bluuebunny/crossref_metadata_2025 huggingface dataset:
Metal‐Catalyzed Synthesis of Functionalized 1,2,4‐Oxadiazoles from Silyl Nitronates and Nitriles
Authors: Nikodemiak Paul , Koert Ulrich
Published: April 2017

The metal‐catalyzed cycloaddition of silyl nitronates and nitriles leading to 1,2,4‐oxadiazoles is described. Silver(I) triflate (AgOTf) and and ytterbium(III) triflate [Yb(OTf)3] are suitable catalysts. A variety of functional groups is tolerated in the nitrile. The reaction works well for alkenyl and aryl silyl nitronates while the use of alkyl silyl nitronates is less efficient. Mechanistic studies are in favour of an elimination of tert‐butyl(dimethyl)silanol (TBSOH) after the cycloaddition step. The new approach has also been applied for the synthesis of the drug ataluren.

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Hydrogen Bonding‐Assisted Enhancement of the Reaction Rate and Selectivity in the Kinetic Resolution of d,l‐1,2‐Diols with Chiral Nucleophilic Catalysts
Authors: Fujii Kazuki , Mitsudo Koichi , Mandai Hiroki , Suga Seiji
Published: April 2017

An extremely efficient acylative kinetic resolution of d,l‐1,2‐diols in the presence of only 0.5 mol% of binaphthyl‐based chiral N,N‐4‐dimethylaminopyridine was developed (selectivity factor of up to 180). Several key experiments revealed that hydrogen bonding between the tert‐alcohol unit(s) of the catalyst and the 1,2‐diol unit of the substrate is critical for accelerating the rate of monoacylation and achieving high enantioselectivity. This catalytic system can be applied to a wide range of substrates involving racemic acyclic and cyclic 1,2‐diols with high selectivity factors. The kinetic resolution of d,l‐hydrobenzoin and trans‐1,2‐cyclohexanediol on a multigram scale (10 g) also proceeded with high selectivity and under moderate reaction conditions: (i) very low catalyst loading (0.1 mol%); (ii) an easily achievable low reaction temperature (0 °C); (iii) high substrate concentration (1.0 M); and (iv) short reaction time (30 min).

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Mild Cobalt(III)‐Catalyzed C–H Hydroarylation of Conjugated C=C/C=O Bonds
Authors: Li Jie , Zhang Zhao , Ma Wenbo , Tang Mengyao , Wang Dawei , Zou Liang‐Hua
Published: April 2017

An efficient cobalt(III)‐catalyzed C‐2‐selective indole C–H hydroarylation of acrolein, enones, and glyoxylates was achieved under mild reaction conditions. The versatile cobalt(III) catalyst displayed excellent positional selectivity with the assistance of pyrimidinyl, pyridyl, and pyrazolyl directing groups, thus overcoming the inherent C‐3 selectivity of an electrophilic indole derivatization. This approach provides an expedient route to indolyl‐substituted aldehydes, ketones, and esters with wide functional group tolerance. In addition, it also features high step‐ and atom‐economy.

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Synthesis and Optimization of MoS2@Fe3O4‐ICG/Pt(IV) Nanoflowers for MR/IR/PA Bioimaging and Combined PTT/PDT/Chemotherapy Triggered by 808 nm Laser
Authors: Liu Bei , Li Chunxia , Chen Guanying , Liu Bin , Deng Xiaoran , Wei Yi , Xia Jun , Xing Bengang , Ma Ping'an , Lin Jun
Published: April 2017

Elaborately designed biocompatible nanoplatforms simultaneously achieving multimodal bioimaging and therapeutic functions are highly desirable for modern biomedical applications. Herein, uniform MoS2 nanoflowers with a broad size range of 80–180 nm have been synthesized through a facile, controllable, and scalable hydrothermal method. The strong absorbance of MoS2 nanoflowers at 808 nm imparts them with high efficiency and stability of photothermal conversion. Then a novel multifunctional composite of MoS2@Fe3O4‐ICG/Pt(IV) (labeled as Mo@Fe‐ICG/Pt) is designed by covalently grafting Fe3O4 nanoparticles with polyethylenimine (PEI) functionalized MoS2, and then loading indocyanine green molecules (ICG, photosensitizers) and platinum (IV) prodrugs (labeled as Pt(IV) prodrugs) on the surface of MoS2@Fe3O4. The resulting Mo@Fe‐ICG/Pt nanocomposites can achieve excellent magnetic resonance/infrared thermal/photoacoustic trimodal biomaging as well as remarkably enhanced antitumor efficacy of combined photothermal therapy, photodynamic therapy, and chemotherapy triggered by a single 808 nm NIR laser, thus leading to an ideal nanoplatform for cancer diagnosis and treatment in future.
Recent Development of Boron Nitride towards Electronic Applications
Authors: Izyumskaya Natalia , Demchenko Denis O. , Das Saikat , Özgür Ümit , Avrutin Vitaliy , Morkoç Hadis
Published: April 2017

Boron nitride occurs in several polymorphs, among which cubic and hexagonal varieties have been extensively studied over many years and have found numerous practical applications. Although various forms of BN have been used as lubricant and abrasive material for many years, the unique electronic properties of BN have not been yet utilized. Due to their wide optical bandgaps (the widest among nitride semiconductors), cubic and hexagonal polymorphs of BN are promising candidates for optoelectronic devices operating in the deep‐ultraviolet range and for high‐power electronic devices for switching and radio‐frequency applications. The layered structure of hexagonal BN allows preparation of ultrathin nanosheets with very smooth surfaces and low defect density, which are proved to be useful as supporting substrates and gate dielectric layers in graphene‐based structures. The first device demonstrations are very encouraging. In this contribution, the recent progress in properties, fabrication technologies, and emerging applications of BN as a wide‐gap semiconductor material is reviewed.
A Highly Responsive Self‐Driven UV Photodetector Using GaN Nanoflowers
Authors: Aggarwal Neha , Krishna Shibin , Sharma Alka , Goswami Lalit , Kumar Dinesh , Husale Sudhir , Gupta Govind
Published: April 2017

The rising demand for optoelectronic devices to be operable in adverse environments necessitates the sensing of ultraviolet (UV) radiation. Here, a self‐driven, highly sensitive, fast responding GaN nanoflower based UV photodetector is reported. By developing unique structures, the light absorption increases efficiently and a maximum responsivity of 10.5 A W−1 is achieved at 1 V bias. The reported responsivity is the highest among the GaN UV photodetectors on Si substrates and commercially available Si‐based UV photodetectors. Under self‐driven condition, the photodetector exhibits very low dark current (≈nA) with a very high responsivity (132 mA W−1) and detectivity (2.4 × 1010 Jones). A remarkably high light‐to‐dark current ratio of ≈260 signifies extremely high photodetection gain compared to planar GaN‐based photodetectors. The self‐driven and biased photodetector device yields highly stable rise and decay time response. A model based on band theory elucidates the origin of self‐driven photodetectors. Implementation of the innovative growth design structures assures an exceptionally high sensitivity toward UV signal, which is capable of substituting the existing technology of UV photodetectors. High responsivity and detectivity from devices based on the GaN nanoflower‐like structure with the advantage of high surface/volume ratio can have numerous applications in fabrication of nanoscale optoelectronic high performance devices such as self‐driven UV photodetectors.
Completely Printed, Flexible, Stable, and Hysteresis‐Free Carbon Nanotube Thin‐Film Transistors via Aerosol Jet Printing
Authors: Cao Changyong , Andrews Joseph B. , Franklin Aaron D.
Published: April 2017

Nanomaterials offer an attractive solution to the challenges faced for low‐cost printed electronics, with applications ranging from additively manufactured sensors to wearables. This study reports hysteresis‐free carbon nanotube thin‐film transistor (CNT‐TFTs) fabricated entirely using an aerosol jet printing technique; this includes the printing of all layers: semiconducting CNTs, metallic electrodes, and insulating gate dielectrics. It is shown that, under appropriate printing conditions, the gate dielectric ink can be reliably printed and yield negligible hysteresis and low threshold voltage in CNT‐TFTs. Flexible CNT‐TFTs on Kapton film demonstrate minimal variations in performance for over 1000 cycles of aggressive bending tests. New insights are also gained concerning the role of charge trapping in Si substrate‐supported devices, where exposure to high substrate fields results in irreversible degradation. This work is a critical step forward as it enables a completely additive, maskless method to fully print CNT‐TFTs of direct relevance for the burgeoning areas of flexible/foldable, wearable, and biointegrated electronics.
A Conductive Molecular Framework Derived Li2S/N,P‐Codoped Carbon Cathode for Advanced Lithium–Sulfur Batteries
Authors: Zhang Jun , Shi Ye , Ding Yu , Peng Lele , Zhang Wenkui , Yu Guihua
Published: April 2017

Li2S is one of the most promising cathode materials for Li‐ion batteries because of its high theoretical capacity and compatibility with Li‐metal‐free anode materials. However, the poor conductivity and electrochemical reactivity lead to low initial capacity and severe capacity decay. In this communication, a nitrogen and phosphorus codoped carbon (N,P–C) framework derived from phytic acid doped polyaniline hydrogel is designed to support Li2S nanoparticles as a binder‐free cathode for Li–S battery. The porous 3D architecture of N and P codoped carbon provides continuous electron pathways and hierarchically porous channels for Li ion transport. Phosphorus doping can also suppress the shuttle effect through strong interaction between sulfur and the carbon framework, resulting in high Coulombic efficiency. Meanwhile, P doping in the carbon framework plays an important role in improving the reaction kinetics, as it may help catalyze the redox reactions of sulfur species to reduce electrochemical polarization, and enhance the ionic conductivity of Li2S. As a result, the Li2S/N,P–C composite electrode delivers a stable capacity of 700 mA h g−1 with average Coulombic efficiency of 99.4% over 100 cycles at 0.1C and an areal capacity as high as 2 mA h cm−2 at 0.5C.
Acceleration of kinetic monte carlo simulations of free radical copolymerization: A hybrid approach with scaling
Authors: Gao Hanyu , Broadbelt Linda J. , Konstantinov Ivan A. , Arturo Steven G.
Published: April 2017

Kinetic Monte Carlo (KMC) has been widely used in the simulation of polymeric reactions. The power of KMC is highlighted by its ability to keep track of the length and sequence of every radical or polymer chain, while it is computationally more expensive than deterministic kinetic models. This paper introduces an acceleration method that significantly reduces the computational cost of KMC simulations, while keeping the same features as the full kinetic Monte Carlo simulations. Case studies are used to demonstrate the general applicability of this method to free radical copolymerization. © 2017 American Institute of Chemical Engineers AIChE J, 63: 4013–4021, 2017
In‐line monitoring of hydrogen peroxide in two‐phase reactions using raman spectroscopy
Authors: Ebrahimi Fatemeh , Viell Jörn , Mitsos Alexander , Mhamdi Adel , Brandhorst Markus
Published: April 2017

Hydrogen peroxide is an environment‐friendly oxidizer, which is used in several chemical processes. However, safety necessitates the determination and control of the concentration of hydrogen peroxide during oxidation reactions. We propose a methodology to monitor hydrogen peroxide in disperse two‐phase reaction mixtures based on in‐line Raman spectroscopy. We compare indirect hard modeling (IHM), peak integration (PI), and partial least squares (PLS). Building predictive PLS and PI calibration models is challenging, whereas the IHM calibration is easy to develop. These methods show good accuracy for known samples (root mean square error of cross validation [RMSECV] of 0.3–0.7 wt %) compared to the classic titration method (RMSECV of 0.4 wt %). After calibration, inline monitoring during reaction is performed demonstrating that the concentration of hydrogen peroxide can be successfully monitored in a fast and reliable way by Raman spectroscopy. The IHM seems to give slightly better inline predictions. © 2017 American Institute of Chemical Engineers AIChE J, 63: 3994–4002, 2017
Multi‐parametric linear programming under global uncertainty
Authors: Charitopoulos Vassilis M. , Papageorgiou Lazaros G. , Dua Vivek
Published: April 2017

Multi‐parametric programming has proven to be an invaluable tool for optimisation under uncertainty. Despite the theoretical developments in this area, the ability to handle uncertain parameters on the left‐hand side remains limited and as a result, hybrid, or approximate solution strategies have been proposed in the literature. In this work, a new algorithm is introduced for the exact solution of multi‐parametric linear programming problems with simultaneous variations in the objective function's coefficients, the right‐hand side and the left‐hand side of the constraints. The proposed methodology is based on the analytical solution of the system of equations derived from the first order Karush–Kuhn–Tucker conditions for general linear programming problems using symbolic manipulation. Emphasis is given on the ability of the proposed methodology to handle efficiently the LHS uncertainty by computing exactly the corresponding nonconvex critical regions while numerical studies underline further the advantages of the proposed methodology, when compared to existing algorithms. © 2017 The Authors AIChE Journal published by Wiley Periodicals, Inc. on behalf of American Institute of Chemical Engineers AIChE J, 63: 3871–3895, 2017
Case‐control study on occupational exposure to extremely low‐frequency electromagnetic fields and glioma risk
Authors: Carlberg Michael , Koppel Tarmo , Ahonen Mikko , Hardell Lennart
Published: April 2017

Background

Exposure to extremely low‐frequency electromagnetic fields (ELF‐EMF) was in 2002 classified as a possible human carcinogen, Group 2B, by the International Agency for Research on Cancer at WHO.

Methods

Life time occupations were assessed in case‐control studies during 1997‐2003 and 2007‐2009. An ELF‐EMF Job‐Exposure Matrix was used for associating occupations with ELF exposure (μT). Cumulative exposure (μT‐years), average exposure (μT), and maximum exposed job (μT) were calculated.

Results

Cumulative exposure gave for astrocytoma grade IV (glioblastoma multiforme) in the time window 1‐14 years odds ratio (OR) = 1.9, 95% confidence interval (CI) = 1.4‐2.6, p linear trend <0.001, and in the time window 15+ years OR = 0.9, 95%CI = 0.6‐1.3, p linear trend = 0.44 in the highest exposure categories 2.75+ and 6.59+ μT years, respectively.

Conclusion

An increased risk in late stage (promotion/progression) of astrocytoma grade IV for occupational ELF‐EMF exposure was found.
Evaluation of QTc in Rett syndrome: Correlation with age, severity, and genotype
Authors: Crosson Jane , Srivastava Siddharth , Bibat Genila M. , Gupta Siddharth , Kantipuly Aditi , Smith‐Hicks Constance , Myers Scott M. , Sanyal Abanti , Yenokyan Gayane , Brenner Joel , Naidu Sakkubai R.
Published: April 2017

Rett syndrome (RTT) is caused by MECP2 mutations, resulting in various neurological symptoms. Prolonged corrected QT interval (QTc) is also reported and is a speculated cause of sudden death in RTT. The purpose of this study was to correlate QTc in RTT patients with age, clinical severity, and genotype. 100 RTT patients (98 females, 2 males) with MECP2 mutations underwent baseline neurological evaluation (KKI‐RTT Severity Scale) and QTc measurement (standard 12 lead electrocardiogram) as part of our prospective natural history study. Mean QTc of the cohort was 422.6 msec, which did not exceed the normal values for age. 7/100 patients (7%) had QTc prolongation (>450 msec). There was a trend for increasing QTc with age and clinical severity (P = 0.09). No patients with R106C, R106W, R133C, R168*, R270*, R294*, R306C, R306H, and R306P mutations demonstrated QTc prolongation. There was a relatively high proportion of QTc prolongation in patients with R255* mutations (2/8, 25%) and large deletions (1/4, 25%). The overall presence of QTc prolongation did not correlate with mutation category (P = 0.52). Our findings demonstrate that in RTT, the prevalence of QTc prolongation is lower than previously reported. Hence, all RTT patients warrant baseline ECG; if QTc is prolonged, then cardiac followup is warranted. If initial QTc is normal, then annual ECGs, particularly in younger patients, may not be necessary. However, larger sample sizes are needed to solidify the association between QTc and age and clinical severity. The biological and clinical significance of mild QTc prolongation above the normative data remains undetermined.
Novel case of paternal paracentric inversion causing partial trisomy 13 and review of the literature
Authors: Douglas Chad , Smith Stephen A. , Rohena Luis
Published: April 2017

Partial trisomies have often been reported secondary to inversion mutations. These occurrences are most frequently associated with pericentric inversions. In this report, we describe the first documented case of partial trisomy 13 secondary to a parental paracentric inversion, in this case a paternal paracentric 13q inversion. Our Patient exhibits a variety of clinical findings including global developmental delay with intellectual disability, sensorineural hearing loss, bilateral congenital polar cataracts with associated foveal and optic nerve hypoplasia, right retinal detachment, atrial septal defect, absence of corpus callosum, celiac disease, microcephaly, as well as other dysmorphic features.
Effective BI‐DIME Ligand for Suzuki–Miyaura Cross‐Coupling Reactions in Water with 500 ppm Palladium Loading and Triton X
Authors: Patel Nitinchandra D. , Rivalti Daniel , Buono Frederic G. , Chatterjee Arindom , Qu Bo , Braith Stefan , Desrosiers Jean‐Nicolas , Rodriguez Sonia , Sieber Joshua D. , Haddad Nizar , Fandrick Keith R. , Lee Heewon , Yee Nathan K. , Busacca Carl A. , Senanayake Chris H.
Published: April 2017

An efficient, sustainable, and broadly applicable procedure has been developed for Suzuki–Miyaura cross‐coupling reactions in environmentally benign solvent (water) by employing as little as 500 ppm Pd(OAc)2 with a monophosphorus BI‐DIME ligand in the presence of inexpensive and commercially available nonionic surfactant Triton X‐100. This method was applied to a broad range of functionalized reaction partners, thereby affording excellent yields of the coupling products, including active pharmaceutical ingredients (APIs). An interesting kinetic study by using reaction calorimetry is also presented, which describes the effect of reaction parameters that enabled the low catalyst loading.
A Convergent Synthesis of the Triterpene Saponin Asiaticoside
Authors: Shao Wenbo , Cao Xin , Shen Lei , Zhang Fuyi , Yu Biao
Published: April 2017

Asiaticoside (1), namely, 2α,3β,23‐trihydroxy‐urs‐12‐en‐28‐oic‐O‐α‐l‐rhamnopyranosyl‐(1→4)‐β‐d‐glucopyranosyl‐(1→6)‐β‐d‐glucopyranoside, the major active biomarker of the traditional medicinal plant Centella asiatica, has been synthesized for the first time. The strategy features a late‐stage gold(I)‐catalyzed glycosidic condensation of a triterpenoid acid and a trisaccharide ortho‐hexynylbenzoate. The overall preparation required a total 31 steps with the longest linear sequence occurring over 14 steps in a 6 % overall yield and starting from ursolic acid (3β‐hydroxy‐urs‐12‐en‐28‐oic acid).
A New Benzodithiophene‐Based Cruciform Electron‐Donor–Electron‐Acceptor Molecule with Ambipolar/Photoresponsive Semiconducting and Red‐Light‐Emissive Properties
Authors: Wang Zhijie , Liu Zitong , Gao Zhenhua , Yang Sifen , Wang Yuancheng , Zhang Guanxin , Zhao Yongsheng , Zhang Deqing
Published: April 2017

The rational design of multifunctional materials with both emissive and semiconducting properties remains a challenge. A multifunctional cruciform donor–acceptor (D–A) molecule, 2,2′‐(((4,8‐bis(5‐(2‐ethylhexyl)thiophen‐2‐yl)benzo[1,2‐b:4,5‐b′]dithiophene‐2,6‐diyl)bis(thiophene‐5,2‐diyl))bis(methanylylidene))dimalononitrile (BDTTM), which contains a benzodithiophene as the central core, has been synthesized and, based on the output and transfer characteristics of the corresponding FETs, thin films of BDTTM exhibited ambipolar semiconducting behavior. Notably, FETs with thin films of BDTTM showed a photoresponse in both p‐ and n‐channels, and drain‐source‐current enhancement under white‐light irradiation could be detected, even at a low light intensity of 0.1 mW cm−2. Furthermore, BDTTM exhibited red‐light emission both in solution and as a crystalline solid. A microplate of BDTTM with red‐light emission displayed typical optical waveguiding behavior.
Are midsagittal tissue bridges predictive of outcome after cervical spinal cord injury?
Authors: Huber Eveline , Lachappelle Patrice , Sutter Reto , Curt Armin , Freund Patrick
Published: April 2017

T2‐weighted scans provided data on the extent and dynamics of neuronal tissue damage and midsagittal tissue bridges at the epicenter of traumatic cervical spinal cord lesions in 24 subacute tetraplegic patients. At 1 month postinjury, smaller lesion area and midsagittal tissue bridges identified those patients with lower extremity evoked potentials and better clinical recovery. Wider midsagittal tissue bridges and smaller lesions at 1 month post‐injury were associated with neurological and functional recovery at 1‐year follow‐up. Neuroimaging biomarkers of lesion size and midsagittal tissue bridges are potential outcome predictors and patient stratifiers in both subacute and chronic clinical trials. Ann Neurol 2017;81:740–748
Elasticity of the Transition State Leading to an Unexpected Mechanical Stabilization of Titin Immunoglobulin Domains
Authors: Yuan Guohua , Le Shimin , Yao Mingxi , Qian Hui , Zhou Xin , Yan Jie , Chen Hu
Published: April 2017

The giant protein titin plays a critical role in regulating the passive elasticity of muscles, mainly through the stochastic unfolding and refolding of its numerous immunoglobulin domains in the I‐band of sarcomeres. The unfolding dynamics of titin immunoglobulin domains at a force range greater than 100 pN has been studied by atomic force microscopy, while that at smaller physiological forces has not been measured before. By using magnetic tweezers, it is found that the titin I27 domain unfolds in a surprising non‐monotonic force‐dependent manner at forces smaller than 100 pN, with the slowest unfolding rate occurring around 22 pN. We further demonstrate that a model with single unfolding pathway taking into account the elasticity of the transition state can reproduce the experimental results. These results provide important novel insights into the regulation mechanism of the passive elasticity of muscle tissues.
Size‐Tunable Photothermal Germanium Nanocrystals
Authors: Sun Wei , Zhong Grace , Kübel Christian , Ali Feysal M. , Qian Chenxi , Wang Lu , Ebrahimi Manuchehr , Reyes Laura M. , Helmy Amr S. , Ozin Geoffrey A.
Published: April 2017

Germanium nanocrystals (ncGe) have not received as much attention as silicon nanocrystals (ncSi). However, Ge has demonstrated superiority over Si nanomaterials in some applications. Examples include, high charge–discharge rate lithium‐ion batteries,[1] small band‐gap opto‐electronic devices,[2] and photo‐therapeutics.[3] When stabilized in an oxide matrix (ncGe/GeOx), its high charge‐retention has enabled non‐volatile memories.[4] It has also found utility as a high‐capacity anode material for Li‐ion batteries with impressive stability.[5] Herein, we report an organic‐free synthesis of size‐controlled ncGe in a GeOx matrix as well as freestanding ncGe, via the thermal disproportionation of GeO prepared from thermally induced dehydration of Ge(OH)2. The photothermal effect of ncGe, quantified by Raman spectroscopy, is found to be size dependent and superior to ncSi. This advance suggests applications of ncGe in photothermal therapy, desalination, and catalysis.
Cu(I)@Fe3O4 nanoparticles supported on imidazolium‐based ionic liquid‐grafted cellulose: Green and efficient nanocatalyst for multicomponent synthesis of N‐sulfonylamidines and N‐sulfonylacrylamidines
Authors: Shojaei Salman , Ghasemi Zarrin , Shahrisa Aziz
Published: April 2017

A novel heterogeneous nanocatalyst was fabricated by depositing copper iodide and Fe3O4 nanoparticles on imidazolium‐based ionic liquid‐grafted cellulose and successfully characterized using Fourier transform infrared spectroscopy, thermogravimetric analysis, powder X‐ray diffraction, scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, vibrating sample magnetometry and flame atomic absorption spectrometry. It was employed to catalyse the reaction of terminal acetylenes with sulfonyl azides to afford highly reactive sulfonyl ketenimine intermediates which were subsequently trapped by secondary amines to give N‐sulfonylamidines and N‐sulfonylacrylamidines under solvent‐free conditions at room temperature. Good to excellent yields, very short reaction times, eco‐friendly processing, easy separation and reusability without significant loss of catalytic activity were found to be the notable features of this synthetic protocol.
Relationship between degree of polymerization and optical and thermal properties of fluorene in polycarbonate polymers
Authors: Kato Noriyuki , Ikeda Shinya , Hirakawa Manabu , Ito Hiroshi
Published: April 2017

The influences of average degree of polymerization (Dp) and terminal group on thermal and optical properties of high refractive indexed transparent polymers were investigated. In this study, 9,9‐bis[4–(2‐hydroxyethoxy) phenyl] fluorene (BPEF) homo polymer was selected because it has been used as a representative monomer in high refractive index polymers as well as its unique property. BPEF has stable amorphous phase and reacts like a polymer. Its unique reaction allows continuous investigation from monomer to polymer. For hydroxyl‐terminated polymer, the refractive index (nd) decreased with increasing Dp. On the other hand, for a phenolic‐terminated group, nd increased with increasing Dp, and both converged to same value in high Dp region. As for glass transition temperatures (Tg), both terminal group series were increased as Dp increased. Though Tg of hydroxyl‐terminated polymer was higher than that of phenolic‐terminated polymer in the low Dp region, both converged to the same value and the inverse number of Tg had linear correlation against the weight percentage of carbonyl groups (CO), which was calculated by Dp. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45042.
Physical and tensile properties of epoxy laminated magnetic bacterial cellulose nanocomposite films
Authors: Mashkour Mahdi , Moradabadi Zahra , Khazaeian Abolghasem
Published: April 2017

Despite many potential applications, the adverse impacts of magnetic nanoparticles on the tensile properties of magnetic cellulose papers and films are well established. On the other hand, water absorption and thickness swelling of cellulose materials are important limiting factors in many engineering applications. These challenges caused limited applications of magnetic cellulose nanocomposites. The aim of this study is to examine the possibility of modifying the physical and mechanical behaviors of magnetic bacterial cellulose films by epoxy resin lamination. Results showed that the tensile modulus and strength of the magnetic bacterial cellulose film, respectively, increased about 280% and 240% after epoxy lamination while they maintained their desirable magnetic and flexibility properties. Furthermore, the water absorption and thickness swelling of the epoxy laminated magnetic nanocomposite films, respectively, improved about 43% and 42%. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45118.
Nonthermal gelation of whey proteins induced by organic acids
Authors: Queirós Ana S. , Lopes‐da‐Silva José A.
Published: April 2017

Gelation of native whey proteins induced by organic acids at ambient temperature was investigated by fundamental small‐deformation oscillatory rheology. Gelling capability, gelation time, and final viscoelastic properties of the gel were dependent on type of acid, protein and acid concentrations, and pH value. Increasing organic acid concentration or increasing the pH (below pI) resulted in lower gelation times and higher gel modulus values. Differential scanning calorimetry demonstrated that the presence of acetic acid significantly reduced denaturation temperature and enthalpy implying a destabilization effect of the protein structure against thermal unfolding, contrarily to what was observed in the presence of HCl at similar pH values. The gelling ability and the denaturing effectiveness of the acids increase with increasing chain length of the alkyl chain, thus suggesting an important contribution of hydrophobic effects promoting denaturation and fostering the establishment of new interactions between the proteins leading to a nonthermal gelation process. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45134.
Synthesis, characterization, and properties of thermosets based on the cocuring of an acetylene‐terminated liquid‐crystal and silicon‐containing arylacetylene oligomer
Authors: Han Mengna , Guo Kangkang , Wang Fan , Zhu Yaping , Qi Huimin
Published: April 2017

A thermotropic acetylene‐terminated liquid‐crystal monomer, 2‐methyl‐1,4‐phenylene bis(4‐ethynylbenzoate) (MPBE), was prepared and used as a modification composition to react and cocure with a silicon‐containing arylacetylene (PSA) oligomer for improving PSA resin. The curing behavior of the PSA–MPBE resins were characterized by differential scanning calorimetry and Fourier transform infrared spectroscopy. The microstructure and morphology of the PSA–MPBE resins were investigated by scanning electron microscopy (SEM) and transmission electron microscopy. Their dynamic mechanical properties and thermostability were measured by dynamic mechanical analysis (DMA) and thermogravimetric analysis. The results indicate that the thermotropic acetylene‐terminated liquid‐crystal monomer melted into a schlieren texture. MPBE and PSA could copolymerize to fix the mesogenic domain in the crosslinked network and form a homogeneous‐phase sea‐island structure, which improved the rigidity and toughness of the materials. DMA showed that the storage modulus of the PSA–MPBE resins increased by about 400 MPa compared to the those of the pure components. The SEM experiments showed a noticeable change in the morphology, from a typical brittle fracture for the pure PSA to microplastic deformation behavior for the PSA–MPBE resins. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45141.
Hydrophilic modification of a poly(ether sulfone) flat‐sheet ultrafiltration membrane applied to coking sewage
Authors: Ouyang Shu Guang , Yao Jun Yan , Zhu Guang Heng Wei , Liu Zhao Yue , Feng Chi , Wang Gang
Published: April 2017

In this article, a new modified poly(ether sulfone) flat‐sheet ultrafiltration membrane, which is expected to effectively handle coking sewage, was prepared by an immersion precipitation phase‐inversion technique to settle the wastewater treatment problem in coking plants. Nanometer TiO2 particle–poly(ethylene glycol) (PEG) blends were used as additives to modify the membranes by a blending method. The effects of different PEG mass concentrations on the membrane structure and properties were studied. The pure water flux and chemical oxygen demand (COD) rejection rate were analyzed as aggregative indicators by the comprehensive evaluation method, and then, the optimal PEG mass concentration was determined. The results show that the best modified effect was obtained at a PEG mass concentration of 0.25%. When coking sewage in a secondary settling tank was filtered with such membranes, the COD rejection rate reached 90.68%, and the water flux was 127.21 L m−2 h−1. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45149.
Survival Disparities Associated with Congenital Diaphragmatic Hernia
Authors: Hinton Cynthia F. , Siffel Csaba , Correa Adolfo , Shapira Stuart K.
Published: April 2017

Background

We assessed sociodemographic and clinical factors that are associated with survival among infants with congenital diaphragmatic hernia (CDH).

Methods

Using data from the Metropolitan Atlanta Congenital Defects Program, we ascertained 150 infants born with CDH between 1979 and 2003 and followed via linkage with state vital records and the National Death Index. Kaplan–Meier survival probabilities and adjusted hazard ratios (HRs) were calculated for socioeconomic and clinical characteristics.

Results

Survival increased from 40 to 62% over the study period. White infants born before 1988 were 2.9 times less likely to survive than those born after 1988. Black infants' survival did not show significant improvement after 1988. White infants' survival was not significantly affected by poverty, whereas black infants born in higher levels of poverty were 2.7 times less likely to survive than black infants born in lower levels of neighborhood poverty. White infants with multiple major birth defects were 2.6 times less likely to survive than those with CDH alone. The presence of multiple defects was not significantly associated with survival among black infants.

Conclusions

Survival among infants and children with CDH has improved over time among whites, but not among blacks. Poverty is associated with lower survival among blacks, but not among whites. The presence of multiple defects is associated with lower survival among whites, but not among blacks. The differential effects of poverty and race should be taken into account when studying disparities in health outcomes. Birth Defects Research 109:816–823, 2017. © 2017 Wiley Periodicals, Inc.
Hydrogen sulfide attenuates homocysteine‐induced cognitive deficits and neurochemical alterations by improving endogenous hydrogen sulfide levels
Authors: Kumar Mohit , Modi Manish , Sandhir Rajat
Published: April 2017

Hyperomocysteinemia (HHcy) has been associated with mild cognitive impairment and dementia. Hydrogen sulfide (H2S) has been suggested to be an endogenous modulator of neuronal functions. However, the effect and mechanisms involved in beneficial effect of H2S has not been investigated in homocysteine (Hcy)‐induced cognitive deficits. This study has been designed to evaluate the effect of exogenous H2S on behavioral deficits and neurochemical alterations in HHcy animals. Hcy levels were significantly elevated in plasma, cortex, and hippocampus of Hcy administered animals. A progressive decline in memory functions and increased anxiolytic behavior was observed in HHcy animals. This was accompanied by decrease in endogenous H2S levels along with decreased activity of cystathionase (CSE) and cystathionine β‐synthase (CBS). However, a significant increase in CSE and CBS mRNAs was observed. In addition, the catecholamine and serotonin levels were reduced and the activity of monoamine oxidase A and B were increased in brain regions of HHcy animals. Haematoxylin and eosin staining revealed higher number of pyknotic cells in brain regions of HHcy animals. H2S administration was found to lower elevated plasma and brain Hcy levels. The activities of CBS, CSE, and levels of H2S were restored in HHcy animals administered H2S. Exogenous H2S also ameliorated behavioral deficits accompanied by significant increase in catecholamines. Histological analysis revealed normal cell morphology in Hcy‐treated animals supplemented with H2S. These results clearly demonstrate that the protective effect of H2S on Hcy‐induced cognitive deficits is mediated through increased catecholamine and H2S levels thereby suggesting its beneficial role in preventing HHcy‐induced neurodegeneration. © 2016 BioFactors, 43(3):434–450, 2017
Interpersonal early‐life trauma alters amygdala connectivity and sustained attention performance
Authors: Fortenbaugh Francesca C. , Corbo Vincent , Poole Victoria , McGlinchey Regina , Milberg William , Salat David , DeGutis Joseph , Esterman Michael
Published: April 2017

Introduction

Interpersonal early life trauma (I‐ELT) is associated with a myriad of functional impairments in adulthood, increased risk of drug addiction, and neuropsychiatric disorders. While deficits in emotional regulation and amygdala functioning are well characterized, deficits in general cognitive functioning have also been documented. However, the neural underpinnings of cognitive dysfunction in adults with a history of I‐ELT and the potential relationship between amygdala‐based functional connectivity and behavioral performance are currently poorly understood. This study examined how I‐ELT affects the cognitive and neural mechanisms supporting sustained attention.

Methods

A total of 66 Veterans (18 with and 48 without a history of I‐ELT) completed a nonemotional sustained attention task during functional MRI.

Results

The individuals with I‐ELT showed significant impairments in sustained attention (i.e., higher error rates, greater response variability). This cohort exhibited increased amygdala functional connectivity with the prefrontal cortex and decreased functional connectivity with the parahippocampal gyrus when compared to those without I‐ELT. These connections were significantly correlated with individual differences in sustained attention performance. Notably, classification analyses revealed that the pattern of amygdala connectivity across the whole brain was able to classify I‐ELT status with 70% accuracy.

Conclusion

These results provide evidence of a lasting negative impact for those with a history of I‐ELT on sustained attention ability. They also highlight a critical role for amygdala functioning in cognitive control and sustained attention for those with a history of I‐ELT, which may underlie the observed attention deficits in clinical assessments and cognitive tests involving both emotional and nonemotional stimuli.
Strategy‐based reasoning training modulates cortical thickness and resting‐state functional connectivity in adults with chronic traumatic brain injury
Authors: Han Kihwan , Davis Rebecca A. , Chapman Sandra B. , Krawczyk Daniel C.
Published: April 2017

Introduction

Prior studies have demonstrated training‐induced changes in the healthy adult brain. Yet, it remains unclear how the injured brain responds to cognitive training months‐to‐years after injury.

Methods

Sixty individuals with chronic traumatic brain injury (TBI) were randomized into either strategy‐based (N = 31) or knowledge‐based (N = 29) training for 8 weeks. We measured cortical thickness and resting‐state functional connectivity (rsFC) before training, immediately posttraining, and 3 months posttraining.

Results

Relative to the knowledge‐based training group, the cortical thickness of the strategy‐based training group showed diverse temporal patterns of changes over multiple brain regions (pvertex < .05, pcluster < .05): (1) increases followed by decreases, (2) monotonic increases, and (3) monotonic decreases. However, network‐based statistics (NBS) analysis of rsFC among these regions revealed that the strategy‐based training group induced only monotonic increases in connectivity, relative to the knowledge‐based training group (|Z| > 1.96, pNBS < 0.05). Complementing the rsFC results, the strategy‐based training group yielded monotonic improvement in scores for the trail‐making test (p < .05). Analyses of brain–behavior relationships revealed that improvement in trail‐making scores were associated with training‐induced changes in cortical thickness (pvertex < .05, pcluster < .05) and rsFC (pvertex < .05, pcluster < .005) within the strategy‐based training group.

Conclusions

These findings suggest that training‐induced brain plasticity continues through chronic phases of TBI and that brain connectivity and cortical thickness may serve as markers of plasticity.
Enhanced direct ethanol production by cofactor optimization of cell surface‐displayed xylose isomerase in yeast
Authors: Sasaki Yusuke , Takagi Toshiyuki , Motone Keisuke , Kuroda Kouichi , Ueda Mitsuyoshi
Published: April 2017

Xylose isomerase (XylC) from Clostridium cellulovorans can simultaneously perform isomerization and fermentation of d‐xylose, the main component of lignocellulosic biomass, and is an attractive candidate enzyme. In this study, we optimized a specified metal cation in a previously established Saccharomyces cerevisiae strain displaying XylC. We investigated the effect of each metal cation on the catalytic function of the XylC‐displaying S. cerevisiae. Results showed that the divalent cobalt cations (Co2+) especially enhanced the activity by 46‐fold. Co2+ also contributed to d‐xylose fermentation, which resulted in improving ethanol yields and xylose consumption rates by 6.0‐ and 2.7‐fold, respectively. Utility of the extracellular xylose isomerization system was exhibited in the presence of mixed sugar. XylC‐displaying yeast showed the faster d‐xylose uptake than the yeast producing XI intracellularly. Furthermore, direct xylan saccharification and fermentation was performed by unique yeast co‐culture system. A xylan‐degrading yeast strain was established by displaying two kinds of xylanases; endo‐1,4‐β‐xylanase (Xyn11B) from Saccharophagus degradans, and β‐xylosidase (XlnD) from Aspergillus niger. The yeast co‐culture system enabled fine‐tuning of the initial ratios of the displayed enzymes (Xyn11B:XlnD:XylC) by adjusting the inoculation ratios of Xylanases (Xyn11B and XlnD)‐displaying yeast and XylC‐displaying yeast. When the enzymes were inoculated at the ratio of 1:1:2 (1.39 × 1013: 1.39 × 1013: 2.78 × 1013 molecules), 6.0 g/L ethanol was produced from xylan. Thus, the cofactor optimization and the yeast co‐culture system developed in this study could expand the prospect of biofuels production from lignocellulosic biomass. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:1068–1076, 2017
Optimization‐based framework for resin selection strategies in biopharmaceutical purification process development
Authors: Liu Songsong , Gerontas Spyridon , Gruber David , Turner Richard , Titchener‐Hooker Nigel J. , Papageorgiou Lazaros G.
Published: April 2017

This work addresses rapid resin selection for integrated chromatographic separations when conducted as part of a high‐throughput screening exercise during the early stages of purification process development. An optimization‐based decision support framework is proposed to process the data generated from microscale experiments to identify the best resins to maximize key performance metrics for a biopharmaceutical manufacturing process, such as yield and purity. A multiobjective mixed integer nonlinear programming model is developed and solved using the ε‐constraint method. Dinkelbach's algorithm is used to solve the resulting mixed integer linear fractional programming model. The proposed framework is successfully applied to an industrial case study of a process to purify recombinant Fc Fusion protein from low molecular weight and high molecular weight product related impurities, involving two chromatographic steps with eight and three candidate resins for each step, respectively. The computational results show the advantage of the proposed framework in terms of computational efficiency and flexibility. © 2017 The Authors Biotechnology Progress published by Wiley Periodicals, Inc. on behalf of American Institute of Chemical Engineers Biotechnol. Prog., 33:1116–1126, 2017
Characterization of mammalian cell culture raw materials by combining spectroscopy and chemometrics
Authors: Trunfio Nicholas , Lee Haewoo , Starkey Jason , Agarabi Cyrus , Liu Jay , Yoon Seongkyu
Published: April 2017

Two of the primary issues with characterizing the variability of raw materials used in mammalian cell culture, such as wheat hydrolysate, is that the analyses of these materials can be time consuming, and the results of the analyses are not straightforward to interpret. To solve these issues, spectroscopy can be combined with chemometrics to provide a quick, robust and easy to understand methodology for the characterization of raw materials; which will improve cell culture performance by providing an assessment of the impact that a given raw material will have on final product quality. In this study, four spectroscopic technologies: near infrared spectroscopy, middle infrared spectroscopy, Raman spectroscopy, and fluorescence spectroscopy were used in conjunction with principal component analysis to characterize the variability of wheat hydrolysates, and to provide evidence that the classification of good and bad lots of raw material is possible. Then, the same spectroscopic platforms are combined with partial least squares regressions to quantitatively predict two cell culture critical quality attributes (CQA): integrated viable cell density and IgG titer. The results showed that near infrared (NIR) spectroscopy and fluorescence spectroscopy are capable of characterizing the wheat hydrolysate's chemical structure, with NIR performing slightly better; and that they can be used to estimate the raw materials’ impact on the CQAs. These results were justified by demonstrating that of all the components present in the wheat hydrolysates, six amino acids: arginine, glycine, phenylalanine, tyrosine, isoleucine and threonine; and five trace elements: copper, phosphorus, molybdenum, arsenic and aluminum, had a large, statistically significant effect on the CQAs, and that NIR and fluorescence spectroscopy performed the best for characterizing the important amino acids. It was also found that the trace elements of interest were not characterized well by any of the spectral technologies used; however, the trace elements were also shown to have a less significant effect on the CQAs than the amino acids. © 2017 The Authors Biotechnology Progress published by Wiley Periodicals, Inc. on behalf of American Institute of Chemical Engineers, 33:1127–1138, 2017
Poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) production from biodiesel by‐product and propionic acid by mutant strains of Pandoraea sp.
Authors: de Paula Fabrício C. , de Paula Carolina B. C. , Gomez José Gregório C. , Steinbüchel Alexander , Contiero Jonas
Published: April 2017

Pandoraea sp. MA03 wild type strain was subjected to UV mutation to obtain mutants unable to grow on propionic acid (PA) but still able to produce poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) [P(3HB‐co‐3HV)] from glycerol and PA at high 3HV yields. In shake flask experiments, mutant prp25 was selected from 52 mutants affected in the propionate metabolism exhibiting a conversion rate of PA into 3HV units of 0.78 g g−1. The use of crude glycerol (CG) plus PA or valeric acid resulted in a copolymer with 3HV contents varying from 21.9 to 30 mol% and 22.2 to 36.7 mol%, respectively. Fed‐batch fermentations were performed using CG and PA and reached a 3HV yield of 1.16 g g−1, which is 86% of the maximum theoretical yield. Nitrogen limitation was a key parameter for polymer accumulation reaching up to 63.7% content and 18.1 mol% of 3HV. Henceforth, mutant prp25 is revealed as an additional alternative to minimize costs and support the P(3HB‐co‐3HV) production from biodiesel by‐products. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:1077–1084, 2017
Analysis of Hydrocolloids in Crystalline Material
Authors: Herfurth Julia , Ulrich Joachim
Published: April 2017

Additives in foods are a commonly applied tool to optimize the product in terms of appearance, handling, quality, and production process. Such additives are ingredients which can change, e.g., the texture within the product and can also influence other main components in a formulation. It is demonstrated that the use of hydrocolloids as texturants in sweets influences the layer formation of crystallized sucrose for coating purposes. An incorporation of hydrocolloids in the crystalline materials changes the storage stability since the produced coated gels lose water, the so‐called syneresis. It is necessary to achieve a pure crystallized sugar layer and, therefore, to develop a tool to control the production process. A successful analysis of hydrocolloids, e.g., of gelatin, agar or carrageenans, in crystallized sucrose was performed by means of precipitation and coloring methods.