bluuebunny/crossref_metadata_2025 huggingface dataset:
Autoclaving‐Derived Surface Coating with In Vitro and In Vivo Antimicrobial and Antibiofilm Efficacies
Authors: Su Yajuan , Zhi Zelun , Gao Qiang , Xie Meihua , Yu Meng , Lei Bo , Li Peng , Ma Peter X.
Published: January 2017

Biomedical device‐associated infections which engender severe threat to public health require feasible solutions. In this study, block copolymers consisting of antimicrobial, antifouling, and surface‐tethering segments in one molecule are synthesized and grafted on polymeric substrates by a facile plasma/autoclave‐assisted method. Hetero‐bifunctional polyethylene glycol (PEG) with allyl and tosyl groups (APEG‐OTs) is first prepared. PEGs with different molecular weights (1200 and 2400 Da) are employed. Polyhexamethylene guanidine (PHMG) which has excellent broad‐spectrum antimicrobial activity and thermal/chemical stability, is conjugated with APEG‐OTs to generate the block copolymer (APEG‐PHMG). Allyl terminated PHMG (A‐PHMG) without PEG segments is also synthesized by reacting PHMG with allyl glycidyl ether. The synthesized copolymers are thermal initiated by autoclaving and grafted on plasma pretreated silicone surface, forming permanently bonded bottlebrush‐like coatings. Both A‐PHMG and APEG1200/2400‐PHMG coatings exhibit potent antimicrobial activity against gram‐positive/negative bacteria and fungus, whereas APEG1200/2400‐PHMG coatings show superior antifouling activity and long‐term reusability to A‐PHMG coating. APEG2400‐PHMG coating demonstrates the most effective in vitro antibiofilm and protein/platelet‐resistant properties, as well as excellent hemo/biocompatibility. Furthermore, APEG2400‐PHMG greatly reduces the bacteria number with 5‐log reduction in a rodent subcutaneous infection model. This rationally designed dual‐functional antimicrobial and antifouling coating has great potential in combating biomedical devices/implant‐associated infections.
Interface Engineering of a Compatible PEDOT Derivative Bilayer for High‐Performance Inverted Perovskite Solar Cells
Authors: Bao Xichang , Wang Junyi , Li Yuan , Zhu Dangqiang , Wu Ying , Guo Peipei , Wang Xuefei , Zhang Yongchao , Wang Jiuxing , Yip Hin‐Lap , Yang Renqiang
Published: January 2017

Interface engineering is an important aspect for the improvement of perovskite solar cells (PVSCs). The hole transport layer with good interface contact, transport capability, and matched energy level is indispensable and critical for high‐performance photovoltaic devices. Herein, anode interface engineering with an excellent compatible bilayer of poly(3,4‐ethylene dioxythiophene):poly(styrenesulfo‐nate)/poly(3,4‐ethylene dioxythiophene) (PEDOT:PSS/PEDOT) doped with grafted sulfonated‐acetone–formaldehyde lignin (PEDOT:GSL) via a low‐temperature and water‐soluble process is presented. As a water‐processable interface material, PEDOT:GSL exhibits higher conductivity, as well as better structural and electronic homogeneities compared with PEDTO:PSS. Consequently, the PEDOT:PSS/PEDOT:GSL bilayer with tuned energy level, optical properties, and the combination of the trap passivation of GSL at the anode/perovskite interface can greatly improve charge extraction ability and reduce the interface recombination. Simultaneously, the homogeneous perovskite film is fabricated through optimizing the annealing process. The device with the power conversion efficiency up to 17.80% is achieved, with 32.6% improvement compared to PEDOT:PSS‐only device (13.42%). Our success to achieve high‐performance inverted PVSCs provides new understanding of PEDOT:PSS, and also new guidelines for anode interface engineering to further advancement of PVSCs. This promising approach paves the way to realize solution processable highly efficient PVSCs for potential practical applications.
Chemical Vapor Deposition of Perovskites for Photovoltaic Application
Authors: Luo Paifeng , Zhou Shengwen , Xia Wei , Cheng Jigui , Xu Chengxi , Lu Yingwei
Published: January 2017

In recent years, high‐efficient and low‐cost perovskite solar cells (PSCs) have triggered a strong interest in the photovoltaic (PV) field. However, it is still challenging to develop cost‐effective perovskite fabrication technologies for meeting the demands of mass production. The latest developed tubular chemical vapor deposition (CVD) with high level of controllability, versatility, and scalability has emerged as a promising preparation method for perovskites. Thus here we summarize the recent progress of perovskites grown by CVD approaches, and give emphasis not only to the preparation methods and reaction mechanisms but also to the related structures and specific properties, and also highlight their prospective PV application.
Hydrogen Silsesquioxane‐Based Nanofluidics
Authors: Punniyakoti Sathyanarayanan , Sivakumarasamy Ragavendran , Vaurette Francois , Joseph Pierre , Nishiguchi Katsuhiko , Fujiwara Akira , Clément Nicolas
Published: January 2017

Nanofluidics show great promise for the control of small volumes and single molecules, especially for biological and energy applications. To build up more and more complex nanofluidics systems, a versatile and reproducible fabrication technique with nanometer precision alignment is desirable. In this article, two e‐beam lithography methods to fabricate nanofluidic channels based on hydrogen silsesquioxane, a high‐resolution negative‐tone inorganic resist, are presented. The robustness and versatility of the fabrication processes are demonstrated on silicon, glass, and flexible substrates. The high precision ability is illustrated with nanometric alignment of nanofluidic channels on gold nanoparticles and nanotransistor sensors, as well as for 3D nanofluidics prototyping. Furthermore, an unexpected extremely slow water evaporation rate (≈1 week for 300 μm long nanochannels) is noticed. This feature enables a simple and reliable manipulation of nanofluidic chips for various studies.
Synergetically Selective Toluene Sensing in Hematite‐Decorated Nickel Oxide Nanocorals
Authors: Suh Jun Min , Shim Young‐Seok , Kim Do Hong , Sohn Woonbae , Jung Youngmo , Lee Seon Yong , Choi Seokhoon , Kim Yeon Hoo , Jeon Jong‐Myeong , Hong Kootak , Kwon Ki Chang , Park Seo Yun , Kim Chulki , Lee Jong‐Heun , Kang Chong‐Yun , Jang Ho Won
Published: January 2017

The decoration of p‐type nickel oxide (NiO) with n‐type hematite (α‐Fe2O3) to achieve vertically ordered 1D nanostructures is an attractive strategy to enhance gas sensing properties. Herein, the authors report a facile method for α‐Fe2O3 decoration of the whole surface of vertical NiO nanorods. An NiO/Fe heterostructure is deposited in multiple steps using a glancing angle deposition method, which is followed by the oxidation of Fe into α‐Fe2O3. Thermally agglomerated α‐Fe2O3 nanoparticles are uniformly distributed on the whole surface of the NiO nanorods. Due to the α‐Fe2O3 decoration, the NiO nanorods exhibit a coral‐like rough surface and, more interestingly, their preferential crystallographic orientation changed from (111) to (200). Compared to bare NiO nanorods, the α‐Fe2O3‐decorated NiO nanocorals exhibit a 45.4 times higher response to 50 ppm toluene (C7H8) at 350 °C. Their theoretical detection limit for C7H8 is calculated to be ≈22 ppb. The observed unprecedented synergetic effects of α‐Fe2O3‐decorated NiO nanocorals for the extremely selective C7H8 sensing, as well as their facile synthetic route, establish a new perspective on heterostructured metal oxide 1D nanostructures for selective gas sensing.
Metal–free Decarboxylative Amination: An Alternative Approach Towards Regioselective Synthesis of β‐Carboline N‐fused Imidazoles
Authors: Singh Dharmender , Kumar Vipin , Devi Nisha , Malakar Chandi C. , Shankar Ravi , Singh Virender
Published: January 2017

Due to significant activity profile and natural abundance of β‐carboline containing alkaloids, β‐carboline N‐fused imidazole derivatives were designed and iodine assisted efficient approach was formulated for the regioselective synthesis of designed prototypes via decarboxylative amination of natural α‐amino acids with 1‐formyl pyrido[3,4‐b]indoles. Additionally, oxidative amination with benzyl amines was also investigated for the synthesis of these β‐carboline D‐ring containing frameworks.

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Lewis Acid‐Mediated [3+3] Annulation for the Construction of Substituted Pyrimidine and Pyridine Derivatives
Authors: Zhou Yao , Tang Zhonghe , Song Qiuling
Published: January 2017

A direct and single‐step procedure towards substituted pyrimidine and pyridine derivatives via Lewis acid‐promoted [3+3] annulation between 3‐ethoxycyclobutanones and enamines or amidines is presented. Diverse substituted pyrimidine and pyridine derivatives were obtained in good to high yields with a wide substrate scope.

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Urea‐Modified Carbon Nitrides: Enhancing Photocatalytic Hydrogen Evolution by Rational Defect Engineering
Authors: Lau Vincent Wing‐hei , Yu Victor Wen‐zhe , Ehrat Florian , Botari Tiago , Moudrakovski Igor , Simon Thomas , Duppel Viola , Medina Elise , Stolarczyk Jacek K. , Feldmann Jochen , Blum Volker , Lotsch Bettina V.
Published: January 2017

The primary amine groups on the heptazine‐based polymer melon, also known as graphitic carbon nitride (g‐C3N4), can be replaced by urea groups using a two‐step postsynthetic functionalization. Under simulated sunlight and optimum Pt loading, this urea‐functionalized carbon nitride has one of the highest activities among organic and polymeric photocatalysts for hydrogen evolution with methanol as sacrificial donor, reaching an apparent quantum efficiency of 18% and nearly 30 times the hydrogen evolution rate compared to the nonfunctionalized counterpart. In the absence of Pt, the urea‐derivatized material evolves hydrogen at a rate over four times that of the nonfunctionalized one. Since “defects” are conventionally accepted to be the active sites in graphitic carbon nitride for photocatalysis, the work here is a demonstrated example of “defect engineering,” where the catalytically relevant defect is inserted rationally for improving the intrinsic, rather than extrinsic, photocatalytic performance. Furthermore, the work provides a retrodictive explanation for the general observation that g‐C3N4 prepared from urea performs better than those prepared from dicyandiamide and melamine. In‐depth analyses of the spent photocatalysts and computational modeling suggest that inserting the urea group causes a metal‐support interaction with the Pt cocatalyst, thus facilitating interfacial charge transfer to the hydrogen evolving centers.
A High‐Efficiency Sulfur/Carbon Composite Based on 3D Graphene Nanosheet@Carbon Nanotube Matrix as Cathode for Lithium–Sulfur Battery
Authors: Zhang Ze , Kong Ling‐Long , Liu Sheng , Li Guo‐Ran , Gao Xue‐Ping
Published: January 2017

Carbon materials have attracted extensive attention as the host materials of sulfur for lithium–sulfur battery, especially those with 3D architectural structure. Here, a novel 3D graphene nanosheet–carbon nanotube (GN–CNT) matrix is obtained through a simple one‐pot pyrolysis process. The length and density of CNTs can be readily tuned by altering the additive amount of carbon source (urea). Specifically, CNTs are in situ introduced onto the surface of the graphene nanosheets (GN) and show a stable covalent interaction with GN. Besides, in the GN–CNT matrix, cobalt nanoparticles with different diameters exist as being wrapped in the top of CNTs or scattering on the GN surface, and abundant heteroatoms (N, O) are detected, both of which can help in immobilizing sulfur species. Such a rationally designed 3D GN–CNT matrix makes much more sense in enhancing the electrochemical performance of the sulfur cathode for rapid charge transfer and favorable electrolyte infiltration. Moreover, the presence of dispersed cobalt nanoparticles is beneficial for trapping lithium polysulfides by strong chemical interaction, and facilitating the mutual transformation between the high‐order polysulfides and low‐order ones. As a result, the S/GN–CNT composite presents a high sulfur utilization and large capacity on the basis of the S/GN–CNT composite as active material.
A continuum‐approach modeling of surface composition and ternary component distribution inside low fat milk emulsions during single droplet drying
Authors: Putranto Aditya , Foerster Martin , Woo Meng Wai , Selomulya Cordelia , Chen Xiao Dong
Published: January 2017

Surface composition of dairy powders plays an important role in determining the functionality. However, the surface composition may be different from the bulk composition because of component migration during drying. In this study, a comprehensive mathematical model has been developed to describe the phenomena. To the best of our knowledge, it is the first mathematical model which predicts the dynamics of surface composition during drying. The model consists of a set of equations of conservation of mass of water, lactose, protein, and fat as well as conservation of heat and momentum in which the effects of diffusion induced material migration and surface activity are incorporated. This model is applicable to describe the kinetics of surface composition of dairy droplets during drying. It suggests that both diffusion and protein surface activity govern the component segregation during drying. The study indicates that the model implementing the measured initial surface composition as the initial conditions generates more realistic profiles than the one using the bulk composition. The modeling confirms that the difference between the surface and bulk composition that occurs prior to drying is not primarily governed by diffusion, but the emulsion's atomization behavior seems to play an essential role in the overrepresentation of fat. © 2017 American Institute of Chemical Engineers AIChE J, 63: 2535–2545, 2017
Anin silicoevaluation of data‐driven optimization of biopharmaceutical processes
Authors: Wang Zhenyu , Georgakis Christos
Published: January 2017

Two methodological improvements of the design of dynamic experiments (C. Georgakis,Ind Eng Chem Res. 2013) for the modeling and optimization of (semi‐) batch processes are proposed. Their effectiveness is evaluated in two representative classes of biopharmaceutical processes. First, we incorporate prior process knowledge in the design of the experiments. Many batch processes and, in particular, biopharmaceutical processes are usually not understood completely to enable the development of an accurate knowledge‐driven model. However, partial process knowledge is often available and should not be ignored. We demonstrate here how to incorporate such knowledge. Second, we introduce an evolutionary modeling and optimization approach to minimize the initial number of experiments in the face of budgetary and time constraints. The proposed approach starts with the estimation of only a linear Response Surface Model, which requires the minimum number of experiments. Accounting for the model's uncertainty, the proposed approach calculates a process optimum that meets a maximum uncertainty constraint. © 2017 American Institute of Chemical EngineersAIChE J, 63: 2796–2805, 2017
The Pathways Between Socioeconomic Status and Adolescent Outcomes: A Systematic Review
Authors: Devenish Bethany , Hooley Merrilyn , Mellor David
Published: January 2017

Socioeconomic status (SES) is a significant risk factor for negative adolescent development outcomes. Identifying the pathways between SES and these outcomes may inform interventions for adolescents from this demographic. We conducted a systematic literature review of eight databases for studies investigating pathways between SES and adolescent psychosocial outcomes. A total of 59 articles met inclusion criteria. Significant risk factors identified include economic stress, chaos in the home, and violence in the community. These risk factors appear to be mediated through parent depression, conflict between parents, parenting practices, and adolescent resilience. Interventions focusing on the identified risk factors are recommended.
Potocki–Shaffer syndrome in a child without intellectual disability—The role of PHF21A in cognitive function
Authors: McCool Caroline , Spinks‐Franklin Adiaha , Noroski Lenora M. , Potocki Lorraine
Published: January 2017

Potocki–Shaffer syndrome is a contiguous gene deletion syndrome involving 11p11.2p12 and characterized by multiple exostoses, biparietal foramina, genitourinary anomalies in males, central nervous system abnormalities, intellectual disability, and craniofacial abnormalities. Current literature implicates haploinsufficiency of three genes (ALX4, EXT2, and PHF21A) in causing some of the cardinal features of PSS. We report a patient with multiple exostoses, biparietal foramina, and history of mild developmental delay. Cognitive and behavioral testing supported formal diagnoses of anxiety, verbal dyspraxia, articulation disorder, and coordination disorder, without intellectual disability. His facial features, though distinctive, were not typical of those observed in PSS. As the chromosomal deletion does not encompass PHF21A, this case lends further support that haploinsufficiency of PHF21A contributes to the intellectual disability and craniofacial abnormalities in PSS and that there are other genes in the region which likely contribute to the behavioral phenotype in this syndrome. © 2017 Wiley Periodicals, Inc.
Molecular and clinical analysis of ALPL in a cohort of patients with suspicion of Hypophosphatasia
Authors: Tenorio Jair , Álvarez Ignacio , Riancho‐Zarrabeitia Leyre , Martos‐Moreno Gabriel Á. , Mandrile Giorgia , de la Flor Crespo Monserrat , Sukchev Mikhail , Sherif Mostafa , Kramer Iza , Darnaude‐Ortiz María T. , Arias Pedro , Gordo Gema , Dapía Irene , Martinez‐Villanueva Julián , Gómez Rubén , Iturzaeta José Manuel , Otaify Ghada , García‐Unzueta Mayte , Rubinacci Alessandro , Riancho José A. , Aglan Mona , Temtamy Samia , Hamid Mohamed Abdel , Argente Jesús , Ruiz‐Pérez Víctor L. , Heath Karen E. , Lapunzina Pablo
Published: January 2017

Hypophosphatasia (HPP) is a rare autosomal dominant or recessive metabolic disorder caused by mutations in the tissue nonspecific alkaline phosphatase gene (ALPL). To date, over 300 different mutations in ALPL have been identified. Disease severity is widely variable with severe forms usually manifesting during perinatal and/or infantile periods while mild forms are sometimes only diagnosed in adulthood or remain undiagnosed. Common clinical features of HPP are defects in bone and tooth mineralization along with the biochemical hallmark of decreased serum alkaline phosphatase activity. The incidence of severe HPP is approximately 1 in 300,000 in Europe and 1 in 100,000 in Canada. We present the clinical and molecular findings of 83 probands and 28 family members, referred for genetic analysis due to a clinical and biochemical suspicion of HPP. Patient referrals included those with isolated low alkaline phosphatase levels and without any additional clinical features, to those with a severe skeletal dysplasia. Thirty‐six (43.3%) probands were found to have pathogenic ALPL mutations. Eleven previously unreported mutations were identified, thus adding to the ever increasing list of ALPL mutations. Seven of these eleven were inherited in an autosomal dominant manner while the remaining four were observed in the homozygous state. Thus, this study includes a large number of well‐characterized patients with hypophosphatasemia which has permitted us to study the genotype:phenotype correlation. Accurate diagnosis of patients with a clinical suspicion of HPP is crucial as not only is the disease life‐threatening but the patients may be offered bone targeted enzymatic replacement therapy. © 2017 Wiley Periodicals, Inc.
Einschaltbare Fluoreszenz in Tetra‐NHC‐Liganden durch Versteifung bei der Komplexbildung: eine Alternative zu aggregationsinduzierter Emission
Authors: Sinha Narayan , Stegemann Linda , Tan Tristan T. Y. , Doltsinis Nikos L. , Strassert Cristian A. , Hahn F. Ekkehardt
Published: January 2017

Mit den Tetraphenylethylen(TPE)‐verbrückten Tetraimidazolium‐Salzen [H4L‐Et](PF6)4 und [H4L‐Bu](PF6)4 wurden die zweikernigen AgI‐ und AuI‐Tetracarben‐Komplexe [Ag2(L‐Et)](PF6)2, [Ag2(L‐Bu)](PF6)2, [Au2(L‐Et)](PF6)2 und [Au2(L‐Bu)](PF6)2 synthetisiert. In verdünnter Lösung zeigen die Tetraimidazolium‐Salze fast keine Fluoreszenz (ΦF<1 %), während die NHC‐Komplexe stark fluoreszieren (ΦF bis zu 47 %). Die Komplexbildung führt zur Versteifung der TPE‐Einheit und zur Verhinderung der intramolekulare Rotation innerhalb der TPE‐Einheit. DFT‐Rechnungen bestätigen, dass die Metalle nicht an der Ausbildung der niedrigsten angeregten Singulett‐ und Triplett‐Zustände beteiligt sind, was auch die Abwesenheit von Phosphoreszenz erklärt. Die Versteifung durch Komplexbildung stellt eine Alternative zum bekannten aggregationsinduzierten Fluoreszenz‐“Einschalten” dar.
Ferromagnetic Interactions in Highly Stable, Partially Reduced TiO2: The S=2 State in Anatase
Authors: Chiesa Mario , Livraghi Stefano , Giamello Elio , Albanese Elisa , Pacchioni Gianfranco
Published: January 2017

We report direct evidence for quintuplet spin states in a particular kind of reduced TiO2 anatase obtained by the mild oxidation of TiB2 under hydrothermal conditions. Continuous‐wave and pulse EPR spectroscopy at X and Q band frequencies provide compelling evidence for the presence of S=2 states, stable in a wide range of temperatures up to room temperature. A tentative model, corroborated by spin‐polarized DFT calculations, is proposed, which consists of four ferromagnetically interacting Ti3+ ions with distances ranging from 0.5 nm to 0.8 nm and tetrahedral arrangement.
Biokatalytische Totalsynthese von Ikarugamycin
Authors: Greunke Christian , Glöckle Anna , Antosch Janine , Gulder Tobias A. M.
Published: January 2017

Die Natur stellt eine unerschöpfliche Diversität organischer Moleküle mit beeindruckenden Architekturen bereit, die starke und selektive Bioaktivitäten aufweisen. Jedoch bleibt das damit verbundene, enorme biomedizinische Potential oft unzugänglich, da die strukturelle Komplexität von Naturstoffen deren Synthese extrem anspruchsvoll macht. Dieses Problem kann mithilfe des von der Natur evolvierten enzymatischen Werkzeugkastens adressiert werden. In dieser Arbeit präsentieren wir eine biokatalytische Totalsynthese des Ikarugamycins. Unter Verwendung einer iterativen PKS/NRPS‐Maschinerie und zweier Reduktasen werden in einer biokatalytischen Eintopfreaktion fünfzehn C‐C‐ und zwei C‐N‐Bindungen aufgebaut. Durch Skalierung dieser Methode demonstrieren wir die Anwendbarkeit biokatalytischer Ansätze zur Ex‐vivo‐Synthese komplexer Naturstoffe.
From Genome to Proteome to Elucidation of Reactions for All Eleven Known Lytic Transglycosylases from Pseudomonas aeruginosa
Authors: Lee Mijoon , Hesek Dusan , Dik David A. , Fishovitz Jennifer , Lastochkin Elena , Boggess Bill , Fisher Jed F. , Mobashery Shahriar
Published: January 2017

An enzyme superfamily, the lytic transglycosylases (LTs), occupies the space between the two membranes of Gram‐negative bacteria. LTs catalyze the non‐hydrolytic cleavage of the bacterial peptidoglycan cell‐wall polymer. This reaction is central to the growth of the cell wall, for excavating the cell wall for protein insertion, and for monitoring the cell wall so as to initiate resistance responses to cell‐wall‐acting antibiotics. The nefarious Gram‐negative pathogen Pseudomonas aeruginosa encodes eleven LTs. With few exceptions, their substrates and functions are unknown. Each P. aeruginosa LT was expressed as a soluble protein and evaluated with a panel of substrates (both simple and complex mimetics of their natural substrates). Thirty‐one distinct products distinguish these LTs with respect to substrate recognition, catalytic activity, and relative exolytic or endolytic ability. These properties are foundational to an understanding of the LTs as catalysts and as antibiotic targets.
Hyper‐Crosslinkers Lead to Temperature‐ and pH‐Responsive Polymeric Nanogels with Unusual Volume Change
Authors: Zhou Ning , Cao Xiaoyan , Du Xuewen , Wang Huaimin , Wang Ming , Liu Shuang , Nguyen Khang , Schmidt‐Rohr Klaus , Xu Qiaobing , Liang Gaolin , Xu Bing
Published: January 2017

Hydrogels consisting of carboxylic acid groups and N‐isopropylacrylamide as pendants on their polymeric network usually exhibit volume expansion upon deprotonation or volume contraction when being heated. Demonstrated here is an anti‐intuitive case of a hydrogel containing multiple carboxylic acid groups at each crosslinking point in the polymeric network, which shrinks upon increasing pH from 1 to 7 at 37 °C or expands upon heating from 25 to 37 °C at pH 1. The unexpected volume change originates from the high percentage of the crosslinker in the polymers, as detected by solid‐state 13C NMR spectroscopy. In addition, the volume changes are thermally reversible. As the first example of the use of functional hyper‐crosslinkers to control the pH and thermal responses of nanogels, this work illustrates a new way to design soft materials with unusual behaviors.
Rational Design and Synthesis of Efficient Sunscreens To Boost the Solar Protection Factor
Authors: Losantos Raúl , Funes‐Ardoiz Ignacio , Aguilera José , Herrera‐Ceballos Enrique , García‐Iriepa Cristina , Campos Pedro J. , Sampedro Diego
Published: January 2017

Skin cancer incidence has been increasing in the last decades, but most of the commercial formulations used as sunscreens are designed to protect only against solar erythema. Many of the active components present in sunscreens show critical weaknesses, such as low stability and toxicity. Thus, the development of more efficient components is an urgent health necessity and an attractive industrial target. We have rationally designed core moieties with increased photoprotective capacities and a new energy dissipation mechanism. Using these scaffolds, we have synthesized a series of compounds with tunable properties suitable for their use in sunscreens, and enhanced properties in terms of stability, light energy dissipation, and toxicity. Moreover, some representative compounds were included in final sunscreen formulations and a relevant solar protection factor boost was measured.
Cycloparaphenylenes and Their Catenanes: Complex Macrocycles Unveiled by Ion Mobility Mass Spectrometry
Authors: Zhang Wen , Abdulkarim Ali , Golling Florian E. , Räder Hans Joachim , Müllen Klaus
Published: January 2017

The insoluble product mixture obtained from cycloparaphenylene (CPP) synthesis from Suzuki coupling and reductive aromatization was analyzed. Traditional mass spectrometry suggests a homologous series of macrocycles with 12 to 84 phenylene units. Ion‐mobility mass spectrometry, however, unravels an unexpected complexity of isomers with identical chemical formula, but different topologies. Whereas macrocycles containing up to 30 phenylene units show only one structure, the homologue with 36 phenylene units forms at least four different isomers with significant molecular size differences. They can be assigned to catenanes composed of CPPs with 2×18 and 12+24 phenylene units together with the ordinary [36]CPP macrocycle. Most likely, a trefoil knot of the CPP with 36 moieties is also present. For the first time, catenanes can be elucidated in a simple reaction mixture by analyzing their ions in the gas phase, an analysis which lies beyond the scope of traditional analytical methods.
Modular Assembly of Spirocarbocyclic Scaffolds through Pd0‐Catalyzed Intermolecular Dearomatizing [2+2+1] Annulation of Bromonaphthols with Aryl Iodides and Alkynes
Authors: Zuo Zhijun , Wang Hui , Fan Liangxin , Liu Jingjing , Wang Yaoyu , Luan Xinjun
Published: January 2017

A novel palladium(0)‐catalyzed dearomatizing [2+2+1] spiroannulation of 1‐bromo‐2‐naphthols with aryl iodides and alkynes was developed for the rapid assembly of spiro[indene‐1,1′‐naphthalen]‐2′‐ones. This three‐component cascade reaction was realized through consecutive Catellani‐type C−H activation, unsymmetrical biaryl coupling, alkyne migratory insertion, and arene dearomatization. The potential utility of our method is illustrated by the one‐step construction of the polycyclic skeletons of dalesconols A and B from alkyne‐tethered aryl iodides and 1‐bromo‐2‐naphthol.
Biocatalytic Total Synthesis of Ikarugamycin
Authors: Greunke Christian , Glöckle Anna , Antosch Janine , Gulder Tobias A. M.
Published: January 2017

Nature provides an inexhaustible diversity of small organic molecules with beautiful molecular architectures that have strong and selective inhibitory activities. However, this tremendous biomedical potential often remains inaccessible, as the structural complexity of natural products can render their synthetic preparation extremely challenging. This problem is addressable by harnessing the biocatalytic procedures evolved by nature. In this work, we present an enzymatic total synthesis of ikarugamycin. The use of an iterative PKS/NRPS machinery and two reductases has allowed the construction of 15 carbon–carbon and 2 carbon–nitrogen bonds in a biocatalytic one‐pot reaction. By scaling‐up this method we demonstrate the applicability of biocatalytic approaches for the ex vivo synthesis of complex natural products.
Protonation versus Oxonium Salt Formation: Basicity and Stability Tuning of Cyanoborate Anions
Authors: Kerpen Christoph , Sprenger Jan A. P. , Herkert Lorena , Schäfer Marius , Bischoff Lisa A. , Zeides Pierre , Grüne Matthias , Bertermann Rüdiger , Brede Franziska A. , Müller‐Buschbaum Klaus , Ignat'ev Nikolai V. , Finze Maik
Published: January 2017

Anhydrous H[BH2(CN)2] crystallizes from acidic aqueous solutions of the dicyanodihydridoborate anion. The formation of H[BH2(CN)2] is surprising as the protonation of nitriles requires strongly acidic and anhydrous conditions but it can be rationalized based on theoretical data. In contrast, [BX(CN)3]− (X=H, F) gives the expected oxonium salts (H3O)[BX(CN)3] while (H3O)[BF2(CN)2]/H[BF2(CN)2] is unstable. H[BH2(CN)2] forms chains via N−H⋅⋅⋅N bonds in the solid state and melts at 54 °C. Solutions of H[BH2(CN)2] in the room‐temperature ionic liquid [EMIm][BH2(CN)2] contain the [(NC)H2BCN−H⋅⋅⋅NCBH2(CN)]− anion and are unusually stable, which enabled the study of selected spectroscopic and physical properties. [(NC)H2BCN−H⋅⋅⋅NCBH2(CN)]− slowly gives H2 and [(NC)H2BCN−BH(CN)2]−. The latter compound is a source of the free Lewis acid BH(CN)2, as shown by the generation of [BHF(CN)2]− and BH(CN)2⋅py.
Design of Artificial Glycosidases: Metallopeptides that Remove H Antigen from Human Erythrocytes
Authors: Yu Zhen , Cowan James Allan
Published: January 2017

Catalysts that promote carbohydrate degradation have a wide range of potential applications, but the use of either enzyme glycosidases or small‐molecule catalysts in biological systems raises significant challenges. Herein, we demonstrate a novel strategy for the design of synthetic agents that mimic natural glycosidases and address current problems for biological use. This strategy is illustrated by application to the development of potential blood substitutes for the rare Bombay blood type that is characterized by a deficiency of H2 antigen. Metallopeptides with 16 to 20 amino acids were constructed as artificial fucosidases that exhibit selective carbohydrate cleavage reactivity toward l‐fucose over d‐glucose. Selective fucose cleavage from the H2‐antigen saccharide enables efficient removal of H2 antigen from erythrocytes and thereby accomplishes the conversion of regular human type‐O blood into a potential blood substitute for the rare Bombay blood type.
Alginate‐gelatin blend with embedded voids for controlled release applications
Authors: Banerjee Arindam , Patra Subhajit , Ganguly Somenath
Published: January 2017

Alginate gel is known for its potential use in the controlled release of drugs, and as a 3‐D structure for tissue harvesting. In this paper, the tuning of the performance of alginate gel by blending gelatin in the aqueous phase, and introducing bubbles in a regular alignment are discussed. Monodisperse bubbles in millimetre or submillimeter size were introduced into the aqueous suspension of the blend prior to gelation, using a novel fluidic arrangement. The CaCl2 solution, added as the crosslinker diffused into the lamella, forming a rigid structure of calcium alginate. The effective blending of gelatin in alginate provided benefits of both the biopolymers in the final product. The benefits are the excellent absorption capacity of alginate and the mechanical strength of gelatin in the blend. The self‐aligned voids enabled further tuning of absorption capacity and/or rate of release. Also, the presence of voids enhanced the elastomeric quality of the composite structure. The uptake of Vitamin B12 solution was measured gravimetrically, and the release in PBS buffer on a shaker was studied using UV‐vis spectrophotometer. For different loadings of void and gelatin, the absorption capacity, mechanical strength and the compression behavior were analysed. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44787.
Surface modification and antimicrobial properties of cellulose nanocrystals
Authors: Bespalova Yulia , Kwon Dong , Vasanthan Nadarajah
Published: January 2017

A novel and simple surface modification of cellulose nanocrystals (CNC) was performed by chloroacetylation and subsequent reaction with tertiary amines to form quaternary ammonium modified CNCs. The acetylation of CNC and quaternary ammonium modified CNCs was confirmed using IR spectroscopy and solid state NMR spectroscopy. The 13C NMR spectrum of quaternary ammonium modified CNC showed several additional resonances ranging from 14.5 ppm to 58.0 ppm compared to 13C NMR spectrum of pure CNC, suggesting that alkyl chains have been added to the pure CNC. The disc diffusion method was used to evaluate the antimicrobial properties of quaternary ammonium modified CNCs. It was found that modified CNCs with alkyl chain longer than ten carbons are effective antimicrobial agents against Staphylococcus aureus and E. coli bacteria. These CNCs can be chemically modified to tailor the properties to improve dispersion in the polymer matrix. This will expand the application of CNC as a reinforcing material. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44789.
Continuous manufacturing of nanofiber yarn with the assistance of suction wind and rotating collection via needleless melt electrospinning
Authors: Ma Xiaolu , Zhang Liyan , Tan Jing , Qin Yongxin , Chen Hongbo , He Wanlin , Yang Weimin , Li Haoyi
Published: January 2017

Nanofiber yarn was continuously manufactured by a needleless melt‐electrospinning method. The suction wind speed was the most important factor influencing the final fiber diameter and determining whether the fibers could be gathered into a well‐aligned strand. The twisting process of the yarn was performed by the adjustment of ratio of the speed of the collecting roller to the speed of the rotating disk. The results show that the higher the assisting suction wind speed was, the smaller the fiber diameter was. The smallest average fiber diameter of 440 nm was obtained at a suction wind speed of 30 m/s. Furthermore, the smaller the ratio of the speed of the collecting roller to the speed of the rotating disk was, the larger the twisting angle of the prepared yarn was. The largest twisting angle obtained in this study was 43 ° at the greatest ratio of the speed of the collecting roller to the speed of the rotating disk. The X‐ray diffraction results show that the alignment degree of the nanofiber twisting and the crystallinity increased with increasing twisting angle. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44820.
Improved mechanical strength of p(AAm) interpenetrating hydrogel network due to microgranular cellulose embedding
Authors: Sahiner Nurettin , Demirci Sahin
Published: January 2017

Here, polyacrylamide [p(AAm)]‐based hydrogels were synthesized via redox polymerization technique in the presence of various amounts of microgranular cellulose (MGCell) such as 0, 10, 25, 50, 100, and 150 mg MGCell/g. The synthesized p(AAm)‐MGCell interpenetrating hydrogels were characterized spectroscopically by FTIR, thermally by TGA analysis, and mechanically via dynamic mechanical measurements. Furthermore, the effect of the amount of MGCell in p(AAm) hydrogels on swelling% (S%) degree and mechanical strength was investigated. It was found that the S% was decreased from 727 ± 9 to 667 ± 6, 642 ± 8 and 619 ± 10, 568 ± 6 for p(AAm)‐MGCell interpenetrating network hydrogels containing 10, 50, 100, and 150 mg MGCell, respectively. On the other hand, the Young modulus of p(AAm)‐based hydrogels increased from 2.8 ± 0.2 kPa to 3.1 ± 0.03, 3.4 ± 0.1, 3.6 ± 0.3 and 4.3 ± 0.3 kPa with the incorporation of 10, 50, 100, and 150 mg MGCell into p(AAm) hydrogels. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44854.
H∞ Preview Control of A Class of Uncertain Discrete‐Time Systems
Authors: Li Li , Liao Fucheng , Deng Jiamei
Published: January 2017

This paper investigates the problem of H∞ preview tracking control with robust performance for uncertain discrete‐time systems. In order to avoid applying the difference operator to the time‐varying matrix, by taking advantage of the difference between the system state variables, input variables, and the corresponding auxiliary variables, instead of the usual difference between system states, an augmented error system including previewed information is constructed, which converts the tracking problem into a regulator problem. A sufficient condition based on the free‐weighting matrices technique and the Lyapunov stability theory is derived for the robust asymptotic stability of uncertain systems. Moreover, a state feedback control law with preview action design method is obtained via the linear matrix inequality approach. Based on these, a state observer for preview control systems is formulated. Previewable reference signals are fully utilized through reformulation of the output equation while designing the state observer. The proposed construction method of augmented error system is applicable to uncertain discrete‐time systems in which the uncertainties are general. Also an integrator is introduced to ensure the closed‐loop system tracking performance with no static error. The numerical results also show the effectiveness of the preview control law for uncertain systems in the paper.
Transition from oxcarbazepine to eslicarbazepine acetate: A single center study
Authors: Mäkinen Jussi , Rainesalo Sirpa , Peltola Jukka
Published: January 2017

Objectives

There is limited clinical evidence for comparison between oxcarbazepine (OXC) and eslicarbazepine acetate (ESL) in terms of tolerability, or how to execute the change from OXC to ESL. We report the process of transitioning patients with focal epilepsy from previous OXC treatment to ESL due to tolerability problems. The rationale for change from OXC is reported, and the outcome with respective to this rationale is analyzed in terms of tolerability and efficacy.

Materials and Methods

The subjects were transitioned overnight from OXC to ESL in a hospital inpatient setting. An evaluation of the effects of the transition was made after 1 and 3 months. All adverse events (AEs) were recorded following the transition period. Subjects were classified by outcome in terms of AEs.

Results

Twenty‐three subjects were transitioned from OXC to ESL. Fifteen patients OXC‐related AEs reduced significantly after transition. Particularly, most of (93%) the AEs presented in the morning resolved after transition to ESL. No patient had an increase in seizure frequency following the transition. The incidence of ESL‐related AEs was 39% at 1 month and 13% at 3 month follow‐up; however, all patients continued ESL throughout the study period.

Conclusions

This study demonstrates that patients suffering from OXC‐related AEs improve in terms of tolerability after a switch to ESL with maintaining seizure control. This improvement is more pronounced if the OXC‐related AEs are most evident following morning dosing of OXC. Transition can be safely executed in an outpatient setting.
Taming hyperactive hDNase I: Stable inducible expression of a hyperactive salt‐ and actin‐resistant variant of human deoxyribonuclease I in CHO cells
Authors: Lam Cynthia , Santell Lydia , Wilson Blair , Yim Mandy , Louie Salina , Tang Danming , Shaw David , Chan Pamela , Lazarus Robert A. , Snedecor Brad , Misaghi Shahram
Published: January 2017

While the most common causes of clonal instability are DNA copy number loss and silencing, toxicity of the expressed protein(s) may also induce clonal instability. Human DNase I (hDNase I) is used therapeutically for the treatment of cystic fibrosis (CF) and may have potential benefit for use in systemic lupus erythematosus (SLE). hDNase I is an endonuclease that catalyzes degradation of extracellular DNA and is inhibited by both salt and G‐actin. Engineered versions of hDNase I, bearing multiple point mutations, which renders them Hyperactive, Salt‐ and Actin‐Resistant (HSAR‐hDNase I) have been developed previously. However, constitutive expression of HSAR‐hDNase I enzymes has been very challenging and, despite considerable efforts and screening thousands of clones, no stable clone capable of constitutive expression had been obtained. Here, we developed a regulated expression system for stable expression of an HSAR‐hDNase I in Chinese Hamster Ovary (CHO) cells. The HSAR‐hDNase I clones were stable and, upon induction, expressed enzymatically functional protein. Our findings suggest that degradation of host's DNA mediated by HSAR‐hDNase I during cell division is the likely cause of clonal instability observed in cells constitutively expressing this protein. Purified HSAR‐hDNase I was both hyperactive and resistant to inhibition by salt and G‐actin, resulting in an enzyme having ca. 10‐fold greater specific activity and the potential to be a superior therapeutic agent to wild type (WT) hDNase I. Furthermore, the ability to regulate hDNase I expression has enabled process development improvements that achieve higher cell growth and product titers while maintaining product quality. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 32:523–533, 2017
Application of Biocatalysis to on‐DNA Carbohydrate Library Synthesis
Authors: Thomas Baptiste , Lu Xiaojie , Birmingham William R. , Huang Kun , Both Peter , Reyes Martinez Juana Elizabeth , Young Robert J. , Davie Christopher P. , Flitsch Sabine L.
Published: January 2017

DNA‐encoded libraries are increasingly used for the discovery of bioactive lead compounds in high‐throughput screening programs against specific biological targets. Although a number of libraries are now available, they cover limited chemical space due to bias in ease of synthesis and the lack of chemical reactions that are compatible with DNA tagging. For example, compound libraries rarely contain complex biomolecules such as carbohydrates with high levels of functionality, stereochemistry, and hydrophilicity. By using biocatalysis in combination with chemical methods, we aimed to significantly expand chemical space and generate generic libraries with potentially better biocompatibility. For DNA‐encoded libraries, biocatalysis is particularly advantageous, as it is highly selective and can be performed in aqueous environments, which is an essential feature for this split‐and‐mix library technology. In this work, we demonstrated the application of biocatalysis for the on‐DNA synthesis of carbohydrate‐based libraries by using enzymatic oxidation and glycosylation in combination with traditional organic chemistry.
Depression/suicide risks for overweight/obese teens with BD
Authors: Knopf Alison
Published: January 2017

Unlike adults with bipolar disorder (BD), adolescents with the condition are no more likely than controls to be overweight or obese, researchers have found. However, adolescents with BD who are obese are three times more likely to attempt suicide or have major depressive disorder than controls without the disorder. In addition, all teens with BD have the risk of becoming adults who are obese.
Scaling the Velocity Gradients in a Vessel Agitated by a Rushton Turbine
Authors: Šulc Radek , Ditl Pavel
Published: January 2017

Scaling of fluctuation velocity gradients was investigated in a vessel agitated by a Rushton turbine. By using turbulence spectrum analysis, it was derived that, for high Reynolds numbers, the squared dimensionless local fluctuation velocity gradient is proportional to the squared impeller Reynolds number. This theoretical prediction was tested on experimental data in the range Re = 50 000 – 110 556. The calculated isotropy ratios are independent of the impeller Reynolds number, and their inter‐ratios depend on the ratio of the axial and the radial components of the fluctuation velocity. The experiments also support the idea that the isotropy ratios differ from zone to zone in an agitated vessel.
Localization improvement of deuterium uptake in hydrogen/deuterium exchange in proteins
Authors: Babić Darko , Smith David M.
Published: January 2017

We present a procedure for localization of deuterium uptake from overlapping proteolytic peptides to contiguous protein parts called segments. A system of linear equations expressing experimental peptide uptakes in segments cannot be solved by ordinary methods because of insufficient rank and/or linearly dependent peptides. Solvable segments are identified, and their uptakes and associated variances are evaluated by using the Moore‐Penrose pseudoinverse. The method also allows consistency check of experimental data and detection of outliers. The conditions for segment solvability are formulated in a peptide graph. From the peptide graph, it is easy to find more useful information hidden in the experimental data, like sums or differences of unsolvable segment uptakes. Expected localization gain was estimated from simulations with random peptide arrangements. The recently proposed averaging method (Keppel TR, Weis DD. J. Am. Soc. Mass Spectrom. 2015; 26: 547) for resolution of exchange halftimes was extended to resolution of uptakes and combined with the present approach to achieve maximum uptake localization, which is also consistent with experimental data.
Aliphatic C−C Bond Cleavage in α‐Hydroxy Ketones by a Dioxygen‐Derived Nucleophilic Iron–Oxygen Oxidant
Authors: Bhattacharya Shrabanti , Rahaman Rubina , Chatterjee Sayanti , Paine Tapan K.
Published: January 2017

A nucleophilic iron–oxygen oxidant, formed in situ in the reaction between an iron(II)–benzilate complex and O2, oxidatively cleaves the aliphatic C−C bonds of α‐hydroxy ketones. In the cleavage reaction, α‐hydroxy ketones without any α‐C−H bond afford a 1:1 mixture of carboxylic acid and ketone. Isotope labeling studies established that one of the oxygen atoms from dioxygen is incorporated into the carboxylic acid product. Furthermore, the iron(II) complex cleaves an aliphatic C−C bond of 17‐α‐hydroxyprogesterone affording androstenedione and acetic acid. The O2‐dependent aliphatic C−C bond cleavage of α‐hydroxy ketones containing no α‐C−H bond bears similarity to the lyase activity of the heme enzyme, cytochrome P450 17A1 (CYP17A1).