bluuebunny/crossref_metadata_2025_split huggingface dataset:
Placement of Single Proteins within the SERS Hot Spots of Self‐Assembled Silver Nanolenses
Authors: Heck Christian , Kanehira Yuya , Kneipp Janina , Bald Ilko 
Published: March 2018

AbstractThis study demonstrates the bottom‐up synthesis of silver nanolenses. A robust coating protocol enabled the functionalization of differently sized silver nanoparticles with DNA single strands of orthogonal sequence. Coated particles 10 nm, 20 nm, and 60 nm in diameter were self‐assembled by DNA origami scaffolds to form silver nanolenses. Single molecules of the protein streptavidin were selectively placed in the gap of highest electric field enhancement. Streptavidin labelled with alkyne groups served as model analyte in surface‐enhanced Raman scattering (SERS) experiments. By correlated Raman mapping and atomic force microscopy, SERS signals of the alkyne labels of a single streptavidin molecule, from a single silver nanolens, were detected. The discrete, self‐similar aggregates of solid silver nanoparticles are promising for plasmonic applications.
Hydrido Complexes of Calcium: A New Family of Molecular Alkaline‐Earth‐Metal Compounds
Authors: Mukherjee Debabrata , Schuhknecht Danny , Okuda Jun 
Published: March 2018

AbstractThe application of solid calcium hydride CaH2 has been mostly confined to its use as a desiccant, although its catalytic activity has long been known. Since the first isolation of a well‐defined molecular calcium hydride in 2006, the past decade has witnessed a gradual emergence of this new family of compounds. Although the detrimental Schlenk equilibrium has kept the number of examples low, the novelty of their reactivity, especially in small‐molecule activation, holds great promise. This Minireview gives an overview of the molecular calcium hydrides reported to date, highlighting their synthesis, structure, and reactivity.
Custom‐Made Ceria Nanoparticles Show a Neuroprotective Effect by Modulating Phenotypic Polarization of the Microglia
Authors: Zeng Feng , Wu Yingwei , Li Xinwei , Ge Xiaojiao , Guo Qinghua , Lou Xiaobing , Cao Zhonglian , Hu Bingwen , Long Nicholas J. , Mao Ying , Li Cong 
Published: March 2018

AbstractThe neuroprotective effect of ceria nanoparticles in the context of brain disorders has been explained by their antioxidant effect. However, the in‐depth mechanism remains unknown. As resident immune cells in the brain, microglia exert a variety of functional reprogramming termed as polarization in response to stress stimuli. Herein, custom‐made ceria nanoparticles were developed and found to scavenge multiple reactive oxygen species with extremely high efficiency. These nanoparticles drove microglial polarization from a pro‐inflammatory phenotype to an anti‐inflammatory phenotype under pathological conditions. Pretreatment of these nanoparticles changed the microglial function from detrimental to protective for the neuronal cells by blocking the pro‐inflammatory signaling. This work not only helps to elucidate the mechanism of ceria‐nanoparticle‐mediated neuroprotection but also provides a new strategy to rebalance the immuno‐environment by switching the equilibrium of the phenotypic activation of microglia.
Two mononuclear cobalt(III) complexes exhibiting phenoxazinone synthase activity
Authors: Mahato Mamata , Van Hecke Kristof , Nayek Hari Pada 
Published: March 2018

Two mononuclear cobalt(III) complexes, namely [LCo(tmtp)(H2O)]ClO4⋅MeOH (1) (tmtp = tri(m‐tolyl)phosphine) and [LCo(PPh3)(H2O)]PF6 (2), have been prepared from a polydentate ligand, N,N′‐bis(3‐methoxysalicylidehydene)cyclohexane‐1,2‐diamine (H2L). Standard analytical techniques such as elemental analysis and UV–visible and Fourier transform infrared spectroscopies were used to characterize both complexes. The solid‐state molecular structures of both complexes were confirmed from single‐crystal X‐ray diffraction analysis. Structural analyses show that the Co(III) ion occupies the centre of a distorted octahedron in a complex cation: [LCo(tmtp)(H2O)]+ and [LCo(PPh3)(H2O)]+ for 1 and 2, respectively. Phenoxazinone synthase activities of both complexes were screened. Kinetic studies and other experimental observations reveal that the reaction follows rate saturation kinetics and proceeds through the formation of a catalyst (complex)–substrate adduct. The turnover number (Kcat) of complex 2 is 54.07 h−1, exhibiting better catalytic activity compared to 1 (Kcat = 45.11 h−1).
A comparison between two Pd‐Ni catalysts supported on two different supports toward Suzuki‐Miyaura coupling reaction
Authors: Taheri Masoud , Ghiaci Mehran , Shchukarev Andrey 
Published: March 2018

When a single metal fails to promote an efficient Suzuki‐Miyaura coupling reaction at ambient temperature, the synergistic cooperation of two distinct metals might improve the reaction. To examine the synergistic effect of palladium and nickel for catalyzing Suzuki coupling reaction, g‐C3N4 supported metal nanoparticles of PdO, NiO and Pd‐PdO‐NiO were prepared, characterized and their catalytic activities evaluated over different aryl halides at room temperature and 78 °C. The morphological characterization of Pd‐PdO‐NiO/g‐C3N4 demonstrated that the bimetallic particles were uniformly dispersed over the g‐C3N4 layers with diameters ranging from 3.5‐7.7 nm. XPS analysis showed that nanoparticles of Pd‐PdO‐NiO consisted of Pd(II), Pd(0) and Ni(II) sites. The experiments performed on the catalytic activity of Pd‐PdO‐NiO/g‐C3N4 showed that the prepared catalyst demonstrated an efficient activity without using toxic solvents.
Synthesis, characterization and binding studies of novel diorganotin(IV) complexes of sodium 2‐mercaptoethanesulfonate
Authors: Kumari Ranjana , Nath Mala 
Published: March 2018

Diorganotin(IV) complexes (1‐4) of MESNA (sodium 2‐mercaptoethanesulfonate HSCH2CH2SO3Na) and a mixed ligand complex of dibutyltin(IV), 1,10‐phenanthroline and MESNA (5) were synthesized with thermal and microwave assisted methods. All the complexes were characterized thoroughly with the help of analytical and various spectroscopic techniques viz. FTIR, NMR (1H, 13C, and 119Sn NMR) spectroscopy and ESI‐MS spectrometery. Various spectrophotometric studies were carried out to decipher the binding mode of MESNA and its diorganotin complexes 1‐5 with calf thymus DNA (CT DNA) and thus, to calculate the binding constant (Kb). Absorption spectrophotometric study confirmed the interaction is through partial intercalation of all the complexes including MESNA, inside the DNA helix and calculated binding constant (Kb) is in the order of 103 M‐1. A series of emission spectrophotometric experiments support the results obtained through the absorption spectrophotometric studies. Circular dichroic (CD) spectroscopic analysis and viscosity measurement of CT DNA further complemented the fact that the partial intercalation plays a major role in the interaction of the studied complexes with CT DNA. All the studies corroborated that complex 2 bound to CT DNA with maximum affinity followed by complex 5 among all the complexes. Involvement of hydroxyl radicals as an active species in the cleavage activity of pBR322 plasmid DNA is proved by carrying out agarose gel electrophoretic technique.
Influence of the processing parameters on needleless electrospinning from double ring slits spinneret using response surface methodology
Authors: Wei Liang , Qiu Qiaohua , Wang Rongwu , Qin Xiaohong 
Published: March 2018

ABSTRACTNeedleless electrospinning technology was an effective processing method which can fabricate large scale nanofibers. We first developed a novel double rings slit spinneret to overcome the shortcomings of current needleless electrospinning spinnerets. The solution of the flow rate was controlled accurately by peristaltic control pump. Response surface methodology was adopted to investigate the influence of the processing parameters on the morphology and diameter of nanofibers. The main spinning processing parameters comprised solution concentration, applied voltage, collection distance and solution flow rate. The analysis of variance was used to evaluate response surface reduced quadratic model for nanofiber diameter. The linear and quadratic coefficients were obtained. The morphology of nanofibers was observed by scanning electron microscopy. Effects of different processing parameters on the nanofiber mean diameter have been discussed. Predicated values have a good agreement with actual values for nanofiber diameter. Actual nanofiber diameter ranges from129.15 to 404.70 nm with different process parameters. Mechanical properties of nanofiber membrane have been investigated. High quality and high throughout nanofiber could be continuously produced. This novel needleless electrospinning spinneret has a great potential for large scale nanofibers production to promote electrospinning technology development. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46407.
Self‐healing polyurethane nanocomposite films with recoverable surface hydrophobicity
Authors: Yu Xi , Yang Pengfei , Zhang Zhiliang , Wang Liang , Liu Lian , Wang Yongqing 
Published: March 2018

ABSTRACTIt is a great challenge for self‐healing materials to recover their mechanical property and surface hydrophobicity simultaneously after being damaged severely, such as deep and wide surface scratches. In this work, a series of hydrophobic films were prepared by mixing perfluoroalkyl‐loaded SiO2 nanoparticles with thermally self‐healing polyurethane. The Diels–Alder reaction of furan groups with bismaleimides endowed the polyurethane with self‐healing property, and the introduction of perfluoroalkyl chains gave surface hydrophobicity. When being heated, the low surface energy compounds could gradually move onto the surface to make the surface hydrophobicity recoverable. The self‐healing mechanical property and recoverable hydrophobicity would improve the durability and expand the application of polyurethane nanocomposites as self‐cleaning and self‐healing coatings/surfaces. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46421.
Polyurethane/clay nanocomposites with improved helium gas barrier and mechanical properties: Direct versus master‐batch melt mixing route
Authors: Adak Bapan , Joshi Mangala , Butola Bhupendra Singh 
Published: March 2018

ABSTRACTThermoplastic polyurethane (TPU)/clay nanocomposite films were produced by incorporation of organo‐modified montmorillonite clay (Cloisite 30B) in TPU matrix by two different melt‐mixing routes (direct and master‐batch‐based mixing), followed by compression molding. In master‐batch mixing where the master‐batch was prepared by mixing of clay and TPU in a solvent, better dispersion of clay‐layers was observed in comparison to the nanocomposites produced by direct mixing. As a consequence, superior mechanical and gas barrier properties were obtained by master‐batch mixing route. The master‐batch processing resulted in 284 and 236% increase in tearing strength and tearing energy, respectively, with 5 wt % clay‐loading. Interestingly, in case of master‐batch mixing, the tensile strength, stiffness as well as breaking extension increased simultaneously up to 3 wt % clay‐loading. The helium gas permeability reduced by about 39 and 31% for the TPU/clay nanocomposites produced by mater‐batch and direct mixing routes, respectively, at 3 wt % loading of clay. Finally, the gas permeability results have been compared using three different gas permeability models and a good correlation was observed at lower volume fraction of clay. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2018,135, 46422.
Terahertz spectroscopic estimation of crystallinity of poly(phenylene sulfide)
Authors: Azeyanagi Chisato , Ohki Yoshimichi 
Published: March 2018

ABSTRACTAs a crystalline polymer, various properties of poly(phenylene sulfide) (PPS) depend on its crystallinity. Evaluation of crystallinity of PPS is examined by terahertz (THz) absorption spectroscopy in this research. For sheets of PPS thermally annealed differently, sharp absorption peaks appearing at 3.2 and 4.2 THz are well proportional to the crystallinity estimated by X‐ray diffraction, differential scanning calorimetry, and Fourier transform infrared (FTIR) absorption spectroscopy. Therefore, THz absorption spectroscopy can be a good tool for estimating the crystallinity of PPS. Especially, it is useful for thick PPS sheets, for which FTIR spectroscopy in transmission mode is difficult to apply due to the saturation of absorbance. Since THz spectroscopy and FTIR spectroscopy are complementary in the vibrations that the two methods can detect, using the two methods should be effective to improve the accuracy of estimation of crystallinity. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46427.
Preparation and characterization of antifouling and antibacterial polysulfone ultrafiltration membranes incorporated with a silver–polydopamine nanohybrid
Authors: Wu Huiqing , Liu Yuejun , Huang Jing , Mao Long , Chen Jianhong , Li Meng 
Published: March 2018

ABSTRACTA silver–polydopamine (Ag–PDA) nanohybird was used to produce polysulfone (PSf) ultrafiltration membranes with excellent antifouling and antibacterial properties. First, the catechol functional groups of polydopamine (PDA) helped with the in situ immobilization of silver (Ag) nanoparticles (<10 nm) on the PDA sphere surface; this led to the formation of the Ag–PDA nanohybrid. Then, Ag–PDA/PSf hybrid membranes were prepared via the phase‐inversion method, and the influence of Ag–PDA loading on the hybrid membrane properties was systematically investigated. When the content of Ag–PDA was 0.5 wt %, the hybrid membrane achieved optimal separation performance, including a dramatically increased pure water flux and a well‐maintained bovine serum albumin rejection. Furthermore, the Ag–PDA/PSf hybrid membranes presented a significantly enhanced protein‐fouling resistance and a good antibacterial activity. These improvements were attributed to the unique structure and properties of the Ag–PDA nanohybrid because of the synergistic effect of the hydrophilic PDA substrate and well‐distributed Ag nanoparticles. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46430.
Nanofiber films of chloroacetated natural rubber/poly(vinyl alcohol) by electrospinning technique: Silica effects on biodegradation
Authors: Azarian Mohammad Hossein , Boochathum Ploenpit 
Published: March 2018

ABSTRACTGreen electrospinning technique was employed to prepare chloroacetated natural rubber (CNR)/poly(vinyl alcohol) (PVA) nanofiber films by varying the addition of PVA in the range 2.5–55 wt % followed by encapsulation of 2.5 wt % fumed silica (FS). In this study, the risk of using organic solvents was eliminated using CNR in latex. The encapsulated electrospun fiber mats showed a fairly homogenous composition with enhanced water absorption ability of 703.54% ± 33.95%. The FS improved the interfacial adhesion and contributed to enhancing the intermolecular interaction between the two polymers. The mean diameter of the nanofibers decreased from 64.0 ± 19.0 to 41.0 ± 13.0 nm and significant improvement in the hydrolytic and enzymatic degradation rate was observed implying that FS can facilitate the degradation rate. Furthermore, loading of PVA and encapsulation of FS resulted in an improved stiffness of CNR at room temperature and storage modulus increased to 2.48 and 2.12 MPa, respectively. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46432.
Flame retardation and thermal stability of novel phosphoramide/expandable graphite in rigid polyurethane foam
Authors: Liu Dong‐Yue , Zhao Bin , Wang Jun‐Sheng , Liu Peng‐Wei , Liu Ya‐Qing 
Published: March 2018

ABSTRACTA novel flame retardant named diethyleneN,N',N''‐tri (diethoxy)phosphoramide (DTP) was synthesized using diethyl phosphate and diethylenetriamine via Atherton–Todd reaction. Then, series of flame‐retardant water‐blown rigid polyurethane foams (RPUFs) with expandable graphite (EG) and DTP were prepared through box‐foaming. The results of thermogravimetric analysis showed that DTP/EG changed thermal degradation process of RPUF and promoted enhancing char residues. The complex flame‐retardant system (EG/DTP) endowed RPUF higher limiting oxygen index (LOI) values (29.1%–30.2%) and lower heat release rate peak (PHRR) values according to LOI and microscale combustion calorimeter tests. More importantly, the synergistic flame‐retardant effect between EG and DTP in RPUF was proved by the analysis of synergistic effectivity values. Based on the analysis of cone calorimetric tests, EG/DTP revealed remarkable effects to inhibit the fire intensity and smoke release of RPUF with decreased PHRR and total smoke production due to good char‐forming action. To further investigate the char‐residues of the foams after combustion, scanning electron microscope and energy dispersive X‐ray spectroscopy analyses were conducted. The results suggested that EG/DTP flame‐retardant system promoted RPUF forming a compact, continuous and phosphorus‐rich char layer as a good fire barrier in combustion. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2018,135, 46434.
Effects of flame‐retardant flax‐fiber on enhancing performance of the rigid polyurethane foams
Authors: Cheng Jia‐Ji , Qu Wen‐Juan , Sun Shao‐Hua 
Published: March 2018

ABSTRACTThe original flax fibers (FF) and the modified FFs were subjected to the treatment with the flame retardant, were used to improve the performance of rigid polyurethane foams (RPUF). The mechanical properties of composites were evaluated by compressive strength test, torsion strength test, and shear stress test. The fire characteristics (smoke and heat production) were studied using cone calorimeter. And the thermal decomposition and flammable properties were further evaluated using thermogravimetric analysis and limiting oxygen index. The results showed that the FF could improve the mechanical properties of RPUF and had a good prospect in reducing the fire hazard for RPUF. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46436.
Mechanical enhancement of amine‐functionalized TiO2 reinforced polyimine composites
Authors: Lv Yanting , Lu Bo , Zhang Si , Li Jiayi , Lu Guolong , Sun Hang , Liang Song , Liu Zhenning 
Published: March 2018

ABSTRACTPolyimine vitrimers are known for their malleability, which endows these materials with properties such as self‐healing, recycling, and reshaping. To enhance the mechanical properties of the polyimine vitrimers, composites were fabricated by incorporating amine‐functionalized TiO2 microspheres (amTiO2MS) into polyimine matrix. The pure polyimine matrix and polyimine composites hybridized with TiO2 microspheres (TiO2MS) without surface modification were also obtained and examined as the controls in characterization. X‐ray powder diffraction, scanning electron microscopy, and energy dispersive X‐ray spectroscopy were employed to demonstrate the presence and distribution of amTiO2MS and TiO2MS in the polyimine matrices. The investigation of mechanical properties of the amTiO2MS enhanced polyimine composites and control samples indicated that incorporation of amTiO2MS and TiO2MS exhibited different characteristic distribution, which strongly affected the performance of the composites. The optimal filling concentration of amTiO2MS was found to be 3%, with which the microspheres were uniformly distributed in the polyimine matrix. The self‐healing behavior of the polyimine‐amTiO2‐X was also studied. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46446.
Habitat protection actions for the Indo‐Pacific humpback dolphin: Baseline gaps, scopes, and resolutions for the Taiwanese subspecies
Authors: Huang Shiang‐Lin , Wang Chun‐Chieh , Yao Chiou‐Ju 
Published: March 2018

Abstract

Information gaps resulting from incomplete data used to describe habitat configuration frequently hinder the efficacy of habitat protection action (HPA) for an animal with a wide distribution range. Such concerns are particularly important for the Indo‐Pacific humpback dolphin, inhabiting disturbed coastal and estuarine habitats.
This study inspected the likely habitat use of the Taiwanese humpback dolphin, an endemic subspecies that inhabits a highly disturbed habitat. Habitat use was evaluated using species distribution modelling with occurrence data from field surveys and remotely sensed oceanographic layers.
Likely core habitats of the Taiwanese humpback dolphin were predicted near estuaries. The chlorophyll‐a concentration was the primary factor affecting the distribution of the Taiwanese humpback dolphin. Bathymetry influenced the humpback dolphin distribution in the early 1980s, but became less important in the early 2010s.
Significant sea surface temperature increases in the estuarine and coastal waters and chlorophyll‐a concentration decreases in the inshore waters were observed from the 1980s to the 2010s, indicating declining ecosystem productivity and shifting ecosystem functions. These oceanographic changes may be associated with adverse consequences of coastal alterations in western Taiwan.
We propose revising the current HPA scope by refining the HPA zoning, integrating coastal and watershed management, implementing regulatory fishery management, and designing and conducting restoration measures in compromised habitats and watershed landscapes. The need to reassess the current baselines of habitat use and HPA complex for the humpback dolphin across its natural range has been addressed.
Fetal Development of Fasciae around the Arm and Thigh Muscles: A Study Using Late Stage Fetuses
Authors: Cho Kwang Ho , Jang Hyung Suk , Abe Hiroshi , Yamamoto Masahito , Murakami Gen , Shibata Shunichi 
Published: March 2018

ABSTRACTTo obtain a better understanding of multi‐laminar deep fascia covering skeletal muscles, we examined nondecalcified histological sections of the arm and thigh of 20 human fetuses aged 25–33 weeks. Morphologies of the fasciae varied between sites and specimens, but the initial morphology was most likely to be a thin and loose sheet on the external surface of the muscles (fascia‐1 or F1). When the F1 became wavy, thick and tight, it was detached from the muscle surface. Beneath the F1, the second lamina of fascia (F2) appeared on the muscle surface and it was also detached. In this manner at 25–33 weeks' gestation, fasciae covering the triceps and vastus lateralis muscles had a three‐layered configuration (F1, F2, and F3). Due to significant individual variations, this process was not correlated to the ages and sizes of specimens. Muscle contractions might facilitate the detachment. In these muscles, the intramuscular tendon joined the F2 or F3 and the latter became thick and aponeurotic. Along the finally developed lamina, muscle fibers carried a desmin‐positive spot for insertion. Increased laminae were accompanied by a reduced number of CD68‐positive macrophages and, nerves were absent, near the developing fascia. In contrast to skin ligaments or superficial fasciae showing de novo development in loose tissue, a deep or muscle‐covering fascia seemed to originate from the skeletal muscle itself at the surface, and this process was repeated to produce multi‐layered fascia. Depending on sites, collagen fibers were added by the intramuscular tendon. Anat Rec, 301:1235–1243, 2018. © 2018 Wiley Periodicals, Inc.