bluuebunny/crossref_metadata_2025 huggingface dataset:
ConjoinedWh‐Questions
Authors: Gračanin‐Yuksek Martina
Published: October 2017

Many languages, in addition to ordinary multiplewh‐questions, have a construction in which two or morewh‐phrases appear to be coordinated at the left periphery of the clause. This construction is referred to as aconjoined wh‐question(CWH). The two kinds of multiple questions differ not only in form, but also in interpretation: while ordinary multiplewh‐questions favor pair‐list readings, CWHs favor single‐pair readings. Somewhat surprisingly, CWHs are found not only in multiplewh‐fronting languages (MF languages), but also in languages that front only one or none of thewh‐phrases (non‐MF languages). While all languages with CWHs allow the coordinatedwh‐phrases to be adjuncts (Whenandwheredid John go to school?), only MF languages allow coordination of twowh‐arguments (*Whoandwhatsaw?). The structure of CWHs seems to vary both across languages and within a single language. This chapter surveys cross‐linguistic typology of CWHs as well as existing accounts of this construction. One type of an analysis of CWHs, the monoclausal account, claims that thewh‐phrases originate in a single clause and are fronted to the left periphery, where they are coordinated. On the other type of account, the biclausal account, CWHs involve a coordination of interrogative clauses. It will be shown that both types of analysis seem to be needed in order to cover the cross‐linguistic diversity of CWHs.
Clitic Clusters
Authors: Pescarini Diego
Published: October 2017

This chapter deals with the morphosyntax of Romance clitic combinations. It summarizes some data and treatments of clitic sequences, focusing on three aspects: combinatorial restrictions, orderings, and morphological irregularities.

First, not all clitic combinations are allowed, as combinatorial gaps arise from both robust cross‐linguistic restrictions (the Person Case Constraint, or PCC) and language‐specific constraints. The former has received much attention in the recent syntactic literature. Besides the PCC, however, Romance displays various kinds of gaps, part of which are arguably due to an identity‐avoidance principle whose morphological or syntactic nature is still under discussion.

Second, the order of clitic elements within a cluster is rigidly set on a language‐specific basis and, third, the morphological shape of the cluster does not result from the agglutination of single clitics, as morphological irregularities arise rather frequently. Previous analyses argued that these aspects are due to some sort of extrasyntactic computation, namely morphological templates, post‐syntactic operations, output constraints, etc..

Such non‐syntactic devices, which do not follow from any general principle of Universal Grammar, are usually postulated to account for language‐specific orderings and irregularities. In fact, however, ordering phenomena and morphological irregularities seem to be systematic, with certain patterns recurring frequently across languages. The second part of the chapter aims to show that ordering phenomena and morphological irregularities are related and both may be deemed evidence of the syntactic make‐up of clitic sequences. In particular, it is shown that, building on a very restrictive theory of linearization, one may deal with the variation in clitic ordering without postulating extrasyntactic levels of computation.
Secondary Predication
Authors: Rothstein Susan
Published: October 2017

This chapter discusses secondary predication primarily from a syntactic perspective. We describe the two major types of secondary predicates,depictivesandresultatives, proposing that so‐calledcircumstantialsshould be identified as depictives under the scope of a modal operator. We show that secondary predication, unlike clausal predication, is adjunct predication and is always thematic, with the secondary predicate assigning an external theta‐role to its subject. What makes the predication secondary is that the subject of the secondary predicate must be independently theta‐marked by another lexical head. We contrast secondary predication with clausal predication, and argue that there is no evidence to support a small clause analysis of secondary predicates. Instead, secondary predicates should be analyzed as AP (or PP) adjuncts that directly modify their subject. We review the syntactic position of these adjuncts, showing that they must be c‐commanded by their subjects. We also review the lexical constraints on choice of depictives and resultatives, and discuss briefly the semantic contrasts between them. Crucially, this explains the fact that while depictives can be predicated of either sentential subjects or direct objects, resultatives can only be predicated of VP‐internal arguments. We conclude by reviewing some recent publications on the topic.
Derived Nominals
Authors: Rozwadowska Bożena
Published: October 2017

Derived nominals are understood as deverbal nominalizations (i.e., nouns derived from verbs through derivational affixes, such as, e.g.,destruction). Cross‐linguistically, derived nominals constitute a mixed category and show intra‐language and inter‐language variation in the degree of their “nouniness” or “verbness” and in morpho‐syntactic patterns. Among many ambiguities, the least controversial is a clear contrast between result nominals and process nominals (i.e., Complex Event Nominals). There is no consensus, however, as to the account of this dichotomy, the relationship of the derived nominal to the base verb and the nature of the nominalization process. The crucial point is the argument distribution in derived nominals as compared to verbs. It is generally assumed that the presence of argument structure (AS) points to the verbal source of the derivation. Among the various approaches, some binary oppositions have been suggested, such as transformationalist vs. lexicalist approach, syntactic vs. lexical derivation, configurational vs. non‐configurational account, and so on. Recent developments in syntactic theory, such as Distributed Morphology or Neo‐Constructivism, dispense with the strict border between the lexicon/morphology and syntax, and within those new approaches, the ambiguities among nominalizations are attributed to the differences in functional structure. Action nominalizations (derived from Agent–Patient verbs likedestroy) have been studied most extensively. They constitute the basis for various accounts, which, on closer scrutiny, do not always work when confronted with derived nominals from a variety of different languages (Germanic, Romance, Slavic, Greek, among others) and from other semantic classes (e.g., psychological nominals). Most recent cross‐linguistic analyses of derived nominals emphasize the relevance of event structure and aspect for their behavioral properties. Also, stative nominalizations have found place on the current research agenda. All these developments significantly enriched the current state of the art in this area and influenced the views on the division of labor between different components of grammar.
A‐not‐A Questions
Authors: Hagstrom Paul
Published: October 2017

An A‐not‐A question is a type of question with a function similar to that of a yes/no question, the surface form of which involves two copies of a predicate with one copy negated. Such questions superficially resemble alternative questions but have distinct syntactic properties. A‐not‐A questions have primarily been studied in Mandarin Chinese and related languages. Morphosyntactically, A‐not‐A questions behave as if formed by a combined negative/interrogative morpheme (called here NQ), structurally in the inflectional layer (IP) of the clause structure, undergoing syntactic movement to a scope position higher (CP) in the clause, and morphologically triggering a kind of reduplication. Diagnostics show many similarities between NQ in A‐not‐A questions and adjunctwh‐words likeweishenme‘why’, including sensitivity to movement islands, interaction with quantifiers, and interaction with focusing morphology. A‐not‐A questions differ pragmatically from yes/no questions, the former being appropriate only in strictly neutral contexts, where neither possible answer to the question is assumed to be the true one. Three other question types (VP‐not‐V questions, VP‐not‐VP questions, and negative particle questions) superficially resemble A‐not‐A questions, and share some syntactic properties but not others. A short discussion of other languages (all of which are related historically or geographically to Mandarin Chinese) reveals that the properties of A‐not‐A questions can be found in questions in languages other than Mandarin Chinese, but potentially with a morphological manifestation other than an A‐not‐A surface form, and even alongside questions that take an A‐not‐A form but are not otherwise analogous to Mandarin A‐not‐A questions. Challenges for the future include clarifying the disagreements in critical judgments, and expanding the cross‐linguistic understanding of these questions beyond Mandarin.
Impersonal Passives
Authors: Hofherr Patricia Cabredo
Published: October 2017

Impersonal passives are passives of intransitive verbs. Applying passivization to an intransitive verb results in a derived verb‐form with no referential argument; the surface subject of the construction is then either absent or realized by an expletive subject. Consequently, the analysis of impersonal passives inherits the complexities of at least three related domains: (i) the cross‐linguistic definition of passives in general, (ii) the analysis of subjectless sentences, and (iii) the syntax of sentences with expletive subjects.

The first section reviews the most influential characterizations of passives in the literature in terms of subject demotion and object promotion. The analyses of impersonal passives in the literature will be presented against this general backdrop.

The second section presents evidence that subject demotion does not yield a uniform class of passives based on the literature on Romance, Celtic, Slavic, and Germanic. In particular, constructions that suppress the logical subject differ in whether they yield a syntactically transitive or intransitive output when applied to a transitive verb. Based on this observation, it has been argued that constructions that suppress the subject but do not de‐transitivize the underlying verb should not be analyzed as passives; instead, these constructions should be treated as impersonal verb forms, more similar to transitive sentences with an overt impersonal subject such as Englishone, Frenchon, and Germanicman/menthan to passives. Arguably, this distinction between valency‐reducing passives and valency‐preserving impersonals is preserved when the relevant constructions are applied to intransitive verbs.

The final section examines the question of what role overt expletives play in the syntax of impersonal passives. The literature on expletives constructions in Germanic and particularly in Scandinavian provides a wealth of data that will be used to place the overt expletive subject found with impersonal passives in the context of expletive constructions more generally.
Amount Relatives
Authors: Grosu Alexander , Landman Fred
Published: October 2017

We introduce amount relatives by discussing three types of relatives: those with a lexically realized amount head (d‐headed relatives); those without such a head, but with an amount interpretation (d‐interpreted relatives); and relatives with an individual interpretation, but with the gap in a position that does not support an individual variable (ep‐relatives). We discuss in some depth several diagnostic tests, which distinguish these types of relatives from ordinary restricted relatives. We argue that, together, these tests justify Carlson's claim that these constructions need to be treated as a coherent subtype of relative clauses: amount relatives. We discuss the strengths and weaknesses of earlier proposals for the syntax and semantics of amount relatives and then provide a syntax and a semantics for the three types of amount relatives (extending and modifying our earlier analysis of ep‐relatives and providing detailed analyses of d‐headed and d‐interpreted relatives). This analysis covers more types of constructions than our earlier work, addresses a broader set of data, and links the syntax and semantics of amount relatives to recent thinking on syntactic and semantic heads in measure and classifier constructions. In an appendix we discuss the complexities arising when the gap of the amount relative is in a modal context (including problems relating to issues of relative‐internal interpretation of relative‐external material). In a second appendix we evaluate some later work on amount relatives in the light of the proposals made here.
Complex Spatial Expressions
Authors: Terzi Arhonto
Published: October 2017

This chapter highlights the main approaches to the syntactic structure of spatial expressions, from the days when they were not distinguished from other prepositions (Ps) until today. It provides a brief overview of Jackendoff's insights on rejecting the status of various Ps as case featu•res of nouns and of van Riemsdijk's work, which set the foundations for articulating a detailed structure of Ps (sometimes classified into motion Ps and others). It continues with Koopman, who clearly distinguished between directional and locative Ps, formulated the idea that directional Ps embed a locative, and proposed the presence of the functional head Place in the structure of the latter. Den Dikken follows by explicitly proposing PDirand investigating in outmost detail the extended projection of both directional and locative Ps in Dutch. Subsequent studies of spatial expressions became cross‐linguistic and even more fine‐grained. Svenonius not only provides a detailed structure of (mainly) English spatial expressions but does so from a substantially different perspective. He is interested in how the meaning of the elements occurring in spatial expressions determines their syntactic structure; and he implements Jackendoff's notion of axial parts (AxPart) to capture this relation. He proposes the functional projection AxPart, with additional structure above and below it. Drawing (mainly) on Greek spatial expressions and their distributional properties, Terzi ends up proposing a similar syntactic structure for locative Ps, but on the basis of morphosyntactic evidence alone, capitalizing on the fact that a part of this structure (either overt or null) demonstrates properties encountered in nominals. Botwinik‐Rotem and Terzi offer supporting evidence from Hebrew, and Nchare and Terzi explore this idea through languages in which locative expressions are superficially indistinguishable from nouns, while raising questions as to how locative expressions differ from referential nouns and when they can remain silent.
Copular Sentences
Authors: Moro Andrea
Published: October 2017

After a short theoretical and historical introduction to the notion of existential sentence,there‐sentences are introduced and their peculiar syntactic properties are illustrated in detail. Two symmetrical accounts are presented as competing to explain these properties: the standard account; and an alternative one, which appears to capture the empirical data in a new, comprehensive fashion, by regardingthere‐sentences as inverse copular sentences. A discussion of the so‐called “definiteness effect” is finally introduced showing howthere‐sentences still challenge dramatically some major issues of theoretical syntax, including the existence of semantic parameters.
Inalienable Possession, Primarily in French
Authors: Guéron Jacqueline
Published: October 2017

Inalienable Possession (IA) refers not to a syntactic structure but to a construal associated with a variety of structures. Each one contains a nominal denoting a body part (BP) plus another nominal denoting the possessor of the body part (poss). IA structures vary within and over languages. Structures I–III are grammatical in French, for example, while only III is grammatical in English.(1)a.Jeanlèvelamain.b.*Johnraisesthehand

(2)a.Jeluiprendslamain.b.*Ihimtakethehand

(3)a.Mariea frappéJeansurlamain.b.MaryhitJohnonthehandThis chapter reviews some studies devoted to Structures I–III. We will first examine syntactic approaches that identify IA with A‐(argument)‐binding, A′‐(operator)‐binding, or syntactic predication. We then consider conceptual analyses that evoke the notion of affect, and semantic analyses that suggest or propose identifying the BP DP in IA as a Weak Definite. In Section 4, we test how far the grammar of IA can be reduced, within the minimalist framework, to the interaction of the content of lexical content with the formal features of lexical and functional items.
Gapping
Authors: Johnson Kyle
Published: October 2017

Gapping is a construction type, found in many languages, in which part of a second conjunct is missing and supplied by material in the first conjunct. It has properties that segregate it from other seemingly similar constructions like VP and clausal ellipsis which are examined in this chapter. Those properties include: a locality condition not found elsewhere, a restriction to coordinations, apparent violations of constituency, and unexpected scope relations. A sketch of the two most promising accounts for Gapping, as well as their problems, are included.
VSOWord Order, Primarily in Arabic Languages
Authors: Benmamoun Elabbas
Published: October 2017

Arabic varieties, such as Classical Arabic, allow the verb to precede the subject and object. As in other verb‐initial languages, a number of issues arise that concern the proper configuration for the VSO order, the surface position of the subject and the verb, how agreement between the verb and the subject obtains, how to account for the agreement asymmetries that arise in the SVO and VSO orders, how Case gets assigned/checked, and whether the verb and the object form a unit at some point in the syntactic derivation or in some position in the syntactic representation. Naturally these issues have been part of the debate about language universals and language variation, the nature and motivations behind movement operations such as verb movement, and the interplay between syntax and its interfaces, particularly the PF interface.
Adverb Classes and Adverb Placement
Authors: Delfitto Denis , Fiorin Gaetano
Published: October 2017

Adverbs are one of the familiar categories of traditional grammar. Traditionally, adverbs are regarded as modifiers of verbs, in comparison with adjectives, which are regarded as modifiers of names. This view, however, runs into problems of both a syntactic and a semantic nature. On one hand, adverbs modify not only verbs but also predicates belonging to other syntactic categories. On the other hand, not all adverbs can be interpreted as predicate operators. This makes it difficult to identify uniform classificatory criteria for the class of adverbs. The interpretive notion ofpredicate modifierdoes not provide us with a criterion of classification sufficient to understand what is common to all adverbs. Adverbial syntax, on the other hand, is fairly complex. Traditionally, adverbs have been analyzed as giving rise to adjunct structures. However, this hypothesis soon proved unable to account for the complex distributional patterns of adverbs. This has led to the view that adverbs are an integral part of clause structure. More recently, however, adjunct‐based theories have regained attention by deriving the distribution of adverbs on the basis of semantic constraints.

In this chapter, we discuss the categorial status of adverbials and present the main attempts to classify adverbials into distinct classes, which are mainly based on interpretive criteria. We then discuss the issue of syntactic placement of adverbials. Two main approaches are considered: adjunct‐based theories, whereby adverbs are adjuncts and their distribution is constrained by semantic principles; and syntax‐based theories, whereby adverbs are licensed by dedicated functional heads and their distribution is determined syntactically. Finally, we face the issue of movement, in particular the peculiar properties ofwh‐movement when applied to adverbs of several types and the status of the argument–adjunct asymmetry.
CCTV Observation: The Effects of Event Type and Instructions on Fixation Behaviour in an Applied Change Blindness Task
Authors: Graham Gemma , Sauer James D. , Akehurst Lucy , Smith Jenny , Hillstrom Anne P.
Published: October 2017

Little is known about how observers' scanning strategies affect performance when monitoring events in closed‐circuit television (CCTV) footage. We examined the fixation behaviour of change detectors and non‐detectors monitoring dynamic scenes. One hundred forty‐seven participants observed mock CCTV videos featuring either a mock crime or no crime. Participants were instructed to look for a crime, to look for something unusual or simply to watch the video. In both videos, two of the people depicted switched locations. Eye movements (the number of fixations on the targets and the average length of each fixation on targets) were recorded prior to and during the critical change period. Change detection (24% overall) was unaffected by event type or task instruction. Fixation behaviour differed significantly between the criminal and non‐criminal event conditions. There was no effect of instructions on fixation behaviour. Change detectors fixated for longer on the target directly before the change than did non‐detectors. Although fixation behaviour before change predicted change detection, fixation count and durations during the critical change period did not. These results highlight the potential value of studying fixation behaviour for understanding change blindness during complex, cognitively demanding tasks (e.g. CCTV surveillance). Copyright © 2017 John Wiley & Sons, Ltd.
Prevalence and Disease‐Specific Risk Factors for Lower Urinary Tract Symptoms in Systemic Sclerosis: An International Multicenter Study
Authors: John Gregor , Avouac Jérôme , Piantoni Silvia , Polito Pamela , Fredi Micaela , Cozzi Franco , Airò Paolo , Truchetet Marie‐Elise , Franceschini Franco , Allanore Yannick , Chizzolini Carlo
Published: October 2017

Objective

To determine the prevalence of lower urinary tract symptoms (LUTS) in systemic sclerosis (SSc), to find specific risk factors, and to assess their impact on quality of life (QoL).

Methods

In a multicenter study, 334 patients completed a self‐administered questionnaire on LUTS and QoL. LUTS were classified into 3 main categories: storage, voiding, and post‐micturition symptoms. Digestive symptoms burden was captured by a visual analog scale, divided into 5 equal categories. Multivariable logistic regressions were performed to test association between risk factors and LUTS categories. Linear regression adjusted the association between LUTS and QoL.

Results

LUTS were recorded in 311 SSc patients (96.0%) and classified as severe in 120 (38.0%). The storage category of LUTS was the most prevalent (91.9%), followed by voiding (72.2%) and then by post‐micturition symptoms (49.8%). Risk factors identified in the multivariable models were higher than the median Health Assessment Questionnaire disability index (HAQ DI; odds ratio [OR] 4.2 [95% confidence interval (95% CI) 1.4–12.9]) in the storage category; higher than the median HAQ DI (OR 2.4 [95% CI 1.2–4.9]) for digestive symptoms burden (OR 1.9 [95% CI 1.3–2.7]) and synovitis (OR 4.8 [95% CI 1.0–22.6) in the voiding category; and higher for digestive symptoms burden (OR 1.2 [95% CI 1.0–1.5]) in the post‐micturition category of symptoms. These factors also increased the odds of having further severe symptoms. QoL was affected by the 3 categories of LUTS and decreased progressively with increasing frequency of symptoms.

Conclusion

Self‐reported LUTS are among the most frequent symptoms in SSc and are associated with digestive symptoms. SSc patients with LUTS have lower QoL.
Palladium‐Catalyzed Cross‐Coupling/Annulation Cascade for Synthesis of 9‐Hydroxy and 9‐Aminofluorenes.
Authors: François Benjamin , Szczubelek Luc , Berrée Fabienne , Roisnel Thierry , Carboni Bertrand
Published: October 2017

9‐Hydroxyfluorenes are easily synthesized via a tandem Suzuki/phenolic aldolisation sequence. This process was extended to 9‐aminofluorenes by simply adding various amines as third partners. X‐ray structures and NMR studies confirmed the presence of intermolecular O−H ⋅ ⋅ ⋅ N hydrogen bonding.

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Stress, sex, and plague: Patterns of developmental stress and survival in pre‐ and post‐Black Death London
Authors: DeWitte Sharon N.
Published: October 2017

Objectives

Previous research revealed declines in survivorship in London before the Black Death (c. 1346–1353), and improvements in survivorship following the epidemic. These trends indicate that there were declines in general levels of health before the Black Death and improvements thereof afterwards. This study expands on previous research by examining whether changes in survivorship were consistent between the sexes, and how patterns of developmental stress markers changed before and after the Black Death.

Materials and Methods

This study uses samples from London cemeteries dated to one of three periods: Early Pre‐Black Death (1000–1200 AD,n = 255), Late Pre‐Black Death (1200–1250 AD,n = 247), or Post‐Black Death (1350–1540 ADn = 329). Temporal trends in survivorship are assessed via Kaplan‐Meier survival analysis, and trends in tibial length (as a proxy for stature) and linear enamel hypoplasia (LEH) are assessed usingt‐tests and Chi‐square tests, respectively.

Results

Survivorship for both sexes decreased before the Black Death and increased afterwards. For males, LEH frequencies increased and stature decreased before the epidemic, and LEH declined and stature increased after the Black Death. For females, the only significant change with respect to developmental stress markers was a decrease in stature after the Black Death.

Conclusions

These results might reflect variation between the sexes in sensitivity to stressors, the effects of nutrition on pubertal timing, disproportionate access to dietary resources for males in the aftermath of the Black Death, the disproportionate deaths of frail individuals during the epidemic, or some combination of these factors.
Secular trends are associated with the demographic and epidemiologic transitions in an indigenous community in Oaxaca, Southern Mexico
Authors: Malina Robert M. , Little Bertis B. , Peña Reyes Maria Eugenia
Published: October 2017

Objective

To test the hypothesis that secular changes in body size and age at menarche are related to the demographic and epidemiologic transitions in an indigenous community in Oaxaca, southern Mexico.

Methods

Data were derived from surveys of a Zapotec‐speaking community conducted between 1968 and 2000. Segmented linear regressions of height, weight, BMI and recalled age at menarche on year of birth in cohorts of adults born before and after the demographic transition were used to evaluate secular changes. Corresponding comparisons of body size (MANCOVA controlling for age) and age at menarche (status quo, probit analysis) were done for samples of children and adolescents born before and after the epidemiological transition.

Results

Height and weight increased in adults born after the demographic transition (mid‐1950s), and especially in children and adolescents born after the epidemiological transition (mid‐1980s). Age at menarche also decreased significantly in women born after the demographic transition, but at a more rapid estimated rate in adolescents born after the epidemiological transition. Secular gains in body weight were proportional to those for height among children and adolescents, but adults, males more so than females, gained proportionally more weight.

Conclusions

The secular trend in height in adults of both sexes was associated with the decade of the demographic transition in the mid‐1950s. Significant secular gains in size attained and age at menarche occurred in children and youth born after the epidemiologic transition which likely reflected improved health and nutritional conditions since the mid‐1980s.
Testing inter‐observer reliability of the Transition Analysis aging method on the William M. Bass forensic skeletal collection
Authors: Fojas Christina L. , Kim Jieun , Minsky‐Rowland Jocelyn D. , Algee‐Hewitt Bridget F. B.
Published: October 2017

Objectives

Skeletal age estimation is an integral part of the biological profile. Recent work shows how multiple‐trait approaches better capture senescence as it occurs at different rates among individuals. Furthermore, a Bayesian statistical framework of analysis provides more useful age estimates. The component‐scoring method of Transition Analysis (TA) may resolve many of the functional and statistical limitations of traditional phase‐aging methods and is applicable to both paleodemography and forensic casework. The present study contributes to TA‐research by validating TA for multiple, differently experienced observers using a collection of modern forensic skeletal cases.

Materials and methods

Five researchers independently applied TA to a random sample of 58 documented individuals from the William M. Bass Forensic Skeletal Collection, for whom knowledge of chronological age was withheld. Resulting scores were input into the ADBOU software and maximum likelihood estimates (MLEs) and 95% confidence intervals (CIs) were produced using the forensic prior. Krippendorff's alpha was used to evaluate interrater reliability and agreement. Inaccuracy and bias were measured to gauge the magnitude and direction of difference between estimated ages and chronological ages among the five observers.

Results

The majority of traits had moderate to excellent agreement among observers (≥0.6). The superior surface morphology had the least congruence (0.4), while the ventral symphyseal margin had the most (0.9) among scores. Inaccuracy was the lowest for individuals younger than 30 and the greatest for individuals over 60. Consistent over‐estimation of individuals younger than 30 and under‐estimation of individuals over 40 years old occurred. Individuals in their 30s showed a mixed pattern of under‐ and over‐estimation among observers.

Discussion

These results support the use of the TA method by researchers of varying experience levels. Further, they validate its use on forensic cases, given the low error overall.
Röhrenförmige Selbstorganisation kovalenter organischer Netzwerke
Authors: Gole Bappaditya , Stepanenko Vladimir , Rager Sabrina , Grüne Matthias , Medina Dana D. , Bein Thomas , Würthner Frank , Beuerle Florian
Published: October 2017

Trotz erheblicher Fortschritte bei der Synthese kovalenter organischer Netzwerke (COFs) wurde für diese Materialien bis jetzt nur sporadisch über den präzisen Aufbau von templatfreien Nano‐ und Mikrostrukturen berichtet. Auf der Suche nach farbstoffhaltigen porösen Materialien konnte ein neues konjugiertes Netzwerk, DPP‐TAPP‐COF, durch reversible Iminkondensationen zwischen 5,10,15,20‐Tetrakis(4‐aminophenyl)porphyrin (TAPP) und einem Diketopyrrolopyrrol‐Dialdehyd (DPP) synthetisiert werden, das eine verstärkte Absorption bis zu λ=800 nm aufweist. Überraschenderweise wurde für dieses COF eine spontane Aggregation zu hohlen Mikroröhren mit äußeren und inneren Durchmessern von d≈300 und 90 nm beobachtet. Detaillierte mechanistische Studien ergaben, dass sich zunächst schichtartige Agglomerate bilden, die mit der Zeit in röhrenförmige Mikrostrukturen transformiert werden.
Mesoporous Carbon@Titanium Nitride Hollow Spheres as an Efficient SeS2 Host for Advanced Li–SeS2 Batteries
Authors: Li Zhen , Zhang Jintao , Guan Bu Yuan , Lou Xiong Wen (David)
Published: October 2017

The introduction of a certain proportion of selenium into sulfur‐based cathodes is an effective strategy for enhancing the integrated battery performance. However, similar to sulfur, selenium sulfide cathodes suffer from poor cycling stability owing to the dissolution of reaction intermediate products. In this study, to exploit the advantages of SeS2 to the full and avoid its shortcomings, we designed and synthesized a hollow mesoporous carbon@titanium nitride (HMC@TiN) host for loading 70 wt % of SeS2 as a cathode material for Li–SeS2 batteries. Benefiting from both physical and chemical entrapment by hollow mesoporous carbon and TiN, the HMC@TiN/SeS2 cathode manifests high utilization of the active material and excellent cycling stability. Moreover, it exhibits promising areal capacity (up to 4 mAh cm−2) with stable cell performance in the high‐mass‐loading electrode.
Layer‐by‐Layer Assembled Conductive Metal–Organic Framework Nanofilms for Room‐Temperature Chemiresistive Sensing
Authors: Yao Ming‐Shui , Lv Xiao‐Jing , Fu Zhi‐Hua , Li Wen‐Hua , Deng Wei‐Hua , Wu Guo‐Dong , Xu Gang
Published: October 2017

The utility of electronically conductive metal–organic frameworks (EC‐MOFs) in high‐performance devices has been limited to date by a lack of high‐quality thin film. The controllable thin‐film fabrication of an EC‐MOF, Cu3(HHTP)2, (HHTP=2,3,6,7,10,11‐hexahydroxytriphenylene), by a spray layer‐by‐layer liquid‐phase epitaxial method is reported. The Cu3(HHTP)2 thin film can not only be precisely prepared with thickness increment of about 2 nm per growing cycle, but also shows a smooth surface, good crystallinity, and high orientation. The chemiresistor gas sensor based on this high‐quality thin film is one of the best room‐temperature sensors for NH3 among all reported sensors based on various materials.
Antibacterial Narrow‐Band‐Gap Conjugated Oligoelectrolytes with High Photothermal Conversion Efficiency
Authors: Wang Bing , Feng Guangxue , Seifrid Martin , Wang Ming , Liu Bin , Bazan Guillermo C.
Published: October 2017

Two conjugated oligoelectrolytes (COEs), WMG1 and WMG2, were designed with the goal of achieving near infrared absorption and high photothermal conversion efficiency. Specifically, electron‐rich thiophene and electron‐poor benzo[1,2‐c:4,5‐c′]bis[1,2,5]thiadiazole subunits were introduced into the conjugated core to modulate the optical gap and to reduce the fluorescence emission efficiency. WMG1 and WMG2 show absorption maxima at around 800 nm, which favors tissue penetration. Although relatively small in size, WMG1 and WMG2 exhibit photothermal conversion efficiencies of circa 60 % and 54 %, respectively. WMG1 shows dark toxicity to the Gram positive bacterium B. subtilis and good photothermal killing efficiency toward both B. subtilis and Gram negative E. coli, features that demonstrate the promising potential of the COE molecular design for photothermal applications.
Are There Carbenes in N‐Heterocyclic Carbene Organocatalysis?
Authors: Gehrke Sascha , Hollóczki Oldamur
Published: October 2017

Azolium cations are widely employed in organocatalysis to catalyse highly valuable synthetic processes in the presence of a base. These reactions are called “N‐heterocyclic carbene catalysis”, based on the assumption that they are initiated by the formation of a free carbene through deprotonation, which can then react with the substrates and thereby affect their reactivity to obtain the desired products. However, we herein provide evidence that an electrophilic aromatic substitution mechanism is energetically more favourable, in which the azolium cation reacts directly with the substrate, avoiding the formation of the free carbene in solution.
Quantitative Prediction of Rate Constants for Aqueous Racemization To Avoid Pointless Stereoselective Syntheses
Authors: Ballard Andrew , Ahmad Hiwa O. , Narduolo Stefania , Rosa Lucy , Chand Nikki , Cosgrove David A. , Varkonyi Peter , Asaad Nabil , Tomasi Simone , Buurma Niklaas J. , Leach Andrew G.
Published: October 2017

Racemization has a large impact upon the biological properties of molecules but the chemical scope of compounds with known rate constants for racemization in aqueous conditions was hitherto limited. To address this remarkable blind spot, we have measured the kinetics for racemization of 28 compounds using circular dichroism and 1H NMR spectroscopy. We show that rate constants for racemization (measured by ourselves and others) correlate well with deprotonation energies from quantum mechanical (QM) and group contribution calculations. Such calculations thus provide predictions of the second‐order rate constants for general‐base‐catalyzed racemization that are usefully accurate. When applied to recent publications describing the stereoselective synthesis of compounds of purported biological value, the calculations reveal that racemization would be sufficiently fast to render these expensive syntheses pointless.
Rhodium(II)‐ or Copper(I)‐Catalyzed Formal Intramolecular Carbene Insertion into Vinylic C(sp2)−H Bonds: Access to Substituted 1H‐Indenes
Authors: Zhou Qi , Li Shichao , Zhang Yan , Wang Jianbo
Published: October 2017

A rhodium(II)‐ or copper(I)‐catalyzed formal intramolecular carbene insertion into vinylic C(sp2)−H bonds is reported herein. This method provides straightforward access to 1H‐indenes with high efficiency and excellent functional‐group compatibility. Mechanistically, the reaction is proposed to involve the following sequence: metal carbene formation, intramolecular nucleophilic addition of the double bond to the electron‐deficient carbene carbon atom, dearomatization, and finally a 1,5‐H shift.
Proton‐Coupled Reduction of the Catalytic [4Fe‐4S] Cluster in [FeFe]‐Hydrogenases
Authors: Senger Moritz , Laun Konstantin , Wittkamp Florian , Duan Jifu , Haumann Michael , Happe Thomas , Winkler Martin , Apfel Ulf‐Peter , Stripp Sven T.
Published: October 2017

In nature, [FeFe]‐hydrogenases catalyze the uptake and release of molecular hydrogen (H2) at a unique iron‐sulfur cofactor. The absence of an electrochemical overpotential in the H2 release reaction makes [FeFe]‐hydrogenases a prime example of efficient biocatalysis. However, the molecular details of hydrogen turnover are not yet fully understood. Herein, we characterize the initial one‐electron reduction of [FeFe]‐hydrogenases by infrared spectroscopy and electrochemistry and present evidence for proton‐coupled electron transport during the formation of the reduced state Hred′. Charge compensation stabilizes the excess electron at the [4Fe‐4S] cluster and maintains a conservative configuration of the diiron site. The role of Hred′ in hydrogen turnover and possible implications on the catalytic mechanism are discussed. We propose that regulation of the electronic properties in the periphery of metal cofactors is key to orchestrating multielectron processes.
Electromechanical instability in silicone‐ and acrylate‐based dielectric elastomers
Authors: Jiang Liang , Zhou Yanfen , Chen Shaojuan , Ma Jianwei , Betts Anthony , Jerrams Stephen
Published: October 2017

Electromechanical instability (EMI) is regarded as a significant factor in preventing dielectric elastomers (DEs) from achieving large voltage‐induced deformations. In this study, the strain‐stiffening effect was used to control the occurrence of EMI in DEs. The results show that the stretching ratio required to provide a feasible strain‐stiffening effect in silicone rubber (SR) was smaller than that needed for a commercial DE material, VHB 4910. The experimental data were compared with currently used models for the simulation of EMI in DEs. We found that EMI could be eliminated in the deformation of these elastomers when prestretching was used. Through the application of a prestretching ratio of above 2.0, EMI was suppressed in both the VHB 4910 and SR samples. The findings of this research are of great significance in the maximization of the electromechanical performance of DE materials. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45733.
Synthesis and properties of phenyl carboxyl polydimethylsiloxane for fabrics treatment
Authors: Ji Chunda , Li Fengfu , Yun Zhi
Published: October 2017

A series of phenyl carboxyl polydimethylsiloxane (PCPDMS) with different relative molecular mass, phenyl and carboxyl content was prepared through condensation reaction and equilibrium polymerization. The effects of reaction conditions on the conversion were investigated, to determine the optimum reaction conditions. According to the thermal gravity analysis of PCPDMS with different relative molecular mass and phenyl content, it was found that the large relative molecular mass can improve the thermal stability of PCPDMS. The thermal stability of PCPDMS was significantly higher than carboxyl polydimethylsiloxane. Moreover, the PCPDMS emulsions were also prepared for the fabrics treatment. The emulsions can improve the wrinkle resistance, smoothness, elasticity, and other properties of the fabrics. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2018,135, 45866.
Positive‐tone photoresist consisting of a multifunctional acrylate resin that can be patterned after photo‐crosslinking
Authors: Sugita Hikaru , Miyashita Yuka , Suzuki Hiroyuki , Takasugi Shingo , Matsumura Nobuji , Yoshizawa Mitsuyo
Published: October 2017

A multifunctional acrylate resin having a tertiary ester structure is synthesized using a thiol‐acrylate Michael addition click reaction. By loading both a photo radical initiator and a photo acid generator into this resin, a positive‐tone photoresist, that can be patterned after photocrosslinking (PPaP), is formulated. After the thin film is irradiated with 365 nm light, radical crosslinking proceeds and a solvent resistant “frozen” film can be obtained. The frozen film works as a positive‐tone photoresist. When the frozen PPaP is irradiated with light containing a wavelength much shorter than 300 nm, the ester structure of the exposed region is decomposed by photo‐chemically generated acid and dissolved in an alkaline solution. Furthermore, a photochemical pattern transfer is achieved using the material. By performing the photo exposure on conventional photoresist patterns on the frozen PPaP underlayer, the photoresist patterns are successfully transferred to the underlayer. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45871.
Interphase‐layer effect on deformation of silicone rubber filled with nanosilica particles
Authors: Adachi Tadaharu , Yamada Yuki , Ishii Yosuke
Published: October 2017

The viscoelastic and statically tensile deformation properties of silicone rubber composites filled with nanosilica (300 nm in diameter) and microsilica particles (1.5 μm in diameter) were investigated on the basis of experimental results to clarify the interphase‐layer effect on these properties. The interphase layers formed around the nanoparticles without chemical coating were found to be glassy, even though the composites were in the rubbery state. The interphase layer thickness was determined to be approximately 20 nm using Guth and Gold's mixture law with the viscoelastic properties of the nanoparticle‐filled rubber in the rubbery state. The determined thickness of the interphase layer was confirmed by comparing the maximum strains at fracture for the nanoparticle‐filled rubber, which decreased for higher volume fraction of the nanoparticles. Therefore, the deformation properties were clarified to depend on the volume fraction of the apparent particles composed of the nanoparticles and interphase layers. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45880.
Thermal, electrical, and dielectric properties of reduced graphene oxide–polyaniline nanotubes hybrid nanocomposites synthesized by in situ reduction and varying graphene oxide concentration
Authors: Devi Madhabi , Kumar Ashok
Published: October 2017

In this study, reduced graphene oxide (RGO) has been introduced as conductive filler within polyaniline (PAni) nanotubes (PAniNTs) by in situ chemical reduction method to enhance the properties of PAniNTs. The effect of varied concentration of in situ reduced GO on the structural, thermal, electrical, and dielectric properties of RGO–PAniNTs nanocomposites have been investigated by high resolution transmission electron microscope, X‐ray diffraction, Fourier transform infrared, thermogravimetric analysis, I–V characteristics, and impedance analyzer. The enhanced thermal stability of the nanocomposites has been analyzed from the derivative thermogravimetric curves in terms of onset and rapid decomposition temperature. The transport mechanisms have been studied by fitting the nonlinear I–V characteristics to the Kaiser model. The dielectric relaxation phenomena have been investigated by permittivity and modulus formalisms. Characteristic relaxation frequency of RGO–PAniNTs nanocomposites shifts toward higher frequency with increasing RGO concentration indicating a distribution in conductivity relaxation. The distribution of relaxation time has been studied by fitting the imaginary modulus spectra of the nanocomposites to Bergman modified KWW function. The ac conductivity spectra are fitted to the Jonscher's power law equation and enhanced conductivity value of 1.26 × 10−3 S cm−1 is obtained for 40 wt % of RGO compared to 1.22 × 10−4 S cm−1 for PAniNTs. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45883.
Tris(hydroxymethyl)aminomethane polyamide thin‐film‐composite antifouling reverse osmosis membrane
Authors: Chen Li‐Ye , Wu Li‐Ping , Zhang Hong‐Li , Gao Yu‐Bing , Gai Jing‐Gang
Published: October 2017

For the applications of reverse osmosis (RO) process, membrane fouling caused by organic molecule adsorption is still a serious problem which significantly decreases membrane lifespan and increases operation costs. In this present article, we report the thin film composite (TFC) RO membrane functionalized with tris(hydroxymethyl)aminomethane (THAM) using one‐step method for improved antifouling property. The results of surface characterization indicated that THAM was successfully grafted onto the active layer of membrane by covalent linkage. Mult‐hydroxyl‐layer was generated and remained steadily on TFC membrane surface after modification. The contact angle decreased from 75.9 ± 3.0° to 46.9 ± 2.3°, which showed a distinct improvement of membrane surface hydrophilicity after modification. The grafted THAM improved water flux by 28.3%, while salt rejection was almost unchanged in membrane property tests. The modified membranes presented preferable antifouling property to foulants of bovine serum albumin, sodium alginate, and dodecyl trimethyl ammonium bromide than that of pristine membranes during dynamic fouling experiments. The method in this study provided an effective way to improve antifouling property of the polyamide thin‐film‐composite RO membrane. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45891.
Environment‐friendly chemical recycling of aliphatic polyurethanes by hydrolysis in a CO2‐water system
Authors: Motokucho Suguru , Nakayama Yu , Morikawa Hiroshi , Nakatani Hisayuki
Published: October 2017

In order to develop a chemical recycling system of polyurethanes (PUs), environment‐friendly hydrolysis of two types of aliphatic PUs was studied under pressured CO2 in water, in which the carbonic acid generated from CO2 acted as an acid catalyst. Two PUs, namely H‐PU or I‐PU, were synthesized starting from 1,4‐butanediol and 1,6‐hexamethylene diisocyanate or isophorone diisocyanate, respectively. The hydrolysis of PUs depended on the experimental conditions, such as the temperature and CO2 pressure. As a result, 98% of H‐PU and 91% of I‐PU were successfully hydrolyzed under the typical conditions of 190 °C for 24 h at 8.0 MPa CO2. The reaction mixtures afforded 1,4‐butanediol and diamines without the formation of any byproducts. Both of these raw materials generated from the originated PUs by selective hydrolytic cleavage of the urethane linkages, and they were easily isolated in high yields simply by evaporation of the water‐soluble components within the reaction mixture. By comparing the results of the two aliphatic PUs with those of an aromatic PU (M‐PU), the hydrolyzability was found to decrease in the order H‐PU, I‐PU, and M‐PU. The difference can be ascribed to the hydrophilicity of the aliphatic or aromatic groups connected to the urethane moieties at the terminals of PUs. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45897.