bluuebunny/crossref_metadata_2025 huggingface dataset:
Antibacterial PVA membranes containing TiO2/N‐halamine nanoparticles
Authors: Ma Wei , Li Lin , Li Jing , Ren Xuehong , Gu Zhi‐Guo , Huang Tung‐Shi
Published: January 2017

Inorganic–organic composites have received considerable attention due to their combined properties. In this study, a N‐halamine precursor poly[5,5‐dimethyl‐3‐(3′‐triethoxysilylpropyl)‐hydantoin] (PSPH) was synthesized and used for the production of inorganic–organic hybrid particles after reacting with nano‐TiO2 by a sol–gel process. The hybrid particles were characterized by FT‐IR, XRD, and TGA‐DTG. After chlorinated in the dilute sodium hypochlorite solution, antibacterial Cl‐PSPH‐TiO2 nanoparticles (NPS) could be obtained and used for production of polyvinyl alcohol (PVA) composite membranes. The synthesized PSPH‐TiO2/PVA composite membranes were characterized by SEM, FT‐IR, XRD, and TGA‐DTG. Meanwhile, antibacterial property, UV light stability, mechanical properties, and storage stability of the composite membranes were tested. The antibacterial composite membranes with Cl‐PSPH‐TiO2 could inactivate 99.97% of Staphylococcus aureus (3.03 logs) and 100% of Escherichia coli O157:H7 (6.12 logs) within 30 min. The antibacterial composite membranes also showed good UV light stability, regeneration ability, and excellent storage stability.
Open‐Circuit Voltage in Organic Solar Cells: The Impacts of Donor Semicrystallinity and Coexistence of Multiple Interfacial Charge‐Transfer Bands
Authors: Ndjawa Guy O. Ngongang , Graham Kenneth R. , Mollinger Sonya , Wu Di M. , Hanifi David , Prasanna Rohit , Rose Bradley D. , Dey Sukumar , Yu Liyang , Brédas Jean‐Luc , McGehee Michael D. , Salleo Alberto , Amassian Aram
Published: January 2017

In organic solar cells (OSCs), the energy of the charge‐transfer (CT) complexes at the donor–acceptor interface, E
CT, determines the maximum open‐circuit voltage (V
OC). The coexistence of phases with different degrees of order in the donor or the acceptor, as in blends of semi‐crystalline donors and fullerenes in bulk heterojunction layers, influences the distribution of CT states and the V
OC enormously. Yet, the question of how structural heterogeneities alter CT states and the V
OC is seldom addressed systematically. In this work, we combine experimental measurements of vacuum‐deposited rubrene/C60 bilayer OSCs, with varying microstructure and texture, with density functional theory calculations to determine how relative molecular orientations and extents of structural order influence E
CT and V
OC. We find that varying the microstructure of rubrene gives rise to CT bands with varying energies. The CT band that originates from crystalline rubrene lies up to ≈0.4 eV lower in energy compared to the one that arises from amorphous rubrene. These low‐lying CT states contribute strongly to V
OC losses and result mainly from hole delocalization in aggregated rubrene. This work points to the importance of realizing interfacial structural control that prevents the formation of low E
CT configurations and maximizes V
OC.
Copper(I)‐Catalyzed Cascade Dearomatization of Tryptophols with 3‐Indolylphenyliodonium Salts
Authors: Liu Chuan , Yi Ji‐Cheng , Dai Li‐Xin , You Shu‐Li
Published: January 2017

A copper(I)‐catalyzed intermolecular cascade dearomatization reaction of 2‐substituted tryptophols with 3‐indolylphenyliodonium salts has been developed. This approach provided a direct and general access to versatile furoindolines with two quaternary stereogenic centers in good to excellent yields under mild reaction conditions.
A systematic review of sinonasal oncocytomas and oncocytic carcinomas: Diagnosis, management, and technical considerations
Authors: Hodzic Zerina , Rowan Nicholas R. , Kashiwazaki Ryota , Willson Thomas J. , Wang Eric W. , Lee Stella E.
Published: January 2017

Background

Oncocytomas and oncocytic carcinomas are rare tumors of the sinonasal cavity with the propensity for local invasion. This report and systematic review details a case of a nasal oncocytoma involving the lacrimal sac and provides an update of the current literature.

Methods

A systematic literature review was performed using PubMed and Ovid databases. The data obtained from published articles with sinonasal oncocytoma/oncocytic carcinoma as the primary diagnosis included patient demographics, presentation, radiographic and histologic findings, management, and recurrence rates.

Results

Twenty cases were identified. The most common symptoms were epistaxis (n = 11) and nasal obstruction (n = 11). Involvement of the nasal cavity was most common (n = 17), followed by the paranasal sinuses (n = 13) and nasolacrimal apparatus (n = 4). Recurrence occurred in 55% of cases. Recurrence was associated with invasion or infiltration found on histology or the presence of both invasion/infiltration and mitotic figures/pleomorphism (p < 0.05), with no significant relationship between recurrence and age at diagnosis (p = 0.42), sex (p = 0.65), and location of tumor (p = 0.14). The authors present the case of a 73‐year‐old woman with a 5‐month history of worsening epistaxis and biopsy‐proven oncocytoma. Complete surgical resection of the tumor using combined endonasal endoscopic and anterior orbitotomy approach is described.

Conclusion

Oncocytomas and oncocytic carcinomas are rare tumors of the sinonasal cavity with a high rate of local recurrence and orbital involvement. Surgical resection is the treatment of choice and complete resection can be achieved with an endoscopic endonasal approach.
Computational fluid dynamic modeling of nose‐to‐ceiling head positioning for sphenoid sinus irrigation
Authors: Craig John R. , Palmer James N. , Zhao Kai
Published: January 2017

Background

After sinus surgery, patients are commonly instructed to irrigate with saline irrigations with their heads over a sink and noses directed inferiorly (nose‐to‐floor). Although irrigations can penetrate the sinuses in this head position, no study has assessed whether sphenoid sinus penetration can be improved by irrigating with the nose directed superiorly (nose‐to‐ceiling). The purpose of this study was to use a validated computational fluid dynamics (CFD) model of sinus irrigations to assess the difference in sphenoid sinus delivery of irrigations after irrigating in a nose‐to‐floor vs nose‐to‐ceiling head position.

Methods

Bilateral maxillary antrostomies, total ethmoidectomies, wide sphenoidotomies, and a Draf III frontal sinusotomy were performed on a single fresh cadaver head. CFD models were created from postoperative computed tomography maxillofacial scans. CFD modeling software was used to simulate a 120‐mL irrigation to the left nasal cavity with the following parameters: flow rate 30 mL/second, angle of irrigation 20 degrees to the nasal floor, and either nose‐to‐floor or nose‐to‐ceiling head positioning.

Results

In the postoperative CFD models, the sphenoid sinuses were completely penetrated by the irrigation while in a nose‐to‐ceiling head position. However, no sphenoid sinus penetration occurred in the nose‐to‐floor position. Other sinuses were similarly penetrated in both head positions, although the ipsilateral maxillary sinus was less penetrated in the nose‐to‐ceiling position.

Conclusion

CFD modeling demonstrated that the nose‐to‐ceiling head position was superior to the nose‐to‐floor position in delivering a 120‐mL irrigation to the sphenoid sinuses.
An Ultrastable and Easily Regenerated Hydrogen‐Bonded Organic Molecular Framework with Permanent Porosity
Authors: Hu Falu , Liu Caiping , Wu Mingyan , Pang Jiandong , Jiang Feilong , Yuan Daqiang , Hong Maochun
Published: January 2017

A robust hydrogen‐bonded organic framework HOF‐TCBP (H4TCBP=3,3′,5,5′‐tetrakis‐(4‐carboxyphenyl)‐1,1′‐biphenyl) has been successfully constructed and structurally characterized. It possesses a permanent 3D porous structure with a 5‐fold interpenetrated dia topological network. This activated HOF‐TCBP has a high BET surface area of 2066 m2 g−1 and is capable of highly selective adsorption and separation of light hydrocarbons under ambient conditions. It shows excellent thermal stability, as demonstrated by PXRD experiments and N2 adsorption tests. Practical use of HOF‐TCBP is facilitated by the ease of its preparation and renewal through rotary evaporation.
Nucleotide‐Independent Copper(II)‐Based Distance Measurements in DNA by Pulsed ESR Spectroscopy
Authors: Lawless Matthew J. , Sarver Jessica L. , Saxena Sunil
Published: January 2017

A site‐specific Cu2+ binding motif within a DNA duplex for distance measurements by ESR spectroscopy is reported. This motif utilizes a commercially available 2,2′‐dipicolylamine (DPA) phosphormadite easily incorporated into any DNA oligonucleotide during initial DNA synthesis. The method only requires the simple post‐synthetic addition of Cu2+ without the need for further chemical modification. Notably, the label is positioned within the DNA duplex, as opposed to outside the helical perimeter, for an accurate measurement of duplex distance. A distance of 2.7 nm was measured on a doubly Cu2+‐labeled DNA sequence, which is in exact agreement with the expected distance from both DNA modeling and molecular dynamic simulations. This result suggests that with this labeling strategy the ESR measured distance directly reports on backbone DNA distance, without the need for further modeling. Furthermore, the labeling strategy is structure‐ and nucleotide‐independent.
Copper‐Catalyzed Three‐Component Annulations of Alkenes, Nitrosoarenes, and N‐Hydroxyallylamines To Form Fused Oxazinane/Isoxazolidine Heterocycles
Authors: Kawade Rahul Kisan , Liu Rai‐Shung
Published: January 2017

One‐pot cascade annulations among nitrosoarenes, alkenes, and N‐hydroxyallylamines have been achieved with CuCl/O2 catalysts, forming fused oxazinane/isoxazolidine heterocycles with excellent diastereoselectivity (d.r. >20:1). To enhance the synthetic utility, we developed a successive cleavage of the two N−O bonds of the resulting heterocycles. A mechanism involving dipolar [3+2] cycloadditions of nitrone intermediates with their tethered alkenes is postulated for formation of these heterocycles.
Stereodivergent‐at‐Metal Synthesis of [60]Fullerene Hybrids
Authors: Marco‐Martínez Juan , Vidal Sara , Fernández Israel , Filippone Salvatore , Martín Nazario
Published: January 2017

Chiral fullerene–metal hybrids with complete control over the four stereogenic centers, including the absolute configuration of the metal atom, have been synthesized for the first time. The stereochemistry of the four chiral centers formed during [60]fullerene functionalization is the result of both the chiral catalysts employed and the diastereoselective addition of the metal complexes used (iridium, rhodium, or ruthenium). DFT calculations underpin the observed configurational stability at the metal center, which does not undergo an epimerization process.
Diversity‐Oriented Synthesis of Cyclic Azapeptides by A3‐Macrocyclization Provides High‐Affinity CD36‐Modulating Peptidomimetics
Authors: Zhang Jinqiang , Mulumba Mukandila , Ong Huy , Lubell William D.
Published: January 2017

Macrocyclization has enabled the use of peptides in drug discovery creating a need for methods to synthesize diverse peptide macrocycles. Azapeptides have advanced to clinically used drugs, however, few cyclic azapeptides have been studied. A multiple component “A3‐macrocyclization” strategy is described for the preparation of diverse cyclic azapeptides and is demonstrated by the synthesis of 15 growth hormone releasing hormone‐6 (GHRP‐6) analogs. Certain cyclic aza‐GHRP‐6 analogs exhibited unprecedented affinity for the CD36 receptor, and capacity to modulate Toll‐like receptor agonist‐induced overproduction of nitric oxide, and reduce pro‐inflammatory cytokine and chemokine production in macrophages.
Gold(I) Carbenoids: On‐Demand Access to Gold(I) Carbenes in Solution
Authors: Sarria Toro Juan M. , García‐Morales Cristina , Raducan Mihai , Smirnova Ekaterina S. , Echavarren Antonio M.
Published: January 2017

Chloromethylgold(I) complexes of phosphine, phosphite, and N‐heterocyclic carbene ligands are easily synthesized by reaction of trimethylsilyldiazomethane with the corresponding gold chloride precursors. Activation of these gold(I) carbenoids with a variety of chloride scavengers promotes reactivity typical of metallocarbenes in solution, namely homocoupling to ethylene, olefin cyclopropanation, and Buchner ring expansion of benzene.
A Columnar Liquid‐Crystal Phase Formed by Hydrogen‐Bonded Perylene Bisimide J‐Aggregates
Authors: Herbst Stefanie , Soberats Bartolome , Leowanawat Pawaret , Lehmann Matthias , Würthner Frank
Published: January 2017

A new perylene bisimide (PBI) dye self‐assembles through hydrogen bonds and π–π interactions into J‐aggregates that in turn self‐organize into liquid‐crystalline (LC) columnar hexagonal domains. The PBI cores are organized with the transition dipole moments parallel to the columnar axis, which is an unprecedented structural organization in π‐conjugated columnar liquid crystals. Middle and wide‐angle X‐ray analyses reveal a helical structure consisting of three self‐assembled hydrogen‐bonded PBI strands that constitute a single column of the columnar hexagonal phase. This remarkable assembly mode for columnar liquid crystals may afford new anisotropic LC materials for applications in photonics.
Light‐Activated Sensitive Probes for Amine Detection
Authors: Valderrey Virginia , Bonasera Aurelio , Fredrich Sebastian , Hecht Stefan
Published: January 2017

Our new, simple, and accurate colorimetric method is based on diarylethenes (DAEs) for the rapid detection of a wide range of primary and secondary amines. The probes consist of aldehyde‐ or ketone‐substituted diarylethenes, which undergo an amine‐induced decoloration reaction, selectively to give the ring‐closed isomer. Thus, these probes can be activated at the desired moment by light irradiation, with a sensitivity that allows the detection of amines at concentrations as low as 10−6 m in solution. In addition, the practical immobilization of DAEs on paper makes it possible to detect biogenic amines, such as cadaverine, in the gas phase above a threshold of 12 ppbv within 30 seconds.
Nucleating agent‐containing P(LLA‐mb‐BSA) multi‐block copolymers with balanced mechanical properties
Authors: Wu Binshuang , Zeng Xiaoqing , Wu Linbo , Li Bo‐Geng
Published: January 2017

In order to obtain high performance bioplastics and thermoplastic elastomers, P(LLA‐mb‐BSA) multi‐block copolymers containing 30 wt % and 70 wt % soft segment (PLBSA30 and PLBSA70 for short) were synthesized via chain extension and coupling of poly(L‐lactic acid) (PLLA) and poly(butylene succinate‐co‐adipate) (PBSA) prepolymers in the presence of 1% nucleating agent (NA). They were characterized with proton nuclear magnetic resonance (1H NMR), gel permeation chromatography (GPC), differential scanning calorimetry (DSC), polarizing optical microscopy (POM), thermal gravimetric analysis (TGA), transmission electron microscope (TEM), and tensile and impact test. The relatively high molecular weights of (Mn 8200 g/mol and 3100 g/mol for PLLA and PBSA, respectively) the polyester sequences are helpful to improve the PLLA crystallization and the flexibility of the PBSA soft segment. Nucleation effect further accelerates the crystallization of PLLA segment. The synergistic effect of these factors results in good balance between stiffness and toughness. PLBSA30s containing 1% zinc citrate (ZnCC) or talc behave as ultra‐tough bioplastics with ultrahigh impact strength over 50 kJ/m2 and excellent tensile properties. PLBSA70 containing 1% ZnCC possesses elongation at break of 600% and retains high modulus (56 MPa) and strength (16 MPa) and therefore behaves as an excellent thermoplastic elastomer. The excellent and balanced properties would extend the end applications of these PLLA‐based materials. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44777.
Investigation of nanoyarn preparation by modified electrospinning setup
Authors: Levitt Ariana S. , Knittel Chelsea E. , Vallett Richard , Koerner Michael , Dion Genevieve , Schauer Caroline L.
Published: January 2017

Higher ordered structures of nanofibers, including nanofiber‐based yarns and cables, have a variety of potential applications, including wearable health monitoring systems, artificial tendons, and medical sutures. In this study, twisted assemblies of polyacrylonitrile (PAN), polyvinylidene fluoride trifluoroethylene (PVDF‐TrFe), and polycaprolactone (PCL) nanofibers were fabricated via a modified electrospinning setup, consisting of a rotating cone‐shaped copper collector, two syringe pumps, and two high voltage power supplies. The fiber diameters and twist angles varied as a function of the rotary speed of the collector. Mechanical testing of the yarns revealed that PVDF‐TrFe and PCL yarns have a higher strain‐to‐failure than PAN yarns, reaching 307% for PCL nanoyarns. For the first time, the porosity of nanofiber yarns was studied as a function of twist angle, showing that PAN nanoyarns are more porous than PCL yarns. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44813.
Effect of layer thickness on the electrical parameters and conduction mechanisms of conjugated polymer‐based heterojunction diode
Authors: Yıldız D. E. , Apaydın D. H. , Toppare L. , Cirpan A.
Published: January 2017

In this study, thickness‐dependent current density–voltage (J–V) characteristics obtained for poly{(9,9‐dioctylfluorene)−2,7‐diyl‐(4,7‐bis(thien‐2‐yl) 2‐dodecyl‐benzo[1,2,3] triazole)} (PFTBT) conjugated copolymer based heterojunction diode fabricated on ITO were investigated in terms of electrical characteristics. In order to analyze J–V plots with ITO/PEDOT:PSS/PFTBT:PC61BM/LiF/Al configuration, the thickness‐dependent J–V measurements were applied in the thickness range between 90 and 200 nm. The effect of PFTBT:PC61BM layer thickness on the forward J–V characteristics were investigated by evaluating electrical parameters such as zero bias barrier height (ΦBo), ideality factor (n), shunt resistance (Rsh), series resistance (Rs), the interface states density (Nss), and space‐charge limited mobility. The results show that at PFTBT:PC61BM layer thickness of 90 and 200 nm, ideality factor for ITO/PEDOT:PSS/PFTBT:PC61BM/LiF/Al heterojunction diodes ranged from 2.726 to 3.121 and the thermionic emission over the heterojunction diodes is crucial at low current densities and the intrinsic thermally generated charge carriers controlled the forward current this region of the heterojunction diode. At relatively higher voltage, the current mechanism of ITO/PFTBT:PC61BM/PEDOT:PSS/LiF/Al heterojunction diodes were found to obey a space charge limited (SCLC) conduction mechanism. The values of Nss and Rs in heterojunction diodes increase with increasing PFTBT:PC61BM layer thickness and effect the main electrical parameters of diodes. In addition, the leakage current of heterojunction diodes are taken and interpreted via Poole‐Frenkel emission and Schottky emission. The leakage current was controlled in ITO/PEDOT:PSS/PFTBT:PC61BM/LiF/Al heterojunction diodes by Poole‐Frenkel emission above 140 nm and by Schottky emission under 140 nm. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44817.
Influence of sulfenamide accelerators on cure kinetics and properties of natural rubber foam
Authors: Charoeythornkhajhornchai Pollawat , Samthong Chavakorn , Somwangthanaroj Anongnat
Published: January 2017

The effect of types of sulfenamide accelerator, i.e., 2‐morpholinothiobenzotiazole (MBS), N‐t‐butylbenzothiazole‐2‐sulfenamide (TBBS), and N‐cyclohexyl benzothiazole‐2‐sulfenamide (CBS) on the cure kinetics and properties of natural rubber foam was studied. It has been found that the natural rubber compound with CBS accelerator shows the fastest sulfur vulcanization rate and the lowest activation energy (Ea) because CBS accelerator produces higher level of basicity of amine species than other sulfenamide accelerators, further forming a complex structure with zinc ion as ligand in sulfur vulcanization. Because of the fastest cure rate of CBS accelerator, natural rubber foam with CBS accelerator shows the smallest bubble size and narrowest bubble size distribution. Moreover, it exhibits the lowest cell density, thermal conductivity and thermal expansion coefficient, as well as the highest compression set as a result of fast crosslink reaction. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44822.
Optically active tyrosine‐containing poly(N‐propargylamides): Synthesis, helical conformation, and infrared emissivity study
Authors: Bu Xiaohai , Zhang Zewu , Hang Zusheng , Huang Ying , Zhou Yuming
Published: January 2017

Novel optically active and racemic poly(N‐propargylamides) bearing tyrosine pendants (LPT, DPT, and RPT) were synthesized and characterized. The polymers possessed moderate molecular weights and were thoroughly soluble in common organic solvents. The secondary structure of these three polymers in chloroform was studied and the results indicated that LPT and DPT could adopt helical structures with predominantly one‐handed screw sense according to their intense Cotton effect and large specific rotation values, while RPT adopted random coiled polymer chain. The amide groups could form amide‐amide hydrogen bonds to engender the twist of dihedral angle and the strong steric repulsion of phenol groups might have the opposite effect on the helix. The helical structure of the optically active polymers were conclusively constructed and stabilized by the optimization of intra‐ and intermolecular hydrogen bonding and steric repulsion of the side chains. Moreover, the infrared emissivity values of LPT and DPT at 30 °C were 0.682 and 0.671, which were much lower than RPT. LPT and DPT also showed superior heat resistance due to their unique helical conformation. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44824.
Thermal degradation of urea‐formaldehyde cellulose composites filled with aluminum particles: Kinetic approach to mechanisms
Authors: Azeem Arshad Muhammad , Maaroufi AbdelKrim , Benavente Rosario , Pinto Gabriel
Published: January 2017

This article reports a study on structural characterization and thermal degradation kinetics of insulating/conducting urea‐formaldehyde cellulose (UFC) composites filled with aluminum particles. Structural characterization of UFC/Al composites carried out by SEM, XRD, and FTIR analyses reveals that composites are fairly homogenous, and the interactions between UFC and aluminum in UFC/Al composites are more probably physical in nature. Measurements of inherent thermal stabilities, probing reaction complexity, and thermal degradation kinetics of UFC and UFC/Al composites have been undertaken by thermogravimetric (TG)/differential thermogravimetric (DTG) analyses under nonisothermal conditions. The integral procedure decompositions temperature (IPDT) elucidates significant thermal stability of UFC, and higher aluminum contents in composites are capable of enhancing the thermal stability of UFC resin. TG/DTG analyses suggest highly complicated thermal degradation profiles of UFC and UFC/Al composites, which consist of various parallel/consecutive reactions. Generalized linear integral isoconversional method has been employed to determine the activation energies of thermal degradation processes. Substantial variations in activation energies of UFC and UFC/Al composites with the advancement of reaction verify their multi‐step reaction pathways. Advanced reaction model determination methodology with the help of a novel kinetic function F(α,T) reveals that the multi‐step thermal degradation of UFC goes to completion by principally following intricate nucleation/growth mechanisms. It is also found that aluminum more likely participates in the thermal degradation of resin and tends to alter its reaction mechanism. Detailed interpretations of the obtained kinetic parameters are given, and their probable physical significances are discussed. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44826.
Renewably sourced phenolic resins from lignin bio‐oil
Authors: Vithanage Anushka E. , Chowdhury Emtias , Alejo Luz D. , Pomeroy Paige C. , DeSisto William J. , Frederick Brian G. , Gramlich William M.
Published: January 2017

Traditional lignin pyrolysis generates a bio‐oil with a complex mixture of alkyl‐functionalized guaiacol and syringol monomers that have limited utility to completely replace phenol in resins. In this work, formate assisted fast pyrolysis (FAsP) of lignin yielded a bio‐oil consisting of alkylated phenol compounds, due to deoxyhydrogenation, that was used to synthesize phenol/formaldehyde resins. A solvent extraction method was developed to concentrate the phenolics in the extract to yield a phenol rich monomer mixture. Phenolic resins were synthesized using phenol (phenol resin), FAsP bio‐oil (oil resin), and an extract mimic (mimic resin) that was prepared to resemble the extract after further purification. All three phenolic sources could synthesize novolac resins with reactive sites remaining for subsequent resin curing. Differential scanning calorimetry and thermogravimetric analysis of the three resins revealed similar thermal and decomposition behavior of phenol and the mimic resins, while the oil resin was less stable. Resins were cured with hexamethylenetetramine and the mimic resin demonstrated improved curing energies compared to the oil resin. The adhesive strength of the mimic resin was found to be superior to that of the oil resins. These results confirmed that extracting a mixture of substituted aromatics from FAsP bio‐oil could synthesize resins with properties similar to those from phenol and improved over the parent bio‐oil. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44827.
Impact of fillers and counterface topography on wear behavior of PTFE polymers for ultrasonic motor
Authors: Wang Qihua , Song Fuzhi , Zhang Xinrui , Zhao Gai , Wang Tingmei
Published: January 2017

Aimed to study the effects of reinforcing or functional fillers on mechanical and tribological properties of PTFE‐based friction materials of ultrasonic motor, carbon fibers reinforced PTFE composites modified with different functional fillers with differences in dimension, size, and hardness are fabricated. The tribological performances of PTFE‐based friction materials are comparatively investigated under different sliding velocities and normal loads on different surface morphologies, respectively. The experimental results reveal that nano‐SiO2 shows excellent performance in improving friction stabilities and wear resistance in different operating conditions. It is believed the silica‐based tribofilms, higher deformation resistance, and bearing capacity play a key role in improving friction stabilities. Furthermore, the results also show that the surface topography plays an important role in wear properties. The lower wear rate (sliding against with the disordered surface) is believed to be attributed to wear debris easy‐store characteristic of the topography, which promotes transfer films formation and decreases the wear rate effectively. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44835.
Effectively enhancing cytotoxic and apoptotic effects of alpha‐momorcharin by integrating a heparin‐binding peptide
Authors: Tan Meng‐Jie , Cao Xue‐Wei , Li Peng‐Fei , Zhai Yi‐Zhou , Zhou Yu , Liu Ye‐Jun , Zhao Jian , Wang Fu‐Jun
Published: January 2017

Alpha‐momorcharin (α‐MMC), a type I ribosome‐inactivating protein, has attracted a great deal of attention because of its antitumor activity. However, the cytotoxicity of α‐MMC is limited due to insufficient cellular internalization in cancer cells. To enhance the cytotoxicity of α‐MMC, a heparin‐binding domain derived from heparin‐binding epidermal growth factor (named heparin‐binding peptide [HBP]) was used as a cell‐penetrating peptide and fused to the C‐terminus of α‐MMC. This novel α‐MMC‐HBP fusion protein was expressed and purified with a Ni2+‐resin. The N‐glycosidase activity and DNase activity assay indicated that the introduction of HBP did not interfere with the intrinsic bioactivities of α‐MMC. HBP was able to efficiently carry α‐MMC into the tested cancer cells and significantly enhance the cytotoxic effects of α‐MMC in a dose‐dependent manner. This enhanced cytotoxic ability occurred due to the higher level of cell apoptosis induced by α‐MMC‐HBP, which was demonstrated in western blot analysis in which α‐MMC‐HBP triggered caspase 8, caspase 9, casapase 3, and PARP more intensely than α‐MMC alone. α‐MMC‐HBP led to an upregulation of cleaved PARP and an increase in the Bax/Bcl‐2 ratio. Our study provided a new practical way to greatly improve the antitumor activity of α‐MMC, which could significantly expand the pharmaceutical applications of α‐MMC.
Hox functional diversity: Novel insights from flexible motif folding and plastic protein interaction
Authors: Ortiz‐Lombardia Miguel , Foos Nicolas , Maurel‐Zaffran Corinne , Saurin Andrew J. , Graba Yacine
Published: January 2017

How the formidable diversity of forms emerges from developmental and evolutionary processes is one of the most fascinating questions in biology. The homeodomain‐containing Hox proteins were recognized early on as major actors in diversifying animal body plans. The molecular mechanisms underlying how this transcription factor family controls a large array of context‐ and cell‐specific biological functions is, however, still poorly understood. Clues to functional diversity have emerged from studies exploring how Hox protein activity is controlled through interactions with PBC class proteins, also evolutionary conserved HD‐containing proteins. Recent structural data and molecular dynamic simulations add further mechanistic insights into Hox protein mode of action, suggesting that flexible folding of protein motifs allows for plastic protein interaction. As we discuss in this review, these findings define a novel type of Hox‐PBC interaction, weak and dynamic instead of strong and static, hence providing novel clues to understanding Hox transcriptional specificity and diversity.
Simultaneous detection of three sex steroid hormone classes using a novel yeast‐based biosensor
Authors: Chamas Alexandre , Pham Ha Thi Minh , Jähne Martin , Hettwer Karina , Uhlig Steffen , Simon Kirsten , Einspanier Almuth , Baronian Kim , Kunze Gotthard
Published: January 2017

A biosensor detecting estrogens, progestogens, and androgens in complex samples and in a single step is described. Three Arxula adeninivorans yeast strains were created, each strain producing a different recombinant human hormone receptor and a different fluorescent reporter protein. These strains were then mixed to create G1212/YRC102‐hHR‐fluo, the biological component of the biosensor. During incubation with G1212/YRC102‐hHR‐fluo, hormones present in a sample bind to their target receptor, which leads to the production of a specific fluorescent protein. Three fluorescence scans of the yeast suspension determine which fluorescence protein has been produced, thus revealing which hormone receptor (estrogen, progesterone, and androgen) has been activated by the hormones or hormone mimics present in the sample. The biosensor has similar sensitivities to the existing A. adeninivorans cell‐based assays. The detection of the three hormone classes in one single experiment reduces the labor and time required to assay for the three hormone classes. The biosensor was also trialed with animal serum samples for the detection of progestogens, androgens, and estrogens and gave results that correlated well with ELISA analysis in case of progestogens. These results highlight the potential usefulness of the biosensor for comprehensive determination of hormone status in samples from veterinary origin. Biotechnol. Bioeng. 2017;114: 1539–1549. © 2017 Wiley Periodicals, Inc.
Randomized clinical trial of preoperative oral versus intravenous iron in anaemic patients with colorectal cancer
Authors: Keeler B D , Simpson J A , Ng O , Padmanabhan H , Brookes M J , Acheson A G , Banerjea A , Walter C , Maxwell-Armstrong C , Williams J , Scholefield J , Abercrombie J , Robinson M , Vitish-Sharma P , Bhandal N , Gornall C , Petsas A , Ward K , Pyke S , Johnson P , Cripps H , Williams G , Green M E , Rankin J , Pinkney T , Iqbal T , Ward D , Tselepis C , Narewal M , Futaba K , Ghods-Ghorbani M , Lund J , Theophilidou E , Peacock O , Longman R , Francis N , Spurdle K , Miskovic D , Moriarty C
Published: January 2017

Background

Treatment of preoperative anaemia is recommended as part of patient blood management, aiming to minimize perioperative allogeneic red blood cell transfusion. No clear evidence exists outlining which treatment modality should be used in patients with colorectal cancer. The study aimed to compare the efficacy of preoperative intravenous and oral iron in reducing blood transfusion use in anaemic patients undergoing elective colorectal cancer surgery.

Methods

Anaemic patients with non-metastatic colorectal adenocarcinoma were recruited at least 2 weeks before surgery and randomized to receive oral (ferrous sulphate) or intravenous (ferric carboxymaltose) iron. Perioperative changes in haemoglobin, ferritin, transferrin saturation and blood transfusion use were recorded until postoperative outpatient review.

Results

Some 116 patients were included in the study. There was no difference in blood transfusion use from recruitment to trial completion in terms of either volume of blood administered (P = 0·841) or number of patients transfused (P = 0·470). Despite this, increases in haemoglobin after treatment were higher with intravenous iron (median 1·55 (i.q.r. 0·93–2·58) versus 0·50 (−0·13 to 1·33) g/dl; P < 0·001), which was associated with fewer anaemic patients at the time of surgery (75 versus 90 per cent; P = 0·048). Haemoglobin levels were thus higher at surgery after treatment with intravenous than with oral iron (mean 11·9 (95 per cent c.i. 11·5 to 12·3) versus 11·0 (10·6 to 11·4) g/dl respectively; P = 0·002), as were ferritin (P < 0·001) and transferrin saturation (P < 0·001) levels.

Conclusion

Intravenous iron did not reduce the blood transfusion requirement but was more effective than oral iron at treating preoperative anaemia and iron deficiency in patients undergoing colorectal cancer surgery.
Did student's hasty dismissal violate her due process rights?
Authors: Gelpi Aileen
Published: January 2017

Angela Borrell became a graduate student in the nurse anesthesia program of Bloomsburg University in 2011. As part of her studies, she worked at the Geisinger Clinic.
Turn challenges into opportunities for enhancing the student‐athlete experience
Authors: McCarthy Claudine
Published: January 2017

Working in college athletics for nearly three decades has left Kim Chandler, M.Ed., with no shortage of challenges to face on a daily basis. But along the way, she's learned the importance of developing innovative strategies for managing those challenges.
RNA Protection is Effectively Achieved by Pullulan Film Formation
Authors: Hsieh Ping‐Yao , Monsur Ali M. , Tram Kha , Jahanshahi‐Anbuhi Sana , Brown Christine L. , Brennan John D. , Filipe Carlos D. M. , Li Yingfu
Published: January 2017

RNA is a functionally versatile polymer but suffers from susceptibility to spontaneous and RNase‐catalyzed degradation. This vulnerability makes it difficult to preserve RNA for extended periods of time, thus limiting its use in various contexts, including practical applications as functional nucleic acids. Here we present a simple method to preserve RNA by pullulan (a complex sugar produced by Aureobasidium pullulans fungus) film formation. This strategy can markedly suppress both spontaneous and RNase degradation. Importantly, the pullulan film readily dissolves in aqueous solution, thus allowing retrieval of fully functional RNA species. In order to illustrate the advantage of this protective method in a practical application, we engineered a simple paper sensor containing a bacteria‐detecting RNA‐cleaving DNAzyme. This detection capability of the device was unchanged after storage at room temperature for six months.
Successful evacuation of large perirenal hematoma after extracorporeal shock wave lithotripsy (ESWL) ‐ step 1 of the IDEAL recommendations of surgical innovation
Authors: Hallmann Steffen , Petersein Jan , Ruttloff Jürgen , Ecke Thorsten H.
Published: January 2017

Key Clinical Message

Larger perirenal hematomas after extracorporeal shock wave lithotripsy (ESWL) are sometimes related to the loss of renal function due to compression of the normal renal tissue. After computed tomography‐guided drainage and locally applied urokinase, the hematoma was fractionally evacuated. This procedure is a save and fast way to recover normal renal function.
Electrochemical Infilling of CuInSe2 within TiO2 Nanotube Layers and Subsequent Photoelectrochemical Studies
Authors: Das Sayantan , Sopha Hanna , Krbal Milos , Zazpe Raul , Podzemna Veronika , Prikryl Jan , Macak Jan M.
Published: January 2017

Anodic self‐organized TiO2 nanotube layers (with different aspect ratios) were electrochemically infilled with CuInSe2 nanocrystals with the aim to prepare heterostructures with a photoelectrochemical response in the visible light. The resulting heterostructure assembly was confirmed by field‐emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and X‐ray diffraction (XRD). High incident photon‐to‐electron conversion efficiency values exceeding 55% were obtained in the visible‐light region. The resulting heterostructures show promise as a candidate for solid‐state solar cells.
Enhanced Urea Activity of Oxidation on Nickel‐Deposited Tin Dendrites
Authors: Singh Ramesh Kumar , Subramanian Palaniappan , Schechter Alex
Published: January 2017

Urea oxidation has gained tremendous research interest, owing to its application in direct urea fuel cells and urea electrolyzers. In this work, the electrochemical oxidation of urea on a Ni/Sn dendrites catalyst is investigated. Ni and Ni/Sn dendrites are synthesized through electrodeposition on porous Toray© carbon paper. The prepared catalysts were characterized by scanning electron microscopy, X‐ray diffraction, and inductively coupled plasma−optical emission spectroscopy. The Ni/Sn dendrites oxidized 0.33 M urea in alkaline solution at an onset potential of 0.34 V vs. Ag/AgCl with a current density of 44 mA cm−2@0.55 V, which is higher than that of electrodeposited Ni/TC (31 mA cm−2 @0.55 V). In situ Raman spectroscopic measurements indicate that urea oxidation on Ni/Sn dendrites is initiated by Ni(III)OOH species. Electrochemical impedance spectroscopy patterns of Ni/Sn dendrites in the presence of urea displayed a single depressed semicircle at potentials of 325 mV and two semicircles above 325 mV with a decreased total charge‐transfer resistance. The Ni/Sn dendrites electrode shows lower resistance at the tested potentials, indicative of faster urea oxidation kinetics.
α‐Aminoxy Peptoids: A Unique Peptoid Backbone with a Preference for cis‐Amide Bonds
Authors: Krieger Viktoria , Ciglia Emanuele , Thoma Roland , Vasylyeva Vera , Frieg Benedikt , de Sousa Amadeu Nader , Kurz Thomas , Janiak Christoph , Gohlke Holger , Hansen Finn K.
Published: January 2017

α‐Peptoids, or N‐substituted glycine oligomers, are an important class of peptidomimetic foldamers with proteolytic stability. Nevertheless, the presence of cis/trans‐amide bond conformers, which contribute to the high flexibility of α‐peptoids, is considered as a major drawback. A modified peptoid backbone with an improved control of the amide bond geometry could therefore help to overcome this limitation. Herein, we have performed the first thorough analysis of the folding propensities of α‐aminoxy peptoids (or N‐substituted 2‐aminoxyacetic acid oligomers). To this end, the amide bond geometry and the conformational properties of a series of model α‐aminoxy peptoids were investigated by using 1D and 2D NMR experiments, X‐ray crystallography, natural bond orbital (NBO) analysis, circular dichroism (CD) spectroscopy, and molecular dynamics (MD) simulations revealing a unique preference for cis‐amide bonds even in the absence of cis‐directing side chains. The conformational analysis based on the MD simulations revealed that α‐aminoxy peptoids can adopt helical conformations that can mimic the spatial arrangement of peptide side chains in a canonical α‐helix. Given their ease of synthesis and conformational properties, α‐aminoxy peptoids represent a new member of the peptoid family capable of controlling the amide isomerism while maintaining the potential for side‐chain diversity.
Active Site Mapping of Xylan‐Deconstructing Enzymes with Arabinoxylan Oligosaccharides Produced by Automated Glycan Assembly
Authors: Senf Deborah , Ruprecht Colin , de Kruijff Goswinus H. M. , Simonetti Sebastian O. , Schuhmacher Frank , Seeberger Peter H. , Pfrengle Fabian
Published: January 2017

Xylan‐degrading enzymes are crucial for the deconstruction of hemicellulosic biomass, making the hydrolysis products available for various industrial applications such as the production of biofuel. To determine the substrate specificities of these enzymes, we prepared a collection of complex xylan oligosaccharides by automated glycan assembly. Seven differentially protected building blocks provided the basis for the modular assembly of 2‐substituted, 3‐substituted, and 2‐/3‐substituted arabino‐ and glucuronoxylan oligosaccharides. Elongation of the xylan backbone relied on iterative additions of C4‐fluorenylmethoxylcarbonyl (Fmoc) protected xylose building blocks to a linker‐functionalized resin. Arabinofuranose and glucuronic acid residues have been selectively attached to the backbone using fully orthogonal 2‐(methyl)naphthyl (Nap) and 2‐(azidomethyl)benzoyl (Azmb) protecting groups at the C2 and C3 hydroxyls of the xylose building blocks. The arabinoxylan oligosaccharides are excellent tools to map the active site of glycosyl hydrolases involved in xylan deconstruction. The substrate specificities of several xylanases and arabinofuranosidases were determined by analyzing the digestion products after incubation of the oligosaccharides with glycosyl hydrolases.
Thermogravimetric characterization of ex situ polymethacrylate (EDMA‐co‐GMA) monoliths
Authors: Acquah Caleb , Danquah Michael K. , Moy Charles K. S. , Anwar Mahmood , Ongkudon Clarence M.
Published: January 2017

The thermo‐molecular mechanisms associated with free radical synthesis of polymethacrylate monoliths offer an effective pathway to tune their pore characteristics. In this work, thermogravimetric analyses were used for ex situ characterization of polymethacrylate monoliths synthesised from ethylene glycol dimethacrylate (EDMA) and glycidyl methacrylate (GMA). Apparent activation energies of the polymeric monoliths were determined by using Ozawa‐Flynn‐Wall (OFW) and Kissinger‐Akahira‐Sunose (KAS) isoconversional methods. The number of degradation stages for the polymers were observed to be as follows: homopolymeric GMA and EDMA (2 degradation stages each) and polymeric EDMA‐co‐GMA monoliths (3 degradation stages). The relationship between apparent activation energy and extent of conversion showed that the degradation of monoliths is based on a complex multi‐step reaction rather than a single reaction model. Kinetic parameters showed that an increase in the composition of EDMA and GMA above 20 % significantly enhances the thermal stability of polymeric EDMA‐co‐GMA monoliths under elevated non‐isothermal conditions. E40/G60 and E60/G40 monoliths were identified as the most thermally stable monoliths from the kinetic analyses.
Platinum Overgrowth on Gold Multipod Nanoparticles: Investigation of Synergistic Catalytic Effects in a Bimetallic Nanosystem
Authors: Moon Youngseo , Mai Hien Duy , Yoo Hyojong
Published: January 2017

Highly ordered heteronanostructures can be synthesized by overgrowth of a secondary material on the as‐prepared seed nanocrystal. The unique morphology of seed nanocrystals directs the shape of the secondary structure, which is exploited to develop structure‐controlled composite nanomaterials. Herein, we report a facile and controllable synthetic strategy toward noble star‐shaped bimetallic nanostructures. Gold multipod nanoparticle (GMN) core–platinum shell nanoparticles (GMN@Pt NPs) are successfully synthesized through the overgrowth of Pt on the surface of GMN seeds. Due to the structural uniqueness of GMNs, GMN@Pt NPs show bimetallic core–shell geometries, which have surface roughness and star‐shaped multi‐branches with sharp edges and tips. The island nucleation and growth of individual Pt particles to form a shell provide larger surface areas and plenty of defects on the bimetallic nanocrystals. GMN@Pt NPs with optimized Pt shells show much higher catalytic activities in 4‐nitrophenol reduction and ethanol electrooxidation than those of GMNs or Pt nanoparticles, mainly due to the synergistic effects of the bicomponent nanosystem.
Side‐Group‐Induced Polymorphism in Self‐Assembled Monolayers: 3,5‐Bis(trifluoromethyl)benzenethiolate Films on Au(111)
Authors: Bashir Asif , Sauter Eric , Al‐Refaie Najd , Rohwerder Michael , Zharnikov Michael , Azzam Waleed
Published: January 2017

The structure and molecular organization of self‐assembled monolayers (SAMs) depend on a complex interplay of intermolecular and molecule–substrate interactions, so that even a small change in molecular composition can result in noticeable changes in the SAM structure. Herein we show that decoration of the most basic aromatic SAM constituent, benzenethiol, with two trifluoromethyl groups leads to distinct polymorphism in the respective SAMs, in which the appearance of a specific structural phase or a combination of several different phases is dependent on the parameters of the preparation procedure. High‐quality films with a single crystallographic phase and significantly large domains could only be prepared after a short immersion time (5 min) and an additional re‐immersion of the sample in pure ethanol at an elevated temperature. A standard 24 h immersion at room temperature led to poorly defined films with a large defect density and only a small portion of the surface covered by well‐ordered molecular domains.
Genome‐Wide Study Links PNPLA3 Variant With Elevated Hepatic Transaminase After Acute Lymphoblastic Leukemia Therapy
Authors: Liu Y , Fernandez CA , Smith C , Yang W , Cheng C , Panetta JC , Kornegay N , Liu C , Ramsey LB , Karol SE , Janke LJ , Larsen EC , Winick N , Carroll WL , Loh ML , Raetz EA , Hunger SP , Devidas M , Yang JJ , Mullighan CG , Zhang J , Evans WE , Jeha S , Pui C‐H , Relling MV
Published: January 2017

Remission induction therapy for acute lymphoblastic leukemia (ALL) includes medications that may cause hepatotoxicity, including asparaginase. We used a genome‐wide association study to identify loci associated with elevated alanine transaminase (ALT) levels after induction therapy in children with ALL enrolled on St. Jude Children's Research Hospital (SJCRH) protocols. Germline DNA was genotyped using arrays and exome sequencing. Adjusting for age, body mass index, ancestry, asparaginase preparation, and dosage, the PNPLA3 rs738409 (C>G) I148M variant, previously associated with fatty liver disease risk, had the strongest genetic association with ALT (P = 2.5 × 10‐8). The PNPLA3 rs738409 variant explained 3.8% of the variability in ALT, and partly explained race‐related differences in ALT. The PNPLA3 rs738409 association was replicated in an independent cohort of 2,285 patients treated on Children's Oncology Group protocol AALL0232 (P = 0.024). This is an example of a pharmacogenetic variant overlapping with a disease risk variant.