bluuebunny/crossref_metadata_2025 huggingface dataset:
Baseline susceptibility of Mediterranean strains of Trialeurodes vaporariorum (Westwood) to cyantraniliprole
Authors: Moreno Inmaculada , Belando Ana , Grávalos Carolina , Bielza Pablo
Published: January 2018

BACKGROUND

Cyantraniliprole is a novel anthranilic diamide insecticide that acts on a broad spectrum of insect pests, exclusively by activating their ryanodine receptors. Cyantraniliprole is very effective against whitefly and it presents a favorable ecotoxicological profile. In this study, the baseline susceptibility to cyantraniliprole of Trialeurodes vaporariorum populations from the Mediterranean area was established in nymphal systemic uptake bioassays.

RESULTS

The bioassay data showed that the susceptibility to cyantraniliprole varied among the strains collected across the Mediterranean basin. The 50% lethal concentration (LC50) range of cyantraniliprole for 16 field populations was from 0.017 to 0.194 mg L‐1, a 11.4‐fold natural variability between the least and most sensitive populations. These LC50 values are similar to those reported in a previous study of the use of cyantraniliprol against another species of whitefly, Bemisia tabaci [LC50 = 0.048 (0.034–0.063) mg L‐1].

CONCLUSION

The current study confirmed the effectiveness of cyantraniliprole against T. vaporarioum strains, adding to the evidence that cyantraniliprole is a promising tool for use in integrated pest management programs. Future shifts in the susceptibility of whitefly field populations to cyantraniliprole may be documented according to the baseline susceptibility range of the populations tested in this research. © 2018 Society of Chemical Industry
Improved insect‐proofing: expressing double‐stranded RNA in chloroplasts
Authors: Bally Julia , Fishilevich Elane , Bowling Andrew J , Pence Heather E , Narva Kenneth E , Waterhouse Peter M
Published: January 2018

RNA interference (RNAi) was discovered almost 20 years ago and has been exploited worldwide to silence genes in plants and animals. A decade later, it was found that transforming plants with an RNAi construct targeting an insect gene could protect the plant against feeding by that insect. Production of double‐stranded RNA (dsRNA) in a plant to affect the viability of a herbivorous animal is termed trans‐kingdom RNAi (TK‐RNAi). Since this pioneering work, there have been many further examples of successful TK‐RNAi, but also reports of failed attempts and unrepeatable experiments. Recently, three laboratories have shown that producing dsRNA in a plant's chloroplast, rather than in its cellular cytoplasm, is a very effective way of delivering TK‐RNAi. Our review examines this potentially game‐changing approach and compares it with other transgenic insect‐proofing schemes. © 2018 The Authors.Pest Management Sciencepublished by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
Hybrid Analytical–Monte Carlo Model of In/GaAs(001) Droplet Epitaxy: Theory and Experiment
Authors: Balakirev Sergey V. , Solodovnik Maxim S. , Ageev Oleg A.
Published: January 2018

We study the droplet epitaxy of indium on the As‐stabilized GaAs(001) substrate using the analytical theory of nucleation combined with kinetic Monte Carlo simulations. The developed model allows considering the atomistic processes of nucleation and growth of droplets without strict binding to the zinc blende structure. We assume that the formation of stable droplets results from the alternation of the processes of assembly and disassembly of subcritical islands. We use a concept of nonmonotonic dynamics of critical size and supersaturation to explain the physical processes on the surface. The thickness of the indium wetting layer exceeds a value of one monolayer and increases gradually with decreasing temperature, which is due to the long‐range interaction of indium with the GaAs substrate. The simulation results are in good agreement with the experiments in a wide range of growth temperatures.
Colloidal Silver Films on Polypropylene and Polyethylene
Authors: Muravitskaya Alina , Kulakovich Olga , Adam Pierre‐Michel , Gaponenko Sergey
Published: January 2018

A simple procedure for the fabrication of colloidal silver films on the surface of flexible polymer substrates, such as polypropylene and polyethylene, with the use of only polyelectrolyte pre‐treatment is presented. The optical properties of these films depend on the number of predeposited polyelectrolyte layers and salt concentration. The uncharged nature of the polymer surface allows to alternate the first polyelectrolyte layer (positively or negatively charged). The proposed method of silver deposition can be used for manufacturing silver films of different density on the polymer surfaces. This approach is low‐cost, does not require special equipment and allows to control the surface properties of the films. Using an average salt concentration (0.5 M) during the deposition of polyelectrolytes allowed to produce the densest films.
Vaccinium angustifolium (lowbush blueberry) leaf extract increases extravillous trophoblast cell migration and invasion in vitro
Authors: Ly Christina , Ferrier Jonathan , Gaudet Jeremiah , Yockell‐Lelièvre Julien , Arnason John Thor , Gruslin Andrée , Bainbridge Shannon
Published: January 2018

Perturbations to extravillous trophoblast (EVT) cell migration and invasion are associated with the development of placenta‐mediated diseases. Phytochemicals found in the lowbush blueberry plant (Vaccinium angustifolium) have been shown to influence cell migration and invasion in models of tumorigenesis and noncancerous, healthy cells, however never in EVT cells. We hypothesized that the phenolic compounds present in V. angustifolium leaf extract promote trophoblast migration and invasion. Using the HTR‐8/SVneo human EVT cell line and Boyden chamber assays, the influence of V. angustifolium leaf extract (0 to 2 × 104 ng/ml) on trophoblast cell migration (n = 4) and invasion (n = 4) was determined. Cellular proliferation and viability were assessed using immunoreactivity to Ki67 (n = 3) and trypan blue exclusion assays (n = 3), respectively. At 20 ng/ml, V. angustifolium leaf extract increased HTR‐8/SVneo cell migration and invasion (p < .01) and did not affect cell proliferation or viability. Chlorogenic acid was identified as a major phenolic compound of the leaf extract and the most active compound. Evidence from Western blot analysis (n = 3) suggests that the effects of the leaf extract and chlorogenic acid on trophoblast migration and invasion are mediated through an adenosine monophosphate‐activated protein (AMP) kinase‐dependent mechanism. Further investigations examining the potential therapeutic applications of this natural health product extract and its major chemical compounds in the context of placenta‐mediated diseases are warranted.
Genipin ameliorates diet‐induced obesity via promoting lipid mobilization and browning of white adipose tissue in rats
Authors: Guan Lili , Gong Dezheng , Yang Sirao , Shen Nana , Zhang Sai , Li Yuchen , Wu Qiong , Yuan Bo , Sun Yiping , Dai Ning , Zhu Liang , Zou Yuan
Published: January 2018

Genipin is the major active component of Gardeniae fructus and has been shown to ameliorate diabetes and insulin resistance in rat models. In this study, we first investigated the effect of genipin on obesity and the related lipid metabolism mechanisms in diet‐induced obese rats. Our results showed that genipin reduced body weight, food intake, and visceral fat mass; ameliorated dyslipidemia, glucose intolerance, insulin intolerance, adipocyte hypertrophy, and hepatic steatosis; and reduced serum tumor necrosis factor‐α level in diet‐induced obese rats. Quantitative real‐time reverse‐transcription polymerase chain reaction results further illustrated that genipin promoted lipolysis and β‐oxidation of fatty acid by upregulating gene expressions of hormone‐sensitive lipase and adipose triglyceride lipase in white adipose tissue (WAT) and peroxisome proliferator‐activated receptor‐α and carnitine palmitoyltransferase 1α in hepatic tissue. Moreover, genipin promoted browning of WAT by upregulating the mRNA and protein levels of uncoupling protein 1 and PRD1‐BF1‐RIZ1 homologous domain containing 16 in WAT. Additionally, genipin inhibited gene expressions of activin receptor‐like kinase 7, tumor necrosis factor‐α, and interlukin‐6 in WAT. These results indicated that genipin had a potential therapeutic role in obesity, in which regulation of lipid mobilization and browning of WAT were involved.
Antiproliferation of keratinocytes and alleviation of psoriasis by the ethanol extract of Artemisia capillaris
Authors: Lee Song Yi , Nam Suyeong , Hong In Kee , Kim Hill , Yang Heejung , Cho Hyun‐Jong
Published: January 2018

The therapeutic potentials of the ethanol extract of Artemisia capillaris (ACE) for psoriasis were verified in HaCaT cells (as an immortalized human keratinocyte cell line) and imiquimod (IMQ)‐induced psoriasis‐like mouse models. In HaCaT cells, IC50 value of ACE was 37.5 μg/ml after incubating for 72 hr. The antiproliferation activity of ACE in HaCaT cells was further verified by apoptosis assays. The percentage of apoptotic population in ACE‐treated group was significantly higher than that of control group (p < .05). The result of cell cycle arrest assay also supported the observed antiproliferation efficacy of ACE in HaCaT cells. In IMQ‐induced psoriasis‐like mouse models, the Psoriasis Area and Severity Index score of ACE (50 mg/ml; ACE50)‐treated group was significantly lower than that of IMQ group on Day 4 (p < .05). After topical application of ACE on psoriasis‐like lesion for 4 days, the epidermal thickness of (IMQ + ACE50) group was significantly lower than that of IMQ group (p < .05). The expression levels of Ki‐67 and intracellular adhesion molecule‐1 in excised skin tissues of (IMQ + ACE50) group were also lower than those of IMQ group. All these findings suggest that ACE can be used as a promising antipsoriatic agent.
Successful treatment by tolvaptan of the syndrome of inappropriate antidiuretic hormone secretion that may be associated with chemotherapy‐induced tumour lysis in a patient with small‐cell lung carcinoma
Authors: Miyashita Koichi , Matsuura Shun , Naoi Hyogo , Tsukui Masaru , Koshimizu Naoki , Suda Takafumi
Published: January 2018

Here, we report the case of a patient with small‐cell lung carcinoma (SCLC) who developed the syndrome of inappropriate antidiuretic hormone secretion (SIADH). This syndrome may be associated with chemotherapy‐induced tumour lysis. Our patient was successfully treated with tolvaptan. A 70‐year‐old man was diagnosed with SCLC and was treated with carboplatin and etoposide. Episodes of hyponatremia occurred after every four cycles of chemotherapy that achieved tumour reduction; however, the hyponatremia was improved by temporary administration of tolvaptan. In SIADH associated with chemotherapy‐induced tumour lysis, tolvaptan may improve hyponatremia and enable the continued administration of effective chemotherapy.
Pleuroparenchymal fibroelastosis after haematopoietic stem cell transplantation without graft‐versus‐host disease findings
Authors: Okimoto Tamio , Tsubata Yukari , Hamaguchi Megumi , Sutani Akihisa , Hamaguchi Shunichi , Isobe Takeshi
Published: January 2018

Although rare, pleuroparenchymal fibroelastosis (PPFE) is a serious late‐onset complication of haematopoietic stem cell transplantation (HSCT). It remains unclear whether graft‐versus‐host disease (GVHD) is involved in the development of PPFE. We report the case of a patient with PPFE after HSCT. The patient experienced pneumothorax repeatedly despite surgical treatment. A surgical specimen demonstrated PPFE findings, without evidence of GVHD. In this case, development of PPFE was not associated with GVHD, and immunosuppressive therapy did not improve pulmonary function. Surgical biopsy is recommended for precise treatment and elucidation of pathogenesis in each suspected PPFE patient.
Preparation of N‐Doped Activated Carbon for Catalytic Pyrolysis of 1‐Chloro‐1,1‐difluoroethane to Vinylidene Fluoride
Authors: Wang Zhikun , Han Wenfeng , Zhang Chunpeng , Zhou Shenglan , Wang Haili , Tang Haodong , Liu Huazhang
Published: January 2018

N‐doped activated carbons were prepared by calcining the mixture of activated carbon and melamine at 700 oC for 4 h. Then they were evaluated as the catalysts for the pyrolysis of 1‐chloro‐1,1‐difluoroethane (HCFC‐142b) to vinylidene fluoride (VDF). Reactions were carried out under 350 oC and space velocity of 600 h−1. Doping of N into the activated carbon increases the conversion of HCFC‐142b significantly. Compared with the temperatures of industrial manufacture for VDF at 600∼700 oC, N‐doped activated carbon reduces the reaction temperature significantly (350 oC). It is suggested that pyridinic N and pyrrolic N are responsible for the dehydrochlorination of HCFC‐142b. The N‐doped activated carbon catalyst provides a promising pathway to produce VDF through a low‐temperature and energy‐saving process via catalytic dehydrochlorination of 1‐chloro‐1,1‐difluoroethane.
Evolution of Vesicular Self‐Assemblies of the Salts of a Natural Triterpenoid Arjunolic Acid into Superstructured Ambidextrous Gels and Study of Their Entrapment Properties
Authors: Majumdar Rakhi , Bag Braja Gopal
Published: January 2018

Generation of supramolecular hydrogel from biocompatible supramolecular building blocks has become an area of tremendous research investigation because of it's potential use in biomedical sciences, food industries, cosmetics, etc. In recent years, the biocompatible nano‐sized trieterpenoid molecules have gained significant attention of the scientific community as supramolecular building blocks because of its unique molecular structures. Herein, we report the hierarchical self‐assembly properties of sodium and potassium salts of a naturally ocurring triterpenoid arjunolic acid in water and aliphatic alcohols. An interesting evolution of vesicular self‐assemblies of the molecules at a lower gelator concentration to giant fibrillar assemblies at a higher gelator concentration affording stable gels were obseved. The vesicular self‐assemblies have been utilized for the entrapment and controlled release of various fluorophores including the anticancer drug doxorubicin at physiological pH.
Carbon‐Supported W@Pt Nanoparticles with a Pt‐Enriched Surface as a Robust Electrocatalyst for Oxygen Reduction Reactions
Authors: Wang Yajun , Yang Yang , Zou Liangliang , Huang Qinghong , Li Qiaoxia , Xu Qunjie , Yang Hui
Published: January 2018

A carbon‐supported surface‐platinum‐enriched tungsten nanoparticles (W@Pt/C) is successfully prepared via a replacement method. X‐ray diffraction results verify that the prepared tungsten (W) nanoparticles are amorphous and that platinum (Pt) particles have been successfully placed onto the surface. Transmission electron microscopy shows that the surface‐platinum‐enriched tungsten (W@Pt) nanoparticles are uniformly dispersed on the surface of the carbon support and have an average size of only 1.9 nm. Energy‐dispersive X‐ray spectroscopy reveals that the Pt and W elements are evenly distributed on the surface of the catalyst. Electrochemical measurements confirm that the as‐prepared catalyst exhibits an enhanced catalytic activity for oxygen reduction reaction (ORR) in comparison with commercial catalyst (JM Pt/C). Furthermore, the mass activity of the W@Pt/C catalyst at a potential of 0.9 V/RHE is 2.1 times higher than that of Pt/C (JM). Importantly, the ORR durability of the catalyst is greatly improved as compared to Pt/C (JM). This result may be due to the fact that the mean particle size of the W@Pt/C remains nearly constant during an accelerated durability test. Based on these results, the W@Pt/C maybe a promising cathode catalyst for use in fuel cells.
Experimental and Theoretical MEDT Study of the Thermal [3+2] Cycloaddition Reactions of Aryl Azides with Alkyne Derivatives
Authors: El Ayouchia Hicham Ben , Lahoucine Bahsis , Anane Hafid , Ríos‐Gutiérrez Mar , Domingo Luis R. , Stiriba Salah‐Eddine
Published: January 2018

The reactivity and regioselectivity of the [3+2] cycloaddition (32CA) reactions of a series of 4‐substituted‐aryl azides/alkynes in toluene have been explored experimentally. These 32CA reactions have been also studied within the Molecular Electron Density Theory (MEDT) using Density Functional Theory (DFT) calculations at the B3LYP/6‐31G(d) computational level. The computed activation energies, in gas phase and in toluene, show that the 1,5‐regioisomeric channels are slightly favoured kinetically as found experimentally. The topological analysis of the electron localisation function (ELF) of some relevant points of the regioisomeric reaction paths shows that while the formation of the 1,4‐diaryl triazoles takes place via a low asynchronous C−N bond formation process, the formation of the favoured 1,5‐diaryl triazoles takes place via a two‐stage one‐step mechanism, as the result of the attack of the most nucleophilic center of the aryl alkyne on the most electrocyclic center of aryl azide.
Metal‐Free Catalytic Reduction of 4‐Nitrophenol by MOFs‐Derived N‐Doped Carbon
Authors: Wang Zhenhua , Chen Qianwang
Published: January 2018

With the development of Metal organic frameworks (MOFs) materials, various functional carbon materials prepared using MOFs as precursors have attracted more and more attention. In this work, the N‐doped carbon nanomaterial N‐C have been synthesized by annealing of ZIF‐8. In the reduction of p‐nitrophenol which is one of the most prevalent organic pollutants, N‐C shows good activity, great stability, reusability and minimal pollution compared with some of the previously metallic catalysts. The N‐C prepared by annealing at different temperatures owns different nitrogen contents and different catalytic activity. It was found that N‐C800 (annealed at 800 °C) shows the highest pyridine N content and the best catalytic activity, and the reaction follows the pseudo‐zero‐order kinetics.
Suppressing Electromagnetic Radiation by Trapping Ferrite Nanoparticles and Carbon Nanotubes in Hierarchical Nanoporous Structures Designed by Crystallization‐Induced Phase Separation
Authors: Sharma Maya , Singh Deepinder , Menon Aishwarya , Madras Giridhar , Bose Suryasarathi
Published: January 2018

Polymer blends are at the forefront of research especially in the field of Electromagnetic Interference (EMI) shielding because of their versatile properties such as ease of processability, economic viability and high strength to weight ratio. Herein, we have attempted to design lightweight blend composites consisting of multiwalled carbon nanotubes (MWNTs) and nickel ferrite (NiFe2O4) nanoparticles. A unique approach was adopted here to prepare ultra‐thin (500 μm), flexible, lightweight composite membranes wherein hierarchical nanoporous structures were initially developed by crystallization induced phase separation in a classical upper critical solution temperature (UCST) pair Polyvinylidene fluoride/poly methyl methacrylate (PVDF/PMMA) and subsequently etching out the PMMA phase. In the next step, functional nanoparticles were trapped in the pores by facile vacuum filtration approach. This unique approach led to the fabrication of nanoporous composite membranes which otherwise is difficult to process using conventional techniques. The composite membranes show high magnetic permeability and high electrical conductivity; the two key requirements for effective shielding of electromagnetic (EM) radiation. A significant improvement in shielding effectiveness (SE) was achieved using these token composite membranes. For instance, porous PVDF composite membranes containing 3 wt % MWNTs (with a thickness of 500 μm) showed an SE of 8 dB which enhanced significantly to 27 dB for composite membranes wherein NiFe2O4 is trapped in the pores. More interestingly, the mechanism of shielding was driven by absorption (nearly 80%) through synergistic properties of interconnected MWNTs and NiFe2O4 nanoparticles.
Interaction of a Triaryl Methane Dye with Cucurbit[7]uril and Bovine Serum Albumin: A Perspective of Cooperative versus Competitive Bindings
Authors: Chakraborty Goutam , Ray Alok. K. , Pal Haridas
Published: January 2018

Interactions of a triaryl methane dye, crystal violet (CV), with cucurbit[7]uril (CB7) and bovine serum albumin (BSA) hosts have been investigated using various photophysical studies. While due to its structural flexibility free CV is very weakly fluorescent its binding to CB7 and BSA hosts leads to significant fluorescence enhancements, the effect being very larger with BSA host than CB7. In both CV‐BSA and CV–CB7 systems, CV binds through 1:1 inclusion complex formation, the binding constant (Kb) being as large as ∼3.4x105 M−1 for the former as compared to a moderate Kb of ∼6.3x103 M−1 for the latter system. In CV–CB7‐BSA ternary system, where measurements were done keeping one of the host concentration constant and significantly higher and gradually increasing the concentration of the other host in the solution, the changes observed in the absorption and fluorescence characteristics of the dye as well as that observed in the binding isotherms clearly indicate a competitive binding interaction of CV with both CB7 and BSA hosts simultaneously present in the solution. To be emphasized that the competitive binding interaction observed for the CV–CB7‐BSA ternary system is similar to the commonly encountered interaction in many dye‐host‐biomacromolecule kind of ternary systems but differs strikingly from the unique cooperative interaction reported earlier for an analogous dye, brilliant green (BG), with the same CB7 and BSA hosts.
Synthesis of Pyrido[2, 3‐a]phenoxazines and Pyrido[2, 3‐a]phenothiazines via Successive SNAr Processes
Authors: Starosotnikov Alexey M. , Nikol'skiy Vladislav V. , Bastrakov Maxim A. , Kachala Vadim V. , Pavlov Alexander A. , Ugrak Bogdan I. , Shevelev Svyatoslav A.
Published: January 2018

An efficient method was developed for the synthesis of novel pyrido[2, 3‐a]phenoxazines and phenothiazines. The base‐promoted reaction of 8‐chloro‐5,7‐dinitroquinoline with binucleophiles (o‐aminophenols and o‐aminothiophenols) results in substitution of the chlorine atom followed by replacement of the nitro group. In case of aminothiophenols the products of in situ Smiles rearrangement were isolated.
An Efficient One‐Pot Synthesis of Chiral N‐Protected 3‐Substituted (Diketo)piperazines via Ugi‐4CR/De‐Boc/Cyclization Process
Authors: Jida Mouhamad , Ballet Steven
Published: January 2018

A convenient and high yielding method to prepare a vast array of enantiomerically pure 3‐substituted diketopiperazines (3‐DKPs), bearing a benzyl protecting group on nitrogen 1 is reported. The methodology describes a simple one‐pot procedure, starting from readily available N‐protected L‐ or D‐amino acids employing the Ugi‐4CR in pure water, followed by a one‐step Boc‐deprotection and final lactamisation in acetic acid. All disubstituted DKPs were obtained in short times and isolated in excellent yields (84‐94%) by simple precipitation in water and subsequent filtration. The practical utility of this procedure proved efficient for the synthesis of cialis (Tadalafil) analogues.
Studies towards the Synthesis of Thermolide–6′
Authors: Satyanarayana Vavilapalli , Muralikrishna Katta , Kumar Gavireddy Chaithanya , Kumar Alleni Suman , Babu Nanubolu Jagadeesh , Yadav Jhillu Singh
Published: January 2018

A highly stereoselective and an efficient approach for studies towards the synthesis of thermolide‐6′ has been described. The salient features of the synthesis are the utilization of desymmetrization protocol, Barton‐McCombie deoxygenation and C−C bond formation from an aldol reaction.
Studies towards the Synthesis of Lepranthin
Authors: Satyanarayana Vavilapalli , Kumar Alleni Suman , Muralikrishna Katta , Kumar Gavireddy Chaithanya , Kumar R Sudheer , Kumar Chinthakrinda Suresh , Yadav Jhillu S.
Published: January 2018

A highly stereoselective and an efficient approach for studies towards the synthesis of lepranthin has been described. The key steps involved in this synthesis are desymmetrization protocol, Brown's asymmetric allylation, Wacker oxidation and Corey‐Bakshi‐Shibata reduction.
Transition‐Metal‐Free Borylation of Alkynes and Alkenes
Authors: Deng Chun M. , Ma Yi F. , Wen Yan M.
Published: January 2018

The transition metal‐free method for borylation of alkynes and alkenes with bis(pinacolato)diboron has been developed, producing the correspondent organoborons under mild reaction conditions. This reaction was an efficient, practical and environment‐friendly process which brings forth vinylboronate products with excellent regioselectivity in the borylation of alkynes with bis(pinacolato)diboron, while in the meantime the diboryl alkanes were obtained using alkenes as substrates.
Effect of Substituents on the Reactivity of Ninhydrin with Urea
Authors: Jong Jacobus A. W. , Moret Marc‐Etienne , Verhaar Marianne C. , Hennink Wim E. , Gerritsen Karin G. F. , van Nostrum Cornelus F.
Published: January 2018

Ninhydrin, i. e. the stable hydrate of the reactive species indanetrione, is a well‐known compound used for the quantification of ammonia and amino acids. However, substituent effects on the reactivity of ninhydrin with nucleophiles are not described. In this work, the kinetics of the reaction of C4‐ and C5‐ substituted ninhydrins with urea was studied and monitored by 13C‐NMR. Surprisingly, the obtained results show that electron donating groups (EDGs) as well as electron withdrawing groups (EWGs) decrease the rate of the reaction. EDGs decrease the electrophilicity of indanetrione, resulting in slower overall kinetics than unsubstituted ninhydrin. The calculated Gibbs free energy differences for the dehydration of unsubstituted and substituted ninhydrins and the subsequent reaction with urea showed that the dehydration of the compounds is more sensitive to electronic effects than the subsequent reaction with urea. Therefore, although EWGs increase the electrophilicity of indanetrione, this is more than counterbalanced by an adverse shift of the hydration equilibrium towards the unreactive hydrate (i. e. ninhydrin), resulting in slower kinetics as well.
Ultrasmall Pb:Ag2S Quantum Dots with Uniform Particle Size and Bright Tunable Fluorescence in the NIR‐II Window
Authors: He He , Lin Yi , Tian Zhi‐Quan , Zhu Dong‐Liang , Zhang Zhi‐Ling , Pang Dai‐Wen
Published: January 2018

Ag2S quantum dots (QDs) are well‐known near‐infrared fluorophores and have attracted great interest in biomedical labeling and imaging in the past years. However, their photoluminescence efficiency is hard to compete with Cd‐, Pb‐based QDs. The high Ag+ mobility in Ag2S crystal, which causes plenty of cation deficiency and crystal defects, may be responsible mainly for the low photoluminescence quantum yield (PLQY) of Ag2S QDs. Herein, a cation‐doping strategy is presented via introducing a certain dosage of transition metal Pb2+ ions into Ag2S nanocrystals to mitigate this intrinsic shortcoming. The Pb‐doped Ag2S QDs (designated as Pb:Ag2S QDs) present a renovated crystal structure and significantly enhanced optical performance. Moreover, by simply adjusting the levels of Pb doping in the doped nanocrystals, Pb:Ag2S QDs with bright emission (PLQY up to 30.2%) from 975 to 1242 nm can be prepared without altering the ultrasmall particle size (≈2.7–2.8 nm). Evidently, this cation‐doping strategy facilitates both the renovation of crystal structure of Ag2S QDs and modulation of their optical properties.
Fabrication and Deformation of 3D Multilayered Kirigami Microstructures
Authors: Humood Mohammad , Shi Yan , Han Mengdi , Lefebvre Joseph , Yan Zheng , Pharr Matt , Zhang Yihui , Huang Yonggang , Rogers John A. , Polycarpou Andreas A.
Published: January 2018

Mechanically guided 3D microassembly with controlled compressive buckling represents a promising emerging route to 3D mesostructures in a broad range of advanced materials, including single‐crystalline silicon (Si), of direct relevance to microelectronic devices. During practical applications, the assembled 3D mesostructures and microdevices usually undergo external mechanical loading such as out‐of‐plane compression, which can induce damage in or failure of the structures/devices. Here, the mechanical responses of a few mechanically assembled 3D kirigami mesostructures under flat‐punch compression are studied through combined experiment and finite element analyses. These 3D kirigami mesostructures consisting of a bilayer of Si and SU‐8 epoxy are formed through integration of patterned 2D precursors with a prestretched elastomeric substrate at predefined bonding sites to allow controlled buckling that transforms them into desired 3D configurations. In situ scanning electron microscopy measurement enables detailed studies of the mechanical behavior of these structures. Analysis of the load–displacement curves allows the measurement of the effective stiffness and elastic recovery of various 3D structures. The compression experiments indicate distinct regimes in the compressive force/displacement curves and reveals different geometry‐dependent deformation for the structures. Complementary computational modeling supports the experimental findings and further explains the geometry‐dependent deformation.
A Universal Upconversion Sensing Platform for the Sensitive Detection of Tumour‐Related ncRNA through an Exo III‐Assisted Cycling Amplification Strategy
Authors: Zhang Keying , Yang Lin , Lu Feng , Wu Xingcai , Zhu Jun‐Jie
Published: January 2018

Here, a sensitive and universal noncoding RNA (ncRNA) upconversion sensing nanoplatform is developed. Gold nanoparticles bearing one hairpin DNA (Hp) molecule are conjugated to the linker DNA modified NaYF4:Yb, Er@NaYF4 upconversion nanoparticles by DNA hybridization, leading to quenching of the upconversion emission through fluorescence resonance energy transfer. A signal DNA (SDNA) sequence is designed to open Hp, recovering the upconversion emission. To achieve universality and high sensitivity of the nanoprobe, an exonuclease III (Exo III)‐assisted cycling amplification strategy is introduced. A multifunctional hairpin DNA (mHp) containing ncRNA recognition sequence and SDNA sequence is designed to recognize ncRNA and trigger Exo III as a biocatalyst to stepwise disintegrate itself, releasing both ncRNA and SDNA. The released ncRNA can be reused to release more SDNA, which greatly improves the sensing sensitivity. By changing the recognition portion of mHp, various ncRNA can be detected. The sensitive detection of both homeobox (HOX) transcript antisense RNA segment and miR‐21 is achieved with this novel strategy, even in human serum, indicating the universality and sensitivity of the proposed strategy. Additionally, the expression level of miR‐21 in human breast cancer cell (MCF‐7) lysate is successfully measured, suggesting its potential in clinical diagnosis.
Evaluation of a dedicated ultrasound fine needle aspiration service for thyroid nodules
Authors: Tan Chelsea , Lavender Ilona , Naismith Amanda , Nguyen Qui , Ptasznik Ronnie , Nandurkar Dee , Wong Jennifer , Kumar Beena , Fuller Peter J. , Coombs Peter R. , Mond Michael
Published: January 2018

Introduction

We studied whether: (1) a quality‐focused thyroid fine needle aspiration (FNA) service reduced the non‐diagnostic (ND) rate of FNA; (2) the implementation of thyroid FNA selection criteria resulted in higher proportion of Bethesda V and VI cytology and malignant histopathology; and (3) impact of radiologist's level of experience on ND rates.

Method

The imaging and pathology computer databases were retrospectively searched for all patients who had thyroid FNAs at our hospitals from July 2004 to December 2016.

Results

Three hundred thirty‐eight and 609 patients in pre‐thyroid and post‐thyroid service groups, respectively, were evaluated. The ND rate of 36.7% in pre‐thyroid service was significantly higher than post‐thyroid service at 14.6% (p < 0.0001). The rates of Bethesda V and VI cytology in the pre‐thyroid service group did not differ significantly from the post‐thyroid group (p = 0.266; p = 0.069). There was no significant difference in the histopathologic malignancy rates between the two groups (p = 0.531). There was no significant difference in the ND rates of radiologists with varying experience (p = 0.873).

Discussion

On‐site cytology improved the ND rate of ultrasound‐guided thyroid FNA. Implementation of FNA selection criteria did not alter the rates of Bethesda V and VI cytology and malignant histopathology. The experience of radiologists did not significantly influence ND rates.
Role of plasticizer and dispersion methods on the properties of poly(vinyl chloride) and clay nanocomposites
Authors: Bohn Samara , Balzer Palova Santos , Becker Daniela
Published: January 2018

This article evaluates the effects of different plasticizers and mixture methods of clay dispersion in a poly(vinyl chloride) (PVC) matrix. Three plasticizers were employed: dioctyl adipate (DOA), dioctyl phthalate (DOP), and a green plasticizer (poly‐ɛ‐caprolactone [PCL]). The effect of clay pre‐dispersion in plasticizers was also evaluated using two mixing methods: sonication and mechanical mixture. A heterogenic dispersion of the clay in the PVC matrix and different plasticization regions were observed in thermal properties and in morphology results. However, it was observed that pre‐dispersion decreased clay agglomerates size and some intercalated/exfoliated regions were also found. The clay addition increased 5% on Young's modulus for PVC/DOP with clay dispersion using sonication methods and 10% for PVC/PCL without clay dispersion. The DOA addition led to a decrease in Young's modulus. According to these results, it can be reasoned that clay pre‐dispersion in plasticizers may facilitate intercalation, but does not eliminate all clay agglomerates, and the morphology and plasticizer type influence mechanical properties of plasticized PVC/clay. J. VINYL ADDIT. TECHNOL., 24:E172–E176, 2018. © 2018 Society of Plastics Engineers
Dynamic metabolic control: towards precision engineering of metabolism
Authors: Liu Di , Mannan Ahmad A , Han Yichao , Oyarzún Diego A , Zhang Fuzhong
Published: January 2018

Advances in metabolic engineering have led to the synthesis of a wide variety of valuable chemicals in microorganisms. The key to commercializing these processes is the improvement of titer, productivity, yield, and robustness. Traditional approaches to enhancing production use the “push–pull-block” strategy that modulates enzyme expression under static control. However, strains are often optimized for specific laboratory set-up and are sensitive to environmental fluctuations. Exposure to sub-optimal growth conditions during large-scale fermentation often reduces their production capacity. Moreover, static control of engineered pathways may imbalance cofactors or cause the accumulation of toxic intermediates, which imposes burden on the host and results in decreased production. To overcome these problems, the last decade has witnessed the emergence of a new technology that uses synthetic regulation to control heterologous pathways dynamically, in ways akin to regulatory networks found in nature. Here, we review natural metabolic control strategies and recent developments in how they inspire the engineering of dynamically regulated pathways. We further discuss the challenges of designing and engineering dynamic control and highlight how model-based design can provide a powerful formalism to engineer dynamic control circuits, which together with the tools of synthetic biology, can work to enhance microbial production.
The Changing Safety Net for Low-Income Parents and Their Children: Structural or Cyclical Changes in Income Support Policy?
Authors: Hardy Bradley , Smeeding Timothy , Ziliak James P.
Published: January 2018

Refundable tax credits and food assistance are the largest transfer programs available to able-bodied working poor and near-poor families in the United States, and simultaneous participation in these programs has more than doubled since the early 2000s. To understand this growth, we construct a series of two-year panels from the 1981–2013 waves of the Current Population Survey Annual Social and Economic Supplement to estimate the effect of state labor-market conditions, federal and state transfer program policy choices, and household demographics governing joint participation in food and refundable tax credit programs. Overall, changing policy drives much of the increase in the simultaneous, biennial use of food assistance and refundable tax credits. This stands in stark contrast from the factors accounting for the growth in food assistance alone, where cyclical and structural labor market factors account for at least one-half of the growth, and demographics play a more prominent role. Moreover, since 2000, the business cycle factors as the leading determinant in biennial participation decisions in food programs and refundable tax credits, suggesting a recent strengthening in the relationship between economic conditions and transfer programs.
Do we work hard or are we just great? The effects of organizational pride due to effort and ability on proactive behavior
Authors: Brosi Prisca , Spörrle Matthias , Welpe Isabell M.
Published: January 2018

This study derives a conceptual framework for examining parallel and differential influences of organizational pride in employees’ efforts versus abilities on proactivity. Data from a field survey (N = 1218) confirm our theoretical model. Organizational pride in employees’ efforts and organizational pride in employees’ abilities both had positive indirect effects on proactive behaviors via affective organizational commitment. Yet, whereas organizational pride in employees’ efforts additionally had a direct positive effect on individual and team member proactivity, organizational pride in employees’ abilities showed a direct negative effect on proactive behaviors for the self, the team, and the organization including a behavioral measurement of employees’ provision of ideas for improvement. These findings contribute to the nascent literature on organizational pride by indicating towards employees as source of organizational pride, highlighting potential negative effects of organizational pride, and introducing the differentiation between employees’ efforts and abilities.
Labels vs. Pictures: Treatment-Mode Effects in Experiments About Discrimination
Authors: Abrajano Marisa A. , Elmendorf Christopher S. , Quinn Kevin M.
Published: January 2018

Does treatment mode matter in studies of the effects of candidate race or ethnicity on voting decisions? The assumption implicit in most such work is that such treatment mode differences are either small and/or theoretically well understood, so that the choice of how to signal the race of a candidate is largely one of convenience. But this assumption remains untested. Using a nationally representative sample of white voting-age citizens and a modified conjoint design, we evaluate whether signaling candidate ethnicity with ethnic labels and names results in different effects than signaling candidate ethnicity with ethnically identifiable photos and names. Our results provide strong evidence that treatment-mode effects are substantively large and statistically significant. Further, these treatment-mode effects are not consistent with extant theoretical accounts. These results highlight the need for additional theoretical and empirical work on race/ethnicity treatment-mode effects.
Computer-assisted learning of communication (CALC): A case study of Japanese learning in a 3D virtual world
Authors: Yamazaki Kasumi
Published: January 2018

This study investigates an instantiation of a 3D virtual world–based Japanese learning curriculum within the context of a Japanese as a foreign language (JFL) classroom. Through a mixed-method case study approach, participants’ natural acquisition of Japanese in a 3D virtual environment was examined. In the present study, four sources of data from 11 university-level JFL students (n=11) were collected and analyzed to evaluate the learning outcomes from a new instructional approach called computer-assisted learning of communication (CALC). Based on both interpretative and statistical analyses of data, the major finding of the present study was that the participants, when immersed in the 3D virtual world of Tokyo, acquired contextualized communicative competence. More specifically, quantitative analyses revealed statistically significant improvement in the participants’ acquisition of incidentally encountered vocabulary, in particular, kanji pronunciation and vocabulary interpretation. Qualitative analyses revealed participants’ acquisition of various communicative competencies specific to the context, including persuasive talk, awareness of audience, and collaborative communication.
Discordant congenital Zika syndrome twins show differential in vitro viral susceptibility of neural progenitor cells
Authors: Caires-Júnior Luiz Carlos , Goulart Ernesto , Melo Uirá Souto , Araujo Bruno Henrique Silva , Alvizi Lucas , Soares-Schanoski Alessandra , de Oliveira Danyllo Felipe , Kobayashi Gerson Shigeru , Griesi-Oliveira Karina , Musso Camila Manso , Amaral Murilo Sena , daSilva Lucas Ferreira , Astray Renato Mancini , Suárez-Patiño Sandra Fernanda , Ventini Daniella Cristina , Gomes da Silva Sérgio , Yamamoto Guilherme Lopes , Ezquina Suzana , Naslavsky Michel Satya , Telles-Silva Kayque Alves , Weinmann Karina , van der Linden Vanessa , van der Linden Helio , de Oliveira João Ricardo Mendes , Arrais Nivia Maria Rodrigues , Melo Adriana , Figueiredo Thalita , Santos Silvana , Meira Joanna Goes Castro , Passos Saulo Duarte , de Almeida Roque Pacheco , Bispo Ana Jovina Barreto , Cavalheiro Esper Abrão , Kalil Jorge , Cunha-Neto Edécio , Nakaya Helder , Andreata-Santos Robert , de Souza Ferreira Luis Carlos , Verjovski-Almeida Sergio , Ho Paulo Lee , Passos-Bueno Maria Rita , Zatz Mayana
Published: January 2018

Congenital Zika syndrome (CZS) causes early brain development impairment by affecting neural progenitor cells (NPCs). Here, we analyze NPCs from three pairs of dizygotic twins discordant for CZS. We compare by RNA-Seq the NPCs derived from CZS-affected and CZS-unaffected twins. Prior to Zika virus (ZIKV) infection the NPCs from CZS babies show a significantly different gene expression signature of mTOR and Wnt pathway regulators, key to a neurodevelopmental program. Following ZIKV in vitro infection, cells from affected individuals have significantly higher ZIKV replication and reduced cell growth. Whole-exome analysis in 18 affected CZS babies as compared to 5 unaffected twins and 609 controls excludes a monogenic model to explain resistance or increased susceptibility to CZS development. Overall, our results indicate that CZS is not a stochastic event and depends on NPC intrinsic susceptibility, possibly related to oligogenic and/or epigenetic mechanisms.
Evolving affinity between Coulombic reversibility and hysteretic phase transformations in nano-structured silicon-based lithium-ion batteries
Authors: Ogata K. , Jeon S. , Ko D.-S. , Jung I. S. , Kim J. H. , Ito K. , Kubo Y. , Takei K. , Saito S. , Cho Y.-H. , Park H. , Jang J. , Kim H.-G. , Kim J.-H. , Kim Y. S. , Choi W. , Koh M. , Uosaki K. , Doo S. G. , Hwang Y. , Han S.
Published: January 2018

Nano-structured silicon is an attractive alternative anode material to conventional graphite in lithium-ion batteries. However, the anode designs with higher silicon concentrations remain to be commercialized despite recent remarkable progress. One of the most critical issues is the fundamental understanding of the lithium–silicon Coulombic efficiency. Particularly, this is the key to resolve subtle yet accumulatively significant alterations of Coulombic efficiency by various paths of lithium–silicon processes over cycles. Here, we provide quantitative and qualitative insight into how the irreversible behaviors are altered by the processes under amorphous volume changes and hysteretic amorphous–crystalline phase transformations. Repeated latter transformations over cycles, typically featured as a degradation factor, can govern the reversibility behaviors, improving the irreversibility and eventually minimizing cumulative irreversible lithium consumption. This is clearly different from repeated amorphous volume changes with different lithiation depths. The mechanism behind the correlations is elucidated by electrochemical and structural probing.
Mössbauer spectroscopy of a monolayer of single molecule magnets
Authors: Cini Alberto , Mannini Matteo , Totti Federico , Fittipaldi Maria , Spina Gabriele , Chumakov Aleksandr , Rüffer Rudolf , Cornia Andrea , Sessoli Roberta
Published: January 2018

The use of single molecule magnets (SMMs) as cornerstone elements in spintronics and quantum computing applications demands that magnetic bistability is retained when molecules are interfaced with solid conducting surfaces. Here, we employ synchrotron Mössbauer spectroscopy to investigate a monolayer of a tetrairon(III) (Fe4) SMM chemically grafted on a gold substrate. At low temperature and zero magnetic field, we observe the magnetic pattern of the Fe4 molecule, indicating slow spin fluctuations compared to the Mössbauer timescale. Significant structural deformations of the magnetic core, induced by the interaction with the substrate, as predicted by ab initio molecular dynamics, are also observed. However, the effects of the modifications occurring at the individual iron sites partially compensate each other, so that slow magnetic relaxation is retained on the surface. Interestingly, these deformations escaped detection by conventional synchrotron-based techniques, like X-ray magnetic circular dichroism, thus highlighting the power of synchrotron Mössbauer spectroscopy for the investigation of hybrid interfaces.
Revealing hole trapping in zinc oxide nanoparticles by time-resolved X-ray spectroscopy
Authors: Penfold Thomas J. , Szlachetko Jakub , Santomauro Fabio G. , Britz Alexander , Gawelda Wojciech , Doumy Gilles , March Anne Marie , Southworth Stephen H. , Rittmann Jochen , Abela Rafael , Chergui Majed , Milne Christopher J.
Published: January 2018

Nanostructures of transition metal oxides, such as zinc oxide, have attracted considerable interest for solar-energy conversion and photocatalysis. Both applications are sensitive to the transport and trapping of photoexcited charge carriers. The probing of electron trapping has recently become possible using time-resolved element-sensitive methods, such as X-ray spectroscopy. However, valence-band-trapped holes have so far escaped observation. Herein we use X-ray absorption spectroscopy combined with a dispersive X-ray emission spectrometer to probe the charge carrier relaxation and trapping processes in zinc oxide nanoparticles after above band-gap photoexcitation. Our results, supported by simulations, demonstrate that within 80 ps, photoexcited holes are trapped at singly charged oxygen vacancies, which causes an outward displacement by ~15% of the four surrounding zinc atoms away from the doubly charged vacancy. This identification of the hole traps provides insight for future developments of transition metal oxide-based nanodevices.