pacientes com idade média de 58,5±9,46 anos. Houve diferença estatisticamente significante entre obtido e predito, respectivamente, para os valores de pressão expiratória máxima (PEmáx): 91 e 111,8 cmH2O; capacidade vital forçada (CVF): 3,14 e 4,08 L; volume expiratório forçado no primeiro segundo (VEF1): 2,42 e 3,12 L; razão VEF1/CVF: 75 e 101%; e capacidade funcional: 453,9 e 562,9 m, sendo que os pacientes apresentaram valores inferiores aos preditos pela literatura, exceto a CVF. Não houve diferença para a pressão inspiratória máxima (PImáx): 110 e 102 cmH2O. Entre os grupos de estadiamento houve diferença apenas para a CVF (inicial: 2,89; avançado: 3,41 L). Conclusão: Os pacientes com diagnóstico de neoplasia pulmonar em pré-operatório de ressecção possuem prejuízos na força muscular expiratória, na função pulmonar e na capacidade funcional.
Efeitos dos exercícios funcionais e neuromusculares no tempo de internação e controle pressórico de pacientes hospitalizados
Authors: Costa Murillo Frazão de Lima e , Petto Jefferson , Gomes Vinícius Afonso , Prazeres Lorena Silles dos , Santos Alan Carlos Nery dos , Almeida Maria da Conceição Gomes , Silva Fabiano Leichsenring , Esquivel Mateus Souza , Oliveira Francisco Tiago Oliveira de
Published: May 2015

Introdução: Exercícios funcionais e neuromusculares são importantes ferramentas em centros de reabilitação, porém são pouco explorados em protocolos hospitalares. Objetivo: Verificar se exercícios funcionais e neuromusculares são mais eficazes na redução do tempo de internamento e controle da pressão arterial (PA) dos indivíduos hospitalizados do que a fisioterapia hospitalar de rotina. Métodos: Foram incluídos pacientes hospitalizados por enfermidades não cardiológicas e sem hipertensão arterial sistêmica, sendo estes randomizados para grupo controle (GC), que realizou exercícios respiratórios, exercícios ativo-livres para membros superiores/inferiores e caminhada no corredor, ou grupo de reabilitação funcional (GRF), submetido a exercícios neuromusculares para membros superiores/inferiores, cicloergômetro e treino de subir/descer degraus. Ambos os grupos receberam intervenção 2x/dia. A PA foi aferida na admissão, durante o internamento e na alta hospitalar. O tratamento estatístico foi realizado adotando-se intervalo de confiança de 95% e nível de significância de 5%. Resultados: Avaliados 42 voluntários, dos quais 26 atenderam aos critérios de elegibilidade. Porém, seis foram excluídos, quatro por permanência hospitalar inferior a três dias e dois por não completarem o protocolo de tratamento. A média de idade no GC foi de 72±11 versus 73±8 no GRF. Não houve diferenças estatísticas da PA na admissão. Evidenciou-se redução da PA apenas no GRF durante o internamento (p<0,01), assim como na alta hospitalar (p<0,01). O GC apresentou maior tempo (dias) de internação 7,2±1,8 versus 5,5±1,3 do GRF (p<0,05). Conclusão: Exercícios funcionais e neuromusculares parecem mais eficazes na redução do tempo de internamento e controle da PA dos indivíduos hospitalizados do que a fisioterapia hospitalar de rotina.
Using ocean bottom pressure from the gravity recovery and climate experiment (GRACE) to estimate transport variability in the southern Indian Ocean
Authors: Makowski Jessica K. , Chambers Don P. , Bonin Jennifer A.
Published: May 2015

Previous studies have suggested that ocean bottom pressure (OBP) from the Gravity Recovery and Climate Experiment (GRACE) can be used to measure the depth‐averaged, or barotropic, transport variability of the Antarctic Circumpolar Current (ACC). Here, we use GRACE OBP observations to calculate transport variability in a region of the southern Indian Ocean encompassing the major fronts of the ACC. We use a statistical analysis of a simulated GRACE‐like data set to determine the uncertainty of the estimated transport for the 2003.0–2013.0 time period. We find that when the transport is averaged over 60° of longitude, the uncertainty (one standard error) is close to 1 Sv (1 Sv = 106 m3 s−1) for low‐pass filtered transport, which is significantly smaller than the signal and lower than previous studies have found. The interannual variability is correlated with the Southern Annual mode (SAM) (0.61), but more highly correlated with circumpolar zonally averaged winds between 45°S and 65°S (0.88). GRACE transport reflects significant changes in transport between 2007 and 2009 that is observed in the zonal wind variations but not in the SAM index. We also find a statistically significant trend in transport (−1.0 ± 0.4 Sv yr−1, 90% confidence) that is correlated with a local deceleration in zonal winds related to an asymmetry in the SAM on multidecadal periods.
D″ discontinuity structure beneath the North Atlantic from Scd observations
Authors: Yao Yao , Whittaker Stefanie , Thorne Michael S.
Published: May 2015

We analyzed transverse and radial component recordings from the 2010 M6.3 southern Spain earthquake (depth = 620 km) recorded on 370 broadband stations in North America. We grouped these seismograms into subarrays and applied fourth root vespa processing (vespagram analysis) in order to enhance low‐amplitude arrivals. These vespagrams show clear Scd arrivals which indicate the existence of the D″ discontinuity beneath the North Atlantic Ocean (45–60°N, 45–55°W). These observations are best fit with a +2–4% velocity increase at the top of the D″ discontinuity at a height above the core‐mantle boundary of 304 ± 14 km. We do not observe Scd arrivals at the eastern end of our study region which is consistent with the presence of the easternmost edge of the ancient Farallon plate.
Generation of nonlinear electric field bursts in the outer radiation belt through the parametric decay of whistler waves
Authors: Agapitov O. V. , Krasnoselskikh V. , Mozer F. S. , Artemyev A. V. , Volokitin A. S.
Published: May 2015

Huge numbers of different nonlinear structures (double layers, electron holes, nonlinear whistlers, etc., referred to as Time Domain Structures, TDS) have been observed by the electric field experiment on the Van Allen Probes. Some of them are associated with whistler waves. Such TDS often emerge on the forward edges of the whistler wave packets and form chains. The parametric decay of a whistler wave into a whistler wave propagating in the opposite direction and an electron acoustic wave is studied experimentally as well as analytically, using Van Allen Probes data. The resulting electron acoustic wave is considered to be the source of electron scale TDS. The measured parameters of the three waves (two whistlers and the electron acoustic wave) are in good agreement with an assumption of their parametric interaction: ω0=ω1+ω2 and . The bicoherence analysis shows the nonlinear nature of the observed electron‐acoustic waves as well as the whistler wave and electron acoustic wave phase relation. The estimated decay instability growth rate shows that the process of three‐wave interaction can develop in a characteristic time smaller than 1 s, thus, the process is rapid enough to explain the observations. This induced parametric interaction can be one of the mechanisms for quasiperiodic TDS generation in the outer Van Allen radiation belt.
Mesoscale eddies and Trichodesmium spp. distributions in the southwestern North Atlantic
Authors: Olson Elise M. , McGillicuddy Dennis J. , Flierl Glenn R. , Davis Cabell S. , Dyhrman Sonya T. , Waterbury John B.
Published: May 2015

Correlations of Trichodesmium colony abundance with the eddy field emerged in two segments of Video Plankton Recorder observations made in the southwestern North Atlantic during fall 2010 and spring 2011. In fall 2010, local maxima in abundance were observed in cyclones. We hypothesized surface Ekman transport convergence as a mechanism for trapping buoyant colonies in cyclones. Idealized models supported the potential of this process to influence the distribution of buoyant colonies over time scales of several months. In spring 2011, the highest vertically integrated colony abundances were observed in anticyclones. These peaks in abundance correlated with anomalously fresh water, suggesting riverine input as a driver of the relationship. These contrasting results in cyclones and anticyclones highlight distinct mechanisms by which mesoscale eddies can influence the abundance and distribution of Trichodesmium populations of the southwestern North Atlantic.
Ultrathin Single‐Crystalline Boron Nanosheets for Enhanced Electro‐Optical Performances
Authors: Xu Junqi , Chang Yangyang , Gan Lin , Ma Ying , Zhai Tianyou
Published: May 2015

Large‐scale single‐crystalline ultrathin boron nanosheets (UBNSs, ≈10 nm) are fabricated through an effective vapor–solid process via thermal decomposition of diborane. The UBNSs have obvious advantages over thicker boron nanomaterials in many aspects. Specifically, the UBNSs demonstrate excellent field emission performances with a low turn‐on field, E
to, of 3.60 V μm−1 and a good stability. Further, the dependence of (turn‐on field) E
to/(threshold field) E
thr and effective work function, Φ
e, on temperature is investigated and the possible mechanism of temperature‐dependent field emission phenomenon has been discussed. Moreover, electronic transport in a single UBNS reveals it to be an intrinsic p‐type semiconductor behavior with carrier mobility about 1.26 × 10−1 cm2 V−1 s−1, which is the best data in reported works. Interestingly, a multiconductive mechanism coexisting phenomenon has been explored based on the study of temperature‐dependent conductivity behavior of the UBNSs. Besides, the photodetector device fabricated from single‐crystalline UBNS demonstrates good sensitivity, reliable stability, and fast response, obviously superior to other reported boron nanomaterials. Such superior electronic‐optical performances are originated from the high quality of single crystal and large specific surface area of the UBNSs, suggesting the potential applications of the UBNSs in field‐emitters, interconnects, integrated circuits, and optoelectronic devices.
Cutaneous manifestations in trisomy 13 mosaicism: A rare case and review of the literature
Authors: Wieser Iris , Wohlmuth Christoph , Rittinger Olaf , Fischer Thorsten , Wertaschnigg Dagmar
Published: May 2015

Trisomy 13 mosaicism is a rare genetic disorder affecting a small minority of all trisomy 13 cases. It occurs when two cell populations that are karyotypically different are present in the same individual and are derived from a single zygote. As a rule, the phenotype is mitigated to a less dysmorphic appearance and longer survival, making genetic counseling a difficult task. Capillary hemangiomas are a common feature of full trisomy 13, seen in 27–56% of all cases. We report on an 18‐months‐old girl with extensive cutaneous anomalies, mild dysmorphic features, and slight psychomotor delay, without structural defects and provide an up‐to‐date review of all cases of trisomy 13 mosaicism with skin involvement. To our knowledge, this is the second clinical report of a patient with trisomy 13 mosaicism with hemangiomas and port wine stains, but no structural defects. © 2015 Wiley Periodicals, Inc.
Primary intestinal lymphangiectasia treated with rapamycin in a child with tuberous sclerosis complex (TSC)
Authors: Pollack Sarah F. , Geffrey Alexandra L. , Thiele Elizabeth A. , Shah Uzma
Published: May 2015

Primary intestinal lymphangiectasia (PIL) is a rare protein‐losing enteropathy characterized by a congenital malformation of the lymphatic vessels of the small intestine causing insufficient drainage and leakage of lymph fluid. Tuberous sclerosis complex (TSC) is an autosomal dominant genetic disorder characterized by benign hamartomas in multiple organ systems. While the lymphatic system has been implicated in TSC through lymphangioleiomyomatosis (LAM) and lymphedema, this paper reports the first case of PIL in TSC, a female patient with a TSC2 mutation. She developed persistent and significant abdominal distension with chronic diarrhea during her first year of life. Due to lack of treatment options and the involvement of the mTOR pathway in TSC, a trial of an mTOR inhibitor, rapamycin, was initiated. This treatment was highly effective, with improvement in clinical symptoms of PIL as well as abnormal laboratory values including VEGF‐C, which was elevated to over seven times the normal upper limit before treatment. This case suggests that PIL is a rare manifestation of TSC, warranting the use of mTOR inhibitors in future studies. © 2015 Wiley Periodicals, Inc.
SemGraph: Extracting keyphrases following a novel semantic graph‐based approach
Authors: Martinez‐Romo Juan , Araujo Lourdes , Duque Fernandez Andres
Published: May 2015

Keyphrases represent the main topics a text is about. In this article, we introduce SemGraph, an unsupervised algorithm for extracting keyphrases from a collection of texts based on a semantic relationship graph. The main novelty of this algorithm is its ability to identify semantic relationships between words whose presence is statistically significant. Our method constructs a co‐occurrence graph in which words appearing in the same document are linked, provided their presence in the collection is statistically significant with respect to a null model. Furthermore, the graph obtained is enriched with information from WordNet. We have used the most recent and standardized benchmark to evaluate the system ability to detect the keyphrases that are part of the text. The result is a method that achieves an improvement of 5.3% and 7.28% in F measure over the two labeled sets of keyphrases used in the evaluation of SemEval‐2010.
Tweets as impact indicators: Examining the implications of automated “bot” accounts onTwitter
Authors: Haustein Stefanie , Bowman Timothy D. , Holmberg Kim , Tsou Andrew , Sugimoto Cassidy R. , Larivière Vincent
Published: May 2015

This brief communication presents preliminary findings on automatedTwitter accounts distributing links to scientific articles deposited on the preprint repository arXiv. It discusses the implication of the presence of such bots from the perspective of social media metrics (altmetrics), where mentions of scholarly documents onTwitter have been suggested as a means of measuring impact that is both broader and timelier than citations. Our results show that automatedTwitter accounts create a considerable amount of tweets to scientific articles and that they behave differently than common social bots, which has critical implications for the use of raw tweet counts in research evaluation and assessment. We discuss some definitions ofTwitter cyborgs and bots in scholarly communication and propose distinguishing between different levels of engagement—that is, differentiating between tweeting only bibliographic information to discussing or commenting on the content of a scientific work.
The linguistic construal of disciplinarity: A data‐mining approach using register features
Authors: Teich Elke , Degaetano‐Ortlieb Stefania , Fankhauser Peter , Kermes Hannah , Lapshinova‐Koltunski Ekaterina
Published: May 2015

We analyze the linguistic evolution of selected scientific disciplines over a 30‐year time span (1970s to 2000s). Our focus is on four highly specialized disciplines at the boundaries of computer science that emerged during that time: computational linguistics, bioinformatics, digital construction, and microelectronics. Our analysis is driven by the question whether these disciplines develop a distinctive language use—both individually and collectively—over the given time period. The data set is the English Scientific Text Corpus (scitex), which includes texts from the 1970s/1980s and early 2000s. Our theoretical basis is register theory. In terms of methods, we combine corpus‐based methods of feature extraction (various aggregated features [part‐of‐speech based], n‐grams, lexico‐grammatical patterns) and automatic text classification. The results of our research are directly relevant to the study of linguistic variation and languages for specific purposes (LSP) and have implications for various natural language processing (NLP) tasks, for example, authorship attribution, text mining, or training NLP tools.
Testing a model of user‐experience with news websites
Authors: Aranyi Gabor , van Schaik Paul
Published: May 2015

Although the Internet has become a major source for accessing news, there is little research regarding users' experience with news sites. We conducted an experiment to test a comprehensive model of user experience with news sites that was developed previously by means of an online survey. Level of adoption (novel or adopted site) was controlled with a between‐subjects manipulation. We collected participants' answers to psychometric scales at 2 times: after presentation of 5 screenshots of a news site and directly after 10 minutes of hands‐on experience with the site. The model was extended with the prediction of users' satisfaction with news sites as a high‐level design goal. A psychometric measure of trust in news providers was developed and added to the model to better predict people's intention to use particular news sites. The model presented in this article represents a theoretically founded, empirically tested basis for evaluating news websites, and it holds theoretical relevance to user‐experience research in general. Finally, the findings and the model are applied to provide practical guidance in design prioritization.
Recovering uncaptured citations in a scholarly network: A two‐step citation analysis to estimate publication importance
Authors: Jiang Zhuoren , Liu Xiaozhong , Chen Yan
Published: May 2015

The citation relationships between publications, which are significant for assessing the importance of scholarly components within a network, have been used for various scientific applications. Missing citation metadata in scholarly databases, however, create problems for classical citation‐based ranking algorithms and challenge the performance of citation‐based retrieval systems. In this research, we utilize a two‐step citation analysis method to investigate the importance of publications for which citation information is partially missing. First, we calculate the importance of the author and then use his importance to estimate the publication importance for some selected articles. To evaluate this method, we designed a simulation experiment—“random citation‐missing”—to test the two‐step citation analysis that we carried out with the Association for Computing Machinery (ACM) Digital Library (DL). In this experiment, we simulated different scenarios in a large‐scale scientific digital library, from high‐quality citation data, to very poor quality data, The results show that a two‐step citation analysis can effectively uncover the importance of publications in different situations. More importantly, we found that the optimized impact from the importance of an author (first step) is exponentially increased when the quality of citation decreases. The findings from this study can further enhance citation‐based publication‐ranking algorithms for real‐world applications.
Research synthesis methods and library and information science: Shared problems, limited diffusion
Authors: Sheble Laura
Published: May 2015

Interests of researchers who engage with research synthesis methods (RSM) intersect with library and information science (LIS) research and practice. This intersection is described by a summary of conceptualizations of research synthesis in a diverse set of research fields and in the context of Swanson's (1986) discussion of undiscovered public knowledge. Through a selective literature review, research topics that intersect with LIS and RSM are outlined. Topics identified include open access, information retrieval, bias and research information ethics, referencing practices, citation patterns, and data science. Subsequently, bibliometrics and topic modeling are used to present a systematic overview of the visibility of RSM in LIS. This analysis indicates that RSM became visible in LIS in the 1980s. Overall, LIS research has drawn substantially from general and internal medicine, the field's own literature, and business; and is drawn on by health and medical sciences, computing, and business. Through this analytical overview, it is confirmed that research synthesis is more visible in the health and medical literature in LIS; but suggests that, LIS, as a meta‐science, has the potential to make substantive contributions to a broader variety of fields in the context of topics related to research synthesis methods.
Why experience matters to privacy: How context‐based experience moderates consumer privacy expectations for mobile applications
Authors: Martin Kirsten , Shilton Katie
Published: May 2015

Two dominant theoretical models for privacy—individual privacy preferences and context‐dependent definitions of privacy—are often studied separately in information systems research. This paper unites these theories by examining how individual privacy preferences impact context‐dependent privacy expectations. The paper theorizes that experience provides a bridge between individuals' general privacy attitudes and nuanced contextual factors. This leads to the hypothesis that, when making judgments about privacy expectations, individuals with less experience in a context rely more on individual preferences such as their generalized privacy beliefs, whereas individuals with more experience in a context are influenced by contextual factors and norms. To test this hypothesis, 1,925 American users of mobile applications made judgments about whether varied real‐world scenarios involving data collection and use met their privacy expectations. Analysis of the data suggests that experience using mobile applications did moderate the effect of individual preferences and contextual factors on privacy judgments. Experience changed the equation respondents used to assess whether data collection and use scenarios met their privacy expectations. Discovering the bridge between 2 dominant theoretical models enables future privacy research to consider both personal and contextual variables by taking differences in experience into account.
Web mining for navigation problem detection and diagnosis in Discapnet: A website aimed at disabled people
Authors: Arbelaitz Olatz , Lojo Aizea , Muguerza Javier , Perona Iñigo
Published: May 2015

The dramatic increase in the amount of information stored on the web makes it more important to familiarize people with disabilities and elderly people with digital devices and applications and to adapt websites to enable their use by these users. Discapnet is a website mainly aimed at visually disabled people, and navigation is a challenging task for its users. In this context, system evaluation and problem detection become crucial aspects for enhancing user experience and may contribute greatly to diminishing the existing technological gap. This study proposes a system based on web‐mining techniques that collects in‐use information while the user is accessing the web (thus, being a noninvasive system). The proposed system models users in the wild and discovers navigation problems appearing in Discapnet and can also be used for problem detection when new users are navigating the site. The system was tested and its efficiency demonstrated in an experiment involving navigation under supervision, in which 82.6% of a set of disabled people were automatically labeled as having problems with the website.
Repetitive speech elicits widespread deactivation in the human cortex: the “Mantra” effect?
Authors: Berkovich‐Ohana Aviva , Wilf Meytal , Kahana Roni , Arieli Amos , Malach Rafael
Published: May 2015

Background

Mantra (prolonged repetitive verbal utterance) is one of the most universal mental practices in human culture. However, the underlying neuronal mechanisms that may explain its powerful emotional and cognitive impact are unknown. In order to try to isolate the effect of silent repetitive speech, which is used in most commonly practiced Mantra meditative practices, on brain activity, we studied the neuronal correlates of simple repetitive speech in nonmeditators – that is, silent repetitive speech devoid of the wider context and spiritual orientations of commonly practiced meditation practices.

Methods

We compared, using blood oxygenated level‐dependent (BOLD) functional magnetic resonance imaging (fMRI), a simple task of covertly repeating a single word to resting state activity, in 23 subjects, none of which practiced meditation before.

Results

We demonstrate that the repetitive speech was sufficient to induce a widespread reduction in BOLD signal compared to resting baseline. The reduction was centered mainly on the default mode network, associated with intrinsic, self‐related processes. Importantly, contrary to most cognitive tasks, where cortical‐reduced activation in one set of networks is typically complemented by positive BOLD activity of similar magnitude in other cortical networks, the repetitive speech practice resulted in unidirectional negative activity without significant concomitant positive BOLD. A subsequent behavioral study showed a significant reduction in intrinsic thought processes during the repetitive speech condition compared to rest.

Conclusions

Our results are compatible with a global gating model that can exert a widespread induction of negative BOLD in the absence of a corresponding positive activation. The triggering of a global inhibition by the minimally demanding repetitive speech may account for the long‐established psychological calming effect associated with commonly practiced Mantra‐related meditative practices.
Sialic Acid Hydroxamate: A Potential Antioxidant and Inhibitor of Metal‐Induced β‐Amyloid Aggregates
Authors: Yadav Rohan , Murthy Raghavendra Vasudeva , Kikkeri Raghavendra
Published: May 2015

Current methods for Alzheimer's treatment require a three‐component system: metal chelators, antioxidants, and amyloid β (Aβ)‐peptide‐binding scaffolds. We report sialic acid (Sia) hydroxamate as a potential radical scavenger and metal chelator to inhibit Aβ aggregation. A cell viability assay revealed that Sia hydroxamate can protect HeLa and glioblastoma (LN229) cells from oxidative damage induced by the Fenton reaction. Sedimentation and turbidity assays showed profound protection of neuroblastoma SH‐SY5Y cells from metal‐induced Aβ aggregation and neural toxicity.
Bioabbaubarkeit von 2‐Ethylhexylacetat, Methylisobutylketon und Methylethylketon in Biotricklingfiltern
Authors: Gerl Thomas , Engesser Karl‐Heinrich , Dobslaw Daniel
Published: May 2015

Die Bioabbaubarkeit eines mit 2‐Ethylhexylacetat, Methylisobutylketon und Methylethylketon kontaminierten Abluftstromes in Biotricklingfiltern wurde hinsichtlich des Einflusses von Nährstoffangebot und Packungsmaterial untersucht. Als Trägermaterialien wurden PU‐Würfel, Hiflow‐Ringe sowie Wurzelholzriss verglichen. Dabei erwiesen sich die PU‐Würfel als das beste Trägermaterial und die Hiflow‐Ringe lieferten den stabilsten Betrieb. Eine quasikontinuierliche Nährstoffzugabe erhöhte und stabilisierte den Wirkungsgrad bei allen drei Reaktoren. Es trat keine gegenseitige Hemmung im Abbau der Komponenten auf.
Synthese von porösen Kohlenstoffmonolithen unter Verwendung von Porenbeton als Templat. Teil II: Untersuchungen mechanischer Eigenschaften
Authors: Taubert Michael , Heider Robert , Erlitz Marcel , Hille Eva , Lange Andreas , Enke Dirk , Klepel Olaf
Published: May 2015

Für den Einsatz poröser Kohlenstoffmaterialien in durchströmten Apparaturen eignen sich besonders monolithische Formen. Ein möglicher Syntheseweg für diese Materialien ist die Templatsynthese. Poröse Kohlenstoffmonolithe wurden unter Verwendung von Porenbeton als Templat präpariert. Erste systematische Untersuchungen zur mechanischen Stabilität zeigen das Potenzial solcher Materialien für einen Einsatz in technischen Komponenten. Es konnte nachgewiesen werden, dass diese Kohlenstoffformkörper stabil sowohl hinsichtlich mechanischer Druckbeanspruchung als auch Durchströmung mit Wasser sind.
Syntheses of (R)‐ and (S)‐3‐Methylheptanoic Acids
Authors: Zhang Shunji , Shi Yong , Tian Weisheng
Published: May 2015

Starting from chiral methyl molecules 3 and 4, both derived from (R)‐4‐methyl‐δ‐valerolactone, we have accomplished the synthesis of (R) and (S)‐3‐methylheptanoic acids. Our methods are amendable to the syntheses of a wide variety of chiral 3‐methyl alkanoic acids.
A Robust Solution‐Based Approach to Monodisperse Hybrid Janus Nanofibers
Authors: Chen Chunyang , Yi Junqi , Dong Haiyan , Chen Daoyong
Published: May 2015

Monodisperse hybrid Janus nanofibers with the structure that one Au nanoparticle (AuNP) is connected to one end of a polymeric nanofiber were prepared by the self‐assembly between polymeric micelles and the tadpole‐like conjugates resulting from one‐to‐one complexation of long DNA chains with AuNPs.
Dithienopyrrole Based Small Molecule with Low Band Gap for Organic Solar Cells
Authors: Li Miaomiao , Ni Wang , Feng Huanran , Kan Bin , Wan Xiangjian , Zhang Yamin , Yang Xuan , Chen Yongsheng
Published: May 2015

A low band gap acceptor‐donor‐acceptor (A‐D‐A) small molecule donor material, named DR3TDTN, has been designed and synthesized for solution‐processed organic solar cells. DR3TDTN shows narrow optical band gap with value of 1.49 eV and broad absorption spectrum from 300 to 820 nm. The HOMO and LUMO energy levels of DR3TDTN are −4.74 and −3.26 eV, respectively. The optimized photovoltaic device based on DR3TDTN:PCB71BBM blend film shows a power conversion efficiency of 3.03% with an open‐circuit voltage of 0.67 V, a short‐circuit current of 8.22 mA·cmP−2 and fill factor of 0.55.
Changing to Poly(rod‐coil) Polymers: a Promising Way for an Optoelectronic Compound to Improve Its Film Formation
Authors: Shao Wei , Liang Long , Xiang Xuan , Li Hong‐jiao , Zhao Fu‐gang , Li Wei‐shi
Published: May 2015

Good film formation is one of basic requirements for organic optoelectronic materials to achieve the capability for fabrication of large area devices. Small molecular optoelectronic compounds have a definite chemical structure and clear device performance, and thus are welcomed in the field. However, they are generally suffering from poor film formation, especially in a large area. For addressing it, this contribution proposes and demonstrates a strategy, that is, changing them into poly(rod‐coil) polymers. With one optoelectronic compound [BDT(DTBT)2] and three poly(rod‐coil) polymers (P1, P2, and P3) having different non‐conjugated coil segments as examples, the work clearly shows that the change to poly(rod‐coil) polymers keeps many basic optoelectronic properties of the reference compound, including light absorption in solution, bandgap and frontier orbital energy levels, but suppresses strong intermolecular interactions and crystalline structure in film state. Further comparisons on film formation quality on glass and ITO glass illustrate that all the three polymers have a better film formation property than the reference compound.
A Triptycene‐Based Porous Organic Polymer that Exhibited High Hydrogen and Carbon Dioxide Storage Capacities and Excellent CO2/N2 Selectivity
Authors: Lu Xi‐Long , Zhou Tian‐You , Wu Doufeng , Wen Qiang , Zhao Xin , Li Qiaowei , Xiang Qun , Xu Jia‐Qiang , Li Zhan‐Ting
Published: May 2015

A novel porous organic polymer (POP) has been constructed through the condensation of triptycene tricatechol and 1,3,5‐benzenetris(4‐phenylboronic acid). This triptycene‐based POP exhibited high H2 uptake (up to 1.84 wt% at 77 K, 1 bar), large CO2 adsorption capacity (up to 18.1 wt% at 273K, 1 bar), and excellent CO2/N2 adsorption selectivity (up to 120/1). The influence of solvent on the gas adsorption performance of the POP has also been investigated.
TBHP/TEMPO‐Mediated Oxidative Synthesis of Imides from Amides
Authors: Yu Hui , Chen Yuegang , Zhang Yonghao
Published: May 2015

A new protocol for the synthesis of imides has been developed. In the presence of copper catalyst, N‐benzylamides were oxidized to the corresponding imides by TBHP/TEMPO system in moderate to good yields.
An Environmentally Benign Catalytic Method for Versatile Synthesis of 1,4‐Dihydropyridines via Multicomponent Reactions
Authors: Cao Shuo , Zhong Shanshan , Hu Changfeng , Wan Jie‐Ping , Wen Chengping
Published: May 2015

The synthesis of diverse 1,4‐dihydropyridines have been achieved via the multicomponent reactions of aldehydes, enaminones and amines. The reactions have been smoothly performed in water to provide all products with moderate to excellent yields by using lactic acid as a green catalyst.
Self‐assembly of Micrometer‐long DNA Nanoribbons with Four Oligonucleotides
Authors: Chao Jie , Ouyang Xiangyuan , Peng Hongzhen , Su Shao , Wang Lianhui
Published: May 2015

DNA nanostructures have found widespread applications in areas including nanoelectronics and biomedicine. However, traditional DNA origami needs a long single‐stranded virus DNA and hundreds of short DNA strands, which make this method complicated and money‐consuming. Here, we present a protocol for the assembly of DNA nanoribbons with only four oligonucleotides. DNA nanoribbons with different dimensions were successfully assembled with a 96‐base scafford strand and three short staples. These biotinylated nanoribbons could also be decorated with streptavidins. This approach suggests that there exist great design spaces for the creation of simple nucleic acid nanostructures which could facilitate their application in plasmonic or drug delivery.
Determinants of conifer distributions across peatland to forest gradients in the coastal temperate rainforest of southeast Alaska
Authors: Bisbing Sarah M. , Cooper David J. , D'Amore David V. , Marshall Kristin N.
Published: May 2015

Wetland determination relies on assumptions that site hydrologic and edaphic conditions limit plant species to certain environments. For example, using species' wetland indicator status for wetland determination assumes that tolerance of wetland conditions best explains distributional patterns. However, abiotic and biotic factors often interact to create complex plant responses across different environments. To evaluate these interactions, we used a hydrologic gradient in the coastal temperate rainforest of southeast Alaska to (1) quantify the primary determinants of conifer distributions, (2) identify thresholds in environmental factors limiting species' success and (3) assess current wetland indicator status of local conifers (Pinus contorta,Picea sitchensis, andTsuga heterophylla). Data were collected using a hierarchical sampling scheme and analyzed within a Bayesian framework. Topography and hydrologic regime were the primary determinants of distributional patterns, but species were limited by specific microsite factors. Competitively dominantP. sitchensisoccurred where hydrology, pH, and nitrogen were most favorable for establishment, while stress‐tolerantP. contortawas competitively excluded from these sites.Tsugaheterophyllaoccurred across the gradient but took advantage of drier conditions, which promoted biomass accumulation. Tree distributions were limited by the interaction between abiotic and biotic factors rather than by abiotic tolerance alone. This knowledge of local and regional drivers of species' distributions and the relative importance of interacting abiotic and biotic drivers provide critical information for land management and regulation. Wetland delineation procedures can be improved through application of the regional empirical limits identified for plant species, as implemented and addressed in this study. Copyright © 2015 John Wiley & Sons, Ltd.
Facile Synthesis of (110)‐Plane‐Exposed Au Microflowers as High Sensitive Hydrogen Peroxide Sensors
Authors: Yu Fengjiao , Liu Zhong , Zhou Wuzong
Published: May 2015

A flower‐like Au microstructure with a dominantly exposed active (110) plane has been prepared by a simple, facile method at room temperature. Various experimental factors that can control the shape of the Au microflowers have been investigated and optimized. Furthermore, the glassy carbon electrode modified with these Au microflowers exhibits high electrochemical activity towards H2O2 reduction. The sensor shows a linear range from 10 μM to 5.53 mM with a detection limit of 2 μM, which can be attributed to the exposed (110) planes and 3D hierarchical structure of the Au microflowers.
Apparent Electrophilic Fluorination of 1,3‐Dicarbonyl Compounds Using Nucleophilic Fluoride Mediated by PhI(OAc)2
Authors: Nash Toby J. , Pattison Graham
Published: May 2015

The apparent electrophilic fluorination of 1,3‐dicarbonyl compounds using Et3N·3HF as a nucleophilic fluoride source is reported. This reaction requires PhI(OAc)2 as oxidant and can be conducted safely in standard laboratory glassware. Alternative selectivity compared to Selectfluor was observed in some cases. This approach may reduce our reliance on difficult‐to‐handle fluorine gas and expensive electrophilic fluorinating agents derived from elemental fluorine. Mechanistic analysis related to the active fluorinating species and fluoride/acetate exchange is presented.
Reply to discussion of Jamaican cenozoic ichnology: review and prospectus: (v. 50, p. 364–382)
Authors: Donovan Stephen K. , Pickerill Ron K.
Published: May 2015

Mitchell and Ramsook comment on the lithostratigraphic assignment of Jamaican Cenozoic ichnofossils discussed in Donovan et al. They argue that the Paleogene Richmond Formation should be subdivided to produce a ‘Moore Town formation’ in eastern Jamaica, but the latter remains undefined as a lithostratigraphic unit and no new lithostratigraphic evidence is produced to support their supposition. Further, their use of a flawed table of trace fossil distributions does not support their thesis. The distribution of trace fossils in the White Limestone Group presented by Donovan et al. follows the lithostratigraphic scheme that was current at the time that the research was originally undertaken in the early 2000s. Yet, whatever lithostratigraphic scheme is utilised for the island, it is apparent that the more accurate data is provided by the biostratigraphy of the larger benthic foraminifers. Copyright © 2015 John Wiley & Sons, Ltd.
Detection of volatile organic compounds indicative of human presence in the air
Authors: Kwak Jae , Geier Brian A. , Fan Maomian , Gogate Sanjay A. , Rinehardt Sage A. , Watts Brandy S. , Grigsby Claude C. , Ott Darrin K.
Published: May 2015

Volatile organic compounds were collected and analyzed from a variety of indoor and outdoor air samples to test whether human‐derived compounds can be readily detected in the air and if they can be associated with human occupancy or presence. Compounds were captured with thermal desorption tubes and then analyzed by gas chromatography with mass spectrometry. Isoprene, a major volatile organic compound in exhaled breath, was shown to be the best indicator of human presence. Acetone, another major breath‐borne compound, was higher in unoccupied or minimally occupied areas than in human‐occupied areas, indicating that its majority may be derived from exogenous sources. The association of endogenous skin‐derived compounds with human occupancy was not significant. In contrast, numerous compounds that are found in foods and consumer products were detected at elevated levels in the occupied areas. Our results revealed that isoprene and many exogenous volatile organic compounds consumed by humans are emitted at levels sufficient for detection in the air, which may be indicative of human presence.
Antecedents of Knowledge Exchange Systems Usage: Motivational and Work Environment Factors
Authors: Gressgård Leif Jarle
Published: May 2015

The use of knowledge exchange systems to facilitate transfer and reuse of knowledge has become commonplace in modern organizations. Factors beyond the technology itself are, however, important for the level and quality of systems usage. Both individual and organizational factors are in this respect central. Based on this acknowledgement, this study develops and tests hypotheses concerning the influence of three work environment characteristics (leadership involvement, employee empowerment, and role clarity) on intrinsic, introjected, and external motivation for knowledge exchange, and further, how these work characteristics and motivation types influence use of knowledge exchange systems. The results show that all work characteristics, as well as intrinsic and external motivation, influence system usage. Introjected motivation, on the other hand, is not related to system usage. Furthermore, the results show that there are significant positive relationships between leader involvement and all motivation types. Employee empowerment is positively related to intrinsic motivation, while role clarity influences introjected and external motivation. Theoretical and practical implications are discussed. Copyright © 2015 John Wiley & Sons, Ltd.
Thin film growth of Cd1‐xZnxTe and its application to X‐ray sensor
Authors: Mochizuki K. , Takahashi J. , Nakamura N.
Published: May 2015

Cd1‐xZnxTe (x∼0.5) thin films with less than 300μm are grown on ITO/glass substrate by Hot‐wall and PVT methods, one of the sublimation methods. In order to obtain the films with high resistivity and good quality for X‐ray sensor, three attempts have been tried in the experiments. The one is stoichiometry control of CZT (x = 0.04) films, which were grown under controlled Cd vapor pressure. The second is excess chlorine doping to the films (x = 0.04) by controlling CdCl2 vapor pressure during growth process. The third is to change composition x = 0.04‐0.50, which increases band gap. Through these methods, best films with good X‐ray response was obtained for the third case of the films with the composition x = 0.20. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Spectroscopic ellipsometry studies of as‐prepared and annealed CdS:O thin films
Authors: Khalilova Khuraman , Shim YongGu , Hasanov Ilham , Asaba Ryo , Wakita Kazuki , Mamedov Nazim
Published: May 2015

Cadmium sulfide thin films on soda lime substrates were obtained by rf‐magnetron sputtering in argon‐oxygen atmosphere. As‐prepared and vacuum annealed films were then studied by spectroscopic ellipsometry at room temperature over photon energy range from 0.5 to 6 eV. The obtained ellipsometric data were treated using optical dispersion models based on Gaussian type oscillators. Dielectric function of oxygen‐free films, as well as those obtained under 3% of O/Ar partial pressure was reliably restored. At the same time, dielectric function obtained for 5% CdS:O can be regarded only as an average over several materials since our XPS examination disclosed presence of several compounds in thin films deposited at O/Ar ratios higher than 3%. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effect of preheating time on uniformity of electrodeposited Cu2ZnSnS4 thin films studied by carrier lifetime and photoluminescence measurements
Authors: Hamada T. , Fukuyama A. , Jiang F. , Ikeda S. , Ikari T.
Published: May 2015

Cu2ZnSnS4 (CZTS) is paid attention to the low‐cost and nontoxic solar cell material. In this study, CZTS thin film was deposited by using an electrodeposition technique followed by a sulfurization after preheating the deposited metallic precursor layer. We investigated the film properties of CZTS thin films for understanding the effect of preheating time on the photovoltaic properties such as carrier lifetime and recombination mechanism by using a microwave photoconductivity decay (μ‐PCD) and a photoluminescence (PL) measurement. The results of the μ‐PCD measurements showed that carrier lifetime increased with increasing the preheating time and longer carrier lifetime was observed in a part of deposited thin film. The PL measurements showed the peak energy shift to lower energy region by a surface position of the sample preheated for 150 min. We found the CZTS crystal quality improved but the homogeneity worsened with increasing the preheating time. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Preparation and characterization of Cu2Six Sn1‐xS3
Authors: Toyonaga Kotoba , Araki Hideaki
Published: May 2015

Cu2SnS3 is a promising compound for use as an absorber layer in thin film solar cells because it is made up of low‐cost and abundant elements, and has a high optical absorption coefficient. However, the band gap energy of monoclinic Cu2SnS3 is less than the value required for absorber layers in single‐junction solar cells. On the other hand, the band gap energy of Cu2SiS3 was reported to be approximately 2.5 eV, which is sufficiently large for this purpose. Therefore, in the present study, an attempt was made to synthesize Cu2Six Sn1‐xS3, which is a solid solution between Cu2SnS3 and Cu2SiS3. In X‐ray diffraction patterns from the synthesized compounds, the diffraction peaks were found to shift to higher 2θ values with increasing x, indicating a decrease in the lattice constants. In addition, the estimated band gap energy increased from 0.85 to 2.56 eV with increasing x. Cu2Six Sn1‐xS3 is therefore a potential candidate for use as the absorber layer in thin film solar cells because its band gap energy can be adjusted simply by varying its composition. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Interaction of methyl radical (CH3) with C60 fullerene: Density functional theory (DFT) study
Authors: Tachikawa Hiroto , Iyama Tetsuji
Published: May 2015

The addition reaction of methyl radical (CH3) to fullerene (C60) surface has been investigated by means of density functional theory (DFT) method. The DFT calculation showed that the CH3 radical binds directly to the carbon atom of C60 and a strong C‐C single bond is formed. The binding energy of CH3 to C60was calculated to be 35.1 kcal/mol at the CAM‐B3LYP/6‐311G(d,p) level. The potential energy curve plotted as a function of a distance of CH3 from the C60 surface showed that the CH3 radical can approach to the carbon atom with very low activation barrier: the barrier height was calculated to be 2.8 kcal/mol. The electronic states of CH3‐C60 complex were discussed on the basis of theoretical results. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)