bluuebunny/crossref_metadata_2025 huggingface dataset:
Di‐
n
‐butyl phthalate [MAK value documentation, 2017]
Authors: Hartwig A. ,   MAK Commission
Published: November 2019

The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated the developmental toxicity of di‐
n
‐butyl phthalate. Available publications are described in detail. In prenatal developmental toxicity studies in rats, the most sensitive endpoint was altered morphometry (size and organization) of the seminiferous cords, the precursor of the seminiferous tubules, at 50 mg/kg body weight and day and above; the NOAEL was 30 mg/kg body weight and day. In rats, teratogenic effects like hypospadia and underdeveloped or absent epididymides were observed at 250 mg/kg KG body weight and day and above; the NOAEL was 100 mg/kg body weight and day.

In a two‐generation reproduction toxicity study in rats, a LOAEL of 80 mg/kg body weight and day, the lowest dose, could be derived for foetotoxicity and decreased live pup weight at birth. In rats, the NOAEL for behavioural toxicity is 291 mg/kg body weight and day in male pups. From a one‐generation reproduction toxicity study in mice, a NOAEL of 420 mg/kg body weight and day could be derived for foetotoxicity and decreased number of live pups. The NOAELs and the LOAEL for developmental toxicity and foetotoxicity can be scaled to concentrations of 32, 107, 84 (LOAEL) and 252 mg/m
3
, respectively, at the workplace. Thus, damage to the embryo or foetus is unlikely when the MAK value of 0.58 mg/m
3
is not exceeded, and the classification in Pregnancy Risk Group C is confirmed.
Remotely Triggered Assembly of 3D Mesostructures Through Shape‐Memory Effects
Authors: Park Jun Kyu , Nan Kewang , Luan Haiwen , Zheng Ning , Zhao Shiwei , Zhang Hang , Cheng Xu , Wang Heling , Li Kan , Xie Tao , Huang Yonggang , Zhang Yihui , Kim Seok , Rogers John A.
Published: November 2019

3D structures that incorporate high‐performance electronic materials and allow for remote, on‐demand 3D shape reconfiguration are of interest for applications that range from ingestible medical devices and microrobotics to tunable optoelectronics. Here, materials and design approaches are introduced for assembly of such systems via controlled mechanical buckling of 2D precursors built on shape‐memory polymer (SMP) substrates. The temporary shape fixing and recovery of SMPs, governed by thermomechanical loading, provide deterministic control over the assembly and reconfiguration processes, including a range of mechanical manipulations facilitated by the elastic and highly stretchable properties of the materials. Experimental demonstrations include 3D mesostructures of various geometries and length scales, as well as 3D aquatic platforms that can change trajectories and release small objects on demand. The results create many opportunities for advanced, programmable 3D microsystem technologies.
Versatile Homoleptic Naphthyl‐Acetylide Heteronuclear [Pt2M4(CC‐Np)8] (M = Ag, Cu) Phosphors for Highly Efficient White and NIR Hybrid Light‐Emitting Diodes
Authors: Fresta Elisa , Fernández‐Cestau Julio , Gil Belén , Montaño Patricia , Berenguer Jesús R. , Moreno María Teresa , Coto Pedro B. , Lalinde Elena , Costa Rubén D.
Published: November 2019

A new family of low‐energy emitting organic phosphors (OPs) based on [Pt2M4(CC‐1‐Np)8] clusters, in which M is either Ag(I) (1) or Cu(I) (2) and CC‐1‐Np is the strongly delocalized 1‐naphthylacetylide ligand, are presented. The inclusion of the 1‐naphthylacetylide moiety is crucial to achieve very emissive and stable OPs that do not experience photoinduced heat generation and oxidation in both white and NIR hybrid light‐emitting diodes (HLEDs) operating under ambient conditions. In short, the first use of these novel OPs leads to i) HLEDs with NIR emission centered at 730 nm, color purity close to 0.99, and remarkable luminous efficacies of ≈1.5 lm W−1 that is comparable to commercial NIR‐LEDs and ii) daylight white LEDs with luminous efficacies of 75 lm W−1 and stabilities of >500 h. Thus, this work provides relevant information for the synthesis, design, and application of a new family of low‐energy emitting OPs toward efficient and stable white and NIR hybrid LEDs.
Identification of Bond‐Weakening Spirosilane Catalyst for Photoredox α‐C−H Alkylation of Alcohols
Authors: Sakai Kentaro , Oisaki Kounosuke , Kanai Motomu
Published: November 2019

The development of catalyst‐controlled site‐selective C(sp3)−H functionalization is a current major challenge in organic synthesis. This paper describes DFT‐guided identification of pentavalent silicate species as a novel bond‐weakening catalyst for the α‐C−H bonds of alcohols together with a photoredox catalyst and a hydrogen atom transfer catalyst. Specifically, Martin's spirosilane accelerated α‐C−H alkylation of alcohols.

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A Large Anisotropic Enhancement of the Charge Carrier Mobility of Flexible Organic Transistors with Strain: A Hall Effect and Raman Study
Authors: Choi Hyun Ho , Yi Hee Taek , Tsurumi Junto , Kim Jae Joon , Briseno Alejandro L. , Watanabe Shun , Takeya Jun , Cho Kilwon , Podzorov Vitaly
Published: November 2019

Utilizing the intrinsic mobility–strain relationship in semiconductors is critical for enabling strain engineering applications in high‐performance flexible electronics. Here, measurements of Hall effect and Raman spectra of an organic semiconductor as a function of uniaxial mechanical strain are reported. This study reveals a very strong, anisotropic, and reversible modulation of the intrinsic (trap‐free) charge carrier mobility of single‐crystal rubrene transistors with strain, showing that the effective mobility of organic circuits can be enhanced by up to 100% with only 1% of compressive strain. Consistently, Raman spectroscopy reveals a systematic shift of the low‐frequency Raman modes of rubrene to higher (lower) frequencies with compressive (tensile) strain, which is indicative of a reduction (enhancement) of thermal molecular disorder in the crystal with strain. This study lays the foundation of the strain engineering in organic electronics and advances the knowledge of the relationship between the carrier mobility, low‐frequency vibrational modes, strain, and molecular disorder in organic semiconductors.
Multifunctional Ultrastretchable Printed Soft Electronic Devices for Wearable Applications
Authors: Tian Bin , Liu Qun , Luo Chengsheng , Feng Yu , Wu Wei
Published: November 2019

Multifunctionality is a major development trend in flexible stretchable wearable electronics, requiring integration of electrical conductivity, sensing performance, and heating management on a portable electronic device. Herein, the silver fractal dendrites (Ag FDs) conductive ink is formulated and deposited into the polystyrene–block–polyisoprene–block–polystyrene (SIS) thin films by a simple and cost‐effective transfer‐printing method for preparing the patterned multifunctional wearable electronics (MWEs). The MWEs based on Ag FDs ink‐38 wt% exhibit high electrical conductivity (4.86 × 105 S m−1), excellent sensing property (highly stretchability of 500% with a maximum gauge factor (GF) of 659.5), low‐voltage driving Joule heating performance (heated to 52.3 °C at 1 V), and good mechanical stability. As strain sensors, the MWEs have been successfully used to monitor the bending motion of the six major joints in the human body. As Joule heaters, the MWEs have been successfully used for thermochromism and hyperthermia. The developed MWEs prepared by a simple and low‐cost transfer‐printing possess highly promising application for next‐generation multifunctional and smart wearable electronics.
High‐Voltage Photogeneration Exclusively via Aggregation‐Induced Triplet States in a Heavy‐Atom‐Free Nonplanar Organic Semiconductor
Authors: Davy Nicholas C. , Koch Marius , Ngongang Ndjawa Guy Olivier , Lin Xin , Man Gabriel J. , Lin YunHui L. , Sorli Jeni C. , Rand Barry P. , Kahn Antoine , Scholes Gregory D. , Loo Yueh‐Lin
Published: November 2019

The electron–hole recombination kinetics of organic photovoltaics (OPVs) are known to be sensitive to the relative energies of triplet and charge‐transfer (CT) states. Yet, the role of exciton spin in systems having CT states above 1.7 eV—like those in near‐ultraviolet‐harvesting OPVs—has largely not been investigated. Here, aggregation‐induced room‐temperature intersystem crossing (ISC) to facilitate exciton harvesting in OPVs having CT states as high as 2.3 eV and open‐circuit voltages exceeding 1.6 V is reported. Triplet excimers from energy‐band splitting result in ultrafast CT and charge separation with nonradiative energy losses of <250 meV, suggesting that a 0.1 eV driving force is sufficient for charge separation, with entropic gain via CT state delocalization being the main driver for exciton dissociation and generation of free charges. This finding can inform engineering of next‐generation active materials and films for near‐ultraviolet OPVs with open‐circuit voltages exceeding 2 V. Contrary to general belief, this work reveals that exclusive and efficient ISC need not require heavy‐atom‐containing active materials. Molecular aggregation through thin‐film processing provides an alternative route to accessing 100% triplet states on photoexcitation.
Positional behavior and substrate use in wild adult bearded capuchin monkeys (Sapajus libidinosus)
Authors: Wright Kristin A. , Biondi Luiz , Visalberghi Elisabetta , Ma Ziyang , Izar Patricia , Fragaszy Dorothy
Published: November 2019

Natural selection for positional behavior (posture and locomotion) has at least partially driven the evolution of anatomical form and function in the order Primates. Examination of bipedal behaviors associated with daily activity patterns, foraging, and terrestrial habitat use in nonhuman primates, particularly those that adopt bipedal postures and use bipedal locomotion, allows us to refine hypotheses concerning the evolution of bipedalism in humans. This study describes the positional behavior of wild bearded capuchins (Sapajus libidinosus), a species that is known for its use of terrestrial substrates and its habitual use of stones as tools. Here, we test the association of terrestrial substrate use with bipedal posture and locomotion, and the influence of sex (which co‐varies with body mass in adults of this species) on positional behavior and substrate use. Behavior and location of 16 wild adult bearded capuchins from two groups were sampled systematically at 15 s intervals for 2 min periods for 1 year (10,244 samples). Despite their different body masses, adult males (average 3.5 kg) and females (average 2.1 kg) in this study did not differ substantially in their positional behaviors, postures, or use of substrates for particular activities. The monkeys used terrestrial substrates in 27% of samples. Bipedal postures and behaviors, while not a prominent feature of their behavior, occurred in different forms on the two substrates. The monkeys crouched bipedally in trees, but did not use other bipedal postures in trees. While on terrestrial substrates, they also crouched bipedally but occasionally stood upright and moved bipedally with orthograde posture. Bearded capuchin monkeys' behavior supports the suggestion from anatomical analysis thatS. libidinosusis morphologically better adapted than its congeners to adopt orthograde postures.
Influence of food availability and climate on behavior patterns of western black crested gibbons (Nomascus concolor) at Mt. Wuliang, Yunnan, China
Authors: Ning Wen‐He , Guan Zhen‐Hua , Huang Bei , Fan Peng‐Fei , Jiang Xue‐Long
Published: November 2019

Food abundance and climatic factors can significantly affect the behavior of animals and constrain their activity budgets. The population of western black crested gibbons (Nomascus concolor) in Mt. Wuliang lives in montane forest and is close to the northern extreme of the distribution for gibbons (Hylobatidae). Their habitats show remarkable seasonal variation in terms of food availability, temperature, and rainfall. To understand behavioral adaptations of western black crested gibbons to different sets of ecological conditions, we examined relationships among food availability, mean temperature, rainfall, and behavior patterns by observing two groups for 1 year each. Our results revealed that activity budget was affected by food availability and mean temperature. The gibbons spent more time eating flowers when that resource was more available and spent less time moving when fruit was more available. The gibbons spent less time feeding and more time resting, and spent less feeding time on fruit and leaves when the mean temperature was lower. These results suggest that the gibbons displayed a pronounced preference for flowers as a food resource and adopted a time minimizer strategy when high‐nutrient food items (i.e., fruit) were more available. In addition, the gibbons adopted an energy‐conserving strategy during periods of low temperature. The flexibility of behavioral patterns in responding to food availability and temperature may potentially improve the gibbons’ prospects of surviving and reproducing in a northern montane forest.
New landmarks in endonasal surgery: from nasal bone to anterior cribriform plate including branches of anterior ethmoidal artery and nerve and terminal nerve
Authors: Roussel Lise‐Marie , Patron Vincent , Maubert Eric , Escalard Clément , Goux Didier , Beaudouin Vincent , Lechapt Emmanuèle , Moreau Sylvain , Hitier Martin
Published: November 2019

Background

Despite the development of anterior skull base surgery, the anatomy of the nasal bone and anterior cribriform plate remains unclear. A recent study confirmed 2 distinct foramina in the anterior part of cribriform plate: the ethmoidal slit (ES) and the cribroethmoidal foramen (CF). The aim of this study was to specify their content, their anatomic relationship to the frontal sinus and skull base, and their potential value in skull base surgery.

Methods

Dissections were performed on 36 cadaver heads. Macro‐ and microscopic examinations were carried out. Microcomputed tomography scans contrasted with osmium were performed to identify vessels and nerves. Histology with neural, meningeal, or luteinizing hormone‒releasing hormone immunomarkers was performed on the content of the foramina. Finally, endonasal surgical dissections were carried out.

Results

The ES and the CF were observed in all cases. They measured a mean of 4.2 and 1.6 mm, respectively. The ES contained dura mater, arachnoid tissues, lymphatics, and the terminal nerve. The CF contained the anterior ethmoidal nerve and artery. This foramen continued forward with the cribroethmoidal groove, which measured a mean of 2.5 mm. This groove was under the frontal sinus and in front of the skull base. We also described a “cribroethmoidal canal” and a “nasal bone foramen.”

Conclusion

The clinical applications of this new anatomic description concern both cribriform plate and frontal sinus surgeries. Identifying the terminal nerve passing through the ES is a step forward in understanding pheromone recognition in humans.
Distinguishing the Topological Zero Mode and Tamm Mode in a Microwave Waveguide Array
Authors: Chen Tao , Yu Ye , Song Yiwen , Yu Dong , Ye Hongmei , Xie Jingya , Shen Xiaopeng , Pan Yiming , Cheng Qingqing
Published: November 2019

The Su–Schrieffer–Heeger (SSH) model has been the subject of extensive experimental research in the context of topological photonics. Ideally, the on‐site potential and hopping strength are sufficiently accurate for implementation in photonic coupled waveguide arrays. Here, two localized edge modes, the topological zero mode and trivial Tamm mode, are proposed and demonstrated in the modified SSH model using a microwave photonic waveguide array. The system used is composed of an array of evanescently coupled ultrathin corrugated metallic “H‐bar” waveguides. Furthermore, the differences between the zero mode and Tamm mode are clearly demonstrated by microwave near‐field experiments on the coupling behavior along the propagation direction for 40 cm at the excitation frequency of 17 GHz. These findings should deepen the understanding of localized edge mode confinement mechanisms, both in coupled waveguide array systems and other topological or quantum systems.
Photoinduced Radical Borylation of Alkyl Bromides Catalyzed by 4‐Phenylpyridine
Authors: Zhang Li , Wu Zhong‐Qian , Jiao Lei
Published: November 2019

Utilizing pyridine catalysis, we developed a visible‐light‐induced transition‐metal‐free radical borylation reaction of unactivated alkyl bromides that features a broad substrate scope and mild reaction conditions. Mechanistic studies revealed a novel nucleophilic substitution/photoinduced radical formation pathway, which could be utilized to trigger a variety of radical processes.
Proton Intercalation/De‐Intercalation Dynamics in Vanadium Oxides for Aqueous Aluminum Electrochemical Cells
Authors: Zhao Qing , Liu Luojia , Yin Jiefu , Zheng Jingxu , Zhang Duhan , Chen Jun , Archer Lynden A.
Published: November 2019

Understanding cation (H+, Li+, Na+, Al3+, etc.) intercalation/de‐intercalation chemistry in transition metal compounds is crucial for the design of cathode materials in aqueous electrochemical cells. Here we report that orthorhombic vanadium oxides (V2O5) supports highly reversible proton intercalation/de‐intercalation reactions in aqueous media, enabling aluminum electrochemical cells with extended cycle life. Empirical analyses using vibrational and x‐ray spectroscopy are complemented with theoretical analysis of the electrostatic potential to establish how and why protons intercalate in V2O5 in aqueous media. We show further that cathode coatings composed of cation selective membranes provide a straightforward method for enhancing cathode reversibility by preventing anion cross‐over in aqueous electrolytes. Our work sheds light on the design of cation transport requirements for high‐energy reversible cathodes in aqueous electrochemical cells.
Photosynthetic Tumor Oxygenation by Photosensitizer‐Containing Cyanobacteria for Enhanced Photodynamic Therapy
Authors: Huo Minfeng , Wang Liying , Zhang Linlin , Wei Chenyang , Chen Yu , Shi Jianlin
Published: November 2019

Sustained tumor oxygenation is of critical importance during type‐II photodynamic therapy (PDT), which depends on the intratumoral oxygen level for the generation of reactive oxygen species. Herein, the modification of photosynthetic cyanobacteria with the photosensitizer chlorin e6 (ce6) to form ce6‐integrated photosensitive cells, termed ceCyan, is reported. Upon 660 nm laser irradiation, sustained photosynthetic O2 evolution by the cyanobacteria and the immediate generation of reactive singlet oxygen species (1O2) by the integrated photosensitizer could be almost simultaneously achieved for tumor therapy using type‐II PDT both in vitro and in vivo. This work contributes a conceptual while practical paradigm for biocompatible and effective PDT using hybrid microorganisms, displaying a bright future in clinical PDT by microbiotic nanomedicine.
Defect‐Directed Growth of Symmetrically Branched Metal Nanocrystals
Authors: Smith Joshua D. , Bladt Eva , Burkhart Joseph A. C. , Winckelmans Naomi , Koczkur Kallum M. , Ashberry Hannah M. , Bals Sara , Skrabalak Sara E.
Published: November 2019

Branched plasmonic nanocrystals (NCs) have attracted much attention due to electric field enhancements at their tips. Seeded growth provides routes to NCs with defined branching patterns and, in turn, near‐field distributions with defined symmetries. Here, a systematic analysis was undertaken in which seeds containing different distributions of planar defects were used to grow branched NCs in order to understand how their distributions direct the branching. Characterization of the products by multimode electron tomography and analysis of the NC morphologies at different overgrowth stages indicate that the branching patterns are directed by the seed defects, with the emergence of branches from the seed faces consistent with minimizing volumetric strain energy at the expense of surface energy. These results contrast with growth of branched NCs from single‐crystalline seeds and provide a new platform for the synthesis of symmetrically branched plasmonic NCs.
Molecular Bridges Stabilize Graphene Oxide Membranes in Water
Authors: Zhang Mengchen , Mao Yangyang , Liu Guozhen , Liu Gongping , Fan Yiqun , Jin Wanqin
Published: November 2019

Recent innovations highlight the great potential of two‐dimensional graphene oxide (GO) films in water‐related applications. However, undesirable water‐induced effects, such as the redispersion and peeling of stacked GO laminates, greatly limit their performance and impact their practical application. It remains a great challenge to stabilize GO membranes in water. A molecular bridge strategy is reported in which an interlaminar short‐chain molecular bridge generates a robust GO laminate that resists the tendency to swell. Furthermore, an interfacial long‐chain molecular bridge adheres the GO laminate to a porous substrate to increase the mechanical strength of the membrane. By rationally creating and tuning the molecular bridges, the stabilized GO membranes can exhibit outstanding durability in harsh operating conditions, such as cross‐flow, high‐pressure, and long‐term filtration. This general and scalable stabilizing approach for GO membranes provides new opportunities for reliable two‐dimensional laminar films used in aqueous environments.
NMR Characterization of Surface Receptor Protein Interactions in Live Cells Using Methylcellulose Hydrogels
Authors: Mateos Borja , Sealey‐Cardona Marco , Balazs Katja , Konrat Judith , Staffler Guenther , Konrat Robert
Published: November 2019

Interactions of transmembrane receptors with their extracellular ligands are essential for cellular communication and signaling and are therefore a major focus in drug discovery programs. The transition from in vitro to live cell interaction studies, however, is typically a bottleneck in many drug discovery projects due to the challenge of obtaining atomic‐resolution information under near‐physiological conditions. Although NMR spectroscopy is ideally suited to overcome this limitation, several experimental impairments are still present. Herein, we propose the use of methylcellulose hydrogels to study extracellular proteins and their interactions with plasma membrane receptors. This approach reduces cell sedimentation, prevents the internalization of membrane receptors, and increases cell survival, while retaining the free tumbling of extracellular proteins.
Polyurethane Thermosets Using Lipidic Poly(α‐Hydroxyketone)
Authors: Briou Benoit , Vu Nam Duc , Caillol Sylvain , Robin Jean‐Jacques , Duguet Nicolas , Lemaire Marc , Etienne Pascal , Bonnet Laurent , Lapinte Vincent
Published: November 2019

Lipidic polyols based on α‐hydroxyketone reactive groups were investigated for polyurethane thermosets. The reactivity of this peculiar secondary alcohol group in triacylglycerol structure was compared, without use of catalyst, to that of poly(1,2‐diol) triacylglycerol and castor oil to demonstrate the influence of ketone in the α position of the alcohol group in the presence of HDI for the urethanization rate. The kinetic effect of the ketone group was also studied on various lipidic architectures: mono(α‐hydroxyketone) ester, di(α‐hydroxyketone) diester and tri(α‐hydroxyketone) triacylglycerol. The presence of hydrogen bonds in the network coming from urethane, residual alcohol, and ketone in hard segments of PU was discussed and correlated with the thermal stability and the soft mechanical properties of the resulting polyurethane thermosets.
A comparative study on the nucleation, growth, and agglomeration kinetics of potassium dihydrogen phosphate crystal in circulating fluidized‐bed crystallizer
Authors: Zheng Dan , Zou Wei , Yan Jie , Peng Chuanfeng , Fu Yuhang , Li Bo , Zeng Li
Published: November 2019

The crystallization in a fluidized‐bed crystallizer has recently received increasing interest for separation and purification of crystals. Past investigations on potassium dihydrogen phosphate (KDP) crystallization mainly focused on process efficiency and thermodynamics and less on kinetics. In this paper, the fluidized crystallization technology is used to investigate a KDP crystallization process. The mechanisms involved in crystal formation have been explored by observation of a continuous withdrawal of a suspension containing target crystals having certain size distribution. The crystallization process of KDP is researched to investigate the key parameters (suspension density [MT], solution supersaturation [ΔC], and fluid shear force [expressed by circulation flow rate; Re]) influencing crystal growth, nucleation, and agglomeration process. Three proposed crystallization kinetic models about crystals growth, nucleation, and agglomeration rates are developed and validated against data from the fluidized‐bed crystallizer. Taking advantage of multivariate nonlinear regression analysis, crystallization kinetic parameters are obtained by adopting the kinetic model in fluidized‐bed crystallization process. The comparative research of three crystallization kinetic rates is also studied. The results indicated that the parameters given by the kinetic mathematics model fit well with the experimental data. The error rate between the experimental and calculated value is also controlled within a reasonable range.
Synthesis and chemical properties of polyethyleneimines crosslinked by penta‐2,4‐dienylideneammonium unit
Authors: Yamaguchi Isao , Matsumoto Yudai , Miyoshi Kiyotaka , Wang Aohan
Published: November 2019

The reaction of N‐(2,4‐dinitrophenyl)pyridinium anion (salt(A); A = Cl−, FeCl4−, and (CN)2N−) with linear polyethyleneimine (LPEI; Mn = 20 380) and branched polyethyleneimines (BPEI1; Mn = 600, BPEI2; Mn = 10 000) at various molar feed ratios without using a catalyst resulted in pyridinium ring opening to yield ionic LPEI and BPEIs that were crosslinked by conjugated penta‐2,4‐dienylideneammonium (PDA) units, LPEI‐PDA, BPEI1‐PDA, and BPEI2‐PDA, respectively. A model compound was synthesized by the reaction of salt(Cl) with diethylamine. The solubilities of BPEI1‐PDA and BPEI2‐PDA depended on the feed ratios between salt(Cl) and BPEI1 or BPEI2. Dipping LPEI‐PDA into water and methanol yielded hydro‐ and organogels, respectively. UV–vis and reflection measurements revealed an expanded π‐conjugation length between the polymer chains due to the through‐space orbital interaction of the electrons on the two nitrogen atoms at the crosslinked positions in LPEI‐PDA, BPEI1‐PDA, and BPEI2‐PDA. Cyclic voltammetry analysis suggested that the polymers underwent electrochemical oxidation. Measurement using a superconducting quantum interference device (SQUID) indicated that LPEI‐PDA having FeCl4− anions was paramagnetic. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48712.
Micro‐tomographic characterization of composite recycled glass‐silicone foams for applications in civil engineering
Authors: Calabrese Luigi , Scalici Tommaso , Khaskhoussi Amani , Proverbio Edoardo , Valenza Antonino
Published: November 2019

Noninvasive X‐ray micro‐computed tomography was applied for a complete quantitative and qualitative analysis of the cellular structure of composite foams constituted by a silicone matrix and a glass production waste filler. Composite foams with different glass filler weight content in the range 0–80% were synthesized and characterized. The tomographic analysis was employed in order to assess the structural heterogeneities, void fraction values, and bubble size distribution for all composite foams. The 3D micro‐CT images analysis, performed at different cross‐sections, highlighted heterogeneous cell growth or more elongated cells in the case of low and high filler content foams, respectively. Batch with 60% of glass filler was identified as a composite foam with effective void fraction values and relatively uniform spheroidal cellular structure (average sphericity 0.723 and diameter 0.107 mm). © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48718.
Explaining library user loyalty through perceived service quality: What is wrong?
Authors: Soares‐Silva Danilo , de Moraes Gustavo Hermínio Salati Marcondes , Cappellozza Alexandre , Morini Cristiano
Published: November 2019

This study validates the adaptation of a loyalty scale for the library scenario and recovers the hierarchical nature of the perceived service quality (PSQ) by operationalizing it as a second‐order level construct, composed by the determinants of service quality (DSQ) identified by Parasuraman, Zeithaml, and Berry in 1985. Our hypothesis was that DSQ are distinct and complementary dimensions, in opposition to the overlapping of DSQ proposed in the SERVQUAL and LibQUAL+® models. In addition, the influence of PSQ on user loyalty (UL) was investigated. Using structural equation modeling, we analyzed the survey data of 1,028 users of a network of academic libraries and report 2 main findings. First, it was shown that the 10 DSQ are statistically significant for the evaluation of PSQ. Second, we demonstrated the positive effect of PSQ for UL. The model presented may be used as a diagnostic and benchmarking tool for managers, coordinators, and librarians who seek to evaluate and/or assess the quality of the services offered by their libraries, as well as to identify and/or manage the loyalty level of their users.
Epidemiologic trends and geographic distribution of esophageal cancer in Canada: A national population‐based study
Authors: Cattelan Leila , Ghazawi Feras M. , Le Michelle , Lagacé François , Savin Evgeny , Zubarev Andrei , Gantchev Jennifer , Tomaszewski Marcel , Sasseville Denis , Waschke Kevin , Litvinov Ivan V.
Published: November 2019

Background

Esophageal cancer can be subdivided into two main histological subtypes with significant variability in their etiology and epidemiology. The incidence of esophageal adenocarcinoma (AC) is increasing across the developed countries, whereas the incidence of esophageal squamous cell carcinoma (SCC) is declining. Several risk factors have been identified in the pathogenesis of each subtype, however, their epidemiologic characteristics and distribution throughout Canada remain poorly understood.

Methods

We performed a retrospective analysis of demographic data across Canada from 1992 to 2010 using two independent population‐based cancer registries. The incidence of esophageal cancer, for each subtype, was examined at the levels of provinces/territories, cities, and postal codes.

Results

A total of 19 790 patients were diagnosed with esophageal cancer in Canada between 1992 and 2010; 74% were males. The average national incidence rate was 33.5 cases per million individuals per year. Incidence of esophageal AC increased over time, with notable high‐incidence rates on the Vancouver Island, the coasts of the Great Lakes, and the coasts of the Northumberland Strait in the Maritimes. The overall incidence of esophageal SCC has decreased. However, high incidence of esophageal SCC was detected in the Vancouver city, rural eastern Québec, and in the Maritimes. We also report clustering for each subtype using postal codes, which sheds light onto new avenues of research for potential environmental etiologies.

Conclusions

This study, for the first time, provides a detailed analysis on the burden of esophageal cancer in Canada, revealing important geographic clustering trends.
Promoter hypermethylation of the CFTR gene as a novel diagnostic and prognostic marker of breast cancer
Authors: Liu Kaisheng , Dong Fajin , Gao Hengyuan , Guo Yaomin , Li Haili , Yang Fang , Zhao Pan , Dai Yong , Wang Jianhong , Zhou Wenbin , Zou Chang
Published: November 2019

Breast cancer is the most commonly diagnosed cancer and the leading cause of cancer‐related deaths among women. New biomarkers with definite diagnostic and prognostic efficacy are urgently needed. Here, we showed that the promoter of the cystic fibrosis transmembrane conductance regulator (CFTR) was hypermethylated in breast cancer. The messenger RNA level of CFTR was downregulated in breast cancer. Notably, all 19 breast cancer patients with hypermethylated CFTR were diagnosed with invasive carcinoma. Moreover, CFTR was upregulated in decitabine (10 μM) treated breast cancer cells. Overexpression of CFTR inhibited cell growth whereas knockdown of CFTR promoted cell invasion. In the tissue array analysis, the CFTR protein level decreased significantly in breast cancer and low CFTR protein level correlated with poor survival with a P‐value of 0.034. Thus, promoter hypermethylation of the CFTR gene might be a novel diagnostic marker of breast cancer.
Enhanced Photocatalytic Nitrogen Fixation on MoO2/BiOCl Composite
Authors: Xiao Cailin , Wang Haipeng , Zhang Ling , Sun Songmei , Wang Wenzhong
Published: November 2019

Converting N2 into NH3 under mild conditions is a great challenge because of the highly stable N≡N bond and the difficult chemisorption of N2 at the active site. Herein, we report that MoO2/BiOCl composites realized excellent photocatalytic nitrogen fixation efficiency when water was used proton source. The strong interaction between BiOCl nanoplates and MoO2 nanosheets regulated the electronic structure of the interface and provided active sites for the catalytic reaction. The Mo−O−Bi bonds formed at the interface of MoO2 and BiOCl worked as the bridge of electrons, facilitating the separation and migration of photo‐generated charge carriers. In addition, the interface of MoO2/BiOCl composite also promoted the adsorption and activation of N2, substantially enhanced N2 reduction. As a result, ammonia production rate of 35 μmol g−1 h−1 was achieved, which is 8‐fold higher than that of pristine BiOCl and 6‐fold higher than that of MoO2. This work presents a feasible route to design the nanocomposites with better performance for photocatalytic nitrogen fixation.
A two‐layer ensemble learning framework for data‐driven soft sensor of the diesel attributes in an industrial hydrocracking process
Authors: Wang Yalin , Wu Dongzhe , Yuan Xiaofeng
Published: November 2019

In the hydrocracking process, it is of great significance to timely measure the product attributes for real‐time process control and optimization. However, they are often very difficult to measure online due to technical and economical limitations. To this end, soft sensor is introduced to predict product attributes through easy‐to‐measure process variables, with the advantages of low cost, fast response, and ease of maintenance. In this paper, a two‐layer ensemble learning framework is developed for soft sensing of three diesel attributes in an industrial hydrocracking process. In this modeling framework, the process variables are first divided into subspace blocks according to process topological structure to capture the local behaviors of different production cells. Then, to overcome the weak generalization ability of a single calibration model with specific hypothesis, different regression learners are constructed on each variable subblock to increase the model diversity. At last, individual models are fused to improve the prediction performance and generalization ability of soft sensor models. The effectiveness and flexibility of the proposed ensemble learning method is validated on a real industrial hydrocracking process.
Mechanical characterization and out‐of‐plane behavior of fabric‐reinforced cementitious matrix overlay on clay brick masonry
Authors: Türkmen Ömer S. , de Vries Boy T. , Wijte Simon N. M.
Published: November 2019

The mechanical behavior of carbon fiber‐reinforced polymer (CFRP) fabric‐reinforced cementitious matrix (FRCM) overlay on clay brick masonry was characterized by means of double‐shear bond, tensile, and out‐of‐plane tests. Different bond lengths in the range 55‐250 mm were analyzed during the double‐shear bond tests. The failure mechanism was slippage of the CFRM mesh, with peak stresses in the fabric around 500 N/mm2 per 100 mm bond length. Tensile tests were performed following AC434.13 with FRCM coupons of 10 and 15 mm thickness, where the mechanical behavior was divided into three stages. The four‐point bending experiments on FRCM‐reinforced prisms showed that the CFRP mesh provided significant added value in both moment capacity (>110%) and deformation capacity (>2800%), when compared to specimens reinforced with solely a cementitious matrix. Additionally, no significant difference was observed between the envelope of the cyclically tested specimen and the statically loaded specimens. A model was proposed where, in contrast to existing design models, the influence of the cementitious matrix layer also was considered. Using the modified tensile test results as input parameters for the model, a good estimation of the experimental results was obtained.
Expanding the Electrochemical Window: New Tunable Aryl Alkyl Ionic Liquids (TAAILs) with Dicyanamide Anions
Authors: Lerch Swantje , Strassner Thomas
Published: November 2019

A set of new tunable aryl alkyl ionic liquids (TAAILs) based on the 1‐aryl‐3‐alkyl imidazolium motif has been synthesized, in which the following variables were systematically changed: alkyl chain length, aryl substitution (group and position), and counter ion. TAAILs with dicyanamide (DCA) and bis(trifluoromethylsulfonyl)imide (N(SO2CF3)2, NTf2) anions showed remarkable differences of their physical properties: NTf2 ionic liquids were found to have high decomposition temperatures and viscosities well below those of the DCA TAAILs. In contrast, the dicyanamide anion increased the electrochemical stability leading to TAAILs with an extremely wide electrochemical window of up to 7.17 V. Additionally, both classes of TAAILs extract transition metals from aqueous solutions: TAAILs with the DCA anion extract both platinum and copper while TAAILs with the NTf2 anion are selective towards platinum. This demonstrates that minor changes of the molecular structure lead to TAAILs with drastically changed physicochemical properties.
Evolution of Ate‐Organoiron(II) Species towards Lower Oxidation States: Role of the Steric and Electronic Factors
Authors: Rousseau Lidie , Herrero Christian , Clémancey Martin , Imberdis Arnaud , Blondin Geneviève , Lefèvre Guillaume
Published: November 2019

Ate‐iron(II) species such as [Ar3FeII]− (Ar=aryl) are key intermediates in Fe‐catalyzed couplings between aryl nucleophiles and organic electrophiles. They can be active species in the catalytic cycle, or lead to Fe0 and FeI oxidation states, which can themselves be catalytically active or lead to unwished organic byproducts. Analysis of the reactivity of the intermediates obtained by step‐by‐step displacement of the mesityl groups in high‐spin [Mes3FeII]− by less hindered phenyl ligands was performed, and uncovered the crucial role of both steric and electronic parameters in the formation of the Fe0 and FeI oxidation states. The formation of quaternized [Ar4FeIIMgBr(THF)]− intermediates allows the bielectronic reductive elimination energy required for the formation of Fe0 to be reduced. Similarly, the small steric pressure of the aryl groups in [Ar3FeII]− enables the formation of aryl‐bridged [{FeII(Ar)2}2(μ‐Ar)2]2− species, which afford the FeI oxidation state by bimetallic reductive elimination. These results are supported by 1H NMR, EPR, and 57Fe Mössbauer spectroscopies, as well as by DFT calculations.
Fe‐Doped CoP Flower‐Like Microstructure on Carbon Membrane as Integrated Electrode with Enhanced Sodium Ion Storage
Authors: Xu Yalin , Li Xueying , Wang Jiangang , Yu Qing , Qian Xiu , Chen Lizhuang , Dan Yuanyuan
Published: November 2019

Poor cyclability and rate performance always impede the development of transition metal phosphide‐based anode materials. Many strategies have been used to address the above problems, such as the designing of hierarchical structures, combination with carbon materials, and doping with other metal elements. Considering those strategies, a flower‐like Fe‐doped CoP material is designed. The synthesis consists of microsheets grown on a carbon membrane (CM, leaves as precursor) through a hydrothermal method and in situ phosphorization. The Fe doping and carbon membrane synergistically induce the formation of a flower‐like hierarchical microstructure during the crystal‐growing process. The unique hierarchical microstructure increases the contact area between electrode and electrolyte, and accommodates the volume expansion during cycling. The hierarchical Fe‐doped CoP grown directly on the carbon membrane increases the active sites for intercalation of sodium species and further promotes the internal electron conduction in the Fe‐doped CoP/CM electrode. Thereby, the Fe‐doped CoP/CM as the anode electrode for sodium ion batteries exhibits a high specific capacity of 515 mA h g−1 at 100 mA g−1 after 100 cycles. Even if the current density rises to 500 mA g−1, the specific capacity is still maintained at 324 mA h g−1 after 500 cycles, showing superior rate performances and cyclability.
Do Gold(III) Complexes Form Hydrogen Bonds? An Exploration of AuIII Dicarboranyl Chemistry
Authors: Chambrier Isabelle , Hughes David L. , Jeans Rebekah J. , Welch Alan J. , Budzelaar Peter H. M. , Bochmann Manfred
Published: November 2019

The reaction of 1,1′‐Li2[(2,2′‐C2B10H10)2] with the cyclometallated gold(III) complex (C^N)AuCl2 afforded the first examples of gold(III) dicarboranyl complexes. The reactivity of these complexes is subject to the trans‐influence exerted by the dicarboranyl ligand, which is substantially weaker than that of non‐carboranyl anionic C‐ligands. In line with this, displacement of coordinated pyridine by chloride is only possible under forcing conditions. While treatment of (C^N)Au{(2,2′‐C2B10H10)2} (2) with triflic acid leads to Au−C rather than Au−N bond protonolysis, aqueous HBr cleaves the Au−N bond to give the pyridinium bromo complex 7. The trans‐influence of a series of ligands including dicarboranyl and bis(dicarboranyl) was assessed by means of DFT calculations. The analysis demonstrated that it was not sufficient to rely exclusively on geometric descriptors (calculated or experimental) when attempting to rank ligands for their trans influence. Complex (C^N)Au(C2B10H11)2 containing two non‐chelating dicarboranyl ligands was prepared similar to 2. Its reaction with trifluoroacetic acid also leads to Au−N cleavage to give trans‐(Hpy^C)Au(OAcF)(C2B10H11)2 (8). In crystals of 8 the pyridinium N−H bond points towards the metal centre, while in 7 it is bent away. The possible contribution of gold(III)⋅⋅⋅H−N hydrogen bonding in these complexes was investigated by DFT calculations. The results show that, unlike the situation for platinum(II), there is no evidence for an energetically significant contribution by hydrogen bonding in the case of gold(III).
Evidence for Non‐Innocence of a β‐Diketonate Ligand
Authors: Vinum Morten Gotthold , Voigt Laura , Bell Colby , Mihrin Dmytro , Larsen René Wugt , Clark Kensha Marie , Pedersen Kasper S.
Published: November 2019

β‐Diketonates, such as acetylacetonate, are amongst the most common bidentate ligands towards elements across the entire periodic table and are considered wholly redox‐inactive in their complexes. Herein we show that complexation of 1,1,1,5,5,5‐hexafluoroacetylacetonate (hfac−) to CrII spontaneously affords CrIII and a reduced β‐diketonate radical ligand scaffold, as evidenced by crystallographic analysis, magnetic measurements, optical spectroscopy, reactivity studies, and DFT calculations. The possibility of harnessing β‐diketonates as electron reservoirs opens up possibilities for new metal–ligand concerted reactivity in the ubiquitous β‐diketonate coordination chemistry.
Stereospecific Synthesis and Photophysical Properties of Propeller‐Shaped C90H48PAH
Authors: Zhang Fangyuan , Michail Evripidis , Saal Fridolin , Krause Ana‐Maria , Ravat Prince
Published: November 2019

Herein, we have synthesized an enantiomerically pure propeller‐shaped PAH, C90H48, possessing three [7]helicene and three [5]helicene subunits. This compound can be obtained in gram quantities in a straightforward manner. The photophysical and chiroptical properties were investigated using UV/Vis absorption and emission, optical rotation and circular dichroism spectroscopy, supported by DFT calculations. The nonlinear optical properties were investigated by two‐photon absorption measurements using linearly and circularly polarized light. The extremely twisted structure and packing of the homochiral compound were investigated by single‐crystal X‐ray diffraction analysis.
Determination of kinetic parameters of homogenous continuous flow esterification of monobutyl chlorophosphate in a microreactor
Authors: Zhang Yuqiang , Li Jun , Jin Yang , Chen Ming , Wang Yubin
Published: November 2019

Synthesized by phosphorus oxychloride and n‐butanol, tri‐n‐butyl phosphate from a three‐step esterification reaction has an extensive range of applications in industrial processes. Similarly, monobutyl chlorophosphate can be obtained rapidly by mixing n‐butanol and phosphorus oxychloride. In view of this, we investigated the kinetics of esterification of monobutyl chlorophosphate with a microchannel system composed of micromixer and coiled capillaries. The reaction started from mixing the phosphorus oxychloride solution and n‐butanol solution in a micromixer, with temperature and residence time in a delayed loop controlled, and then quenching the solution in a container with magnetic agitation. The rate constants for the esterification reaction of monobutyl chlorophosphate were determined to be within a temperature range of 298‐318 K. It was found that the reaction kinetics is second order with respect to monobutyl chlorophosphate concentration and first order to n‐butanol concentration. In our research, a kinetic model was established, the values of the pre‐exponential factor and the activation energy of the reaction were obtained. The reaction kinetic model can interpret the synthesis mechanism of phosphate esters well, thus playing a guiding role in process intensification of phosphate esters synthesis in the future. Additionally, our model is also valuable because it contributes to the establishment of a reaction kinetics network model for the cascade reaction to synthesize phosphate esters.