bluuebunny/crossref_metadata_2025 huggingface dataset:
ZD2‐Engineered Gold Nanostar@Metal‐Organic Framework Nanoprobes for T1‐Weighted Magnetic Resonance Imaging and Photothermal Therapy Specifically Toward Triple‐Negative Breast Cancer
Authors: Zhang Luyun , Liu Chuang , Gao Yang , Li Zihou , Xing Jie , Ren Wenzhi , Zhang Lili , Li Aiguo , Lu Guangming , Wu Aiguo , Zeng Leyong
Published: October 2018

Compared with other subtypes of breast cancer, triple‐negative breast cancer (TNBC) is seriously threatening to human life. Therefore, it is a matter of urgency to develop multifunctional nanoprobes for visualized theranostics of TNBC, achieving specific targeting toward only TNBC, but not other subtypes. Nanoscale metal–organic frameworks (MOFs) show important potential in visualized theranostics of tumors, but it is critical to synthesize well‐defined core–shell MOF‐based nanocomposites by encapsulating a single nanoparticle within MOF. In this study, a TNBC‐targeted peptide (ZD2)‐engineered, and a single gold nanostar (AuNS) coated within MIL‐101‐NH2(Fe) by coating MOF with four cycles, obtain well‐defined core–shell AuNS@MOF‐ZD2 nanocomposites, which are expected to achieve T1‐weighted magnetic resonance imaging and photothermal therapy (PTT) specifically targeting toward TNBC. The prepared AuNS@MOF‐ZD2 nanocomposites possess good biocompatibility, efficient T1‐weighted magnetic resonance (MR) relaxivity and stable photothermal conversion ability with an efficiency of 40.5%. The in vitro and in vivo characterizations prove their performances of T1‐weighted MR and PTT with a low power density of 808 nm laser, achieving excellent theranostic efficacy in TNBC. Importantly, it is demonstrated that the prepared AuNS@MOF‐ZD2 nanoprobes can specifically target TNBC cells (MDA‐MB‐231), but not other subtypes of breast cancer cells (MDA‐MB‐435, MDA‐MB‐468, and MCF‐7), indicating their promising application in visualized theranostics of breast cancers with molecular classification.
Construction of Magnetoelectric Composites with a Large Room‐Temperature Magnetoelectric Response through Molecular–Ionic Ferroelectrics
Authors: Li Dong , Zhao Xue‐Mei , Zhao Hai‐Xia , Dong Xin‐Wei , Long La‐Sheng , Zheng Lan‐Sun
Published: October 2018

Magnetoelectric materials with a large magnetoelectric response, a low operating magnetic (or electric) field, and a room‐temperature (or higher) operating temperature are of key importance for practical applications. However, such materials are extremely rare because a large magnetoelectric response often requires strong coupling between spins and electric dipoles. Herein, an example of a magnetoelectric composite is prepared by using a room‐temperature multiaxial molecular–ionic ferroelectric, tetramethylammonium tetrachlorogallate(III) (1). Investigation of the magnetoelectric effect of the magnetoelectric laminate composite indicates that its room‐temperature magnetoelectric voltage coefficient (αME) is as high as 186 mV cm−1 Oe−1 at HDC = 275 Oe and at the HAC frequency of ≈39 kHz, providing a valid approach for the preparation of magnetoelectric materials and adding a new member to the magnetoelectric material family.
Induced Formation of Structural Domain Walls and Their Confinement on Phase Dynamics in Strained Manganite Thin Films
Authors: Feng Qiyuan , Jin Feng , Zhou Haibiao , Wang Lingfei , Meng Wenjie , Zhang Kexuan , Wang Jihao , Zhang Jing , Hou Yubin , Lu Qingyou , Wu Wenbin
Published: October 2018

Domain walls (DWs) in strongly correlated materials have provided fertile ground for the discovery of exotic phenomena, and controlling the formation of DWs is still a challenge. Here, it is demonstrated that a new type of structural DW can be induced in a series of manganite thin films, which are engineered to achieve a robust charge‐ordering insulating (COI) ground state by selecting various films and substrates. The monoclinic domains are somewhat irregular in shape, and the corresponding DWs, taking the shape of closed loops, are ferromagnetic and metallic (FMM) at low temperatures. Remarkably, the DWs exhibit little dependence on temperature or magnetic field, due to the structural origins of the domains. Additionally, using magnetic force microscopy, the role played by DWs in the dynamics of the COI and FMM phases at the mesoscopic scale is revealed. They function as barriers, strictly confining the phase dynamics within each domain, reflecting the strong coupling of electronic phases with the lattice. Each domain exhibits binary occupation by a single pure phase, resulting in a quasi‐periodic phase separation. The universal behaviors of the multiple engineered films elucidate the possibility of controlling the formation of DWs and tuning phase dynamics through DW design.
Stabilization of Colloidal Crystals Engineered with DNA
Authors: Oh Taegon , Park Sarah S. , Mirkin Chad A.
Published: October 2018

A postsynthetic method for stabilizing colloidal crystals programmed from DNA is developed. The method relies on Ag+ ions to stabilize the particle‐connecting DNA duplexes within the crystal lattice, essentially transforming them from loosely bound structures to ones with very strong interparticle links. Such crystals do not dissociate as a function of temperature like normal DNA or DNA‐interconnected superlattices, and they can be moved from water to organic media or the solid state, and stay intact. The Ag+‐stabilization of the DNA bonds is accompanied by a nondestructive ≈25% contraction of the lattice, and both the stabilization and contraction are reversible with the chemical extraction of the Ag+ ions, by AgCl precipitation with NaCl. This synthetic tool is important, since it allows scientists and engineers to study such crystals in environments that are incompatible with structures made by conventional DNA programmable methods and without the influence of a matrix such as silica.
Vertical Integration of Cell‐Laden Hydrogels with Bioinspired Photonic Crystal Membranes
Authors: Pei Yi , Shahoei Sayyed Hamed , Li Yanfen , Reece Peter J. , Nelson Erik R. , Gooding J. Justin , Kilian Kristopher A.
Published: October 2018

The native architecture of tissue segregates populations of cells through nanostructured membranes of biopolymers (e.g., basement membranes) which serve the dual purpose of providing scaffolding for cells and filtration through size‐exclusion. A multilayered approach to fabricate tissue scaffolds where populations of encapsulated cells are separated by porous silicon (PSi)‐based photonic crystal membranes with nano‐ and microstructure that mimics the basement membranes is reported here. The PSi films are fabricated to display discreet photonic bandgaps such that remote optical interrogation provides a specific resonance for each film. Through careful control of surface chemistry, nanostructured PSi films are engineered to serve as optical biosensors and biomolecule release reservoirs, where the optical signature can report on these distinct functions remotely using a simple light source. The promise of this approach is demonstrated as a “smart” tissue scaffolding by monitoring matrix metalloprotease (MMP) activity from encapsulated multilayered co‐cultures of mesenchymal stem cells and human microvascular endothelial cells, with concurrent attenuation of MMP activity through release of angiogenic‐modulating compounds. The integration of optically registered biosensing and drug‐release capabilities—within a multilayered hydrogel scaffold with multiple cell types—provides a new approach to tissue engineering where dynamic bioactivity can be monitored remotely in real‐time.
Transition Metal‐Doped Edge‐Terminated MoS2 Superstructures as Efficient Catalysts for H2 Production
Authors: Ding Jiabao , Shao Qi , Bai Shuxing , Huang Xiaoqing
Published: October 2018

As the most important layered transition metal dichalcogenide, molybdenum disulfide (MoS2) is applicable for simultaneous H2 production and CO elimination by water‐gas shift reaction (WGSR), while its performance is still not satisfactory. To further promote the catalytic activities of MoS2, herein a series of transition metals (M = Mn, Fe, Co, Ni, Cu, and Zn) into the column‐like superstructures with edge‐terminated MoS2 nanosheet building blocks (termed as M‐ET MoS2 SSs) is doped as the efficient catalysts for WGSR. A precise M doping into ET MoS2 SSs reveals that the M‐ET MoS2 SSs exhibit the volcano‐like activity toward WGSR as a function of specific M with the 5%Ni‐ET MoS2 SSs displaying the best average rate of 50.48 µmolH2 gcat.
−1 s−1 in WGSR at 473 K, which is 4 and 13 times higher than those of the ET MoS2 SSs and commercial MoS2, respectively, and is even comparable to many noble‐metal‐based catalysts. The valence band spectra reveal that the boosted WGSR activity of 5%Ni‐ET MoS2 SSs can be ascribed to the downshift of the d‐band center relative to the Fermi level, which facilitates the H desorption to produce H2 in WGSR, showing a highly efficient and earth‐abundant catalysts for WGSR and beyond.
Ultrahigh Performance On‐Chip Single Crystal Diamond NEMS/MEMS with Electrically Tailored Self‐Sensing Enhancing Actuation
Authors: Liao Meiyong , Sang Liwen , Teraji Tokuyuki , Koizumi Satoshi , Koide Yasuo
Published: October 2018

All‐electrical nano‐electromechanical or micro‐electromechanical systems (NEMS/MEMS) with integrated sensing and actuation are essential to fulfill the functionalities of single‐crystal diamond (SCD) NEMS/MEMS by integrated circuits for sensors or quantum systems. However, the implementation of all‐electrical on‐chip SCD NEMS/MEMS transducers has encountered bottlenecks due to the lack of shallow dopants in diamond and the difficulty of integrating active materials on diamond. In the present work, an on‐chip SCD NEMS/MEMS with unprecedented figure‐of‐merits is demonstrated by proposing a self‐sensing enhancing actuation scheme to circumvent the bottlenecks in diamond. The on‐chip SCD NEMS/MEMS show high self‐sensitivity, low actuation voltage, little energy dissipation, and high‐frequency and high‐temperature operation (873 K). The present work provides a platform for the development of ultrahigh‐performance and robust SCD NEMS/MEMS in sensors and quantum science fields, superior to other semiconductors.
Vacuum‐Powered Soft Pneumatic Twisting Actuators to Empower New Capabilities for Soft Robots
Authors: Jiao Zhongdong , Ji Chen , Zou Jun , Yang Huayong , Pan Min
Published: October 2018

Vacuum‐powered soft pneumatic actuators (V‐SPAs) are a promising enabling technology for a wide range of emerging applications, including artificial muscles, programmable locomotion, and flexible grippers. This is due to their flexible deformation, clean power supply, safe interaction with users, and high reliability compared with alternative actuators. A new vacuum‐powered soft pneumatic twisting actuator (V‐SPTA) is designed, which has a single seamless chamber and is completely soft, with no rigid frames. The actuator has two degrees of freedom (DoFs) and offers the advantages of diverse functions, ease of manufacture, high load capability, and is cost efficient. Their potential to achieve linear, twisting, and radial movements is shown by employing different combinations of V‐SPTAs. The feasibility of the V‐SPTA is demonstrated using prototypes based on flexible joint and wrist, rotating crawling robot, pipe‐climbing robot, and V‐SPTAs‐driven car. The V‐SPTA successfully enhances the capability of existing V‐SPAs by providing an important additional DoF. The work therefore expands the capability of soft robots while minimizing the complexity of actuator design and reducing the manufacturing cost.
High Brightness and Enhanced Stability of CsPbBr3‐Based Perovskite Light‐Emitting Diodes by Morphology and Interface Engineering
Authors: Liu Xue , Guo Xiaoyang , Lv Ying , Hu Yongsheng , Fan Yi , Lin Jie , Liu Xiaomin , Liu Xingyuan
Published: October 2018

A CsPbBr3‐based all‐inorganic perovskite light‐emitting diode (PeLED) with ultrahigh brightness and enhanced stability is prepared by controlling of morphology and interface engineering. A nonionic surfactant polyoxyethylene (20) sorbitan monolaurate is introduced into the CsPbBr3 film, which induces tightly arranged grains in the perovskite film, thus highly passivating the defects at the grain boundaries, resulting in a performance‐enhanced PeLED with a highest brightness of 111 000 cd m−2, a peak current efficiency (CE) of 21.1 cd A−1, a maximum external quantum efficiency (EQE) of 5.55%, and an operational lifetime of 4.5 h. The device properties are further improved by adding an anionic surfactant sodium dodecyl benzene sulfonate to modify the hole injection layer poly(ethylenedioxythiophene):polystyrenesulfonate. The hole current density is increased, further balancing the charge injection and transport. Finally, the optimal device displays an ultrahigh brightness of 179 000 cd m−2, a peak CE of 28.0 cd A−1, a maximum EQE of 7.39%, and a further prolonged lifetime of 6 h.
Assessing the pKa‐Dependent Activity of Hydroxyl Hydrogen Bond Donors in the Organocatalyzed Cycloaddition of Carbon Dioxide to Epoxides: Experimental and Theoretical Study
Authors: Yingcharoen Prapussorn , Kongtes Chutima , Arayachukiat Sunatda , Suvarnapunya Kittipong , Vummaleti Sai V. C. , Wannakao Sippakorn , Cavallo Luigi , Poater Albert , D' Elia Valerio
Published: October 2018

The development of hydrogen bond donors (HBDs) as catalytic moieties in the cycloaddition of carbon dioxide to epoxides is an active field of research to access efficient, inexpensive and sustainable metal‐free systems for the conversion of carbon dioxide to useful chemicals. Thus far, no systematic attempt to correlate the activity of a diverse selection of HBDs to their physico‐chemical properties has been undertaken. In this work, we investigate factors influencing the catalytic activity of hydroxyl HBDs from different chemical families under ambient conditions by considering the HBDs Brønsted acidity (expressed as pKa), the number of hydroxyls and structural aspects. As an effect, this study highlights the crucial role of the hydroxyl protons’ Brønsted acidity in determining the catalytic activity of the HBDs, identifies an ideal range for the hydroxyl HBDs proton acidity (9 <pKa <11) and leads to a revaluation of phenol and to the discovery of a simple ascorbic acid derivative as efficient HBDs for the title cycloaddition reaction. Density functional theory (DFT) calculations show mild reactions barriers for the reaction catalysed by phenol and suggest the occurrence of aggregation between molecules of ascorbic acid as a further factor affecting catalytic activity.

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Recent Advances in Memory Devices with Hybrid Materials
Authors: Hwang Bohee , Lee Jang‐Sik
Published: October 2018

Increasing demands for information‐storage capacity and for miniaturization of memory cells have driven exploration of new‐generation data storage devices, because the conventional Si‐based memory technology is approaching its fundamental physical limits. Hybrid materials and novel device structure may lead to a paradigm shift toward memory devices that have high density, multifunctionality, and low power consumption. Here, the structure and operation mechanism of resistive switching memory devices are described, then recent advances in hybrid materials (e.g., graphene‐based polymer composites, organic–inorganic hybrid perovskite materials) for fabrication of these devices are summarized. How to increase the ON/OFF ratio and the density of memories, and to decrease programming voltage by selecting appropriate active materials, and engineering the active layers, are also demonstrated. Finally, the current challenges and future directions in memory devices based on hybrid materials are summarized.
Dual‐Functional Graphene Composites for Electromagnetic Shielding and Thermal Management
Authors: Kargar Fariborz , Barani Zahra , Balinskiy Michael , Magana Andres Sanchez , Lewis Jacob S. , Balandin Alexander A.
Published: October 2018

The synthesis and characterization of epoxy‐based composites with few‐layer graphene fillers, which are capable of dual‐functional applications, are reported. It is found that composites with certain types of few‐layer graphene fillers reveal an efficient total electromagnetic interference shielding, SEtot ≈ 45 dB, in the important X‐band frequency range, f = 8.2 −12.4 GHz, while simultaneously providing high thermal conductivity, K ≈ 8 W m−1 K−1, which is a factor of ×35 larger than that of the base matrix material. The efficiency of the dual‐functional application depends on the filler characteristics: thickness, lateral dimensions, aspect ratio, and concentration. Graphene loading fractions above the electrical and thermal “percolation thresholds” allow for strong enhancement of both the electromagnetic interference shielding and heat conduction properties. Interestingly, graphene composites can block the electromagnetic energy even below the electrical percolation threshold, remaining electrically insulating, which is an important feature for some types of thermal interface materials. The dual functionality of the graphene composites can substantially improve the electromagnetic shielding and thermal management of airborne systems while simultaneously reducing their weight and cost.
Scheduling‐informed optimal design of systems with time‐varying operation: A wind‐powered ammonia case study
Authors: Allman Andrew , Palys Matthew J. , Daoutidis Prodromos
Published: October 2018

The time‐varying operation of chemical plants offers economic advantages, particularly in the presence of time‐sensitive electricity markets and renewable energy generation. However, the uncertainty and short‐timescale variability associated with renewable energy production, as well as the nonconvex process and cost models typically associated with chemical processes, make finding the optimal design of such systems challenging. In this work, a new approach is presented to finding the optimal design of systems with time‐varying operation, called scheduling‐informed design, whereby the optimal operation of many designs is determined and the resulting cost correlations into the optimal design problem are embedded. This method is applied to a case study of wind‐powered ammonia generation and showed that it greatly improves the computational tractability of the optimal design problem and predicts with greater accuracy operating costs realized because of uncertainty in forecasting. © 2018 American Institute of Chemical Engineers AIChE J, 65: e16434 2019
Loss of the GPI‐anchor in B‐lymphoblastic leukemia by epigenetic downregulation of PIGH expression
Authors: Loeff Floris C. , Rijs Kevin , van Egmond Esther H. M. , Zoutman Willem H. , Qiao Xiaohang , Kroes Wilhelmina G. M. , Veld Sabrina A. J. , Griffioen Marieke , Vermeer Maarten H. , Neefjes Jacques , Frederik Falkenburg J. H. , Halkes Constantijn J. M. , Jedema Inge
Published: October 2018

Adult B‐lymphoblastic leukemia (B‐ALL) is a hematological malignancy characterized by genetic heterogeneity. Despite successful remission induction with classical chemotherapeutics and novel targeted agents, enduring remission is often hampered by disease relapse due to outgrowth of a pre‐existing subclone resistant against the treatment. In this study, we show that small glycophosphatidylinositol (GPI)‐anchor deficient CD52‐negative B‐cell populations are frequently present already at diagnosis in B‐ALL patients, but not in patients suffering from other B‐cell malignancies. We demonstrate that the GPI‐anchor negative phenotype results from loss of mRNA expression of the PIGH gene, which is involved in the first step of GPI‐anchor synthesis. Loss of PIGH mRNA expression within these B‐ALL cells follows epigenetic silencing rather than gene mutation or deletion. The coinciding loss of CD52 membrane expression may contribute to the development of resistance to alemtuzumab (ALM) treatment in B‐ALL patients resulting in the outgrowth of CD52‐negative escape variants. Additional treatment with 5‐aza‐2′‐deoxycytidine may restore expression of CD52 and revert ALM resistance.
Untersuchungen zu Grenzen der Bivalenz mit DNA‐basierter räumlicher Rasterung
Authors: Dubel Natali , Liese Susanne , Scherz Franziska , Seitz Oliver
Published: October 2018

Multivalenz kann eine Komplexbildung ermöglichen, selbst wenn monovalente Ligand/Rezeptor‐Interaktionen schwach sind. Allerdings sollte eine verstärkte Interaktion zweier multivalenter Bindungspartner vermieden werden können, beispielsweise falls bivalente Rezeptoren multimolekulare Wechselwirkungen eingehen, um Bindungspartner zu vernetzen. Hier stellen wir die erste systematische Untersuchung zu den Kriterien vor, die festlegen, ob ein bivalentes System von bivalenzverstärkten Wechselwirkungen profitiert oder verbrückende Bindungen eingeht. Wir verwendeten die DNA‐instruierte Selbstassemblierung, um Wirt‐Gast‐Systeme auf Basis von Cucurbit[7]uril und Adamantan in 70–360 Å Abständen anzuordnen. Messungen sowie Analysen mithilfe von statistischer Mechanik enthüllen, dass der Affinitätsgewinn von i) dem Abstand der Erkennungsmodule, ii) der Gerüstflexibilität und – am wichtigsten – iii) der Stärke der monovalenten Interaktion abhängt. Wir zeigen, dass der bivalente Effekt auch bei Abständen größer als 150 Å wirken kann und diskutieren, wie, in gegensätzlicher Weise, schwache monovalente Interaktionen die Konzentrationsgrenze für die quervernetzende Bindung erniedrigen. Die Ergebnisse sind von Interesse für das Design von Inhibitoren.
Segmental 13C‐Labeling and Raman Microspectroscopy of α‐Synuclein Amyloid Formation
Authors: Flynn Jessica D. , Jiang Zhiping , Lee Jennifer C.
Published: October 2018

Mapping conformational changes of α‐synuclein (α‐syn) from soluble, unstructured monomers to β‐sheet‐ rich aggregates is crucial towards understanding amyloid formation. Raman microspectroscopy is now used to spatially resolve conformational heterogeneity of amyloid aggregates and monitor amyloid formation of segmentally 13C‐labeled α‐syn in real‐time. As the 13C‐isotope shifts the amide‐I stretching frequency to lower energy, the ligated construct, 13C1–8612CS87C–140‐α‐syn, exhibits two distinct bands allowing for simultaneous detection of secondary structural changes in N‐terminal 1–86 and C‐terminal 87–140 residues. The disordered‐to‐β‐sheet conformational change is first observed for the N‐terminal followed by the C‐terminal region. Finally, Raman spectroscopic changes occurred prior to Thioflavin T fluorescence enhancement, indicating that the amide‐I band is a superior probe of amyloid formation.
Pyridinethiol‐Assisted Dissolution of Elemental Gold in Organic Solutions
Authors: Räisänen Minna , Heliövaara Eeva , Al‐Qaisi Feda'a , Muuronen Mikko , Eronen Aleksi , Liljeqvist Henri , Nieger Martin , Kemell Marianna , Moslova Karina , Hämäläinen Jani , Lagerblom Kalle , Repo Timo
Published: October 2018

Dissolution of elemental gold in organic solutions is a contemporary approach to lower the environmental burden associated with gold recycling. Herein, we describe fundamental studies on a highly efficient method for the dissolution of elemental Au that is based on DMF solutions containing pyridine‐4‐thiol (4‐PSH) as a reactive ligand and hydrogen peroxide as an oxidant. Dissolution of Au proceeds through several elementary steps: isomerization of 4‐PSH to pyridine‐4‐thione (4‐PS), coordination with Au0, and then oxidation of the Au0 thione species to AuI simultaneously with oxidation of free pyridine thione to elemental sulfur and further to sulfuric acid. The final dissolution product is a AuI complex bearing two 4‐PS ligands and SO42− as a counterion. The ligand is crucial as it assists the oxidation process and stabilizes and solubilizes the formed Au cations.
Incorporation of Homochirality into a Zeolitic Imidazolate Framework Membrane for Efficient Chiral Separation
Authors: Chan Jun Yong , Zhang Huacheng , Nolvachai Yada , Hu Yaoxin , Zhu Haijin , Forsyth Maria , Gu Qinfen , Hoke David E. , Zhang Xiwang , Marriot Philip J. , Wang Huanting
Published: October 2018

Homochiral metal–organic frameworks (MOFs) have gained much attention because of their chiral properties and disposition for chiral separation. However, the fabrication of high‐quality homochiral MOF membranes remains challenging because of the difficulty in controlling growth of MOF membranes with chiral functionalities. A homochiral zeolitic imidazolate framework‐8 (ZIF‐8) membrane is reported for efficient chiral separation. The membrane is synthesized by incorporating a natural amino acid, l‐histidine (l‐His), into the framework of ZIF‐8. The homochiral l‐His‐ZIF‐8 membrane exhibits a good selectivity for the R‐enantiomer of 1‐phenylethanol over the S‐enantiomer, showing a high enantiomeric excess value up to 76 %.
Exploring the Limits of Bivalency by DNA‐Based Spatial Screening
Authors: Dubel Natali , Liese Susanne , Scherz Franziska , Seitz Oliver
Published: October 2018

Multivalency can facilitate complex formation when monovalent receptor–ligand interactions are weak. However, enhanced binding of two multivalent binding partners should be avoidable, for example when bivalent receptors ought to utilize multimolecular interactions to cross‐link binding partners. We herein report the first systematic study to assess the criteria deciding whether a bivalent system engages in bivalency‐enhanced interactions or cross‐linking. We used DNA‐instructed self‐assembly to arrange the cucurbit[7]uril–adamantane host–guest system in 70–360 Å distance. Measurements and statistical mechanics analyses revealed that the affinity gain is controlled by 1) the distance between recognition modules, 2) the scaffold flexibility, and, importantly, 3) the strength of the monovalent interaction. We show that the bivalency effect can extend beyond 150 Å and discuss how, on the contrary, weak monovalent interactions reduce the concentration threshold for cross‐linking. The findings are of interest for inhibitor design.
Mild Ring‐Opening 1,3‐Hydroborations of Non‐Activated Cyclopropanes
Authors: Wang Di , Xue Xiao‐Song , Houk Kendall N. , Shi Zhuangzhi
Published: October 2018

The Brown hydroboration reaction, first reported in 1957, is the addition of B−H across an olefin in an anti‐Markovnikov fashion. Here, we solved a long‐standing problem on mild 1,3‐hydroborations of non‐activated cyclopropanes. A three‐component system including cyclopropanes, boron halides, and hydrosilanes has been developed for borylative ring‐opening of cyclopropanes following the anti‐Markovnikov rule, under mild reaction conditions. Density functional theory (M06‐2X) calculations show that the preferred pathway involves a cationic boron intermediate which is quenched by hydride transfer from the silane.
Counteranion‐ and Solvent‐Mediated Chirality Transfer in the Supramolecular Polymerization of Luminescent Platinum(II) Complexes
Authors: Wan Qingyun , Xiao Xin‐Shan , To Wai‐Pong , Lu Wei , Chen Yong , Low Kam‐Hung , Che Chi‐Ming
Published: October 2018

The chirality of supramolecular polymeric materials is subtly affected by a delicate balance among various non‐covalent interactions, the details of which are inadequately understood. Now, a fine balance of intermolecular interactions, including closed‐shell metal–metal, dispersive and electrostatic interactions, is used to direct the delicate orientation of monomeric building blocks, thereby achieving the successful preparation of different nanostructures with distinct supramolecular chirality. Moreover, kinetically trapped and thermodynamically stable aggregates were monitored over time in the supramolecular polymerization of cationic PtII complexes. The dynamic self‐assembly process can be successfully controlled by modifying the counteranion and solvent composition. A chiral doping approach can also be used to induce the chirality of an achiral PtII complex at the supramolecular level.
Novel Fe3O4/hydroxyapatite/β‐cyclodextrin nanocomposite adsorbent: Synthesis and application in heavy metal removal from aqueous solution
Authors: Ansari Ali , Vahedi Shahrokh , Tavakoli Omid , Khoobi Mehdi , Faramarzi Mohammad Ali
Published: October 2018

The increased global concern on environmental protection has made researchers focus their attention on new and more efficient methods of pollutant removal. In this research, novel nanocomposite adsorbents,i.e., magnetic hydroxyapatite (Fe3O4@HA) and magnetic hydroxyapatite β‐cyclodextrin (Fe3O4@HA‐CD) were synthesized and used for heavy metal removal. The adsorbents were characterized by FTIR, XRD, TGA, VSM, and SEM. In order to investigate the effect of β‐cyclodextrin (β‐CD) removal efficiency, adsorption results of nine metal ions were compared for both adsorbents. β‐CD showed the most increasing effect for Cd2+ and Cu2+ removal, so these two ions were selected for further studies. The effect of diverse parameters including pH, contact time, initial metal ion concentration and adsorbent dosage on the adsorption process was discussed. The optimum pH was 6 and adsorption equilibrium was achieved after 1 hr. Adsorption kinetic data were well fitted by pseudo‐second‐order model proposing that metal ions were adsorbed via chemical reaction. Adsorption isotherm was best described by the Langmuir model, and maximum adsorption capacity for Cd2+ and Cu2+ was 100.00 and 66.66 (mg/g), respectively. Desorption experiment was also done, and the most efficient eluent used for desorption of metal ions was EDTA (0.001 M) with 91% and 88% of Cd2+ and Cu2+ release, respectively. Recyclability studies also showed a 19% decrease in the adsorption capacity of the adsorbent after five cycles of regeneration. Therefore, the synthesized adsorbents were recognized as potential candidates for heavy metal adsorption applications.
Cytotoxicity of new pyridazin‐3(2H)‐one derivatives orchestrating oxidative stress in human triple‐negative breast cancer (MDA‐MB‐468)
Authors: Bouchmaa Najat , Ben Mrid Reda , Boukharsa Youness , Nhiri Mohamed , Ait Mouse Hassan , Taoufik Jamal , Ansar M'hammed , Zyad Abdelmajid
Published: October 2018

Triple‐negative breast cancer (TNBC) is a complex and aggressive subtype of breast cancer characterized by high morbidity and mortality. In the absence of targeted therapy, only chemotherapy is available in this case of cancer. The current study investigated the antitumor effect of new pyridazin‐3(2H)‐one derivatives on the human TNBC cell line, MD‐MB‐468. The in vitro cytotoxic activities were investigated using the tetrazolium‐based MTT assay. Lipid peroxidation, H2O2 content, and the specific activities of antioxidant enzymes were also determined. Two molecules, 6f and 7h, were found to be selectively highly active against tumor cells with IC50 values of 3.12 and 4.9 µM, respectively. Furthermore, cells exposed to 6f showed a significant increase in H2O2 and lipid peroxidation levels, accompanied by a decrease in the enzyme activities of glutathione reductase (GR) and thioredoxin reductase (TrxR). The cytotoxicity of the compound 6f may improve the therapeutic efficacy of the current treatment for TNBC via the inhibition of GR and TrxR activities.
Mxene‐Directed Dual Amphiphilicity at Liquid, Solid, and Gas Interfaces
Authors: Duan Jingjing , Jiang Lili , Guo Xin , Chen Sheng , Wang Guoxiu , Zhao Chuan
Published: October 2018

MXenes represent a category of two‐dimensional functional nanomaterials with remarkable structural and chemical properties, which have been manipulated into different architectures for versatile applications. These manipulation processes generally take place at the interfaces between liquid, solid, and gas; and therefore, the investigation of the interfacial property of MXenes is the key. Here we show that MXenes exhibit amphiphilic behaviours at interfaces. Different from common amphiphiles, MXenes have the dual function of both colloidal and molecular activities owing to their two abrupt structural length scales: their large lateral sheet size allows for behaving like colloidal amphiphiles for creating emulsions, while their small sheet thickness allows for serving as molecular amphiphiles for dispersing solid substances. Further, such dual colloidal‐molecular amphiphility has driven MXenes to accumulate at the interfaces of water and nitrogen gas, and the assembly into thin film electrodes for electrochemical energy storage. All these findings open up enormous opportunities for processing various MXenes‐related functional materials and devices.
Synergistic effect of rice bran extract and extremely low‐frequency electromagnetic fields on dermal papilla/melanocytes in melanogenesis
Authors: Kwon Soon‐Joung , Kim Yu‐Mi , Jang Hyun‐Jun , Seo Young‐Kwon
Published: October 2018

Melanocytes in hair are located around dermal papilla cells at the tip of the hair follicle. In this study, we examined the melanogenesis of a three‐dimensional (3D) hair dermal papilla model treated with natural extracts and electromagnetic fields (EMFs). The 3D model involved dermal papilla‐like tissue (DPLT), an aggregation of a mixture of dermal papilla cells, and melanocytes in microwells. Rice bran extract (RBE), an EMF, and RBE/EMF were applied to different DPLT groups. The LDH assay indicated no cell stress in all experimental groups, and detection of tyrosinase activity demonstrated high activity in the RBE/EMF group. Western blot analysis of the RBE, EMF, and RBE/EMF groups revealed increased MITF, TRP‐1, and tyrosinase expression. In addition, the mRNA expression of ET‐1, laminin, bFGF, β‐catenin, MITF, and tyrosinase was increased in the RBE/EMF group, as demonstrated by RT‐qPCR analysis. HMB45 and Fontana–Masson immunostaining showed that the RBE/EMF group had the highest melanin content. Therefore, RBE and EMF may be used as a material and therapy, respectively, for the treatment of vitiligo and white hair, through activation of melanogenesis in melanocytes. Bioelectromagnetics. 39:595–603, 2018. © 2018 The Authors. Bioelectromagnetics Published by Wiley Periodicals, Inc..
RNAs, Phase Separation, and Membrane‐Less Organelles: Are Post‐Transcriptional Modifications Modulating Organelle Dynamics?
Authors: Drino Aleksej , Schaefer Matthias R.
Published: October 2018

Membranous organelles allow sub‐compartmentalization of biological processes. However, additional subcellular structures create dynamic reaction spaces without the need for membranes. Such membrane‐less organelles (MLOs) are physiologically relevant and impact development, gene expression regulation, and cellular stress responses. The phenomenon resulting in the formation of MLOs is called liquid–liquid phase separation (LLPS), and is primarily governed by the interactions of multi‐domain proteins or proteins harboring intrinsically disordered regions as well as RNA‐binding domains. Although the presence of RNAs affects the formation and dissolution of MLOs, it remains unclear how the properties of RNAs exactly contribute to these effects. Here, the authors review this emerging field, and explore how particular RNA properties can affect LLPS and the behavior of MLOs. It is suggested that post‐transcriptional RNA modification systems could be contributors for dynamically modulating the assembly and dissolution of MLOs.
Impact of postoperative complications on outcomes after oesophagectomy for cancer
Authors: Goense L , Meziani J , Ruurda J P , van Hillegersberg R
Published: October 2018

Background

To allocate healthcare resources optimally, complication-related quality initiatives should target complications that have the greatest overall impact on outcomes after surgery. The aim of this study was to identify the most clinically relevant complications after oesophagectomy for cancer in a nationwide cohort study.

Methods

Consecutive patients who underwent oesophagectomy for cancer between January 2011 and December 2016 were identified from the Dutch Upper Gastrointestinal Cancer Audit. The adjusted population attributable fraction (PAF) was used to estimate the impact of specific postoperative complications on the clinical outcomes postoperative mortality, reoperation, prolonged hospital stay and readmission to hospital in the study population. The PAF represents the percentage reduction in the frequency of a given outcome (such as death) that would occur in a theoretical scenario where a specific complication (for example anastomotic leakage) was able to be prevented completely in the study population.

Results

Some 4096 patients were analysed. Pulmonary complications and anastomotic leakage had the greatest overall impact on postoperative mortality (risk-adjusted PAF 44·1 and 30·4 per cent respectively), prolonged hospital stay (risk-adjusted PAF 31·4 and 30·9 per cent) and readmission to hospital (risk-adjusted PAF 7·3 and 14·7 per cent). Anastomotic leakage had the greatest impact on reoperation (risk-adjusted PAF 47·1 per cent). In contrast, the impact of other complications on these outcomes was relatively small.

Conclusion

Reducing the incidence of pulmonary complications and anastomotic leakage may have the greatest clinical impact on outcomes after oesophagectomy.
Focal adhesion kinase activation limits efficacy of Dasatinib in c‐Myc driven hepatocellular carcinoma
Authors: Liu Xianqiong , Song Xinhua , Zhang Jie , Xu Zhong , Che Li , Qiao Yu , Ortiz Pedraza Yunuen , Cigliano Antonio , Pascale Rosa M. , Calvisi Diego F. , Liu Yanju , Chen Xin
Published: October 2018

Hepatocellular carcinoma (HCC) is a deadly malignancy with limited treatment options. Recently, it was found that Dasatinib treatment led to synthetic lethality in c‐Myc high‐expressing human cancer cells due to inhibition of p‐Lyn. Overexpression of c‐Myc is frequently seen in human HCC. We investigated the sensitivity to Dasatinib in vitro using HCC cell lines and in vivo using c‐Myc mouse HCC model. We found that HCC cell line responsiveness to Dasatinib varied significantly. However, there was no correlation between c‐Myc expression and IC50 to Dasatinib. In c‐Myc‐induced HCC in mice, tumors continued to grow despite Dasatinib treatment, although the eventual tumor burden was lower in Dasatinib treatment cohort. Molecular analyses revealed that Dasatinib was effective in inhibiting p‐Src, but not p‐Lyn, in HCC. Importantly, we found that in HCC cell lines as well as c‐Myc mouse HCC, Dasatinib treatment induced up regulation of activated/phosphorylated (p)‐focal adhesion kinase(FAK). Concomitant treatment of HCC cell lines with Dasatinib and FAK inhibitor prevented Dasatinib‐induced FAK activation, leading to stronger growth restraint. Altogether, our results suggest that Dasatinib may have limited efficacy as single agent for HCC treatment. Combined treatment with Dasatinib with FAK inhibitor might represent a novel therapeutic approach against HCC.
Antioxidant Defenses in Wild Growing Halophyte Crithmum maritimum from Inland and Coastline Populations
Authors: Gil Lorenzo , Pinya Samuel , Tejada Silvia , Capó Xavier , Sureda Antoni
Published: October 2018

Traditional Mediterranean diet includes the halophyte Crithmum maritimum L. (Apiaceae) which can be found in the coastline of the Balearic Islands but also inland. Both areas differed in the environmental conditions, mainly in salinity which can affect the oxidative status of this species. The aim was to evaluate the antioxidant enzyme activities, polyphenols and the lipid peroxidation in leaves of wild C. maritimum growing in a natural coastal area influenced by marine salinity and an inland area without marine influence. The activities of the antioxidant enzymes catalase, superoxide dismutase and glutathione peroxidase as well as polyphenol and reduced glutathione content were significantly higher in the samples from coastline population, whereas no significant differences were found in glutathione reductase activity and in malondialdehyde levels. The production of H2O2 was also significantly higher in the population from coastline. In conclusion, C. maritimum adapt their antioxidant defense machinery to the different salinity conditions, avoiding the instauration of oxidative stress.
The Bacterial Extracellular Matrix Protein TapA Is a Two‐Domain Partially Disordered Protein
Authors: Abbasi Razan , Mousa Reem , Dekel Noa , Amartely Hadar , Danieli Tsafi , Lebendiker Mario , Levi‐Kalisman Yael , Shalev Deborah E. , Metanis Norman , Chai Liraz
Published: October 2018

Biofilms are aggregates of microbial cells that form on surfaces and at interfaces, and are encased in an extracellular matrix. In biofilms made by the soil bacterium Bacillus subtilis, the protein TapA mediates the assembly of the functional amyloid protein TasA into extracellular fibers, and it anchors these fibers to the cell surface. We used circular dichroism and NMR spectroscopy to show that, unlike the structured TasA, TapA is disordered. In addition, TapA is composed of two weakly interacting domains: a disordered C‐terminal domain and a more structured N‐terminal domain. These two domains also exhibited different structural changes in response to changes in external conditions, such as increased temperatures and the presence of lipid vesicles. Although the two TapA domains weakly interacted in solution, their cooperative interaction with lipid vesicles prevented disruption of the vesicles. These findings therefore suggest that the two‐domain composition of TapA is important in its interaction with single or multiple partners in the extracellular matrix in biofilms.
Improving dry‐fractionated corn fermentation by supplementation of corn germ meal and pasta mill feed from agro‐food industries
Authors: Kumar Deepak , Singh Vijay
Published: October 2018

Background and objectives

Separation of germ from corn using dry fractionation in modified dry‐grind processes results in the sluggish and incomplete fermentation of remaining corn because of nutrient deficiency for yeast. This study investigated the use of two low‐value co‐products, germ meal from corn wet milling and mill feed from pasta manufacturing, as additives to improve the fermentation of corn grits.

Findings

Addition of 5% germ meal or 2.5% mill feed in corn grits resulted in the complete (no residual glucose) and faster fermentation, compared to 4.3% residual glucose during fermentation of only corn grits. Final ethanol yield (0.51 L/kg) was about 22% higher compared to control (0.42 L/kg). Increase in supplementation (10% of grits) further increased the fermentation rates, however, led to similar final ethanol concentrations and ethanol yields.

Conclusions

Both germ meal and pasta mill feed can improve fermentation rate and efficiency of dry‐fractionated grits and avoid the need for expensive supplements or enzymes.

Significance and novelty

This research provides an innovative solution to the challenge of inefficient fermentation of dry‐fractionated corn and also identifies new potential market for two low‐value co‐products from the agro‐food industries.
Microtube‐Membrane Methodology for Electrochemical Synthesis and Study of Electroactive and Ionically Conductive Materials, and the Conductivity of MnO2
Authors: Experton Juliette , Wu Xiaojian , Wang Gelan , Martin Charles R.
Published: October 2018

A membrane‐based methodology for electrochemical synthesis and study of electroactive and ionically conductive materials is described. The Li+‐intercalation material MnO2 was used to demonstrate this methodology. The membrane was a polymeric support containing monodisperse gold microtubes (diameter 600 nm) that span the thickness of the membrane. Bipolar electrochemical synthesis of MnO2, from Mn2+ solutions, was conducted across this membrane, resulting in deposition of monodisperse, hemispherical MnO2 particles at the open ends of the tubes on one face of the membrane. The resulting microtube/MnO2 composite membrane makes a convenient construct for investigating the transport properties of the MnO2 particles. This was accomplished by mounting the membrane in a U‐tube cell, placing electrolyte solutions on either side, and driving an ionic current through the membrane. The ionic conductivity of MnO2 was measured in this way, and found to be 40±10 μS cm−1 when LiCl or LiClO4 solutions were used as the electrolyte. The mechanism of ionic conductivity through these MnO2 particles is discussed.
Strategies for the Design of Donors and Precursors of Reactive Sulfur Species
Authors: Xu Shi , Hamsath Akil , Neill Deshka L. , Wang Yingying , Yang Chun‐tao , Xian Ming
Published: October 2018

Reactive sulfur species (RSS) play regulatory roles in biological systems. Many RSS are highly reactive and transient molecules, making their study difficult. RSS donors or precursors, which are used to specifically produce or deliver RSS, are useful research tools, as well as possible therapeutic agents. In this Minireview, we summarized the chemical strategies that have been used in the design of donors/precursors of hydrogen sulfide relevant RSS (including hydrogen sulfide, hydrogen polysulfides, persulfides, and S‐nitroso‐hydrogen sulfide). The potential problems of applying these strategies in biological settings are also discussed.
Designing Two‐Dimensional Nanosheets for Improving Drug Delivery to Fucose‐Receptor‐Overexpressing Cancer Cells
Authors: Gupta Nitin , Jangid Ashok Kumar , Singh Mandeep , Pooja Deep , Kulhari Hitesh
Published: October 2018

Targeted drug delivery has shown promise in improving the therapeutic efficacy of anticancer drugs. Gemcitabine hydrochloride (GEM) is a broad‐range chemotherapeutic agent for the treatment of various cancers. However, systemic use of free GEM is restricted because of its poor physicochemical properties and nonspecific drug delivery, resulting in dose‐dependent adverse effects. In this study, a fucose‐conjugated graphene oxide (GO)‐based smart targeted nanocarrier system was designed to provide high loading, sustained release, and targeted high concentrations of GEM to cancer cells. Fucose‐conjugated GO nanosheets (FGONS) and GEM‐loaded fucose‐conjugated GO nanosheets (GEM‐FGONS) were prepared and characterized by various techniques. About 36.2 % of GEM was loaded to the FGONS, which showed a pH‐dependent release over a period of 48 h. A colloidal suspension of GEM‐FGONS was found to be physiochemically stable for up to 96 h. In cytotoxicity studies, GEM‐FGONS demonstrated time‐ and dose‐dependent high toxicities on fucose‐receptor‐overexpressing MDA‐MB‐231 human breast cancer cells and A549 human lung cancer cells. Moreover, targeted formulations were more efficacious than non‐targeted or free GEM. Overall, bioconjugation of fucose helps in the stabilizing and targeting of graphene oxide nanosheets.