bluuebunny/crossref_metadata_2025_split huggingface dataset:
Die Suche nach einkernigem Gold(II) und seine mögliche Rolle in Photokatalyse und Medizinalchemie
Authors: Heinze Katja 
Published: September 2017

AbstractDie Chemie des Goldes wird von den allgegenwärtigen Oxidationsstufen +I und +III beherrscht. In einkernigen Goldverbindungen wird die Oxidationsstufe +II im Allgemeinen vermieden. In den letzten Jahren wurde Gold(II) wiederholt als Schlüsselintermediat in künstlichen Photosynthese‐Systemen mit Gold(III)‐Einheiten als Elektronenakzeptoren, in Gold‐katalysierten Photoredoxreaktionen und in der Radikalchemie vorgeschlagen. Dieser Kurzaufsatz fasst alle bestätigten und charakterisierten offenschaligen Gold(II)‐Komplexe zusammen. Aktuelle Erkenntnisse über Strukturmotive und Reaktivitätsmuster werden diskutiert. Spannende Entwicklungen auf den Gebieten der Photosynthese, der Photokatalyse und der Medizinalchemie werden umrissen.
Structure and Mechanism of the Monoterpene Cyclolavandulyl Diphosphate Synthase that Catalyzes Consecutive Condensation and Cyclization
Authors: Tomita Takeo , Kobayashi Masaya , Karita Yuma , Yasuno Yoko , Shinada Tetsuro , Nishiyama Makoto , Kuzuyama Tomohisa 
Published: September 2017

AbstractWe report the three‐dimensional structure of cyclolavandulyl diphosphate (CLPP) synthase (CLDS), which consecutively catalyzes the condensation of two molecules of dimethylallyl diphosphate (DMAPP) followed by cyclization to form a cyclic monoterpene, CLPP. The structures of apo‐CLDS and CLDS in complex with Tris, pyrophosphate, and Mg2+ ion were refined at 2.00 Å resolution and 1.73 Å resolution, respectively. CLDS adopts a typical fold for cis‐prenyl synthases and forms a homo‐dimeric structure. An in vitro reaction using a regiospecifically 2H‐substituted DMAPP substrate revealed the intramolecular proton transfer mechanism of the CLDS reaction. The CLDS structure and structure‐based mutagenesis provide mechanistic insights into this unprecedented terpene synthase. The combination of structural and mechanistic insights advances the knowledge of intricate terpene synthase‐catalyzed reactions.
Stoichiometric Reactions of CO2 and Indium‐Silylamides and Catalytic Synthesis of Ureas
Authors: Xu Maotong , Jupp Andrew R. , Stephan Douglas W. 
Published: September 2017

AbstractThe indium compounds In(N(SiMe3)2)2Cl⋅THF (2) and In(N(SiMe3)2)Cl2⋅(THF)n (3) were shown to react with CO2 to give [(Me3Si)2N)InX(μ‐OSiMe3)]2 (X=N(SiMe3)2 4, Cl 5). 0.05–2.0 mol % of the species 3 acts as a pre‐catalyst for the conversion of aryl and alkyl silylamines under CO2 (2–3 atm) to give the corresponding ureas in 70–99 % yields. A proposed mechanism is supported by experimental and computational data.
Asymmetric Iron‐Catalyzed C−H Alkylation Enabled by Remote Ligand meta‐Substitution
Authors: Loup Joachim , Zell Daniel , Oliveira João C. A. , Keil Helena , Stalke Dietmar , Ackermann Lutz 
Published: September 2017

AbstractHighly enantioselective iron‐catalyzed C−H alkylations by inner‐sphere C−H activation were accomplished with ample scope. High levels of enantiocontrol proved viable through a novel ligand design that exploits a remote meta‐substitution on N‐heterocyclic carbenes within a facile ligand‐to‐ligand H‐transfer C−H cleavage.
Encapsulation of Isolated Luminophores within Supramolecular Cages
Authors: Handke Marcel , Adachi Takuji , Hu Chunhua , Ward Michael D. 
Published: September 2017

AbstractThe sequestration of luminophores within supramolecular polyhedral compartments of a crystalline zeolite‐like hydrogen‐bonded framework illustrates a unique approach to limiting the self‐quenching ordinarily exhibited at the high concentrations achievable in this framework. A range of differently sized luminescent guests, namely coumarin 1, coumarin 4, fluorescein, [Ru(bpy)3]Cl2, and rhodamine B, can be encapsulated in amounts of up to one molecule per cage, equivalent to a concentration of 0.175 m, which is significantly higher than the concentration at which aggregation‐induced quenching occurs in other media. The luminescence spectra of the encapsulated guests are consistent with the presence of isolated monomers and the absence of self‐quenching. The emission color of the single crystals can be tuned readily from blue to red through the choice of guest molecules. These observations promise an approach to organic solid‐state lasing compounds if crystals of sufficient size and quality can be prepared.
Iridium‐Catalyzed Direct C−H Amidation Polymerization: Step‐Growth Polymerization by C−N Bond Formation via C−H Activation to Give Fluorescent Polysulfonamides
Authors: Jang Yoon‐Jung , Hwang Soon‐Hyeok , Choi Tae‐Lim 
Published: September 2017

AbstractWe report a powerful strategy for activation of C−H bonds to produce polysulfonamides by an atom‐economical and green method using iridium‐catalyzed direct C−H amidation polymerization (DCAP). After screening various directing groups, additives, silver salts, concentrations, and temperatures to optimize DCAP, high‐molecular‐weight (up to 149 kDa) and defect‐free polysulfonamides were synthesized from various bis‐sulfonyl azides. Although these polymers do not have conventional fluorescent conjugated cores, they emit blue light with large Stokes shifts and high quantum yields upon photoexcitation owing to an excited‐state intramolecular proton‐transfer process.
Doubly N‐Confused [36]Octaphyrin(1.1.1.1.1.1.1.1): Isomerization, Bis‐Metal Coordination, and Topological Chirality
Authors: Mitsuno Koki , Yoshino Takafumi , Gupta Iti , Mori Shigeki , Karasawa Satoru , Ishida Masatoshi , Furuta Hiroyuki 
Published: September 2017

AbstractA novel [36]octaphyrin analogue embedding two N‐confused pyrrole units demonstrated unique prototropy‐coupled isomerization between the Figure‐of‐eight and dumbbell conformers. Upon bis‐metal coordination, fixation of fully π‐conjugated Figure‐of‐eight structures was achieved as referred from the X‐ray crystal structure. Chirogenesis of the helical enantiomers was proved by intense circular dichroism (CD) response in the near infrared (NIR) region.
Mass Production and Pore Size Control of Holey Carbon Microcages
Authors: Zhang Lei , Liu Xiaoxiao , Dou Yuhai , Zhang Binwei , Yang Huiling , Dou Shixue , Liu Huakun , Huang Yunhui , Hu Xianluo 
Published: September 2017

AbstractArchitectural control of porous solids, such as porous carbon cages, has received considerable attention for versatile applications because of their ability to interact with liquids and gases not only at the surface, but throughout the bulk. Herein we report a scalable, facile spray‐pyrolysis route to synthesize holey carbon microcages with mosquito‐net‐like shells. Using the surfaces of water droplets as the growth templates, styrene–butadiene rubber macromolecules are controllably cross‐linked, and size‐controllable holes on the carbon shells are generated. The as‐formed carbon microcages encapsulating Si nanoparticles exhibit enhanced lithium‐storage performances for lithium‐ion batteries. The scalable, inexpensive synthesis of porous carbon microcages with controlled porosity and the demonstration of outstanding electrochemical properties are expected to extend their uses in energy storage, molecular sieves, catalysis, adsorbents, water/air filters, and biomedical engineering.
Fate of Worn‐Out Functional Teeth in the Upper Jaw Dentition of Sicyopterus japonicus (Gobioidei: Sicydiinae) During Tooth Replacement
Authors: Sahara Noriyuki , Moriyama Keita , Iida Midori , Watanabe Shun 
Published: September 2017

ABSTRACTMochizuki and Fukui (Jpn J Ichthyol 30 () 27–36) studied the development and replacement of the upper jaw teeth in a Japanese fish species, Sicyopterus japonicus (Gobioidei: Sicydiinae), and they reported that worn‐out functional teeth in the upper jaw were not shed outside the skin but were taken into the soft tissue of the upper jaw and completely resorbed there. To date, however, this phenomenon appears poorly documented. Furthermore, the mechanism for the resorption of these teeth remains to be determined. In this study, we examined this phenomenon by using 3D microcomputed tomography (m‐CT), scanning electron microscopy (SEM), and various techniques of light (LM) and electron (EM) microcopy. This study demonstrated that the upper jaw dentition of this fish was more or less simultaneously replaced with the replacement occurring during short time periods and that the lingual movement of the replacement teeth to the functional tooth position advanced simultaneously in a given row. Furthermore, our study also revealed that many worn‐out functional teeth were engulfed by the oral epithelium, invaginated into the lingual shallow ditch of the premaxilla, and were resorbed/degraded completely by numerous foreign body giant cells rather than by odontoclasts during periods of at least three intervals of tooth replacement. The complete resorption/degradation of worn‐out functional teeth in the soft tissue of the upper jaw suggests the possibility of the reuse of their components (minerals such as Ca and P, including Fe) for rapid and successional production of new replacement teeth in the upper jaw of adult S. japonicus. Anat Rec, 2017. © 2017 Wiley Periodicals, Inc. Anat Rec, 301:111–124, 2018. © 2017 Wiley Periodicals, Inc.
First Natural Endocranial Cast of a Fossil Snake (Cretaceous of Patagonia, Argentina)
Authors: Triviño Laura N. , Albino Adriana M. , Dozo María T. , Williams Jorge D. 
Published: September 2017

ABSTRACTIn this study, we describe a natural endocranial cast included in a partially preserved medium‐sized skull of the Upper Cretaceous South American snake Dinilysia patagonica. The endocast is composed of sedimentary filling of the cranial cavity in which the posterior brain, the vessels, the cranial nerves, and the inner ear surrounded by delicate semicircular canals, are represented. It is simple in form, with little differentiation between the three main areas (Forebrain, Midbrain, and Hindbrain), and without flexures. The nervous system is well preserved. The posterior brain surface is smooth, except for two small prominences that make up the cerebellum. A large inner ear is preserved on the right side; it consists of a voluminous central mass, the vestibule, which occupies most of the space defined by the three semicircular canals. In particular, the lateral semicircular canal is very close to the vestibule. This characteristic, in combination with the medium to large body size of Dinilysia, its large skull and dorsally exposed orbits, and vertebrae bearing a rather high neural spine on a depressed neural arch, suggests that this snake would have had a semifossorial lifestyle. Anat Rec, 2017. © 2017 Wiley Periodicals, Inc. Anat Rec, 301:9–20, 2018. © 2017 Wiley Periodicals, Inc.
Changes on the Pancreas in Experimental Diabetes and the Effect of Lycopene on These Changes: Pdx‐1, Ngn‐3, and Nestin Expressions
Authors: Sandikci Mustafa , Karagenc Levent , Yildiz Mustafa 
Published: September 2017

ABSTRACTThe aim of the present study was to investigate changes occurring in the number of beta cells, as well as the expressions of Ngn‐3, nestin and Pdx‐1 of pancreatic progenitor cells in the pancreas of experimentally‐induced adult diabetic rats and to determine the effect of orally‐administered lycopene on these changes. Following the administration of 50 mg/kg streptozotocin to rats, four groups of animals were established: control + corn oil, control + lycopene, diabetic + corn oil and diabetic + lycopene. The animals in the control + lycopene and diabetic + lycopene groups received 4 mg/kg lycopene for a period of four weeks. The expressions of insulin, Ngn‐3, nestin, and Pdx‐1 were determined through immunohistochemistry in sections taken from pancreas tissue samples at the end of the experiment. The number of insulin‐positive cells was found to be significantly low in the diabetic groups compared to the control groups. In addition, the presence of Ngn‐3 and nestin‐positive cells within the exocrine pancreas surrounding the islands was noted in the diabetic groups. Lycopene, in general did not have any effect in any of the parameters analyzed in the present study. It is suggested that these cells would function as stem cells to replace the lost beta‐cell population. It is also suggested that it is possible to demonstrate the antioxidant effects of lycopene in the pancreas of diabetic rats by increasing the dose and duration of lycopene administration. Anat Rec, 300:2200–2207, 2017. © 2017 Wiley Periodicals, Inc.
The Hospital Anxiety and Depression scale: Factor structure and psychometric properties in older adolescents and young adults with autism spectrum disorder
Authors: Uljarević Mirko , Richdale Amanda L. , McConachie Helen , Hedley Darren , Cai Ru Ying , Merrick Hannah , Parr Jeremy R. , Le Couteur Ann 
Published: September 2017

Despite the high frequency of anxiety and depression symptoms in individuals with Autism Spectrum Disorder (ASD) and a significant impact of these comorbidities on both individuals with ASD and their families, research on the validity of anxiety and depression measures in the ASD population is currently lacking. The aim of this study was to explore the psychometric properties of the Hospital Anxiety and Depression Scale [HADS; Zigmond & Snaith, ] in a sample of older adolescents and young adults with ASD. One hundred and fifty one participants (UK Transition longitudinal study: N = 106; 75 males, Mage = 16.04 years, SD = 1.28; Longitudinal Study of Australian Schools Leavers with ASD: N = 45, 30 males; Mage = 18.35 years, SD = 2.55) completed the HADS and a range of mental health and well‐being measures. Combination of the Principal Component Analysis and Parallel Analysis indicated two factors as an optimal solution in our sample, accounting for 43.77% of variance with factors being identical in terms of content with the structure found in the general population. Internal consistency was good for the HADS anxiety scale (HADS‐A; .82–.84) and acceptable for the HADS depression scale (HADS‐D; .60–.72). Convergent validity of both HADS‐A and HADS‐D scales was excellent and divergent validity was acceptable. Our study represents a significant contribution to the literature by providing an initial validation of the HADS in older adolescents and younger adults with ASD. Autism Res 2018, 11: 258–269. © 2017 International Society for Autism Research, Wiley Periodicals, Inc.Lay SummaryResearch on the validity of measurement of anxiety and depression in ASD is currently lacking. The aim of this study was to explore the properties of the Hospital Anxiety and Depression Scale (HADS) in a sample of 151 young people with ASD. Participants completed HADS and a range of mental health and well‐being measures. Encouragingly, our findings suggest that HADS provides a reliable and valid assessment of anxiety and depression in ASD.
Highly efficient antibacterial diblock copolypeptides based on lysine and phenylalanine
Authors: Su Xiaokai , Zhou Xinyu , Tan Zhengzhong , Zhou Chuncai 
Published: September 2017

AbstractA series of amphiphilic diblock copolypeptides (K30‐b‐F15, K30‐b‐F30, and K30‐b‐F45) were synthesized via N‐carboxy‐α‐amino‐anhydride ring‐opening polymerization. The copolypeptides had excellent antibacterial efficacy to both Gram positive (S. aureus) and Gram negative (E. coli) bacteria. The minimum inhibitory concentrations (MICs) against E. coli and S. aureus are 8 μg mL−1 and 2 μg mL−1, respectively, lower than most natural and artificial antimicrobial peptides (AMPs). The morphological changes of the bacteria treated with diblock copolypeptides were investigated by transmission electron microscopy; the results proved that the diblock copolypeptides had a similar antibacterial pore‐forming mechanism to natural cationic peptides. This was confirmed by laser scanning confocal microscope images. CCK‐8 results and the MICs showed that the diblock copolypeptides have high selectivity to bacteria, which suggested that the diblock copolypeptides could be excellent candidates to replace traditional antibiotics in future.
Formic acid as a secondary substrate for succinic acid production by metabolically engineered Mannheimia succiniciproducens
Authors: Ahn Jung Ho , Bang Junho , Kim Won Jun , Lee Sang Yup 
Published: September 2017

AbstractThere has been much effort exerted to reduce one carbon (C1) gas emission to address climate change. As one promising way to more conveniently utilize C1 gas, several technologies have been developed to convert C1 gas into useful chemicals such as formic acid (FA). In this study, systems metabolic engineering was utilized to engineer Mannheimia succiniciproducens to efficiently utilize FA. 13C isotope analysis of M. succiniciproducens showed that FA could be utilized through formate dehydrogenase (FDH) reaction and/or the reverse reaction of pyruvate formate lyase (PFL). However, the naturally favored forward reaction of PFL was found to lower the SA yield from FA. In addition, FA assimilation via FDH was found to be more efficient than the reverse reaction of PFL. Thus, the M. succiniciproducens LPK7 strain, which lacks in pfl, ldh, pta, and ack genes, was selected as a base strain. In silico metabolic analysis confirmed that utilization of FA would be beneficial for the enhanced production of SA and suggested FDH as an amplification target. To find a suitable FDH, four different FDHs from M. succiniciproducens, Methylobacterium extorquens, and Candida boidinii were amplified in LPK7 strain to enhance FA assimilation. High‐inoculum density cultivation using 13C labeled sodium formate was performed to evaluate FA assimilation efficiency. Fed‐batch fermentations of the LPK7 (pMS3‐fdh2 meq) strain was carried out using glucose, sucrose, or glycerol as a primary carbon source and FA as a secondary carbon source. As a result, this strain produced 76.11 g/L SA with the yield and productivity of 1.28 mol/mol and 4.08 g/L/h, respectively, using sucrose and FA as dual carbon sources. The strategy employed here will be similarly applicable in developing microorganisms to utilize FA and to produce valuable chemicals and materials from FA.
A role for the non‐receptor tyrosine kinase ACK1 in TNF‐alpha‐mediated apoptosis and proliferation in human intestinal epithelial caco‐2 cells
Authors: Zhao Xinmei , Lv Chaolan , Chen Shengbo , Zhi Fachao 
Published: September 2017

AbstractThe roles of tumor necrosis factor alpha (TNF‐alpha) and its mediators in cellular processes related to intestinal diseases remain elusive. In this study, we aimed to determine the biological role of activated Cdc42‐associated kinase 1 (ACK1) in TNF‐alpha‐mediated apoptosis and proliferation in Caco‐2 cells. ACK1 expression was knocked down using ACK1‐specific siRNAs, and ACK1 activity was disrupted using a small molecule ACK1 inhibitor. The Terminal deoxynucleotidyl transferase biotin‐dUTP Nick End Labeling (TUNEL) and the BrdU incorporation assays were used to measure apoptosis and cell proliferation, respectively. ACK1‐specific siRNA and the pharmacological ACK1 inhibitor significantly abrogated the TNF‐alpha‐mediated anti‐apoptotic effects and proliferation of Caco‐2 cells. Interestingly, TNF‐alpha activated ACK1 at tyrosine 284 (Tyr284), and the ErbB family of proteins was implicated in ACK1 activation in Caco‐2 cells. ACK1‐Tyr284 was required for protein kinase B (AKT) activation, and ACK1 signaling was mediated through recruiting and phosphorylating the down‐stream adaptor protein AKT, which likely promoted cell proliferation in response to TNF‐alpha. Moreover, ACK1 activated AKT and Src enhanced nuclear factor‐кB (NF‐кB) activity, suggesting a correlation between NF‐кB signaling and TNF‐alpha‐mediated apoptosis in Caco‐2 cells. Our results demonstrate that ACK1 plays an important role in modulating TNF‐alpha‐induced aberrant cell proliferation and apoptosis, mediated in part by ACK1 activation. ACK1 and its down‐stream effectors may hold promise as therapeutic targets in the prevention and treatment of gastrointestinal cancers, in particular, those induced by chronic intestinal inflammation.
Low‐Cost Noninvasive Real‐Time Imaging for Tubular Continuous‐Flow Crystallization
Authors: Jiang Mo , Braatz Richard D. 
Published: September 2017

AbstractA key design limitation to the effective monitoring and control of continuous crystallization processes is the ability to characterize crystals in real time. A low‐cost system composed of a basic stereomicroscope and video camera for the in situ imaging of sub‐millimeter crystals through curved walls of millifluidic tubular crystallizers is described. Real‐time videos taken for millimeter‐size slurry slugs are used to guide the experimental design for a recently developed multiphase‐flow crystallization process, including the improvement of the slug aspect ratio, visualization of crystal shapes, and observation of the extent of aggregation. Design considerations are also discussed for the use of multiple stereomicroscopes in other continuous‐flow tubular experiments.
Surface Modification of Polysulfone Membranes Using Poly(Acrylic Acid)‐Decorated Alumina Nanoparticles
Authors: Ghaemi Negin , Daraei Parisa , Palani Shiva 
Published: September 2017

AbstractAlumina nanoparticles were decorated with poly(acrylic acid) (PAA) as a hydrophilic polymer by thermal polymerization of acrylic acid in the presence of alumina nanoparticles. The obtained PAA‐decorated alumina (PAA‐d‐Al) nanoparticles were embedded in the polysulfone membrane matrix via nanofiller dispersion in the casting solution. The prepared membranes were characterized by porosity and water contact angle measurements, scanning electron and atomic force microscopy, and fouling tests using whey proteins. The presence of nanoparticles had significant effects on the membrane hydrophilicity and surface softness, resulting in fouling mitigation and flux recovery enhancement compared with the virgin polysulfone membrane. Moreover, the prepared membrane embedded with 0.25 wt % of PAA‐d‐Al nanofillers showed a remarkable durability and reusability during the filtration tests.
Photo‐Induced Assembly of a Luminescent Tetraruthenium Square
Authors: Laramée‐Milette Baptiste , Nastasi Francesco , Puntoriero Fausto , Campagna Sebastiano , Hanan Garry S. 
Published: September 2017

AbstractSelf‐assembly is a powerful synthetic tool that has led to the development of one‐, two‐ and three‐dimensional architectures. From MOFs to molecular flasks, self‐assembled materials have proven to be of great interest to the scientific community. Here we describe a strategy for the construction and de‐construction of a supramolecular structure through unprecedented photo‐induced assembly and dis‐assembly. The combination of two approaches, a [n×1]‐directional bonding strategy and a ligand photo‐dissociation strategy, allows the photo‐induced assembly of a polypyridyl RuII precursor into a discrete molecular square. Diffusion‐ordered NMR spectroscopy confirmed the synthesis of a higher volume species, while the identity of the species was established by high‐resolution mass spectrometry and single‐crystal X‐ray diffraction studies. The self‐assembled square is not obtained by classical thermal techniques in similar conditions, but is obtained only by light‐irradiation. The tetraruthenium square has an excited‐state lifetime (135 ns), 40 times that of its mononuclear precursor and its luminescence quantum yield (1.0 %) is three orders of magnitude higher. These remarkable luminescence properties are closely related to the relatively rigid square structure of the tetraruthenium assembly, as suggested by slow radiationless decay and transient absorption spectroscopy. The results described herein are a rare example of photo‐induced assembly and dis‐assembly processes, and can open the way to a new avenue in supramolecular chemistry, leading to the preparation of structurally organized supermolecules by photochemical techniques.