bluuebunny/crossref_metadata_2025 huggingface dataset:
Structural equation modeling of office environment quality, sick building syndrome, and musculoskeletal complaints on aggregate satisfaction of office workers
Authors: Shin Dong Seok , Jeong Byung Yong , Park Myoung Hwan
Published: January 2018

This study aims to analyze the effects of office environment quality (OEQ), sick building syndrome (SBS), and musculoskeletal complaints on aggregate office satisfaction level using the structural equation. A questionnaire survey targeting 483 office workers of 18 public agencies was conducted and surveyed on workers’ characteristics (gender, age, work experience, work hours, and computer time of day), OEQ satisfaction level (temperature and humidity, lighting, noise, and air quality), SBS frequency (eye, noise, throat, skin, and headache), musculoskeletal complaints intensity (neck, shoulder, arm, wrist, waist, and leg), and aggregate office satisfaction level. As a result of the model using the structural equation, the level of OEQ on temperature and humidity, noise, and air quality directly affect the level of SBS frequency. Also, the OEQ level indirectly affects both musculoskeletal complaints’ intensity and aggregate office satisfaction level via the level of SBS frequency. Thus, providing pleasant office environments can be an effective measure to enhance office workers’ satisfaction, because workers’ levels for musculoskeletal complaints and aggregate office satisfaction depend on OEQ and SBS levels.
Water‐level dynamics in natural and artificial pools in blanket peatlands
Authors: Holden Joseph , Moody Catherine S. , Edward Turner T. , McKenzie Rebecca , Baird Andy J. , Billett Mike F. , Chapman Pippa J. , Dinsmore Kerry J. , Grayson Richard P. , Andersen Roxane , Gee Clare , Dooling Gemma
Published: January 2018

Perennial pools are common natural features of peatlands, and their hydrological functioning and turnover may be important for carbon fluxes, aquatic ecology, and downstream water quality. Peatland restoration methods such as ditch blocking result in many new pools. However, little is known about the hydrological function of either pool type. We monitored six natural and six artificial pools on a Scottish blanket peatland. Pool water levels were more variable in all seasons in artificial pools having greater water level increases and faster recession responses to storms than natural pools. Pools overflowed by a median of 9 and 54 times pool volume per year for natural and artificial pools, respectively, but this varied widely because some large pools had small upslope catchments and vice versa. Mean peat water‐table depths were similar between natural and artificial pool sites but much more variable over time at the artificial pool site, possibly due to a lower bulk specific yield across this site. Pool levels and pool‐level fluctuations were not the same as those of local water tables in the adjacent peat. Pool‐level time series were much smoother, with more damped rainfall or recession responses than those for peat water tables. There were strong hydraulic gradients between the peat and pools, with absolute water tables often being 20–30 cm higher or lower than water levels in pools only 1–4 m away. However, as peat hydraulic conductivity was very low (median of 1.5 × 10−5 and 1.4 × 10−6 cm s−1 at 30 and 50 cm depths at the natural pool site), there was little deep subsurface flow interaction. We conclude that (a) for peat restoration projects, a larger total pool surface area is likely to result in smaller flood peaks downstream, at least during summer months, because peatland bulk specific yield will be greater; and (b) surface and near‐surface connectivity during storm events and topographic context, rather than pool size alone, must be taken into account in future peatland pool and stream chemistry studies.
Representing causal knowledge in environmental policy interventions: Advantages and opportunities for qualitative influence diagram applications
Authors: Carriger John F , Dyson Brian E , Benson William H
Published: January 2018

This article develops and explores a methodology for using qualitative influence diagrams in environmental policy and management to support decision-making efforts that minimize risk and increase resiliency. Influence diagrams are representations of the conditional aspects of a problem domain. Their graphical properties are useful for structuring causal knowledge relevant to policy interventions and can be used to enhance inference and inclusivity of multiple viewpoints. Qualitative components of influence diagrams are beneficial tools for identifying and examining the interactions among the critical variables in complex policy development and implementation. Policy interventions on social–environmental systems can be intuitively diagrammed for representing knowledge of critical relationships among economic, environmental, and social attributes. Examples relevant to coastal resiliency issues in the US Gulf Coast region are developed to illustrate model structures for developing qualitative influence diagrams useful for clarifying important policy intervention issues and enhancing transparency in decision making. Integr Environ Assess Manag 2018;14:381–394. Published 2018. This article is a US Government work and is in the public domain in the USA.

Key Points

A qualitative influence diagram (QID) provides structural explanations about a problem domain. QIDs can be beneficial tools for policy development and implementation. Causal pathway analysis with QIDs can help target uncertainties that are important to evaluate and track for policy design and implementation. QIDs can easily be adapted to dynamic situations and updated as new data and knowledge become available.
Surrogate scale for evaluating respiratory function based on complete blood count parameters
Authors: Guang Yang , Jie Zhou , Feng Dong , Hui Liu
Published: January 2018

Background

In this study, we aimed to identify a simple method for evaluating respiratory function using complete blood count parameters.

Methods

The complete blood count parameters, including red blood cell (RBC) count, hemoglobin (Hb) level, lymphocyte (Lym) and platelet (Plt) count, and partial pressure of oxygen (PO2) level, were measured using automated analyzers in patients with chronic obstructive pulmonary disease (COPD), aged subjects, and young subjects (control group). The red cell index (RCI) was calculated using the following equation: (RBC × Hb)/(Lym × Plt); in theory, the RCI is inversely proportional to the respiratory function.

Results

We observed a significant relationship between the RCI and PCO2 values, and between the RCI and FEV1/FVC values (P < .05). The RCI in the COPD, and aged subject groups were all significantly higher than that in the control group (P < .05). The cutoff value for normal respiratory function was 2.3. The positive rates for an abnormal increase in RCI were also considerably higher in each observation group than in the control group (P < .05).

Conclusion

The RCI can be considered as a simple and effective tool for evaluating respiratory function.
Cancer associated fibroblasts tailored tumor microenvironment of therapy resistance in gastrointestinal cancers
Authors: Sun Yeqi , Wang Ruifen , Qiao Meng , Xu Yanchun , Guan Wenbin , Wang Lifeng
Published: January 2018

Gastrointestinal cancers (GI), are a group of highly aggressive malignancies with heavy cancer‐related mortalities. Even if continued development of therapy methods, therapy resistance has been a great obstruction for cancer treatment and thereby inevitably leads to depressed final mortality. Peritumoral cancer associated fibroblasts (CAFs), a versatile population assisting cancer cells to build a facilitated tumor microenvironment (TME), has been demonstrated exerting a promotion influence on cancer proliferation, migration, invasion, metastasis, and also therapy resistance. In this review, we provide an update progress in describing how CAFs mediate therapy resistance in GI by various means, meanwhile highlight the crosstalk between CAFs and cancer cells and present some vital signaling pathways activated by CAFs in this resistant process. Furthermore, we discuss the current advances in adopting novel drugs against CAFs and how the knowledge contributing to improved therapy efficacy in clinical practice. In sum, CAFs create a therapy‐resistant TME in several aspects of GI progression, although some key problems about distinguishing CAFs subpopulations and controversial issues on pleiotropic CAFs in medication need to be solved for subsequent clinical application. Predictably, targeting therapy‐resistant CAFs is a promising adjunctive treatment to benefit GI patients.
An accurate determination of the phase center position of transitions into 2‐dimensional regions
Authors: Uyguroğlu Rasime , Embais Khadija
Published: January 2018

Correct estimation of the phase centers of the input and output ports is important in Rotman‐type bootlace lens applications. Any shift in the position of the phase center of a port used as a transition between the feed lines and the 2‐dimensional region will cause phase errors, which will create adverse effects on the radiation patterns. This paper introduces a method for determining the phase centers of the transitions radiating into parallel plate regions. A study has been conducted for linearly tapered and multistep transitions (ie, radiators). The results of the study show that the estimated phase centers are displaced from the aperture of the transitions. This displacement is smaller for the multistep transitions compared with the linearly tapered transitions. The simulation results of these transitions also show that, the use of the estimated phase center position reduces the phase errors significantly over wide coverage angles. The results also show that the phase errors do not change with the distance from the aperture. On the other hand, phase errors varies with frequency. These errors are smaller for the stepped transitions compared with the linearly tapered transitions. A separate simulation study of radiation patterns of a linear array fed by a Rotman lens has shown that deterioration occurs in sidelobes and minima levels and a small shift in the off‐axis beam positions when short transitions are used without phase center position correction.
Analyzing tunable terahertz grating based on hybrid graphene‐metal structure by using the HIE‐FDTD method
Authors: Chen Juan , Hao Guocheng , Liu Qing Huo
Published: January 2018

A hybrid graphene‐metal grating is simulated and analyzed at terahertz frequency band by using the hybrid implicit‐explicit finite‐difference time domain (HIE‐FDTD) method. To simulate the graphene layer accurately, both the interband and intraband conductivity of the graphene are incorporated into the HIE‐FDTD method by using the auxiliary differential equations and Pade fitting technique. Numerical results show that the HIE‐FDTD method has excellent computational accuracy and its computational efficiency is considerably improved from that of the conventional FDTD method. Besides, numerical results validate that the graphene can achieve tunable terahertz grating through controlling its chemical potential, and the interband conductivity of the graphene has important effects on the performance of the grating.
A 31‐year climatology of tropical cyclone size from the NCEP Climate Forecast System Reanalysis
Authors: Mok Derek K. H. , Chan Johnny C. L. , Chan Kelvin T. F.
Published: January 2018

A 31‐year tropical cyclone (TC) size climatology (1980–2010) is established using the NCEP Climate Forecast System Reanalysis for the western North Pacific (WNP) and the North Atlantic (NA). The size of a TC, defined as the azimuthally averaged radius of 17 m s−1 wind near the sea surface, is estimated using the strong relationship between TC size and azimuthally averaged winds in the outer‐core region of the TC. The estimation method is verified by comparing the TC size climatology established using the QuikSCAT satellite data. The monthly and annual variations in both climatologies agree with each other.

Based on this 31‐year data set, the mean TC sizes over the WNP and NA are 2.01° and 1.61° latitude, respectively. TC size in both basins exhibits temporal intra‐seasonal and annual as well as spatial variations. Inter‐annual TC size variations in the WNP are highly correlated (r = 0.816) with El Niño‐Southern Oscillation events. In WNP, the highest percentage of large TCs occurs near 25°N, which agrees with previous modelling and observational studies.
Non‐enzymatic cross‐linking of collagen type II fibrils is tuned via osmolality switch
Authors: Pouran Behdad , Moshtagh Parisa R. , Arbabi Vahid , Snabel Jessica , Stoop Reinout , Ruberti Jeffrey , Malda Jos , Zadpoor Amir A. , Weinans Harrie
Published: January 2018

An important aspect in cartilage ageing is accumulation of advanced glycation end products (AGEs) after exposure to sugars. Advanced glycation results in cross‐links formation between the collagen fibrils in articular cartilage, hampering their flexibility and making cartilage more brittle. In the current study, we investigate whether collagen cross‐linking after exposure to sugars depends on the stretching condition of the collagen fibrils. Healthy equine cartilage specimens were exposed to l‐threose sugar and placed in hypo‐, iso‐, or hyper‐osmolal conditions that expanded or shrank the tissue and changed the 3D conformation of collagen fibrils. We applied micro‐indentation tests, contrast enhanced micro‐computed tomography, biochemical measurement of pentosidine cross‐links, and cartilage surface color analysis to assess the effects of advanced glycation cross‐linking under these different conditions. Swelling of extracellular matrix due to hypo‐osmolality made cartilage less susceptible to advanced glycation, namely, the increase in effective Young's modulus was approximately 80% lower in hypo‐osmolality compared to hyper‐osmolality and pentosidine content per collagen was 47% lower. These results indicate that healthy levels of glycosaminoglycans not only keep cartilage stiffness at appropriate levels by swelling and pre‐stressed collagen fibrils, but also protect collagen fibrils from adverse effects of advanced glycation. These findings highlight the fact that collagen fibrils and therefore cartilage can be protected from further advanced glycation (“ageing”) by maintaining the joint environment at sufficiently low osmolality. Understanding of mechanochemistry of collagen fibrils provided here might evoke potential ageing prohibiting strategies against cartilage deterioration. © 2018 The Authors. Journal of Orthopaedic Research Published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society. J Orthop Res 36:1929–1936, 2018.
Selective enrichment of N‐linked glycopeptides and glycans by using a dextran‐modified hydrophilic material
Authors: Chen Linlin , Ding Di , Sheng Qianying , Yu Long , Liu Xiuping , Liang Xinmiao
Published: January 2018

Glycosylation analysis of proteins from biological sources utilizing mass spectrometry based approaches is challenging due to the relatively low abundance of glycopeptides, the structural diversity of glycans, and the coexisting matrices. In this study, a customized dextran‐bonded silica‐based stationary phase was introduced for selective enrichment of glycopeptides and glycans from complex biological samples. This material has exhibited superior selectivity and broader glycosylation site coverage over commercial Sepharose in glycoproteomic evaluation. Additionally, the glycomic analysis of fetuin, α1‐acid glycoprotein, and human serum N‐glycome also indicated the relatively higher sensitivity, selectivity, and glycoform coverage of dextran‐bonded silica than that of Sepharose and porous graphitized carbon. Therefore, the dextran‐bonded silica is expected to make contributions in the fields of glycoproteomics and glycomics.
Rapid profiling of polymeric phenolic acids in Salvia miltiorrhiza by hybrid data‐dependent/targeted multistage mass spectrometry acquisition based on expected compounds prediction and fragment ion searching
Authors: Shen Yao , Feng Zijin , Yang Min , Zhou Zhe , Han Sumei , Hou Jinjun , Li Zhenwei , Wu Wanying , Guo De‐an
Published: January 2018

Phenolic acids are the major water‐soluble components in Salvia miltiorrhiza (>5%). According to previous studies, many of them contribute to the cardiovascular effects and antioxidant effects of S. miltiorrhiza. Polymeric phenolic acids can be considered as the tanshinol derived metabolites, e.g., dimmers, trimers, and tetramers. A strategy combined with tanshinol‐based expected compounds prediction, total ion chromatogram filtering, fragment ion searching, and parent list‐based multistage mass spectrometry acquisition by linear trap quadropole‐orbitrap Velos mass spectrometry was proposed to rapid profile polymeric phenolic acids in S. miltiorrhiza. More than 480 potential polymeric phenolic acids could be screened out by this strategy. Based on the fragment information obtained by parent list‐activated data dependent multistage mass spectrometry acquisition, 190 polymeric phenolic acids were characterized by comparing their mass information with literature data, and 18 of them were firstly detected from S. miltiorrhiza. Seven potential compounds were tentatively characterized as new polymeric phenolic acids from S. miltiorrhiza. This strategy facilitates identification of polymeric phenolic acids in complex matrix with both selectivity and sensitivity, which could be expanded for rapid discovery and identification of compounds from complex matrix.
Second‐Harmonic Generation from Hyperbolic Plasmonic Nanorod Metamaterial Slab
Authors: Marino Giuseppe , Segovia Paulina , Krasavin Alexey V. , Ginzburg Pavel , Olivier Nicolas , Wurtz Gregory A. , Zayats Anatoly V.
Published: January 2018

Hyperbolic plasmonic metamaterials provide numerous opportunities for designing unusual linear and nonlinear optical properties. In this work, second‐harmonic generation in a hyperbolic metamaterial due to a free‐electron nonlinear response of a plasmonic component of the metamaterial is studied. It is shown that owing to a rich modal structure of an anisotropic plasmonic metamaterial slab, the overlap of fundamental and second‐harmonic modes results in the broadband enhancement of radiated second‐harmonic intensity by up to 2 orders of magnitude for TM‐ and TE‐polarized fundamental light, compared to a smooth Au film under TM‐polarised illumination. Compared to the radiated second‐harmonic intensity from a bulk LiNbO3 nonlinear crystal of the same thickness, the SHG intensity from a metamaterial slab may be up to 2 orders of magnitude higher at the certain metamaterial resonances. The results open up possibilities to design tuneable frequency‐doubling integratable metamaterial with the goal to overcome limitations associated with classical phase matching conditions in thick nonlinear crystals.
Vertical‐Cavity Silicon‐Integrated Laser with In‐Plane Waveguide Emission at 850 nm
Authors: Kumari Sulakshna , Haglund Emanuel P. , Gustavsson Johan S. , Larsson Anders , Roelkens Gunther , Baets Roel G.
Published: January 2018

A continuous‐wave electrically‐pumped short‐wavelength hybrid vertical‐cavity silicon‐integrated laser (VCSIL) with in‐plane emission into a silicon nitride (SiN) waveguide is experimentally demonstrated. The coupling from the vertical cavity into the in‐plane SiN waveguide is achieved by a weak grating on the SiN waveguide placed inside the cavity. The grating provides coupling, sets the polarization of the lasing output, and provides transverse mode control. A 5 µm oxide‐aperture diameter device with a threshold current of 1.1 mA produces 73 µW single‐sided waveguide‐coupled optical output power at 2.6 mA bias current at a wavelength of 856 nm and a side‐mode suppression ratio (SMSR) of 29 dB.
The synergistic effect of PDT and oxacillin on clinical isolates of Staphylococcus aureus
Authors: Iluz Natanel , Maor Yasmin , Keller Natan , Malik Zvi
Published: January 2018

Background

Staphylococcus aureus is a major pathogen in clinical microbiology. It is known to cause infections at various body sites and can be life‐threatening. The development of resistance to many well‐established antibiotic treatments and the prevalence of methicillin‐resistant S. aureus (MRAS) among hospital patients and the general community pose challenges in treating the pathogen. The antimicrobial effect of photodynamic therapy (PDT) has been a subject of study for a long time and can offer new strategies for dealing with resistant strains.

Objective

In our study, we searched for a positive synergistic relationship between PDT and the standard antibiotics used to treat S. aureus and MRSA infections.

Materials and Methods

The phototoxic profile of deuteroporphyrin (DP) in both resistant and susceptible clinical strains of S. aureus was determined by plating of treated and untreated broth cultures. Electron microscopy imaging was done to explore possible sites of damage and free‐radical accumulation in the cells during DP‐PDT. Minimal inhibitory concentration (MIC) of oxacillin, gentamicin, vancomycin, rifampin, and fusidic acid was determined using the broth dilution method, and the checkerboard method was used to detect and evaluate the synergistic potential of DP‐PDT and antibiotic combinations. A synergistic combination was further characterized using broth cultures and plating.

Results

DP‐PDT using a light dose of 15 J/cm2 showed a bactericidal effect even with a small concentration of 17 μM DP. Transmission electron microscopy indicated profound damage in the cell wall and cell membrane, and the appearance of mesosome‐like structures. Free radicals tend to localize in the cell membrane and inside the mesosome. No synergistic effect was detected by combining PDT with gentamicin, vancomycin, rifampin, and fusidic acid treatments. A positive synergistic effect was observed only in DP‐PDT‐oxacillin combined treatment using the checkerboard method. The effect was observed in clinical antibiotic‐resistant isolates after DP‐PDT using a light dose of 46 J/cm2 and small concentrations of DP. Oxacillin MIC decreased below 2 μg/ml in resistant strains under such conditions. Cultures which did not undergo new cycles of DP‐PDT recovered their original oxacillin resistance after a few generations.

Conclusions

PDT with porphyrins shows possible new therapeutic options in treating drug‐resistant S. aureus at body sites suitable for irradiation. The synergistic effect of DP‐PDT with oxacillin on clinical strains illustrates the potential of PDT to augment traditional antibiotic treatment based on cell wall inhibitors. Lasers Surg. Med. 50:535–551, 2018. © 2018 Wiley Periodicals, Inc.
Antibacterial and Antifungal Activity of Poly(Lactic Acid)–Bovine Lactoferrin Nanofiber Membranes
Authors: Machado Raul , da Costa André , Silva Dina M. , Gomes Andreia C. , Casal Margarida , Sencadas Vitor
Published: January 2018

Antimicrobial materials have become relevant for local therapies preventing microbial resistance induced by systemic antibiotic treatments. This work reports the development of electrospun poly(lactic acid) (PLLA) nanofiber membranes loaded with bovine lactoferrin (bLF) up to 20 wt%. The membranes present smooth and nondefective fibers with mean diameters between 717 ± 197 and 495 ± 127 nm, and an overall porosity of ≈80%. The hydrophobicity of the PLLA membranes is reduced by the presence of bLF. The release profile of bLF correlates with an anomalous transport model, with 17.7 ± 3.6% being released over 7 weeks. The nanofiber mats show no cytotoxicity on human skin fibroblasts and even promote cell proliferation after short exposure periods. Furthermore, the developed membranes display antifungal activity against Aspergillus nidulans by inhibiting spore germination and mycelial growth. These results evidence the strong potential of bLF–PLLA nanofiber membranes to be used as antifungal dressings.
Facile Fabrication of Mussel‐Inspired Multifunctional Polymeric Membranes with Remarkable Anticoagulant, Antifouling, and Antibacterial Properties
Authors: Shao Mingze , Wang Rui , Zhao Weifeng , Li Jianshu , Zhao Changsheng
Published: January 2018

Herein, a facile one‐step surface modification technique of coating functional biopolymer conjugated mussel‐inspired catechol (CA) onto substrate is applied to confer polyethersulfone (PES) membranes with remarkable blood compatibility, antifouling property, and antibacterial property, respectively. CA conjugated poly(2‐acrylamido‐2‐methylpropanesulfonic acid) (PAMPS), poly(sulfobetaine methacrylate) (PSBMA), and poly(methacryloxyethyltrimethyl ammonium chloride) are synthesized via free radical polymerization in the presence of CA, and simultaneously coated onto PES membrane surface. The surface chemical compositions, surface zeta‐potential convince the successful preparation of the modified PES membranes. PAMPS‐coated membrane exhibits excellent blood compatibility, especially anticoagulation property; PSBMA‐coated membrane displays excellent antifouling property and blood compatibility; meanwhile, PDMC‐coated membrane shows robust bactericidal property. In general, this work demonstrates that the mussel‐inspired surface modification protocol provides a facile and versitile method to confer the substrate with excellent blood compatibility, antifouling property, and antibacterial property, respectively, which has great potential for multibiomedical applications, such as blood purification, hemodialysis, and organ implantation.
A Novel Approach to Design Nanoporous Polyethylene/Polyester Composite Fabric via TIPS for Human Body Cooling
Authors: Liu Rong , Wang Xinwei , Yu Junrong , Wang Yan , Zhu Jing , Hu Zuming
Published: January 2018

In this study, in order to obtain a wearable infrared‐transparent material based on nanoporous polyethylene, a newly ultrahigh molecular weight polyethylene (UHMWPE)/polyester composite fabric with nanoporous structure is developed via thermally induced phase separation (TIPS) method. A polyester mesh with loose warp/weft weaves is chosen as the intermediate to enhance the fabric mechanical strength and air permeability. Meanwhile, methoxy‐poly(ethylene glycol)‐aminoethyl/polydopamine particles (mPPDAPs) are used to improve the hydrophilicity of UHMWPE. The fabric is composited with mPPDAPs/UHMWPE/liquid paraffin mixture at high temperature. Then the nanoporous structure is formed via TIPS in UHMWPE phase in the composite fabric. This newly UHMWPE/polyester composite fabric possesses a unique connective nanoporous structure with the pore sizes distributed from 50 to 100 nm and it also has many disconnected honeycomb pores that are ≈1000 nm in diameter. These characteristics endow the composite fabric with excellent properties of wearability and optical properties, including sufficient moisture wicking rate, air permeability, and mechanical strength, high infrared‐transparent and ultraviolet/visible‐opaque properties. It is an effective, economical, and practical novel composite textile for human body cooling.
Water‐Processable Multiwalled Nanotube: Phenol‐Induced Reversible Oxidation Process and Ambipolar Charge Transport Property
Authors: Huang Ju , Jiang Yan‐Yun
Published: January 2018

Due to the fascinating electronic, thermal, and mechanical properties of single‐walled carbon nanotubes (SWCNTs), extensive efforts have been devoted to the development of SWCNT‐based materials. These materials' semiconducting properties and related applications, such as field‐effect transistors (FETs), have been investigated by researchers for many years. However, despite the significant progress achieved, it remains challenging to separate semiconducting and metallic nanotubes from the mixtures of as‐grown SWCNTs. In a few studies, composites of water‐processable phenol formaldehyde resin/multiwalled carbon nanotubes (MWCNTs) have been found to exhibit a quasireversible oxidation process and to behave as semiconductors or field‐effect transistors. This finding has rarely been reported for MWCNTs, and it differs greatly from findings regarding intrinsic semiconductive SWCNTs. Significantly, field‐effect transistors fabricated with MWCNT composites as their semiconductor active layers have shown ambipolar charge transport characteristics. The results provide a high value‐added application pathway for the application of polymer/MWCNTs as the FET materials for electronic devices that offer higher performance at a lower cost.
Chemical Composition Fractionation of Olefin Plastomers/Elastomers by Solvent and Thermal Gradient Interaction Chromatography
Authors: Ndiripo Anthony , Albrecht Andreas , Monrabal Benjamin , Wang Jingbo , Pasch Harald
Published: January 2018

Olefin plastomers/elastomers are typically copolymers with high comonomer contents and low crystallinities. Therefore, the fractionation of these materials with crystallization‐based methods is not feasible. On the other hand, solvent and temperature gradient interaction chromatography (SGIC and TGIC, respectively) are suitable techniques for the separation of olefin copolymers with regard to their chemical composition. In this study, the application ranges of both techniques are investigated and compared for ethylene–propylene (EP) copolymers. A linear dependency of ethylene content versus elution volume is obtained with SGIC in practically the whole ethylene range. In the case of TGIC, a linear dependency is obtained within certain ethylene content limits. The accessible ethylene content separation range for TGIC is 50–100 mol% ethylene, and a broader 26–100 mol% ethylene range is accessible for SGIC, the latter being the technique of choice in the analysis of EP rubbers.
Polypeptide Polymer Brushes by Light‐Induced Surface Polymerization of Amino Acid N‐Carboxyanhydrides
Authors: Stukenkemper Timo , Paquez Xavier , Verhoeven M. W. G. M. , Hensen Emiel J. M. , Dias Aylvin A. , Brougham Dermot F. , Heise Andreas
Published: January 2018

Silicon wafers are decorated with photoamine generator 4,5‐dimethoxy‐2‐nitrobenzyl 3‐(triethoxysilyl)propyl carbamate. UV‐irradiation in the presence of benzyl‐l‐glutamate N‐carboxyanhydride is carried out, resulting in the release of the surface‐bound primary amines, making them viable N‐carboxyanhydride (NCA) polymerization initiators. Successful polypeptide grafting is confirmed by water contact angle measurements as well as by ellipsometry, revealing a poly(benzyl‐l‐glutamate) (PBLG) layer of ≈3 nm. X‐ray photoelectron spectroscopy confirms the presence of amide groups in the grafted PBLG while time‐of‐flight secondary ion mass spectroscopy provides additional evidence for the presence of PBLG on the surface. Evaluation of negative control samples confirms successful UV surface grafting. The approach is thus established as a viable general method for light exposure directable polypeptide functionalization of silicon surfaces.
Exoproteome Profiling Reveals the Involvement of the Foldase PrsA in the Cell Surface Properties and Pathogenesis of Staphylococcus aureus
Authors: Lin Mei‐Hui , Li Chi‐Chun , Shu Jwu‐Ching , Chu Hao‐Wei , Liu Chao‐Chin , Wu Chih‐Ching
Published: January 2018

Staphylococcus aureus is a bacterial pathogen that produces and exports many virulence factors that cause diseases in humans. PrsA, a membrane‐bound foldase, is expressed ubiquitously in Gram‐positive bacteria and required for the folding of exported proteins into a stable and active structure. To understand the involvement of PrsA in posttranslocational protein folding in S. aureus, a PrsA‐deficient mutant of S. aureus HG001 was constructed. Using isobaric tags for relative and absolute quantification (iTRAQ)‐based mass spectrometry analyses, the exoproteomes of PrsA mutant and wild type S. aureus were comparatively profiled, and 163 cell wall‐associated proteins and 67 exoproteins with altered levels have been identified in the PrsA‐deficient mutant. Bioinformatics analyses further reveal that prsA deletion altered the amounts of proteins that are potentially involved in the regulation of cell surface properties and bacterial pathogenesis. To determine the relevancy of our findings, we investigated the functional consequence of prsA deletion in S. aureus. PrsA deficiency can enhance bacterial autoaggregation and increase the adhesion ability of S. aureus to human lung epithelial cells. Moreover, mice infected with PrsA‐deficient S. aureus had a better survival rate compared with those infected with the wild‐type S. aureus. Collectively, our findings reveal that PrsA is required for the posttranslocational folding of numerous exported proteins and critically affects the cell surface properties and pathogenesis of S. aureus.
The Plantain Proteome, a Focus on Allele Specific Proteins Obtained from Plantain Fruits
Authors: Campos Nádia A. , Swennen Rony , Carpentier Sebastien C.
Published: January 2018

Proteomics has been applied with great potential to elucidate molecular mechanisms in plants. This is especially valid in the case of non‐model crops of which their genome has not been sequenced yet, or is not well annotated. Plantains are a kind of cooking bananas that are economically very important in Africa, India, and Latin America. The aim of this work was to characterize the fruit proteome of common dessert bananas and plantains and to identify proteins that are only encoded by the plantain genome. We present the first plantain fruit proteome. All data are available via ProteomeXchange with identifier PXD005589. Using our in‐house workflow, we found 37 alleles to be unique for plantain covered by 59 peptides. Although we do not have access (yet) to whole‐genome sequencing data from triploid banana cultivars, we show that proteomics is an easily accessible complementary alternative to detect different allele specific SNPs/SAAPs. These unique alleles might contribute toward the differences in the metabolism between dessert bananas and plantains. This dataset will stimulate further analysis by the scientific community, boost plantain research, and facilitate plantain breeding.
Covalently linked nanocomposites of polypyrrole with graphene: Strategic design toward optimized properties
Authors: Naidek Naiane , Zarbin Aldo J. G. , Orth Elisa S.
Published: January 2018

Graphene‐based nanocomposites with conducting polymers have attracted increasing interest due to the enhanced synergistic properties, which can potentiate and broaden applications. In this context, covalent functionalization stands out as a strategic designing tool, which optimizes the interaction between the nanocomposites components. Herein, covalently linked polymeric nanocomposites were obtained between graphene derivatives and polypyrrole (Ppy) under mild routes (i.e., aqueous, room temperature). First, pyrrole was covalently functionalized on graphene oxide (GO) through stable amide bonds and further polymerization with FeCl3 led to the polymeric nanocomposites. Finally, to improve conductivity, GO was reduced using NaBH4. Similarly, analogous non‐covalent nanocomposites were obtained for comparison purposes. All samples were thoroughly characterized by thermogravimetric analysis, scanning electron microscopy, and infrared and Raman spectroscopy, confirming the targeted functionalization, polymerization, and reduction processes. Moreover, the covalent link effectively enhances the interaction of the nanocomposite's components as evidenced by its improved electrochemical stability (300 cycles), compared to the non‐covalent composites which loses conductivity in the initial stages. Indeed, Ppy is known for its low stability, limiting its applications. Overall, the results herein evidence that covalently linked nanocomposites can be successfully obtained with optimized electrochemical response, promising for applications as supercapacitors and artificial muscles. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 579–588
High‐Responsivity Photodetectors Based on Formamidinium Lead Halide Perovskite Quantum Dot–Graphene Hybrid
Authors: Pan Rui , Li Haiyang , Wang Jun , Jin Xiao , Li Qinghua , Wu Zhiming , Gou Jun , Jiang Yadong , Song Yinglin
Published: January 2018

Highly performance photodetector requires a wide range of responses of the incident photons and converts them to electrical signals efficiently. Here, a photodetector based on formamidinium lead halide perovskite quantum dots (e.g., FAPbBr3 QDs)–graphene hybrid, aiming to take the both advantages of the two constituents. The FAPbBr3 QD–graphene layer not only benefits from the high mobility and wide spectral absorption of the graphene material but also from the long charge carrier lifetime and low dark carrier concentration of the FAPbBr3 QDs. The photodetector based on FAPbBr3 QD–graphene hybrid exhibits a broad spectral photoresponse ranging from 405 to 980 nm. A photoresponsivity of 1.15 × 105AW−1 and an external quantum efficiency as high as 3.42 × 107% are obtained under an illumination power of 3 µW at 520 nm wavelength. In detail, a high responsivity is achieved in 405–538 nm, while a relatively low but fast response is observed in 538–980 nm. The photoelectric conversion mechanism of this hybrid photodetector is investigated in the view of built‐in electric field from the QD–graphene contact which improves the photoconductive gain.
Dual Template Engaged Synthesis of Hollow Ball‐in‐Tube Asymmetrical Structured Ceria
Authors: Wang Yong , Gao Daowei , Li Cuncheng , Li Chunsheng , Rosei Federico , Ma Dongling , Chen Guozhu
Published: January 2018

Hollow materials with different configurations are of interest due to their unique structural features, which induce interesting properties e.g. catalysis. Here, the synthesis of asymmetrical hollow ball‐in‐tube (HBT) structured CeO2 is reported, which is achieved using a dual template engaged solid–liquid interfacial reaction. In this reaction, the SiO2 sphere (hard template)‐embedded Ce(OH)CO3 nanorod (sacrificial template) composite is first treated with NaOH solution, followed by an acid wash to obtain asymmetrical hollow structured CeO2. Such HBT structured CeO2 is demonstrated to be a good support for Au nanoparticles toward CO oxidation as compared to simple hollow CeO2 nanotubes, leading to significantly increase catalytic activity.
Self‐Propelled Micro/Nanoparticle Motors
Authors: Guix Maria , Weiz Sonja M. , Schmidt Oliver G. , Medina‐Sánchez Mariana
Published: January 2018

The growing interest in the design and fabrication of novel autonomous micro‐ and nanoparticles is motivated by the vast advances in their motion efficiency and their further implementation in both biomedical and environmental fields. The present review covers the motion principle and fabrication procedures of synthetic and hybrid particle‐like micromotors reported to date to give a comprehensive view of the key design parameters and different approaches for optimal motor guidance. The applications of self‐propelled micro‐ and nanoparticles in different fields are classified accordingly to clarify not only the latest advances but also the current challenges and constraints in the field. This review aims to provide clues to develop more efficient and biocompatible autonomous microparticles in the future, with advanced multitasking and sensing capabilities while being able to perform cooperative work.
Pd–Ru Bimetallic Nanocrystals with a Porous Structure and Their Enhanced Catalytic Properties
Authors: Wan Shulin , Wang Qingxiao , Ye Haihang , Kim Moon J. , Xia Xiaohu
Published: January 2018

This work, for the first time, reports the synthesis, characterization, and catalytic properties of a novel type of bimetallic nanocrystals—Pd–Ru nanocrystals with a highly porous structure on the surface. The synthesis relies on a seed‐mediated growth, at which Ru atoms are added to the surface of preformed Pd nanocubes as the seeds. The key to the successful synthesis is to direct the crystal growth along a 3D island mode through kinetic control. The Ru shells on Pd surfaces primarily take a hexagonal close packing (hcp) crystal structure. The extent of porosity for Ru shells can be conveniently controlled by adjusting the amount of Ru precursor introduced to a synthesis. The Pd–Ru porous nanocrystals exhibit a substantially enhanced peroxidase‐like activity with a catalytic constant (Kcat) as high as 4.8 × 105 s−1, which is two‐orders‐of‐magnitude greater than the Kcat value of natural peroxidases.
Synthesis of Flower‐Like AuPd@SiO2 Nanoparticles with a Broad Light Extinction for Application to Efficient Dye‐Sensitized Solar Cells
Authors: Tsuji Masaharu , Uto Keiko , Hayashi Jun‐Ichiro , Yoshiwara Akihiko
Published: January 2018

Flower‐like AuPd alloy nanoparticles (NPs) are prepared by reducing a mixture of HAuCl4/H2PdCl4 in an aqueous solution. Transmittance electron microscope (TEM), TEM‐energy dispersed X‐ray spectroscopy, and X‐ray diffraction data indicate that AuPd alloy NPs are composed of Pd rich core and Au rich shell. Crystal growth mechanism of ununiform AuPd alloy NPs is discussed in terms of oxidative etching by Cl−/O2. Even when AuPd alloy NPs are covered by SiO2 shells for the use of dye‐sensitized solar cells (DSSCs), ununiform alloy structure of AuPd NPs is reserved after sintering at 450 °C. When 0.36–4.8 wt% of AuPd@SiO2 NPs are added to TiO2–N719–DSSCs, the photoconversion efficiency (PCE) is enhanced by 7–38% in comparison with that obtained without addition of metallic NPs. The enhancement of PCE by the addition of AuPd@SiO2 NPs is discussed in terms of near‐field surface plasmon resonance (SPR) effect of metallic NPs and far‐field light‐scattering effect of large TiO2 aggregates formed by the addition of a small amount of distilled water into TiO2 pastes. On the basis of the short‐circuit current density (Jsc) and the open‐circuit voltage (Voc) changes upon the addition of AuPd@SiO2, the enhancement of PCE is attributed to synergy effects of far‐field scattering of large TiO2 aggregates and near‐field SPR of AuPd@SiO2 NPs.
Improving the Light‐Extraction Efficiency of AlGaN DUV‐LEDs by Using a Superlattice Hole Spreading Layer and an Al Reflector
Authors: Maeda Noritoshi , Jo Masafumi , Hirayama Hideki
Published: January 2018

AlGaN based deep‐ultraviolet light‐emitting diodes (DUV‐LEDs) have a wide range of applications and a large market is expected. However, the efficiency of DUV‐LEDs is still much lower than that of blue LEDs due to a quite low light‐extraction efficiency (LEE). We improved the LEE of DUV‐LEDs by using a superlattice (SL) hole spreading p‐AlGaN contact layer, a dot matrix Ni/Au electrode and an Al reflector. DUV‐LED samples in which the SL p‐AlGaN contact layer has various period lengths, and forms two different p‐type electrodes, a conventional Ni/Au electrode and a dot matrix Ni/Au electrode with an Al reflector are fabricated. By comparing these LED samples, it is confirmed that contact layers with relatively longer periods are suitable both for vertical hole injection and lateral spreading of the holes. By increasing the Al content and recovering the transparency of the SL p‐AlGaN contact layer, the LEE is increased by up to a factor of 1.6.
Exciton Bound to 1D Intersection of Stacking Fault Plane with a ZnSe Quantum Well
Authors: Smirnov Dmitry S. , Belyaev Kirill G. , Kirilenko Demid A. , Nestoklon Mikhail O. , Rakhlin Maxim V. , Toropov Alexey A. , Sedova Irina V. , Sorokin Sergey V. , Ivanov Sergey V. , Gil Bernard , Shubina Tatiana V.
Published: January 2018

Emerging part of condensed matter science, which deals with the systems of extreme two‐dimensionality, renews the interest in natural 2D objects such as planar stacking faults (SFs) in semiconductor crystals. We report on the observation of an excitonic state localized at the 1D intersection of the SF with a high quality ZnSe quantum well (QW). The micro‐photoluminescence measurements are performed in a specimen used for preceding transmission electron microscopy studies. We demonstrate that the observed narrow lines are polarized along SFs and their linewidths depend on the SFs length. For short SFs, the linewidth can be as low as 0.15 meV. Using the combination of the effective mass approach and the density functional theory calculations we show that the exciton localization is due to the intrinsic electric field inside the SF, which also leads to a spatial separation of electron and hole in the exciton. The 1D intersection of perfect natural and artificial 2D objects can serve as a promising playground for the study of subtle excitonic effects in single defects.
Boson Heat Capacity Peak in Metallic Glasses: Evidence of the Same Defect‐Induced Heat Absorption Mechanism in Structurally Relaxed and Partially Crystallized States
Authors: Khonik Vitaly A. , Kobelev Nikolai P. , Mitrofanov Yurii P. , Zakharov Konstantin V. , Vasiliev Alexander N.
Published: January 2018

The evolution of the Boson heat capacity peak in a typical metallic glass upon structural relaxation and partial crystallization is studied. It is found that heat treatment changes the peak height in both fully amorphous and partially crystalline states in line with the prediction of the Interstitialcy theory.
In vitro and in vivo metabolite identification of a novel benzimidazole compound ZLN005 by liquid chromatography/tandem mass spectrometry
Authors: Sun Wenchao , Nguyen Khoa Dinh , Fitch William L. , Banister Samuel D. , Tang Hongxiang , Zhang Xiaolan , Yu Lewis , Engleman Edgar G. , Rajadas Jayakumar
Published: January 2018

Rationale

A novel benzimidazole compound ZLN005 was previously identified as a transcriptional activator of peroxisome proliferator‐activated receptor γ coactivator 1α (PGC‐1α) in certain metabolic tissues. Upregulation of PGC‐1α by ZLN005 has been shown to have a beneficial effect in a diabetic mouse model and in a coronary artery disease model in vitro. ZLN005 could also have therapeutic potential in neurodegenerative diseases involving down‐regulation of PGC‐1α. Given the phenotypic efficacy of ZLN005 in several animal models of human disease, its metabolic profile was investigated to guide the development of novel therapeutics using ZLN005 as the lead compound.

Methods

ZLN005 was incubated with both rat and human liver microsomes and S9 fractions to identify in vitro metabolites. Urine from rats dosed with ZLN005 was used to identify in vivo metabolites. Extracted metabolites were analyzed by liquid chromatography/tandem mass spectrometry (LC/MS/MS) using a hybrid linear ion trap triple quadrupole mass spectrometer in full scan, enhanced product ion scan, neutral loss scan and precursor scan modes. Metabolites in plasma and brain of ZLN005‐treated rats were also profiled using multiple reaction monitoring.

Results

Identified in vitro transformations of ZLN005 include mono‐ and dihydroxylation, further oxidation to carboxylic acids, and mono‐O‐glucuronide and sulfate conjugation to hydroxy ZLN005 as well as glutathione conjugation. Identified in vivo metabolites are mainly glucuronide and sulfate conjugates of dihydroxyl, carboxyl, and hydroxy acid of the parent compound. The parent compound as well as several major phase I metabolites were found in rat plasma and brain.

Conclusions

Using both in vitro and in vivo methods, we elucidated the metabolic pathway of ZLN005. Phase I metabolites with hydroxylation and carboxylation, as well as phase II metabolites with glucuronide, sulfate and glutathione conjugation, were identified.
On strong controllability for planar affine nonlinear systems
Authors: Sun Yimin , Yu Gaohang
Published: January 2018

Different to linear systems, a controllable nonlinear system does not generally imply that it is strongly controllable. This paper will investigate the strong controllability of planar affine nonlinear systems and obtain its necessary and sufficient condition by introducing the variation function of the control curve. These conditions are imposed on the system structure only. In addition, we also point out that, for a class of polynomial systems, their strong controllability is equivalent to their controllability. Finally, some examples are given to show the application of our results.