bluuebunny/crossref_metadata_2025_split huggingface dataset:
Accuracy of low‐dose proton CT image registration for pretreatment alignment verification in reference to planning proton CT
Authors: Cassetta Roberto , Piersimoni Pierluigi , Riboldi Marco , Giacometti Valentina , Bashkirov Vladmir , Baroni Guido , Ordonez Caesar , Coutrakon George , Schulte Reinhard 
Published: April 2019

AbstractPurposeProton CT (pCT) has the ability to reduce inherent uncertainties in proton treatment by directly measuring the relative proton stopping power with respect to water, thereby avoiding the uncertain conversion of X‐ray CT Hounsfield unit to relative stopping power and the deleterious effect of X‐ ray CT artifacts. The purpose of this work was to further evaluate the potential of pCT for pretreatment positioning using experimental pCT data of a head phantom.MethodsThe performance of a 3D image registration algorithm was tested with pCT reconstructions of a pediatric head phantom. A planning pCT simulation scan of the phantom was obtained with 200 MeV protons and reconstructed with a 3D filtered back projection (FBP) algorithm followed by iterative reconstruction and a representative pretreatment pCT scan was reconstructed with FBP only to save reconstruction time. The pretreatment pCT scan was rigidly transformed by prescribing random errors with six degrees of freedom or deformed by the deformation field derived from a head and neck cancer patient to the pretreatment pCT reconstruction, respectively. After applying the rigid or deformable image registration algorithm to retrieve the original pCT image before transformation, the accuracy of the registration was assessed. To simulate very low‐dose imaging for patient setup, the proton CT images were reconstructed with 100%, 50%, 25%, and 12.5% of the total number of histories of the original planning pCT simulation scan, respectively.ResultsThe residual errors in image registration were lower than 1 mm and 1° of magnitude regardless of the anatomic directions and imaging dose. The mean residual errors ranges found for rigid image registration were from −0.29 ± 0.09 to 0.51 ± 0.50 mm for translations and from −0.05 ± 0.13 to 0.08 ± 0.08 degrees for rotations. The percentages of sub‐millimetric errors found, for deformable image registration, were between 63.5% and 100%.ConclusionThis experimental head phantom study demonstrated the potential of low‐dose pCT imaging for 3D image registration. Further work is needed to confirm the value pCT for pretreatment image‐guided proton therapy.
Construction of Nanozyme‐Hydrogel for Enhanced Capture and Elimination of Bacteria
Authors: Sang Yanjuan , Li Wei , Liu Hao , Zhang Lu , Wang Huan , Liu Zhengwei , Ren Jinsong , Qu Xiaogang 
Published: April 2019

AbstractThe widespread multidrug resistance resulting from the abuse of antibiotics motivates researchers to explore alternative methods to treat bacterial infections. Recently, the emergence of nanozymes has provided a potential approach to combat bacteria. Such nanozymes can mimic the functions of natural enzymes to induce the production of highly toxic reactive oxygen species (ROS) as an antibacterial. However, the lack of effective interaction between nanozymes and bacteria, and the intrinsic short lifetime and diffusion distance of ROS greatly compromise their bactericidal activity. Furthermore, the dead bacteria left in the infected area can give rise to unexpected tissue inflammation. Herein, for the first time, a nanozyme‐hydrogel is constructed to realize reinforced antibacterials. The nanozyme‐hydrogel with the traits of positive charge and macropore can capture and restrict bacteria in the range of ROS destruction. Significantly, by combining the near‐infrared photothermal property of nanozymes, the nanozyme‐hydrogel can achieve a synergistic bactericidal effect. More importantly, the nanozyme‐hydrogel can eliminate bacteria and reduce the risk of inflammation. In consequence, the current work manifests an original strategy to improve the antibacterial performance of nanozymes, concurrently promote wound healing.
Modern Scattering‐Type Scanning Near‐Field Optical Microscopy for Advanced Material Research
Authors: Chen Xinzhong , Hu Debo , Mescall Ryan , You Guanjun , Basov D. N. , Dai Qing , Liu Mengkun 
Published: April 2019

AbstractInfrared and optical spectroscopy represents one of the most informative methods in advanced materials research. As an important branch of modern optical techniques that has blossomed in the past decade, scattering‐type scanning near‐field optical microscopy (s‐SNOM) promises deterministic characterization of optical properties over a broad spectral range at the nanoscale. It allows ultrabroadband optical (0.5–3000 µm) nanoimaging, and nanospectroscopy with fine spatial (<10 nm), spectral (<1 cm−1), and temporal (<10 fs) resolution. The history of s‐SNOM is briefly introduced and recent advances which broaden the horizons of this technique in novel material research are summarized. In particular, this includes the pioneering efforts to study the nanoscale electrodynamic properties of plasmonic metamaterials, strongly correlated quantum materials, and polaritonic systems at room or cryogenic temperatures. Technical details, theoretical modeling, and new experimental methods are also discussed extensively, aiming to identify clear technology trends and unsolved challenges in this exciting field of research.
Möglichkeiten und Limitierungen verschiedener Trenntechniken zur Analyse der Proteinkorona
Authors: Weber Claudia , Morsbach Svenja , Landfester Katharina 
Published: April 2019

AbstractDie gebildete Proteinkorona ist für das Verhalten von Nanoträgern im biologischen System mitverantwortlich. Die Aufklärung der Bildung und des Einflusses der Proteinkorona auf die biologische Antwort ist daher entscheidend. Ergebnisse der Proteinkorona‐Charakterisierung können jedoch nicht ohne Weiteres untereinander verglichen werden, da es zahlreiche verschiedene Verfahren zur Probenvorbereitung gibt, die jeweils für unterschiedliche Materialien und Fragestellungen geeignet sind. Abhängig von der verwendeten Methode wird der Nanoträger‐Protein‐Komplex auf bestimmte Weise verändert, sodass der individuelle Einfluss der Probenvorbereitung auf die Proteinkorona berücksichtigt werden muss. Ziel dieses Kurzaufsatzes ist es daher, einen Überblick über Probevorbereitungsverfahren für die Analyse der Proteinkorona zu geben und ihren Einfluss auf das Ergebnis zu beurteilen, besonders im Hinblick auf die eingeführten Begriffe “weiche” und “harte” Proteinkorona. Im Fokus liegen dabei vor allem die am häufigsten verwendeten Techniken wie Zentrifugation, magnetische sowie chromatographische Trennungen.
Nanocomposites based on epoxidized poly(styrene‐co‐butadiene) rubber and graphene nanoplatelets
Authors: Kumar Vineet , Schneider Uwe , Rose Viktor , Giese Ulrich 
Published: April 2019

ABSTRACTNanofillers play as reinforcing agents of the polymer matrix. The reinforcement and dynamic mechanical properties of nanocomposites based on filled epoxidized‐poly(styrene‐co‐butadiene) rubber are investigated. The modification of the polymer matrix allows improvement in polymer–filler interaction, and thus the mechanical properties of the vulcanizates. Here, the rubber was modified by introducing the epoxy functional groups in the matrix. The quantification for epoxidation rate was analyzed by means of NMR and ~8.8% epoxidation was optimized. The nanocomposites were prepared by melt‐mixing technique. The influence of rubber epoxidation in enhancing dynamic mechanical and thermal properties was demonstrated. Stable filler networking using exfoliated graphene nanoplatelets (xg C750) and carbon black (CB‐N234) in epoxidized rubber is described through multihysteresis measurements. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47802.
Metal‐containing Ionic Liquid/Polyacrylonitrile‐derived Carbon Nanofibers for Oxygen Reduction Reaction and Flexible Zn–Air Battery
Authors: Wang Cancan , Li Qi , Guo Jiangna , Ren Yongyuan , Zhang Juewen , Yan Feng 
Published: April 2019

AbstractPractical applications of Zn–air batteries are usually limited by sluggish kinetics of oxygen reduction reaction. Replacing Pt‐based catalysts with convenient, efficient and low‐cost materials to boost oxygen reduction reaction is highly desirable. Herein, a class of Fe−N co‐doped carbon nanofibers is successfully synthesized by pyrolysis of polyacrylonitrile/metal‐containing ionic liquid‐based electrospun films. The ionic liquids act as porogen to provide multiscale pores as well as activator to bring carbon nanofibers active sites. The catalyst possessing appropriate active sites and unique 3D porous architecture exhibits remarkable long‐term stability and electrocatalytic activity. Particularly, the catalyst maintains a shape of membrane after carbonization, manifesting its direct use as air electrode without binders. It is notable that an all solid‐state Zn–air battery based on the carbon nanofibers exhibits good flexibility, indicating its promising application as wearable devices.
Rolled‐Up Monolayer Graphene Tubular Micromotors: Enhanced Performance and Antibacterial Property
Authors: Zhang Biran , Huang Gaoshan , Wang Lu , Wang Tianbo , Liu Lu , Di Zengfeng , Liu Xuanyong , Mei Yongfeng 
Published: April 2019

AbstractThe motion of catalytic tubular micromotors are driven by the oxygen bubbles generated from chemical reaction and is influenced by the resistance from the liquid environment. Herein, we fabricated a rolled‐up graphene tubular micromotor, in which the graphene layer was adopted as the outmost surface. Due to the hydrophobic property of the graphene layer, the fabricated micromotor performed a motion pattern that could escape from the attraction from the bubbles. In addition, Escherichia coli and Staphylococcus culture experiments proved that the graphene outer surface displays antibacterial property. Considering the bubble‐avoiding and antibacterial properties, the rolled‐up graphene tubular micromotor holds great potential for various applications such as in vivo drug delivery and biosensors.
Diastereoselective Total Syntheses of (±)‐Caseabalansin A and (±)‐18‐Epicaseabalansin A via Intramolecular Robinson‐type Annulation
Authors: Okutomi Naoto , Matsuzawa Akinobu , Sugita Kazuyuki 
Published: April 2019

AbstractHighly diastereoselective total syntheses of (±)‐caseabalansin A (1) and (±)‐18‐epicaseabalansin A (2) are described in this paper. We revealed that the intramolecular Robinson‐type annulation of an alkynone was effective in the stereocontrolled construction of the bicyclic skeleton of 1 and 2. Further transformation of the resulting enone, including diastereoselective reduction by LiAlH(OtBu)3, hydroxy‐group‐directed hydrogenation, cyclization to form the cyclic acetal moiety, and introduction of a side chain by a C(sp3)−C(sp3) Stille coupling reaction, resulted in the total syntheses of (±)‐1 and (±)‐2.
Improvement of the acid resistance, catalytic efficiency, and thermostability of nattokinase by multisite‐directed mutagenesis
Authors: Liu Zhongmei , Zhao Han , Han Laichuang , Cui Wenjing , Zhou Li , Zhou Zhemin 
Published: April 2019

AbstractNattokinase (NK) is a serine protease of the subtilisin family; as a potent fibrinolytic enzyme, it is potentially useful for thrombosis therapy. For NK to be applied as an oral medicine for the treatment of cardiovascular diseases, it must overcome the extremely acidic environments of the gastrointestinal tract despite its limited acidic stability. In this study, three strategies were adopted to improve the acid resistance of NK: (a) Surface charge engineering, (b) sequence alignment, and (c) mutation based on the literature. Eleven variants were constructed and four single‐point mutations were screened out for their distinctive catalytic properties: Q59E increased the specific activity; S78T improved the acid stability; Y217K enhanced the acid and thermal stabilities; and N218D improved the thermostability. Based on these observations, multipoint variants were constructed and characterized, and one variant with better acid stability, catalytic efficiency, and thermostability was obtained. Molecular dynamics simulation was carried out to clarify the molecular mechanism of the increased stability of S78T and Y217K mutants under acidic conditions. This study explored effective strategies to engineer acid resistance of NK; moreover, the NK variants with better catalytic properties found in this study have potential applications for the medical industry.
Sustainable financing practices through green bonds: What affects the funding size?
Authors: Barua Suborna , Chiesa Micol 
Published: April 2019

AbstractFinancing through the supply‐driven green bonds market has significantly surged in recent years. In this paper, we examine the factors influencing the size of financing though green bond supply, using cross‐section OLS regressions on a global dataset for 8 years (2010–2017) sourced from Bloomberg. We consider a set of tridimensional factors: bond characteristics, issuer characteristics, and market characteristics and examine their effects on issue size. Alongside whole sample estimation, we produce year‐wise estimations to realize the evolution and persistence of the effects over time. We then produce estimates across rating grades of the bonds. Finally, we carry Blinder–Oaxaca decomposition to see if average issue size has significantly changed over time and whether the factors considered can explain the difference. We find a large number of factors affecting issue size asymmetrically; however, many of the effects do not persist over time and are heterogeneous across rating grades. In contrast to the aggregate market trend, we find no evidence of increases in average issue size in the recent year. Furthermore, the average financing size is found significantly lower for high‐grade bonds. The paper provides a basis for encouraging green bond supply, particularly considering the rating of the bonds and the issuers.
Clinical outcomes of percutaneous mitral valve repair with MitraClip for the management of functional mitral regurgitation
Authors: Marmagkiolis Konstantinos , Hakeem Abdul , Ebersole Douglas G. , Iliescu Cezar , Ates Ismail , Cilingiroglu Mehmet 
Published: April 2019

AbstractObjectivesTo evaluate the safety and efficacy of percutaneous mitral valve repair for the management of functional mitral insufficiency.BackgroundSevere FMR is present in 25–30% of patients with heart failure and is an independent predictor of mortality and hospitalizations in patients with both ischemic and nonischemic cardiomyopathy. MitraClip therapy has been approved for high surgical risk patients with primary mitral regurgitation. Recent studies including two randomized trials have yielded conflicting results in terms of its clinical efficacy and outcomes for FMR. A quantitative evaluation and synthesis of this information are essential in elucidating the role of MitraClip repair for FMR.MethodsWe performed a literature search using PubMed, EMBASE, and Cochrane Central Register of Controlled Trials from September 2008 to September 2018. Studies comparing percutaneous mitral valve repair using the MitraClip device against conservative therapy for the management of functional mitral regurgitation were included.ResultsSeven studies with 1,174 patients in MitraClip group and 1,015 patients in medical therapy group met inclusion criteria. The 12‐month mortality in the MitraClip group was 18.4% compared with 25.9% in the medical therapy group (odds ratio [OR]: 0.65 [0.50, 0.86]; p < .002). The rate of readmission at 12 months was 29.9% in the MitraClip group compared with 54.1% in the medical therapy group (OR: 040 [0.32–0.49]; p < .0001. The prognostic efficacy of MitraClip repair appears to be more substantial over longer follow‐up period over medical therapy alone.ConclusionsBased on the results of this meta‐analysis, percutaneous mitral valve repair with MitraClip appears to be superior to medical therapy for symptomatic moderate‐to‐severe functional mitral insufficiency. Further clinical research is needed to identify the ideal patient subgroups who receive maximum benefit with the MitraClip therapy.
Versatile and Homogeneous DNA Tetraplex Platform for Constructing Label‐Free Logic Devices: From Design to Application
Authors: Huang Dan , Yang Chunrong , Yao Ye , Li Jicheng , Guo Chen , Chen Jianchi , Zhang Yi , Yang Shu , Yang Qianfan , Tang Yalin 
Published: April 2019

AbstractThe design of DNA‐based logic circuits has become an active research field in DNA nanotechnology and holds great potential in intelligent bioanalysis. To date, although many DNA‐based logic systems have been realized, the implementation of advanced logic functions is still challenging, especially with simple and homogeneous compositions. Herein, by integrating two DNA tetraplex structures (G‐quadruplex and i‐motif), a completely label‐free logic platform with high scalability was established, with which a series of advanced functions were realized, including arithmetic (adders and subtractors) and nonarithmetic ones (majority and dual‐transfer gates). Furthermore, the platform was also applied as an intelligent biosensor to coanalyze two cancer‐related micro‐RNAs with high sensitivities and specificities. Considering the excellent versatility, expandability, and biocompatibility, the platform may promote the development of DNA computing and hold great potential in multiparameter sensing and medical diagnosis.
Photosalient Effect of Diarylethene Crystals of Thiazoyl and Thienyl Derivatives
Authors: Nakagawa Yuma , Morimoto Masakazu , Yasuda Nobuhiro , Hyodo Kengo , Yokojima Satoshi , Nakamura Shinichiro , Uchida Kingo 
Published: April 2019

AbstractThe photoresponse of diarylethene crystals is found to depend on the intensity of UV light, that is, photoinduced bending is switched to photosalient phenomena by increasing the light intensity. The change in the size of the crystal unit cell upon UV irradiation is larger for asymmetric diarylethenes with thiazole and thiophene rings than that for the corresponding symmetric diarylethenes. As a result, the crystals of an asymmetric diarylethene show much more drastic photosalient effects than those of the corresponding symmetric diarylethene crystals upon UV irradiation. It is also found that the crystals of diarylethene, which have not previously been reported to exhibit a photosalient effect, show photosalient phenomena upon irradiation with strong UV light. Furthermore, the dependence of photosalient phenomena on the size and shape of the crystals is reported.
MOF Decomposition and Introduction of Repairable Defects Using a Photodegradable Strut
Authors: Yan Jingjing , MacDonald John C. , Maag Alex R. , Coudert François‐Xavier , Burdette Shawn C. 
Published: April 2019

AbstractPhotoswitchable components can modulate the properties of metal organic frameworks (MOFs); however, photolabile building blocks remain underexplored. A new strut NPDAC (2‐nitro‐1,4‐phenylenediacetic acid) that undergoes photodecarboxylation has been prepared and incorporated into a MOF, using post‐synthetic linker exchange (PSLE) from the structural analogue containing PDAC (p‐phenylenediacetic acid). Irradiation of NPDAC‐MOF leads to MOF decomposition and concomitant formation of amorphous material. In addition to complete linker exchange, MOFs containing a mixture of PDAC and NPDAC can be obtained through partial linker exchange. In NPDAC30‐MOF, which contains approximately 30 % NPDAC, the MOF retains crystallinity after irradiation, but the MOF contains defect sites consistent with loss of decarboxylated NPDAC linkers. The defect sites can be repaired by exposure to additional PDAC or NPDAC linkers at a much faster rate than the initial exchange process. The photoremoval and replacement process may lead to a more general approach to customizable MOF structures.
Direct and Regioselective Di‐α‐fucosylation on the Secondary Rim of β‐Cyclodextrin
Authors: Verkhnyatskaya Stella A. , de Vries Alex H. , Douma‐de Vries Elmatine , Sneep Renze J. L. , Walvoort Marthe T. C. 
Published: April 2019

AbstractInvited for the cover of this issue is the group of Marthe Walvoort at the University of Groningen. The image depicts a cyclodextrin ring as a dartboard, which is hit with fucose darts at specific positions to give a di‐fucosylated product. Read the full text of the article at 10.1002/chem.201806090.
Synthesis and Cytotoxicity of Octahydroepoxyisoindole‐7‐carboxylic Acids and Norcantharidin–Amide Hybrids as Norcantharidin Analogues
Authors: Hizartzidis Lacey , Gilbert Jayne , Gordon Christopher P. , Sakoff Jennette A. , McCluskey Adam 
Published: April 2019

AbstractOctahydroepoxyisoindole analogues of norcantharidin were accessed through a Diels–Alder reaction of an amine‐substituted furan with maleic anhydride and subsequent reduction of the bicyclo[2.2.1]heptene olefin. Despite retention of the carboxylate and the ether bridgehead known to impart cytotoxic activity to norcantharidin, none of these analogues displayed notable cytotoxicity against the 11 cell lines examined: HT29 (colon), MCF‐7 (breast), A2780 (ovarian), H460 (lung), A431 (skin), Du145 (prostate), BE2‐C (neuroblastoma), SJ‐G2 and U87 (glioblastoma), MIA (pancreatic), and SMA (spontaneous murine astrocytoma). The incorporation of an amino‐substituted system post‐synthesis of norcantharidin afforded facile access to 14 acid/amide‐substituted norcantharidin analogues. Of these, only four displayed sufficient activity at the initial 25 μm compound screening dose to warrant full evaluation of growth inhibition. Common to these analogues was the presence of a 4‐biphenyl moiety, and in particular 3‐(2‐(furan‐2‐ylmethyl)‐3‐(4‐biphenylamino)‐3‐oxopropylcarbamoyl)‐7‐oxabicyclo[2.2.1]heptane‐2‐carboxylic acid (13 c) and 3‐(2‐(pyrrole‐2‐ylmethyl)‐3‐(4‐biphenylamino)‐3‐oxopropylcarbamoyl)‐7‐oxabicyclo[2.2.1]heptane‐2‐carboxylic acid (24) displayed high levels of cytotoxicity, returning GI50 values of 15 nm (HT29) to 2.9 μm (U87) and 17 nm (SMA) to 2.8 μm (U87), respectively. These are the most cytotoxic norcantharidin analogues reported to date.
Broadening the Scope of Biocatalysis in Sustainable Organic Synthesis
Authors: Sheldon Roger A. , Brady Dean 
Published: April 2019

AbstractThis Review is aimed at synthetic organic chemists who may be familiar with organometallic catalysis but have no experience with biocatalysis, and seeks to provide an answer to the perennial question: if it is so attractive, why wasn't it extensively used in the past? The development of biocatalysis in industrial organic synthesis is traced from the middle of the last century. Advances in molecular biology in the last two decades, in particular genome sequencing, gene synthesis and directed evolution of proteins, have enabled remarkable improvements in scope and substantially reduced biocatalyst development times and cost contributions. Additionally, improvements in biocatalyst recovery and reuse have been facilitated by developments in enzyme immobilization technologies. Biocatalysis has become eminently competitive with chemocatalysis and the biocatalytic production of important pharmaceutical intermediates, such as enantiopure alcohols and amines, has become mainstream organic synthesis. The synthetic space of biocatalysis has significantly expanded and is currently being extended even further to include new‐to‐nature biocatalytic reactions.