bluuebunny/crossref_metadata_2025 huggingface dataset:
Enzyme‐Instructed Self‐Assembly (EISA) and Hydrogelation of Peptides
Authors: Gao Jie , Zhan Jie , Yang Zhimou
Published: April 2019

Self‐assembly is a powerful tool for constructing supramolecular materials for many applications, ranging from energy harvesting to biomedicine. Among the methods to prepare supramolecular materials for biomedical applications, enzyme‐instructed self‐assembly (EISA) has several advantages. Herein, the unique properties and advantages of EISA in preparing biofunctional supramolecular nanomaterials and hydrogels from peptides are highlighted. EISA can trigger molecular self‐assembly in situ. Therefore, using overexpression enzymes in disease sites, supramolecular materials can be formed in situ to improve the selectivity and efficacy of the treatment. The precursor may be involved during the EISA process, and it is actually a two‐component self‐assembly process. The precursor can help to stabilize the assembled nanostructures of hydrophobic peptides formed by EISA. More importantly, the precursor may determine the outcome of molecular self‐assembly. Recently, it was also observed that EISA can kinetically control the peptide folding and morphology and cellular uptake behavior of supramolecular nanomaterials. With the combination of other methods to trigger molecular self‐assembly, researchers can form supramolecular nanomaterials in a more precise mode and sometimes under spatiotemporal control. EISA is a powerful and unique methodology to prepare supramolecular biofunctional materials that cannot be generated from other common methods.
MXene Ti3C2Tx: A Promising Photothermal Conversion Material and Application in All‐Optical Modulation and All‐Optical Information Loading
Authors: Wang Cong , Wang Yunzheng , Jiang Xiantao , Xu Jiawei , Huang Weichun , Zhang Feng , Liu Jiefeng , Yang Fumei , Song Yufeng , Ge Yanqi , Wu Qing , Zhang Meng , Chen Hong , Liu Jie , Zhang Han
Published: April 2019

All‐optical modulators, where one light modulates the parameters of another light (intensity, phase, frequency, etc.) without external electronic control, have drawn extraordinary attention in all‐optical information processing. In this contribution, by taking advantage of the two‐pass structure of Michelson interferometer and the strong photothermal conversion efficiency of MXene nanomaterials, an all‐optical modulator is demonstrated with a modulation depth of >27 dB, a free spectrum range of 16.8 nm and a pump‐induced phase shift slope of 0.043 π mW−1. Moreover, the all‐optical modulator is successfully employed to switch on/off the intensity of the signal light and load information from one channel to another with comparable response time and baudrate. It is believed that the MXene‐based all‐optical modulator will open a door to practical applications of 2D materials‐based all‐optical devices in all‐optical signal processing.
Memristors for Hardware Security Applications
Authors: Pang Yachuan , Gao Bin , Lin Bohan , Qian He , Wu Huaqiang
Published: April 2019

Memristors have recently been explored for hardware security applications such as true random number generators (TRNGs) and physical unclonable functions (PUFs). Several typical designs for memristor‐based PUFs and TRNGs are summarized. PUFs are a novel hardware security primitive utilizing the intrinsic randomness of a physical system, and PUFs have broad potential applications in key protection and authentication. Unlike most conventional PUFs based on manufacturing variations, memristors have both manufacturing variations and intrinsic randomness in their resistance‐switching mechanisms that can be utilized as entropy sources; for instance, device to device (D2D) variation and probabilistic switching behaviors. TRNGs are a cornerstone of hardware security and are widely used in secure chips and encryption protocols. Memristors have random telegraph noise (RTN) and cycle to cycle (C2C) variation characteristics that can be used for high‐quality TRNGs. Here, research progress in memristor‐based PUFs and TRNGs is reviewed, and how these sources of randomness are leveraged to generate security primitives is discussed.
Computation‐Guided Design of LiTaSiO5, a New Lithium Ionic Conductor with Sphene Structure
Authors: Xiong Shan , He Xingfeng , Han Aijie , Liu Zhantao , Ren Zhensong , McElhenny Brian , Nolan Adelaide M. , Chen Shuo , Mo Yifei , Chen Hailong
Published: April 2019

The development of all‐solid‐state Li‐ion batteries requires solid electrolyte materials with many desired properties, such as ionic conductivity, chemical and electrochemical stability, and mechanical durability. Computation‐guided materials design techniques are advantageous in designing and identifying new solid electrolytes that can simultaneously meet these requirements. In this joint computational and experimental study, a new family of fast lithium ion conductors, namely, LiTaSiO5 with sphene structure, are successfully identified, synthesized, and demonstrated using a novel computational design strategy. First‐principles computation predicts that Zr‐doped LiTaSiO5 sphene materials have fast Li diffusion, good phase stability, and poor electronic conductivity, which are ideal for solid electrolytes. Experiments confirm that Zr‐doped LiTaSiO5 sphene structure indeed exhibits encouraging ionic conductivity. The lithium diffusion mechanisms in this material are also investigated, indicating the sphene materials are 3D conductors with facile 1D diffusion along the [101] direction and additional cross‐channel migration. This study demonstrates a novel design strategy of activating fast Li ionic diffusion in lithium sphenes, a new materials family of superionic conductors.
Why are Hot Holes Easier to Extract than Hot Electrons from Methylammonium Lead Iodide Perovskite?
Authors: Dursun Ibrahim , Maity Partha , Yin Jun , Turedi Bekir , Zhumekenov Ayan A. , Lee Kwang Jae , Mohammed Omar F. , Bakr Osman M.
Published: April 2019

Charge‐carriers photoexcited above a semiconductor's bandgap rapidly thermalize to the band‐edge. The cooling of these difficult to collect “hot” carriers caps the available photon energy that solar cells–including efficient perovskite solar cells–may utilize. Here, the dynamics and efficiency of hot carrier extraction from MAPbI3 (MA = methylammonium) perovskite by spiro‐OMeTAD (a hole‐transporting layer) and TiO2 (an electron‐transporting layer) are investigated and explained using both ultrafast electronic spectroscopy and theoretical modeling. Time‐resolved spectroscopy reveals a quasi‐equilibrium distribution of hot carriers forming upon excess‐energy excitation of the perovskite–a distribution largely unaffected by the presence of TiO2. In contrast, the quasi‐equilibrium distribution of hot carriers is virtually nonexistent when spiro‐OMeTAD is present, which is indicative of efficient hot hole extraction at the interface of MAPbI3. Density functional theory calculations predict that deep energy‐levels of MAPbI3 exhibit electronically delocalized character, with significant overlap with the localized valence band charge of the spiro‐OMeTAD molecules lying on the surface of MAPbI3. Consequently, hot holes are easily extracted from the deep energy‐levels of MAPbI3 by spiro‐OMeTAD. These findings uncover the origins of efficient hot hole extraction in perovskites and offer a practical blueprint for optimizing solar cell interlayers to enable hot carrier utilization.
Shape Conformal and Thermal Insulative Organic Solar Absorber Sponge for Photothermal Water Evaporation and Thermoelectric Power Generation
Authors: Zhu Liangliang , Ding Tianpeng , Gao Minmin , Peh Connor Kang Nuo , Ho Ghim Wei
Published: April 2019

Solar‐driven interfacial vaporization by localizing solar‐thermal energy conversion to the air–water interface has attracted tremendous attention due to its high conversion efficiency for water purification, desalination, energy generation, etc. However, ineffective integration of hybrid solar thermal devices and poor material compliance undermine extensive solar energy exploitation and practical outdoor use. Herein, a 3D organic bucky sponge that has a combination of desired chemical and physical properties, i.e., broadband light absorbing, heat insulative, and shape‐conforming abilities that render efficient photothermic vaporization and energy generation with improved operational durability is reported. The highly compressible and readily reconfigurable solar absorber sponge not only places less constraints on footprint and shape defined fabrication process but more importantly remarkably improves the solar‐to‐vapor conversion efficiency. Notably, synergetic coupling of solar‐steam and solar‐electricity technologies is realized without trade‐offs, highlighting the practical consideration toward more impactful solar heat exploitation. Such solar distillation and low‐grade heat‐to‐electricity generation functions can provide potential opportunities for fresh water and electricity supply in off‐grid or remote areas.
Advanced Carbon‐Based Anodes for Potassium‐Ion Batteries
Authors: Wu Xuan , Chen Yanli , Xing Zheng , Lam Christopher Wai Kei , Pang Su‐Seng , Zhang Wei , Ju Zhicheng
Published: April 2019

The ever‐increasing demand for large‐scale energy storage systems requires novel battery technologies with low‐cost and sustainable properties. Due to earth‐abundance and cost effectiveness, the development of rechargeable potassium ion batteries (PIBs) has recently attracted much attention. Since carbon‐based materials are abundant, inexpensive, nontoxic, and safe, extensive feasibility investigations have suggested that they can become promising anode materials for PIBs. This review not only attempts to provide better understanding of the potassium storage mechanism, but also summarizes the availability of new carbon‐based materials and their electrochemical performance covering graphite, graphene, and hard carbon materials plus carbon‐based composites. Finally, the critical issues, challenges, and perspectives are discussed to demonstrate the developmental direction of PIBs.
TBHP‐Initiated Transamidation of Secondary Amides via C−N Bond Activation: A Metal‐Free Approach
Authors: Mishra Ankush , Chauhan Swati , Verma Pratibha , Singh Sundaram , Srivastava Vandana
Published: April 2019

In the present study, a facile, efficient, and environmentally benign approach for secondary amide transamidation by using tert‐butyl hydroperoxide (TBHP) as a radical initiator has been developed. The method involves a two‐step approach in which the first step is the C−N bond activation via N‐functionalization with Boc to weaken the amide C−N bond by making amide non‐planar and electronically destabilized. In the second step, an N‐Boc‐activated secondary amides undergoes transamidation with the various primary, secondary, aliphatic, aromatic, as well as the sterically hindered amines, using TBHP as a radical initiator to give the products in good to excellent yields. TBHP is easily available, inexpensive, and an environmentally friendly radical initiator. A broad substrate scope with extensive functional group tolerance, metal and catalyst‐free approach, and operational simplicity are the important characteristics of the present protocol.
Boron‐Catalyzed Hydroamination/Hydroallylation and Hydroamination/Hydrocyanation of Unactivated Alkynes
Authors: Shibuya Masatoshi , Kawano Shohei , Fujita Shoji , Yamamoto Yoshihiko
Published: April 2019

B(C6F5)3‐catalyzed tandem double hydrofunctionalization reactions initiated by intramolecular hydroamination of unactivated alkynes are described herein. In the hydroamination/hydroallylation reaction, in situ preparation of anhydrous B(C6F5)3 from B(C6F5)3 ⋅ nH2O and the use of 2,6‐di‐tert‐butylphenol as a proton source were effective. In the hydroamination/hydrocyanation reaction, a combination of B(C6F5)3 ⋅ nH2O and H2O as the proton source provided good results.
Scandium‐Triflate‐Catalyzed Regioselective Ring Opening of Purines with Aminocyclopropanes
Authors: Liang Tao , Xie Ming‐Sheng , Qu Gui‐Rong , Guo Hai‐Ming
Published: April 2019

An efficient route to acyclic purine nucleoside analogues with an amino group at the C1′ position of the side chains has been reported. Using Sc(OTf)3 as the catalyst, the ring‐opening reaction of purines with aminocyclopropanes afforded acyclic nucleoside analogues with moderate to good yields and in a regioselective manner. Furthermore, phenyl cyclopropane also gave the desired acyclic nucleoside analogue with a phenyl linked at C1′ position. Furthermore, generation of a penciclovir analogue may also occur from the ring‐opening product via a reduction reaction.
Soybean Trypsin Inhibitor Assay: The Sequence Effect of Adding Reagents, Factors Involved, and Mechanistic Explanations
Authors: Liu Keshun
Published: April 2019

For assaying trypsin inhibitor activity (TIA) of protein‐based inhibitors, the sequence of adding enzyme, substrate, and inhibitor has profound effects on measured values. This study systematically investigated this reagents’ sequence effect, with regard to factors involved and mechanistic explanations, using raw and toasted soy flours. When the AOCS standard method (Ba 12‐75), which features adding substrates last, was used, TIA values measured varied greatly with not only the pH and Ca2+ concentration of the premix (the mixture of the first two reagents) and preincubation time, but also extractant, postextraction workup (addition of Tris assay buffer and/or centrifugation), and extract dilution levels. Raw and toasted soy flours showed different TIA changes with these factors. Yet, when the standard method was slightly modified by adding enzyme last, TIA values obtained were unaffected by the premix pH and Ca2+ concentration, preincubation time, and extract dilution levels, and thus remained constant. Strong interactions of some factors also existed, as exemplified by significant suppression of the reagents’ sequence effect by the Ca2+ presence in the premix when the premix was neutral and alkaline, but not acidic. These observations are explainable by three proposed mechanisms: limited hydrolysis of the trypsin inhibitor by trypsin in acidic medium according to a reactive site model of the inhibitor, trypsin autolysis in neutral or alkaline medium, and trypsin protection by Ca2+. This study provided a strong basis for modifying the standard method. Because the reactive site model of soybean trypsin inhibitors is applicable to many other protein‐based proteinase inhibitors, the reagents’ sequence will affect the results when assaying their activities.
MicroRNA‐1225 activates Keap1‐Nrf2‐HO‐1 signalling to inhibit TNFα‐induced osteoclastogenesis by mediating ROS generation
Authors: Reziwan Keyimu , Sun Dalei , Zhang Bo , Zhao Zhihe
Published: April 2019

The influence of miRNA‐1225‐5p (miR‐1225) and Keap1‐Nrf2 signalling on in vitro osteoclast differentiation in mouse models was studied along with the underlying mechanism. In differentiated bone marrow–derived macrophages (BMMs), downregulated miR‐1225 and upregulated Keap1 were observed in the course of receptor activator of nuclear factor kappa‐Β ligand (RANKL)–mediated osteoclastogenesis. Bioinformatic analysis and dual‐luciferase reporter assay showed that miR‐1225 targeted the three prime untranslated region (3′‐UTR) of Keap1 mRNA and caused its degradation. Transfection of a miR‐1225 mimic or Keap1 silencing was found to inhibit osteoclastogenesis as evidenced by loss of activity and tartrate‐resistant acid phosphatase (TRAP) staining, decreased expression of osteoclast markers, and associated genes and reduced number of multinuclear cells; in contrast, a miR‐1225 inhibitor or Keap1 overexpression increased this process. In addition, transfection with the miR‐1225 mimic or Keap1 silencing decreased the level of tumour necrosis factor (TNF)α, which was increased after miR‐1225 inhibition and Keap1 overexpression. TNFα overexpression promoted Keap1 depletion–inhibited BMM osteoclastogenesis. Furthermore, reactive oxygen species (ROS) generation that is related to osteoclastogenesis and the Keap‐Nrf2 axis was impaired by the miR‐1225 mimic and Keap1 silencing, whereas it was increased following miR inhibition and overexpression of Keap1 and TNFα. Thus, miR‐1225 inhibits osteoclastogenesis by directly activating the Keap1‐Nrf2‐HO‐1 axis to repress TNFα‐mediated ROS generation.

Significance of the study

Our study showed that miR‐1225 is significant in multiple malignancies and other pathological reactions. Transfection of a miR‐1225 mimic or Keap1 silencing inhibits osteoclastogenesis. After miR‐1225 inhibition and Keap1 overexpression, TNF was increased. TNFα overexpression promoted Keap1 depletion–inhibited BMM osteoclastogenesis. miR‐1225 activates Keap1‐Nrf2‐HO‐1 signal to inhibit TNFα‐induced osteoclastogenesis.
Heavy Enzymes and the Rational Redesign of Protein Catalysts
Authors: Scott Alan F. , Luk Louis Y.‐P. , Tuñón Iñaki , Moliner Vicent , Allemann Rudolf K.
Published: April 2019

An unsolved mystery in biology concerns the link between enzyme catalysis and protein motions. Comparison between isotopically labelled “heavy” dihydrofolate reductases and their natural‐abundance counterparts has suggested that the coupling of protein motions to the chemistry of the catalysed reaction is minimised in the case of hydride transfer. In alcohol dehydrogenases, unnatural, bulky substrates that induce additional electrostatic rearrangements of the active site enhance coupled motions. This finding could provide a new route to engineering enzymes with altered substrate specificity, because amino acid residues responsible for dynamic coupling with a given substrate present as hotspots for mutagenesis. Detailed understanding of the biophysics of enzyme catalysis based on insights gained from analysis of “heavy” enzymes might eventually allow routine engineering of enzymes to catalyse reactions of choice.
Unravelling the Mechanism and Selectivity of the NHC‐catalyzed Three‐Membered Ring‐Opening/Fluorination of Epoxy Enals: A DFT Study
Authors: Wang Yang , Qu Ling‐Bo , Lan Yu , Wei Donghui
Published: April 2019

Regio‐ and stereo‐divergent construction of carbon‐fluorine bond remains a challenge in fluorine chemistry, especially reactions involving fluorination at the α‐position of a carbonyl group. Herein, we present a detailed study for predicting the origins of regio‐ and stereo‐selectivity for organocatalyst catalyzed fluorination reaction. Possible mechanisms and origins of selectivities of NHC (N‐heterocyclic carbene)‐catalyzed fluorination reaction of epoxy‐enals were investigated by using DFT (density functional theory) method. The computational results show that the C−F bond formation step determines stereoselectivity and regioselectivity. LP⋅⋅⋅π and C−H⋅⋅⋅F interactions were identified as the main contributors for the stereoselectivity control, in which R‐configured product was preferred. It was found that α‐fluorination is more energetically favorable than γ‐fluorination, which is possibly due to higher reactivity of the α‐carbon; deduced by the local reactivity index analysis. This work would provide valuable insights for predicting origin of the selectivity of fluorination reactions and developing of more effective organocatalyst with high selectivity.
Ion Association in Lanthanide Chloride Solutions
Authors: Finney Aaron R. , Lectez Sébastien , Freeman Colin L. , Harding John H. , Stackhouse Stephen
Published: April 2019

A better understanding of the solution chemistry of the lanthanide (Ln) salts in water would have wide ranging implications in materials processing, waste management, element tracing, medicine and many more fields. This is particularly true for minerals processing, given governmental concerns about lanthanide security of supply and the drive to identify environmentally sustainable processing routes. Despite much effort, even in simple systems, the mechanisms and thermodynamics of LnIII association with small anions remain unclear. In the present study, molecular dynamics (MD), using a newly developed force field, provide new insights into LnCl3(aq) solutions. The force field accurately reproduces the structure and dynamics of Nd3+, Gd3+ and Er3+ in water when compared to calculations using density functional theory (DFT). Adaptive‐bias MD simulations show that the mechanisms for ion pairing change from dissociative to associative exchange depending upon cation size. Thermodynamics of association reveal that whereas ion pairing is favourable, the equilibrium distribution of species at low concentration is dominated by weakly bound solvent‐shared and solvent‐separated ion pairs, rather than contact ion pairs, reconciling a number of contrasting observations of LnIII–Cl association in the literature. In addition, we show that the thermodynamic stabilities of a range of inner sphere and outer sphere
coordination complexes are comparable and that the kinetics of anion binding to cations may control solution speciation distributions beyond ion pairs. The techniques adopted in this work provide a framework with which to investigate more complex solution chemistries of cations in water.
Phantom walkabouts: A customisable source location privacy aware routing protocol for wireless sensor networks
Authors: Gu Chen , Bradbury Matthew , Jhumka Arshad
Published: April 2019

Source location privacy (SLP) is an important property for a large class of security‐critical wireless sensor network (WSN) applications such as monitoring and tracking. In the seminal work on SLP, phantom routing was proposed as a viable approach to address SLP. However, recent work has shown some limitations of phantom routing such as poor data yield and low SLP. In this paper, we propose phantom walkabouts, a novel and more general version of phantom routing, which performs phantom routes of variable lengths. Through extensive simulations, we show that phantom walkabouts provides high SLP level than phantom routing under specific network configuration.
Phosphorene‐Supported Transition‐Metal Dimer for Effective N2 Electroreduction
Authors: Tang Qing , Jiang De‐en
Published: April 2019

The electrochemical reduction of N2 to NH3 at ambient conditions is a promising alternative to the energy‐intensive, high‐temperature, high‐pressure Haber‐Bosch process. But it is extremely challenging to find an electrocatalyst that can effectively activate N2 and reduce it to NH3. From first principles density functional theory, we found that the Ti dimer supported on single‐layer phosphorene can be used as a promising electrocatalyst for N2 capture and conversion to NH3. The overpotential (relative to the standard hydrogen electrode) was found to be as low as 0.20, much lower than those predicted on the Ti surface (1 to 1.5 V) or their nitrides (0.5 to 1 V). In addition, we found that hydride is involved in the N2 reduction on the Ti dimer catalyst via formation of Ti2‐H species, and the hydride would favorably transfer onto the adsorbed N2* to form *NNH intermediate and further reduced to NH3. Moreover, we also examined other first‐row transition metal dimers, and found that Sc and Fe dimer to be potential catalysts which could catalyze N2 reduction at a low overpotential of about 0.21 and 0.45 V, respectively. Our predictions hence suggest Ti, Sc and Fe dimer clusters supported on phosphorene as promising electrocatalysts for N2 reduction to NH3.
Thermoelectric Properties of Pure SnSe Single Crystal Prepared by a Vapor Deposition Method
Authors: Jin Min , Jiang Jun , Li Rongbin , Wang Xianghu , Chen Yunxia , Chen Yuqi , Xu Jiayue
Published: April 2019

As a promising eco‐friendly high‐performance thermoelectric material, SnSe single crystal has attracted much attention during the past several years. In this work, SnSe single crystal is prepared through a novel vapor deposition method in which polycrystalline SnSe is volatilized on a hot side (800–850 °C) and single‐crystalline SnSe spontaneously nucleates on the cold side (500–650 °C) based on the inside wall of a quartz ampoule. This crystal growth technique is beneficial for obtaining high‐purity SnSe crystal as some metal ions, such as Li+, Na+, and K+, in the quartz ampoule will be restricted from diffusing into the material. SnSe single crystal along the a‐axis is measured to experience a Pnma–Cmcm phase transition around 800 K where power factor (PF) exhibits the highest value of 6.2 µW cm−1 K−2 and total thermal conductivity ktot shows the lowest value of 0.48 W m−1 K−1. Accordingly, SnSe single crystal reaches a maximum ZT = 0.98 near phase transition temperature. These results not only provide an effective approach for pure SnSe single crystal fabrication, but also reveal the intrinsic electronic and phononic transport properties of thermoelectric SnSe.
Nondairy ice cream based on fermented yam (Dioscoreasp.)
Authors: Batista Nádia N. , Ramos Cíntia L. , Pires Josiane F. , Moreira Silvino I. , Alves Eduardo , Dias Disney R. , Schwan Rosane F.
Published: April 2019

Background

The demand for industrialized foods that contribute to health and well‐being has characterized the new generation of consumers. Yam (Dioscoreasp.) is a nutritious food; however, it is not used very much in industrial food processes. The objective of this study was to develop and to characterize a truly dairy‐free low‐fat ice cream prepared from unfermented and fermented with yam dough.

Results

The fermentation was conducted byLeuconostoc lacticCCMA 0415 remained viable (107 CFU/g) during 90 days of storage. The fermentation process reduced the starch concentration from 26.82% to 22.35% and the protein concentration from 4.68% to 3.99% and increased the concentration of some minerals (K, S, Cu, Mn, Zn, and Fe). The total phenolic contents for fermented and unfermented ice creams were 51 and 54 mg, respectively. The radical scavenging activity were 18% and 10% with the 1,1‐diphenyl‐2‐picrylhydrazyl method and 44% and 26% with the 2,2’‐azino‐bis (3 ethylbenzo‐thiazoline‐6‐sulfonic acid) method for the unfermented and fermented samples, respectively. The fermented and unfermented ice creams were both characterized as non‐Newtonian fluids exhibiting pseudoplastic behaviors.

Conclusions

These results indicated that yam is a suitable substitute for milk, thus making it an option to produce edible lactose‐free ice cream with low fat.
Radiation‐induced sensitivity of tissue‐resident mesenchymal stem cells in the head and neck region
Authors: Spiegel Jennifer L. , Hambrecht Mario , Kohlbauer Vera , Haubner Frank , Ihler Friedrich , Canis Martin , Schilling Arndt F. , Böker Kai O. , Dressel Ralf , Streckfuss‐Bömeke Katrin , Jakob Mark
Published: April 2019

Background

Tissue‐resident mesenchymal stem cells (MSCs) possess the ability to migrate to areas of inflammation and promote the regeneration of damaged tissue. However, it remains unclear how radiation influences this capacity of MSC in the head and neck region.

Methods

Two types of MSCs of the head and neck region (mucosa [mMSC] and parotid gland [pMSC]) were isolated, cultured and exposed to single radiation dosages of 2 Gy/day up to 10 days. Effects on morphology, colony forming ability, apoptosis, chemokine receptor expression, cytokine secretion, and cell migration were analyzed.

Results

Although MSC preserved MSC‐specific regenerative abilities and immunomodulatory properties following irradiation in our in vitro model, we found a deleterious impact on colony forming ability, especially in pMSC.

Conclusions

MSC exhibited robustness and activation upon radiation for the support of tissue regeneration, but lost their potential to replicate, thus possibly leading to depletion of the local MSC‐pool after irradiation
Chemoradiation induces epithelial‐to‐mesenchymal transition in esophageal adenocarcinoma
Authors: Steins Anne , Ebbing Eva A. , Creemers Aafke , van der Zalm Amber P. , Jibodh Rajni A. , Waasdorp Cynthia , Meijer Sybren L. , van Delden Otto M. , Krishnadath Kausilia K. , Hulshof Maarten C.C.M. , Bennink Roelof J. , Punt Cornelis J.A. , Medema Jan Paul , Bijlsma Maarten F. , van Laarhoven Hanneke W.M.
Published: April 2019

Multimodality treatment has advanced the outcome of esophageal adenocarcinoma (EAC), but overall survival remains poor. Therapeutic pressure activates effective resistance mechanisms and we characterized these mechanisms in response to the currently used neoadjuvant treatment against EAC: carboplatin, paclitaxel and radiotherapy. We developed an in vitro approximation of this regimen and applied it to primary patient‐derived cultures. We observed a heterogeneous epithelial‐to‐mesenchymal (EMT) response to the high therapeutic pressure exerted by chemoradiation. We found EMT to be initiated by the autocrine production and response to transforming growth factor beta (TGF‐β) of EAC cells. Inhibition of TGF‐β ligands effectively abolished chemoradiation‐induced EMT. Assessment of TGF‐β serum levels in EAC patients revealed that high levels after neoadjuvant treatment predicted the presence of fluorodeoxyglucose uptake in lymph nodes on the post‐chemoradiation positron emission tomography‐scan. Our study shows that chemoradiation contributes to resistant metastatic disease in EAC patients by inducing EMT via autocrine TGF‐β production. Monitoring TGF‐β serum levels during treatment could identify those patients at risk of developing metastatic disease, and who would likely benefit from TGF‐β targeting therapy.
Fisetin and 5‐fluorouracil: Effective combination for PIK3CA‐mutant colorectal cancer
Authors: Khan Naghma , Jajeh Farah , Eberhardt Emily L. , Miller Devon D. , Albrecht Dawn M. , Van Doorn Rachel , Hruby Melissa D. , Maresh Morgan E. , Clipson Linda , Mukhtar Hasan , Halberg Richard B.
Published: April 2019

The normal colon epithelium is transformed into its neoplastic counterpart through a series of genetic alterations in driver genes including activating mutations in PIK3CA. Treatment often involves surgery followed by 5‐fluorouracil (5‐FU) based therapy, which has limited efficiency and serious side effects. We sought to determine whether fisetin, a dietary flavonoid, alone or in combination with 5‐FU affected tumorigenesis in the mammalian intestine. We first determined the effect of fisetin, 5‐FU or their combination on PIK3CA‐mutant and PIK3CA wild‐type colon cancer cells by assessing cell viability, colony formation, apoptosis and effects on PI3K/AKT/mTOR signaling. Treatment of PIK3CA‐mutant cells with fisetin and 5‐FU reduced the expression of PI3K, phosphorylation of AKT, mTOR, its target proteins, constituents of mTOR signaling complex and this treatment increased the phosphorylation of AMPKα. We then determined whether fisetin and 5‐FU together or singly affected tumorigenesis in ApcMin/+ mice that also express constitutively active PI3K in the distal small intestine and colon. Tumor incidence was markedly lower in fisetin‐treated FC13K1ApcMin/+ mice that also express constitutively active PI3K in distal small intestine and colon, as compared to control animals, indicating that fisetin is a strong preventive agent. In addition, the combination of fisetin and 5‐FU also reduced the total number of intestinal tumors. Fisetin could be used as a preventive agent plus an adjuvant with 5‐FU for the treatment of PIK3CA‐mutant colorectal cancer.
Emerging in‐plane anisotropic two‐dimensional materials
Authors: Li Liang , Han Wei , Pi Lejing , Niu Ping , Han Junbo , Wang Chengliang , Su Bin , Li Huiqiao , Xiong Jie , Bando Yoshio , Zhai Tianyou
Published: April 2019

Black phosphorus (BP) is a rapidly up and coming star in two‐dimensional (2D) materials. The unique characteristic of BP is its in‐plane anisotropy. This characteristic of BP ignites a new type of 2D materials that have low‐symmetry structures and in‐plane anisotropic properties. On this basis, they offer richer and more unique low‐dimensional physics compared to isotropic 2D materials, thus providing a fertile ground for novel applications including electronics, optoelectronics, molecular detection, thermoelectric, piezoelectric, and ferroelectric with respect to in‐plane anisotropy. This article reviews the recent advance in characterization and applications of in‐plane anisotropic 2D materials.
Comparing mand training and other instructional methods to teach a foreign language
Authors: Wu Wai‐Ling , Lechago Sarah A. , Rettig Lisa A.
Published: April 2019

The purpose of the current study was to examine the effects of mand, tact, and native‐to‐foreign (NFI) and foreign‐to‐native (FNI) intraverbal training on the acquisition of a foreign language. We used a multiple‐baseline design across participants with an embedded adapted alternating treatments design to compare the effects of mand training, tact training, NFI training, and FNI training on the acquisition rate of Chinese words in four typically developing adults. We also examined the emergence of untrained foreign language responses for each training condition. Data for 3 out of the 4 participants suggest that mand training was the most efficient training procedure with respect to acquisition rate. The greatest amount of emergent responding was observed for the mand and tact training conditions.
Effective delivery of mitomycin‐C and meloxicam by double‐layer electrospun membranes for the prevention of epidural adhesions
Authors: Shi Rui , Huang Yuelong , Zhang Jingshuang , Wu Chengai , Gong Min , Tian Wei , Zhang Liqun
Published: April 2019

Epidural adhesion between the spinal dura and the surrounding fibrous tissue often occurs post‐laminectomy, resulting in clinical symptoms such as nerve compression and severe pain. In this study, we report a drug‐loaded double‐layered electrospun nanofiber membrane to prevent the occurrence of epidural adhesion. The nanofibers in both layers are made of a mixture of polycaprolactone (PCL) and chitosan (CS) but at different weight ratios. The bottom layer contacting to the spinal dura is loaded with meloxicam (MX) to prevent inflammation. The top layer that contacts to the fibrous tissue is doped with mitomycin‐C (MMC) to inhibit the synthesis of DNA and collagen. The two types of drugs are released from the double‐layered membrane within about 12 days. Meanwhile, the membrane can inhibit fibroblasts proliferation in vitro while show no cytotoxicity. In a rabbit laminectomy model, the double‐layered membrane can effectively prevent the epidural adhesion formation based on the adhesion scores, histological and biochemical evaluations. The combination release of MX and MMC can signally reduce the inflammation reaction and collagen I/III expression relative to the case with the membranes loaded with only either one type of the drugs. This approach offers new progresses in constructing dual drug delivery system and provides innovative barrier strategy in inhibiting epidural adhesion post‐laminectomy.
Study on CuO/Al2O3 catalytic ozone treatment of acid red B solution
Authors: Qian Jianhua , Chen Mingming , Li Junhua , Zhang Dan , Liu Lin , Xing Jinjuan
Published: April 2019

A CuO/Al2O3 catalyst was prepared using the impregnation method. The catalytic activity of CuO/Al2O3 for the ozonation of acid red B (ARB) in aqueous solution was studied, the chemical oxygen demand (COD) removal rate was an indicator for catalytic activity evaluation. The effects of initial ARB concentration, solution pH, and different oxidative degradation systems on oxidative degradation of ARB solution were studied. The CuO/Al2O3 catalyst was characterized using X‐ray diffractometry (XRD), N2 adsorption desorption test, X‐ray photoelectron spectroscopy (XPS), and zero‐point charge (pHzpc). The results show that copper species on the carrier were in the form of CuO and highly dispersed on the carrier. CuO can increase the alkalinity of the Al2O3 surface, and the CuO/Al2O3 catalyst facilitates the decomposition of O3 into ·OH, which was beneficial for the catalytic O3 oxidation degradation reaction. With the increase of the initial concentration of simulated wastewater, the CuO/Al2O3 catalytic reaction still has a high COD removal rate. Alkaline solution was of benefit to catalyze the degradation of ARB solution. When the ARB solution pH = 8.93, the degradation reaction was carried out for 40 min, the COD removal rate reached 83.2%. The degradation reaction was dominated by the hydroxyl radical (·OH) reaction.
RETRACTED: Downregulation of miRNA‐30a enhanced autophagy in osthole‐alleviated myocardium ischemia/reperfusion injury
Authors: Liu Shengzhong , He Ying , Shi Jun , Liu Lulu , Ma Hao , He Li , Guo Yingqiang
Published: April 2019

Osthole could alleviate myocardial ischemia/reperfusion (I/R) injury. However, the underlying mechanism remains unclear. In this study, we explored whether microRNA (miR)‐30a and its target autophagy marker Beclin‐1 involved in the osthole protective role in the rat and cells myocardial I/R injury models. The myocardial damages including increases in myocardial collagen content and cell apoptosis in I/R injury model were observed by Masson's Trichrome Staining and terminal deoxynucleotidyl transferase dUTP nick‐end labeling (TUNEL) assays. Osthole significantly inhibited the myocardial damages. Osthole inhibited the induction of miR‐30a expression by I/R in rat and hypoxia/reoxygenation (H/R) in myocardial cells. After knockdown, the expression of miR‐30a by miR‐30a inhibitor, H/R induced cell apoptosis was significantly inhibited. The level of Beclin‐1 expression and ratio of LC3BII/LC3BI were inhibited by I/R in rat and H/R in myocardial cells, whereas osthole significantly increased them. Knockdown of miR‐30a significantly upregulated the Beclin‐1 expression and ratio of LC3BII/LC3BI. Inhibition of autophagy by 3‐MA significantly reversed the protective role of osthole in H/R myocardial cell. Therefore, we concluded that the mechanism by which osthole alleviate myocardial I/R injury may be achieved by enhancing the autophagy partially via inhibiting the expression of miR‐30a.
Clinical prognostic evaluation of immunocytes in different molecular subtypes of breast cancer
Authors: Zenan Huang , Zixiong Li , Zhicheng Yao , Mei Huang , Xiongbin Yang , Tiantian Wang , Min Dong , Renbin Liu , Changchang Jia
Published: April 2019

To retrospectively analyze the relationship between preoperative blood parameters and postoperative clinical outcomes in patients with different molecular subtypes of breast cancer (BC), a cohort of 601 patients with BC in the Third Affiliated Hospital, Sun Yat‐sen University, was retrospectively reviewed. They were categorized into four subtypes according to the expression of ER, PR, HER‐2, and KI‐67%. White blood cell, neutrophil, lymphocyte, monocyte, eosinophil, basophil, and platelet counts, the neutrophil‐to‐lymphocyte ratio (NLR), the neutrophil‐to‐monocyte ratio (NMR), the lymphocyte‐to‐monocyte ratio (LMR), and the platelet‐to‐lymphocyte ratio (PLR) were recorded. Univariate and multivariate analyses were performed to identify the relationship between parameters and ratios and disease‐free survival (DFS) and overall survival (OS). Luminal subtypes of BC had smaller tumor volume, better differentiation degree of invasive ductal carcinoma, less lymph node metastasis, and better clinical outcome than the HER‐2 overexpression and triple‐negative BC (TNBC) subtypes. In multivariate analysis, age and LMR were the independent prognostic factors of DFS in patients with luminal A (age, p = 0.005; LMR, P = 0.026); PLR in patients with luminal B (DFS; p = 0.032; OS, p= 0.012); LMR in patients with HER‐2 overexpression (DFS; p = 0.008; OS, p = 0.017); and NLR for DFS (p = 0.014); and WBC for OS (p = 0.008) in patients with TNBC. LMR was the benign predictor of luminal A and HER‐2 overexpression. PLR was the adverse predictor of luminal B. WBC and NLR were the adverse predictors of TNBC. Therefore, these peripheral blood parameters can play an important role in the diagnosis and treatment of patients with different molecular subtypes of BC.
Hepatitis B core antigen can regulate NLRP3 inflammasome pathway in HepG2 cells
Authors: Ding Xiaolin , Lei Qingsong , Li Tianju , Li Lin , Qin Bo
Published: April 2019

Hepatitis B virus (HBV) has four open reading frames (ORFs) of whichORF Cis consists of thepre CoreandCoregenes encodes the Hepatitis B core antigen (HBcAg) and Hepatitis B e antigen (HBeAg). Studies have shown that HBeAg significantly inhibits the NLRP3 inflammasome activation and interleukin‐1β (IL‐1β) production. However, the role of HBcAg and ORF C proteins (in this paper, ORF C proteins = HBcAg + HBeAg) were remain unclear. Our study aims to assess whether HBcAg and ORF C proteins can affect the NLRP3 inflammasome pathway. Vectors expressing ORF C proteins and HBcAg were designed and transfected into HepG2 cells. And then, cells were stimulated with lipopolysaccharide (LPS). Activation of the NLRP3 inflammasome and the levels of IL‐1β and IL‐18 were evaluated by Western blot analysis, quantitative reverse‐transcription polymerase chain reaction, enzyme‐linked immunosorbent assay, and immunofluorescence. The expression of NLRP3 and IL‐1β peaked when HepG2 cells were stimulated with 1000 ng/mL LPS for 18 to 24 hours. HBcAg, but not ORF C proteins, promoted LPS‐induced NLRP3 inflammasome activation and IL‐1β production. These findings provide a novel mechanism on how the HBV causes liver inflammation and may provide insights into the search for new therapeutic strategies.
The global warming hiatus has faded away: An analysis of 2014–2016 global surface air temperatures
Authors: Zhang Chao , Li Shuanglin , Luo Feifei , Huang Zhen
Published: April 2019

We present an analysis of the global annual mean surface temperature anomaly in 2014, 2015, and 2016 based on five datasets of historical observational records of surface temperature. These three years are the three warmest on record in all but one of the datasets. The largest warming occurred over land, especially at high latitudes. Since the strong El Niño event that occurred in 2015/2016 was similar to the 1997/1998 El Niño, we compared the 2014–2016 period with 1998, the warmest year in the 20th century. The contribution to the annual mean surface temperature anomaly of climate variations at different time scales was assessed using ensemble empirical mode decomposition. Results based on the HadCRUT4 dataset suggest that the interannual component may have contributed an anomaly of −0.01°C in 2014, 0.12°C in 2015, and 0.06°C in 2016. These values are substantially lower than the contribution in 1998 (0.18°C). In comparison, the combined contribution of the decadal‐to‐multidecadal (DM) component and the long‐term warming trend was 0.64°C in 2014, 0.70°C in 2015, and 0.77°C in 2016, which are substantially greater than that in 1998 (0.41°C). Similar results were obtained using the other four datasets. The larger contribution from the DM component and the long‐term warming trend implies that warmer years like 2014–2016 may occur more frequently in the near future. We conclude that the so‐called warming hiatus has faded away.
Probable maximum precipitation in tropical zone (Thailand) as estimated by generalized method and statistical method
Authors: Wangwongwiroj Nittaya , Khemngoen Chatchapol
Published: April 2019

The objective of this research was to estimate probable maximum precipitation (PMP) for the duration of 1 to 3 days in Thailand. Rainfall data were collected from 217 meteorological stations. Two methods for estimating PMP were applied: the generalized method which analysed actual storms data using meteorological process, and the Hershfield's statistical method which applied the frequency analysis of the annual maximum rainfall. Both methods were commonly used and were recommended by the World Meteorological Organization (WMO) for estimating PMP. PMP estimation results were presented as isohyetal maps. For the generalized method, most PMP values were found higher in the east and decreased towards the west. However, there was no clear trend with the statistical method in the PMP's spatial distribution. An analysis of the 3‐day PMP averages showed that PMP estimation using the generalized method is 10% higher than that of the statistical method. The study results were then applied to estimate PMP of six large dams in Thailand and compared with the ones used in the design of the spillways. It was found that PMP estimation based on the generalized method was closer to the value used in the spillway design of those dams than PMP estimation based on the statistical method.
Blending the Effectiveness of Anionic Polymerization with the Versatility of RAFT by Use of the Atom Transfer Radical Addition–Fragmentation Technique
Authors: Forrester Michael J. , Bradley William , Lin Fang‐Yi , Hernández Nacú B. , Williams R. Chris , Kraus George , Cochran Eric W.
Published: April 2019

The efficient conversion of a living anionic polymer chain end to a macrochain transfer agent suitable for reversible addition–fragmentation chain transfer (RAFT) polymerization is reported. Conversion to the macrochain transfer agent efficiency reached as high as 97% by capping the polyanion with alcohol, coupling with α‐bromoisobutryl bromide, followed by atom‐transfer radical addition–fragmentation with bis(thiobenzyl)disulfide to add the chain transfer agent functionality. To our knowledge, this is the most efficient marriage of anionic and reversible addition–fragmentation transfer polymerization reported to date, and can be carried out under common industrial processing conditions. The combination of these polymerization methods broadens the scope of commercially accessible block copolymers by exploiting the advantages of both RAFT and anionic polymerization chemistries.
Preparation of Single Chain Nanoparticles via Photoinduced Double Collapse Process
Authors: Dashan Irem , Balta Demet Karaca , Temel Binnur Aydogan , Temel Gokhan
Published: April 2019

A straightforward method is described to achieve polymeric nanoparticles by double folding of single linear chains. The side chain functional polystyrene with controlled molecular weight is converted to pendant azide and benzophenone motifs via postmodification reactions. Resulting functionalized chains undergo intramolecular crosslinking upon ultraviolet (UV) illumination using simultaneous and subsequent pathways at a dilute concentration. Particle size of nanoparticles can be tuned by changing the degree of crosslinking using a second folding process. Obtained single and double collapsed chains indicate higher glass transition temperatures and lower hydrodynamic radii compared to their intermediates. To our knowledge, the combination of photoinduced azide crosslinking and radical coupling processes is the first attempt to prepare double folding single polymer chains.
Expanding the phenotype for the recurrent p.Ala391Glu variant in FGFR3: Beyond crouzon syndrome and acanthosis nigricans
Authors: Rymer Karen , Shiang Rita , Hsiung Anting , Pandya Arti , Bigdeli Tim , Webb Bradley T. , Rhodes Jennifer
Published: April 2019

Background

Craniosynostosis, or premature fusion of the skull sutures, is a group of disorders that can present in isolation (nonsyndromic) or be associated with other anomalies (syndromic). Delineation of syndromic craniosynostosis is confounded due to phenotypic overlap, variable expression as well as molecular heterogeneity. We report on an infant who presented at birth with multisuture synostosis, turribrachycephaly, midface hypoplasia, beaked nose, low set ears, a high palate and short squat appearing thumbs, and great toes without deviation. The additional MRI findings of choanal stenosis and a Chiari I malformation suggested a diagnosis of Pfeiffer syndrome. First tier molecular testing did not reveal a pathogenic variant.

Methods

Whole exome sequencing on DNA samples from the proband and her unaffected parents was utilized to delineate the variant causative for the Pfeiffer syndrome diagnosis.

Results

On whole exome sequencing, a de novo NM_000142.4:c.1428C>A missense variant causing a p.Ala391Glu amino acid change in FGFR3 has been identified. The p.Ala391Glu change has been predominantly identified in patients with Crouzon syndrome with acanthosis nigricans.

Conclusions

This finding illustrates the first reported case of a child with an overlap with Pfeiffer syndrome to have the p.Ala391Glu variant.