bluuebunny/crossref_metadata_2025_split huggingface dataset:
Size/Charge Changeable Acidity‐Responsive Micelleplex for Photodynamic‐Improved PD‐L1 Immunotherapy with Enhanced Tumor Penetration
Authors: Dai Liangliang , Li Ke , Li Menghuan , Zhao Xiaojing , Luo Zhong , Lu Lu , Luo Yanfeng , Cai Kaiyong 
Published: March 2018

AbstractThe checkpoint blockade‐based immunotherapy has recently emerged as a promising approach for tumor treatment, but its clinical implementation has been impeded by poor tumor penetration of the nanocarriers and activation of antitumor immune response. To overcome the obstacles, a tumor acidity‐responsive micellar nanocomplex co‐loaded with programmed death‐ligand 1 (PD‐L1)‐blockade siRNA and mitochondrion‐targeting photosensitizer for the synergistic integration of photodynamic therapy and immunotherapy is reported in the present study. The nanosystem is coated with long‐circulating polyethylene glycol (PEG) shells, which can be shed in response to the weakly acidic tumor microenvironment and lead to significant size reduction and increasing positive charge. These transitions facilitate penetration and uptake of nanocarriers against tumors. Subsequently, under the mild acidic endo/lysosome condition, the micellar nanocomplexes are rapidly protonated and disintegrated to release the PD‐L1‐blockade siRNA and photosensitizer through sponge effect. Results from in vitro and in vivo experiments collectively reveal that the nanosystem efficiently activates a photodynamic therapy‐induced immune response and silences immune resistance mediated by the checkpoint gene PD‐L1. In consequence, melanoma growth is inhibited and the recurrence rate is reduced via triggering systemic antitumor immune responses. This study offers an alternative strategy for the development of efficient antitumor immune therapy.
Efficient and Stable Perovskite Solar Cells via Dual Functionalization of Dopamine Semiquinone Radical with Improved Trap Passivation Capabilities
Authors: Xue Qifan , Liu Meiyue , Li Zhenchao , Yan Lei , Hu Zhicheng , Zhou Jiawen , Li Wenqiang , Jiang Xiao‐Fang , Xu Baomin , Huang Fei , Li Yuan , Yip Hin‐Lap , Cao Yong 
Published: March 2018

AbstractHighly efficient planar heterojunction perovskite solar cells (PVSCs) with dopamine (DA) semiquinone radical modified poly(3,4‐ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) (DA‐PEDOT:PSS) as a hole transporting layer (HTL) were fabricated. A combination of characterization techniques were employed to investigate the effects of DA doping on the electron donating capability of DA‐PEDOT:PSS, perovskite film quality and charge recombination kinetics in the solar cells. Our study shows that DA doping endows the DA‐PEDOT:PSS‐modified PVSCs with a higher radical content and greater perovskite to HTL charge extraction capability. In addition, the DA doping also improves work function of the HTL, increases perovskite film crystallinity, and the amino and hydroxyl groups in DA can interact with the undercoordinated Pb atoms on the perovskite crystal, reducing charge‐recombination rate and increasing charge‐extraction efficiency. Therefore, the DA‐PEDOT:PSS‐modified solar cells outperform those based on PEDOT:PSS, increasing open‐circuit voltage (V
oc) and power conversion efficiency (PCE) to 1.08 V and 18.5%, respectively. Even more importantly, the efficiency of the unencapsulated DA‐PEDOT:PSS‐based PVSCs are well retained with only 20% PCE loss after exposure to air for 250 hours. These in‐depth insights into structure and performance provide clear and novel guidelines for the design of effective HTLs to facilitate the practical application of inverted planar heterojunction PVSCs.
Epitaxial Growth of Honeycomb Monolayer CuSe with Dirac Nodal Line Fermions
Authors: Gao Lei , Sun Jia‐Tao , Lu Jian‐Chen , Li Hang , Qian Kai , Zhang Shuai , Zhang Yu‐Yang , Qian Tian , Ding Hong , Lin Xiao , Du Shixuan , Gao Hong‐Jun 
Published: March 2018

Abstract2D transition metal chalcogenides have attracted tremendous attention due to their novel properties and potential applications. Although 2D transition metal dichalcogenides are easily fabricated due to their layer‐stacked bulk phase, 2D transition metal monochalcogenides are difficult to obtain. Recently, a single atomic layer transition metal monochalcogenide (CuSe) with an intrinsic pattern of nanoscale triangular holes is fabricated on Cu(111). The first‐principles calculations show that free‐standing monolayer CuSe with holes is not stable, while hole‐free CuSe is endowed with the Dirac nodal line fermion (DNLF), protected by mirror reflection symmetry. This very rare DNLF state is evidenced by topologically nontrivial edge states situated inside the spin–orbit coupling gaps. Motivated by the promising properties of hole‐free honeycomb CuSe, monolayer CuSe is fabricated on Cu(111) surfaces by molecular beam epitaxy and confirmed success with high resolution scanning tunneling microscopy. The good agreement of angle resolved photoemission spectra with the calculated band structures of CuSe/Cu(111) demonstrates that the sample is monolayer CuSe with a honeycomb lattice. These results suggest that the honeycomb monolayer transition metal monochalcogenide can be a new platform to study 2D DNLFs.
How to Design a Self‐Healing Polymer: General Concepts of Dynamic Covalent Bonds and Their Application for Intrinsic Healable Materials
Authors: Dahlke Jan , Zechel Stefan , Hager Martin D. , Schubert Ulrich S. 
Published: March 2018

AbstractIn this work, the fundamental design principles of intrinsic self‐healing, polymeric materials with reversible, covalent bonds are described and summarized. The most important properties with regard to the healing ability and potential applications are discussed. A classification of synthetic strategies toward polymers as well as polymer networks and their effect on the properties is given to gain further insight into known design strategies for healable materials. In order to evaluate the advantages and disadvantages of different covalent bonding types, recent examples of intrinsic healable polymers are compared and evaluated. In addition, the unique behavior of vitrimers as a new type of polymer networks is explained. In the end, a short outlook on future work in the field of self‐healing polymers concludes this review.
ZnO as photocatalyst for photoinduced electron transfer–reversible addition–fragmentation chain transfer of methyl methacrylate
Authors: Liang Enxiang , Liu Mu‐sheng , He Binhong , Wang Guo‐Xiang 
Published: March 2018

AbstractIn this article, photoinduced electron transfer–reversible addition–fragmentation chain transfer (PET‐RAFT) polymerization of methyl methacrylate (MMA) was investigated at moderate temperature in N,N‐dimethylformamide with ZnO as photocatalyst. The polymerization has a living characteristic: a linear increase in molecular weight (Mn,GPC), good agreement between experimental (Mn,GPC) and theoretical molecular weights (Mn,th), a decrease in molecular weight distribution (Mw/Mn) with increasing monomer conversion, and chain extension. The PET‐RAFT polymerization of MMA can be regulated by switching “ON” and “OFF” the light.
Incorporation of magnetite particles in 3D matrices made from the blends of collagen, chitosan, and hyaluronic acid
Authors: Sionkowska Alina , Grabska Sylwia 
Published: March 2018

AbstractIn this study, 3D biopolymeric materials based on the blends of collagen (Coll), chitosan (CTS), and hyaluronic acid (HA) were prepared by lyophilization technique. Magnetic particles synthesized by precipitation of iron (II) sulfate heptahydrate and iron (III) chloride hexahydrate in an aqueous solution of chitosan were added to a biopolymer mixture. Dialdehyde starch (DAS) was used as a cross‐linking agent for the materials. The structure of the obtained materials was studied using infrared spectroscopy and scanning electron microscope imaging. The properties of the 3D materials such as density, porosity, swelling ability and mechanical properties were studied. It was found that 3D composites made from collagen, chitosan, and hyaluronic acid with magnetic particles are hydrophilic with a high swelling ability (up to 2,646%). Cross‐linking of such biopolymeric materials with DAS alters the swelling degree and porosity of materials. The cross‐linking process has no significant effect on the density of the materials. The addition of magnetic particles to Coll/CTS/HA materials decreases its swelling ability (1,795% for material containing 30% of magnetic particles) and increases the density of the studied materials. 3D materials based on Coll/CTS/HA with magnetic particles are rigid and inflexible. With the increasing content of magnetic particles in the polymer blend, the Young's modulus decreases. 3D material with magnetite particles can be used in biomedical applications, such as tissue repair and drug delivery.
Realizing Crack Diagnosing and Self‐Healing by Electricity with a Dynamic Crosslinked Flexible Polyurethane Composite
Authors: Pu Wuli , Fu Daihua , Wang Zhanhua , Gan Xinpeng , Lu Xili , Yang Li , Xia Hesheng 
Published: March 2018

AbstractCombining self‐healing functions with damage diagnosing, which can achieve timely healing autonomously, is expected to improve the reliability and reduce life cycle cost of materials. Here, a flexible conductive composite composed of a dynamically crosslinked polyurethane bearing Diels–Alder bonds (PUDA) and carbon nanotubes (CNTs), which possess both crack diagnosing and self‐healing functions, is reported. The introduced dynamic Diels–Alder bonds endow the materials self‐healing function and the powder‐based preparation route based on the specially designed CNTs‐coated PUDA micropowders leads to the formation of segregated CNTs network, which makes the composite possess excellent mechanical properties and high conductivity. Because of the sufficient electrothermal and photothermal effect of CNTs, the composites can be healed rapidly and repeatedly by electricity or near‐infrared light based on the retro‐Diels–Alder reaction. An obvious color difference in the infrared thermograph resulting from the resistance difference between damaged and undamaged area can be observed when applying the voltage, which can be used for crack diagnosing. Using the same electrical circuit, the crack in the PUDA/CNTs composite can be noninvasively detected first and then be autonomously healed. The composites also exhibit a strain‐sensing function with good sensitivity and high reliability, thus will have potential applications in electronic strain sensors.
Trees down, hazards abound: Observations and lessons from Hurricane Sandy
Authors: Ochsner Michele , Marshall Elizabeth G. , Lefkowitz Daniel 
Published: March 2018

BackgroundGiven predictions that climate change will lead to an increase in severe storms, it is important to more fully understand the risks experienced by workers charged with the cleanup and removal of storm damaged trees. These hazards have received little attention in the occupational safety and health literature.MethodsThis paper is based on semi‐structured interviews with 23 stakeholders involved in the Hurricane Sandy cleanup effort.ResultsInterview participants identified at risk sectors, gaps in training and preparedness, and raised particular concerns about storm downed trees, electrical hazards, and fatigue and suggested steps to reduce these hazards.ConclusionsStakeholders’ observations about storm response suggest directions for improving the health and safety of this critical workforce.
Pleural abnormalities and exposure to elongate mineral particles in Minnesota iron ore (taconite) workers
Authors: Perlman David , Mandel Jeffrey H. , Odo Nnaemeka , Ryan Andy , Lambert Christine , MacLehose Richard F. , Ramachandran Gurumurthy , Alexander Bruce H. 
Published: March 2018

BackgroundIron ore (taconite) mining and processing are an important industry in northern Minnesota and western Michigan. Concerns around exposures have centered largely on exposure to non‐asbestiform amphibole elongate mineral particles (EMPs) found in the eastern portion of the Minnesota iron range.MethodsA cross sectional survey was undertaken of current and former taconite workers and spouses along with a detailed exposure assessment. Participants provided an occupational history and had a chest radiograph performed.ResultsA total of 1188 workers participated. Potential exposures to non‐amphibole EMPs were evident across multiple jobs in all active mines. Pleural abnormalities were found in 16.8% of workers. There was an association of pleural abnormalities with cumulative EMP exposure that was not specific to the eastern portion of the range.ConclusionThere was evidence of a mild to moderate increase in pleural abnormalities in this population of miners, associated with geographically non‐specific cumulative EMP exposure.
Myelin abnormality in Charcot–Marie–Tooth type 4J recapitulates features of acquired demyelination
Authors: Hu Bo , McCollum Megan , Ravi Vignesh , Arpag Sezgi , Moiseev Daniel , Castoro Ryan , Mobley Bret , Burnette Bryan , Siskind Carly , Day John , Yawn Robin , Feely Shawna , Li Yuebing , Yan Qing , Shy Michael , Li Jun 
Published: March 2018

ObjectiveCharcot–Marie–Tooth type 4J (CMT4J) is a rare autosomal recessive neuropathy caused by mutations in FIG4 that result in loss of FIG4 protein. This study investigates the natural history and mechanisms of segmental demyelination in CMT4J.MethodsOver the past 9 years, we have enrolled and studied a cohort of 12 CMT4J patients, including 6 novel FIG4 mutations. We evaluated these patients and related mouse models using morphological, electrophysiological, and biochemical approaches.ResultsWe found sensory motor demyelinating polyneuropathy consistently in all patients. This underlying myelin pathology was associated with nonuniform slowing of conduction velocities, conduction block, and temporal dispersion on nerve conduction studies, which resemble those features in acquired demyelinating peripheral nerve diseases. Segmental demyelination was also confirmed in mice without Fig4 (Fig4−/−). The demyelination was associated with an increase of Schwann cell dedifferentiation and macrophages in spinal roots where nerve–blood barriers are weak. Schwann cell dedifferentiation was induced by the increasing intracellular Ca2+. Suppression of Ca2+ level by a chelator reduced dedifferentiation and demyelination of Schwann cells in vitro and in vivo. Interestingly, cell‐specific knockout of Fig4 in mouse Schwann cells or neurons failed to cause segmental demyelination.InterpretationMyelin change in CMT4J recapitulates the features of acquired demyelinating neuropathies. This pathology is not Schwann cell autonomous. Instead, it relates to systemic processes involving interactions of multiple cell types and abnormally elevated intracellular Ca2+. Injection of a Ca2+ chelator into Fig4−/− mice improved segmental demyelination, thereby providing a therapeutic strategy against demyelination. Ann Neurol 2018;83:756–770
Positron emission tomography–guided magnetic resonance spectroscopy in Alzheimer disease
Authors: Sheikh‐Bahaei Nasim , Sajjadi S. Ahmad , Manavaki Roido , McLean Mary , O'Brien John T. , Gillard Jonathan H. 
Published: March 2018

ObjectiveTo determine whether the level of metabolites in magnetic resonance spectroscopy (MRS) is a representative marker of underlying pathological changes identified in positron emission tomographic (PET) images in Alzheimer disease (AD).MethodsWe performed PET‐guided MRS in cases of probable AD, mild cognitive impairment (MCI), and healthy controls (HC). All participants were imaged by 11C‐Pittsburgh compound B (11C‐PiB) and 18F‐fluorodeoxyglucose (18F‐FDG) PET followed by 3T MRS. PET images were assessed both visually and using standardized uptake value ratios (SUVRs). MRS voxels were placed in regions with maximum abnormality on amyloid (Aβ+) and FDG (hypometabolic) areas on PET scans. Corresponding normal areas were selected in controls. The ratios of total N‐acetyl (tNA) group, myoinositol (mI), choline, and glutamate + glutamine over creatine (Cr) were compared between these regions.ResultsAβ + regions had significantly higher (p = 0.02) mI/Cr and lower tNA/Cr (p = 0.02), whereas in hypometabolic areas only tNA/Cr was reduced (p = 0.003). Multiple regression analysis adjusting for sex, age, and education showed mI/Cr was only associated with 11C‐PiB SUVR (p < 0.0001). tNA/Cr, however, was associated with both PiB (p = 0.0003) and 18F‐FDG SUVR (p = 0.006). The level of mI/Cr was not significantly different between MCI and AD (p = 0.28), but tNA/Cr showed significant decline from HC to MCI to AD (p = 0.001, p = 0.04).InterpretationmI/Cr has significant temporal and spatial associations with Aβ and could potentially be considered as a disease state biomarker. tNA is an indicator of early neurodegenerative changes and might have a role as disease stage biomarker and also as a valuable surrogate marker for treatment response. Ann Neurol 2018;83:771–778
Experimental Identification of Ultrafast Reverse Hole Transfer at the Interface of the Photoexcited Methanol/Graphitic Carbon Nitride System
Authors: Chen Zongwei , Zhang Qun , Luo Yi 
Published: March 2018

AbstractAn experimental scrutiny of the photoexcited hole dynamics in a prototypical system is presented in which hole‐scavenging methanol molecules are chemisorbed on a graphitic carbon nitride (g‐C3N4) substrate. A set of comparison and control experiments by means of femtosecond time‐resolved transient absorption (fs‐TA) spectroscopy were conducted. The elusive reverse hole transfer (RHT) process was identified, which occurs on a timescale of a few hundred picoseconds. The critical role of interfacially chemisorbed methoxy (instead of methanol) as the dominant species responsible for hole scavenging was confirmed by a control experiment using protonated g‐C3N4 as the substrate. A hot‐hole transfer effect was revealed by implementing different interband photoexcitation scenarios. The RHT rate is the key factor governing the hole‐scavenging ability of different hole scavengers.
Diverging Mechanisms: Cytochrome‐P450‐Catalyzed Demethylation and γ‐Lactone Formation in Bacterial Gibberellin Biosynthesis
Authors: Nagel Raimund , Peters Reuben J. 
Published: March 2018

AbstractBiosynthesis of the gibberellin (GA) plant hormones evolved independently in plants and microbes, but the pathways proceed by similar transformations. The combined demethylation and γ‐lactone ring forming transformation is of significant mechanistic interest, yet remains unclear. The relevant CYP112 from bacteria was probed by activity assays and 18O2‐labeling experiments. Notably, the ability of tert‐butyl hydroperoxide to drive this transformation indicates use of the ferryl‐oxo (Compound I) from the CYP catalytic cycle for this reaction. Together with the confirmed loss of C20 as CO2, this necessitates two catalytic cycles for carbon–carbon bond scission and γ‐lactone formation. The ability of CYP112 to hydroxylate the δ‐lactone form of GA15, shown by the labeling studies, is consistent with the implied use of a further oxygenated heterocycle in the final conversion of GA24 into GA9, with the partial labeling of GA9, thus demonstrating that CYP112 partitions its reactants between two diverging mechanisms.
Über die Ursachen der deutlich unterschiedlichen Reaktivität von Ruthenium unter den [MO]+/CH4‐Systemen (M=Fe, Ru, Os)
Authors: Sun Xiaoyan , Zhou Shaodong , Yue Lei , Schlangen Maria , Schwarz Helmut 
Published: March 2018

AbstractDie thermischen Gasphasenreaktionen von [RuO]+ mit Methan wurden mittels FT‐ICR‐Massenspektrometrie und quantenchemischen Rechnungen untersucht. Im Gegensatz zu den bereits beschriebenen Reaktionspaaren [FeO]+/CH4 und [OsO]+/CH4, die unter Sauerstoff‐ und Wasserstoffatomübertragungen bzw. unter Dehydrierung reagieren, bildet [RuO]+ in der Reaktion mit CH4 selektiv [Ru(CH)2]+ und H2O, allerdings mit einer viel geringeren Effizienz. Unterschiedliche mechanistische Szenarien wurden untersucht und die entsprechenden elektronischen Ursachen durch quantenchemische Rechnungen identifiziert. Es ist das Zusammenspiel der Effizienz von Spin‐Bahn‐Kopplung, Orbitalüberlappung und relativistischer Effekte, auf dem die beobachteten unterschiedlichen Reaktivitäten der Reaktionspaare [MO]+/CH4 (M=Fe, Ru, Os) beruhen.
Enhancing Capacity Performance by Utilizing the Redox Chemistry of the Electrolyte in a Dual‐Electrolyte Sodium‐Ion Battery
Authors: Senthilkumar Sirugaloor Thangavel , Bae Hyuntae , Han Jinhyup , Kim Youngsik 
Published: March 2018

AbstractA strategy is described to increase charge storage in a dual electrolyte Na‐ion battery (DESIB) by combining the redox chemistry of the electrolyte with a Na+ ion de‐insertion/insertion cathode. Conventional electrolytes do not contribute to charge storage in battery systems, but redox‐active electrolytes augment this property via charge transfer reactions at the electrode–electrolyte interface. The capacity of the cathode combined with that provided by the electrolyte redox reaction thus increases overall charge storage. An aqueous sodium hexacyanoferrate (Na4Fe(CN)6) solution is employed as the redox‐active electrolyte (Na‐FC) and sodium nickel Prussian blue (Nax‐NiBP) as the Na+ ion insertion/de‐insertion cathode. The capacity of DESIB with Na‐FC electrolyte is twice that of a battery using a conventional (Na2SO4) electrolyte. The use of redox‐active electrolytes in batteries of any kind is an efficient and scalable approach to develop advanced high‐energy‐density storage systems.
Effiziente lichtinduzierte pKa‐Modulation, gekoppelt mit basenkatalysierter Photochromie
Authors: Gurke Johannes , Budzák Šimon , Schmidt Bernd M. , Jacquemin Denis , Hecht Stefan 
Published: March 2018

AbstractPhotoschaltbare Säure‐Base‐Paare, die eine reversible Veränderung ihrer pKa‐Werte ermöglichen, sind für die Steuerung chemischer und biologischer Prozesse von großem Interesse. Eine signifikante, lichtinduzierte pKa‐Änderung dreier Einheiten in wässrigem Medium wurde zwischen zwei thermisch stabilen Zuständen realisiert, die sich mit UV‐ und grünem Licht ineinander umwandeln lassen. Die lichtinduzierte pKa‐Modulation beruht auf dem Einbau einer 3‐H‐Thiazol‐2‐on‐Einheit in das Gerüst eines Diarylethen‐Photoschalters, der bei photochemischem Ringschluss die heteroaromatische Stabilisierung der korrespondierenden, negativ geladenen Base verliert und somit deutlich weniger sauer wird. Zusätzlich wird die Effizienz der Photoreaktionen im deprotonierten Zustand drastisch erhöht, was zu einer katalytisch verstärkten Photochromie führt. Es scheint, dass die Protonierung einen signifikanten Einfluss auf die Form der Potentialenergiefläche von Grund‐ und angeregtem Zustand hat, wie durch quantenchemische Rechnungen gezeigt wird.
A Synchrotron‐Based Study of the Mary Rose Iron Cannonballs
Authors: Simon Hayley , Cibin Giannantonio , Robbins Phil , Day Sarah , Tang Chiu , Freestone Ian , Schofield Eleanor 
Published: March 2018

AbstractPost‐excavation iron corrosion may be accelerated by the presence of Cl−, leading to conservation methods designed to remove Cl. This study exploits a unique opportunity to assess 35 years of conservation applied to cast‐iron cannon shot excavated from the Mary Rose. A combination of synchrotron X‐ray powder diffraction (SXPD), absorption spectroscopy (XAS), and fluorescence (XRF) mapping have been used to characterise the impact of conservation on the crystalline corrosion products, chlorine distribution, and speciation. The chlorinated phase akaganeite, β‐FeO(OH,Cl), was found on shot washed in corrosion inhibitor Hostacor IT with or without an additional reduction stage. No chlorinated phases were observed on the surface of shot stored in sodium sesquicarbonate (Na2CO3/NaHCO3); however, hibbingite, β‐Fe2(OH)3Cl, was present in metal pores. It is proposed that surface β‐FeO(OH,Cl) formed in the early stages of active conservation owing to oxidation of β‐Fe2(OH)3Cl at near‐neutral pH.