bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanisms of DABCO‐ and DMAP‐catalyzed [2 + 4] cycloaddition reactions of methylallenoate with methyleneindolonone: A DFT study
Authors: Li Yan , Liu Tingting , Fu Wenwen
Published: June 2017

The mechanisms and stereoselectivities of the [2 + 4] cycloaddition reaction of methylallenoate R1 with methyleneindolonone R2 catalyzed by DABCO (Equation 1) and DMAP (Equation 2) organocatalysts have been examined with density functional theory (M06‐2X) calculations. Several possible reaction pathways (paths 1a, 1b, and 1c for Equation 1 and paths 2a and 2b for Equation 2) were located and compared. The results of our study reveal that for both reactions, three reaction stages have been characterized: nucleophilic addition of the catalyst (DABCO or DMAP) to R1 (Stage I), addition of the other reactant R2 (Stage II), intramolecular cycloaddition and liberation of the catalyst (DABCO or DMAP) afforded the final product (Stage III). For the DABCO‐catalyzed cycloaddition, we predict that path 1a leading to P(E) is the most energy favorable pathway among the three possible pathways. The carbon–carbon bond formation step is the rate‐determining step (ΔG‡=23.6 kcal/mol). With DMAP catalyst, the same reaction gave P(Z) as the major product. The barrier for the rate‐determining step (addition of R1 to DMAP) is 25.8 kcal/mol. The calculated results are in agreement with the experimental findings. Moreover, for both reactions, the analysis of global reactivity indexes has been carried out to examine the role of catalyst. The present study should provide a general mechanistic framework for the rational design of this kind of reactions.
Development of an autonomous bridge deck inspection robotic system
Authors: La Hung M. , Gucunski Nenad , Dana Kristin , Kee Seong‐Hoon
Published: June 2017

The threat to safety of aging bridges has been recognized as a critical concern to the general public due to the poor condition of many bridges in the United States. Currently, the bridge inspection is conducted manually, and it is not efficient to identify bridge condition deterioration in order to facilitate implementation of appropriate maintenance or rehabilitation procedures. In this paper, we report a new development of the autonomous mobile robotic system for bridge deck inspection and evaluation. The robot is integrated with several nondestructive evaluation (NDE) sensors and a navigation control algorithm to allow it to accurately and autonomously maneuver on the bridge deck to collect visual images and conduct NDE measurements. The developed robotic system can reduce the cost and time of the bridge deck data collection and inspection. For efficient bridge deck monitoring, the crack detection algorithm to build the deck crack map is presented in detail. The impact‐echo (IE), ultrasonic surface waves (USW), and electrical resistivity (ER) data collected by the robot are analyzed to generate the delamination, concrete elastic modulus, corrosion maps of the bridge deck, respectively. The presented robotic system has been successfully deployed to inspect numerous bridges in more than ten different states in the United States.
A Cost‐Effective, Unmodified Platform for the Detection of Heavy Metals via Anodic Stripping Voltammetry at Nanomolar Level
Authors: Perween Mosarrat , Srivastava Divesh N.
Published: June 2017

A new carbon based cost‐effective platform for stripping voltammetry has been reported. A Flat, self‐standing polymer composite chip electrode, having less than 500 micron thickness, has been developed using graphite and poly (methyl methacrylate) in 3:2 ratio. The dimensions and physical state of the chip is best suited for off‐laboratory applications. The utilization of such chip in detection of mercury, lead and cadmium by anodic stripping voltammetry has been tried individually as well as simultaneously over as‐prepared electrode without any modification. Under optimized conditions, limit of detection was found to be 200, 60, 350 nM (40, 15, 40 ppb) in individual analysis, whereas 250, 130, 400 nM (50, 25, 50 ppb) in simultaneous analysis for Hg (II), Pb (II) and Cd (II) ions respectively. The protocol has been extended for the estimation of aforesaid ions in the natural water samples.
Preparation of Modified MWCNT with Dithiooxamide for Preconcentration and Determination of Trace Amounts of Cobalt Ions in Food and Natural Water Samples
Authors: Mirabi Ali , Rad Ali Shokuhi , Abdollahi Masoumeh
Published: June 2017

A fast, sensitive and simple method using multi wall carbon nanotube (MWCNT) coated with dithiooxamide as nanostructure sorbent has been effectively established for extraction and pre‐concentration of trace amounts of cobalt ions before their determination by FAAS (flame atomic absorption spectrometry). Modified MWCNT was synthesized by the reaction of dithiooxamide with functionalized MWCNT. Initially, the surface of MWCNT was oxidized by a mixture of nitric and sulfuric acid and then was functionalized using thionyl chloride, following the ligand was attached to the MWCNT. The properties of nanostructure sorbent were characterized by SEM, BET, TGA, elemental analysis CHNS and FT‐IR techniques. Some effective parameters on extraction and complex formation, such as pH, modified MWCNT dosage, concentration and type of eluent, contacting time, salt effect and sample volume have been optimized. We achieved the calibration graph in linear range of 3–2000 ng mL−1 with limit of detection (LOD) of 0.64 ng mL−1. Relative standard deviation (RSD) for Co (II) ions is calculated to be 2.2 %. The projected technique has been used to assay of cobalt ions at ng mL−1 levels in real samples such as tomato, potato, wheat flour, red beans, oat, tap water, river water and seawater with suitable fallouts.
Temperature Dependent Characteristics of Perovskite Solar Cells
Authors: Wang Mingkui , Yim Wai‐Leung , Liao Peizhe , Shen Yan
Published: June 2017

In this work we report the characterization of perovskite solar cells with mesoscopic TiO2/Al2O3/NiO/carbon architecture by analyzing the dependence of photovoltaic parameters on temperature and illumination intensity. This perovskite device shows impressive power conversion efficiency at room temperature (>14 %) and at low temperature of 80 K (>5 %). This enables unequivocal identification of the contribution of CH3NH3PbI3 to construction of the built‐in electric field, and thus, the temperature dependent photovoltaic parameters. The typical feature of this type solar cell is that open‐circuit voltage follows behaviour of the dielectric constant of CH3NH3PbI3. In addition, the dependence of current on light intensity shifts from the space‐charge‐limited to diffusion‐limited mechanisms as increasing temperature. By using the observed significant short‐circuit current density of 12.76 mA cm−2 at 80 K the exciton‐binding energy of CH3NH3PbI3 is evaluated to be less 6.9 meV in an operating device, which can be further verified with Elliott's formula.
Preparation of Bifunctional CuWO4‐Based Heterostructure Nanocomposites for Noble‐Metal‐Free Photocatalysts
Authors: Kannan Selvaraj , Mohanraj Kannusamy , Sivakumar Ganesan
Published: June 2017

This article describes the preparation of copper tungstate (
)‐based heterostructured nanocomposites by facile two‐step polyol assisted hydrothermal‐annealed process. A series of characterization techniques (FESEM, EDS, HRTEM, XPS, XRD and FTIR etc.) were confirmed the formation of type‐I

) and type‐II
heterojunction as function of pH and annealing temperatures. Also
,
,
,
and CuO were found as secondary phases with
. These nanocomposites exhibited the enhanced visible light absorption and the band gap (ca. 1.7 eV) of
is smaller than the early reported value (2.1‐2.3 eV). In photocatalytic degradation, the
/
and
were showed 1.66 fold times higher and nearly equal apparent rate constant respectively than that of
. In photoelectrochemical (PEC) studies, the
,
/
,
and
nanocomposites showed more photocurrent density of 3.5, 2.2, 0.71 and 0.41 mA/cm2 at 1.23 VRHE respectively than CuWO4. The existence of dual co‐catalysts (Cu2O and CuO) with CuWO4, strongly promote the electron‐hole pair separation and migration. Among the nanocomposite, the
was showed the similar static photocurrent as that of
under 1 Sun illumination. The advantage of present work is noble‐metal‐free photocatalysts prepared with binder free, less time, low energy consumption and cost, and environmental benign.
Controllable N‐Doped CuCo2O4@C Film as a Self‐Supported Anode for Ultrastable Sodium‐Ion Batteries
Authors: Wang Xiaojun , Cao Kangzhe , Wang Yijing , Jiao Lifang
Published: June 2017

Rational synthesis of flexible electrodes is crucial to rapid growth of functional materials for energy‐storage systems. Herein, a controllable fabrication is reported for the self‐supported structure of CuCo2O4 nanodots (≈3 nm) delicately inserted into N‐doped carbon nanofibers (named as 3‐CCO@C); this composite is first used as binder‐free anode for sodium‐ion batteries (SIBs). Benefiting from the synergetic effect of ultrasmall CuCo2O4 nanoparticles and a tailored N‐doped carbon matrix, the 3‐CCO@C composite exhibits high cycling stability (capacity of 314 mA h g−1 at 1000 mA g−1 after 1000 cycles) and high rate capability (296 mA h g−1, even at 5000 mA g−1). Significantly, the Na storage mechanism is systematically explored, demonstrating that the irreversible reaction of CuCo2O4, which decomposes to Cu and Co, happens in the first discharge process, and then a reversible reaction between metallic Cu/Co and CuO/Co3O4 occurrs during the following cycles. This result is conducive to a mechanistic study of highly promising bimetallic‐oxide anodes for rechargeable SIBs.
Dual‐Action Cancer Therapy with Targeted Porous Silicon Nanovectors
Authors: Cifuentes‐Rius Anna , Ivask Angela , Sporleder Ester , Kaur Ishdeep , Assan Yasmin , Rao Shasha , Warther David , Prestidge Clive A. , Durand Jean‐Olivier , Voelcker Nicolas H.
Published: June 2017

There is a pressing need to develop more effective therapeutics to fight cancer. An idyllic chemotherapeutic is expected to overcome drug resistance of tumors and minimize harmful side effects to healthy tissues. Antibody‐functionalized porous silicon nanoparticles loaded with a combination of chemotherapy drug and gold nanoclusters (AuNCs) are developed. These nanocarriers are observed to selectively deliver both payloads, the chemotherapy drug and AuNCs, to human B cells. The accumulation of AuNCs to target cells and subsequent exposure to an external electromagnetic field in the microwave region render them more susceptible to the codelivered drug. This approach represents a targeted two‐stage delivery nanocarrier that benefits from a dual therapeutic action that results in enhanced cytotoxicity.
Development of Constitutive Models for Extrapolative Prediction of Nb–Ti Micro Alloyed Steel
Authors: Wu Siwei , Zhou Xiaoguang , Chen Qiyuan , Ren Jiakuan , Cao Guangming , Liu Zhenyu
Published: June 2017

The experimental stress–strain data from hot compression tests at temperatures from 900 to 1050 °C and strain rates of 0.1, 1, and 10 s−1 are used to develop the constitutive models to predict flow stress of Nb–Ti micro alloyed steel. The Arrhenius‐type model considering compensation of strain, Bayesian regularization neural network model, and integrated model are investigated. The results show that although the Arrhenius‐type model considering compensation of strain can predict the correct variation trends under different deformation conditions, the accuracy is far from being satisfactory. On the other hand, the Bayesian regularization neural network model shows high accuracy in the training data range, but rather uncertainty for the data outside the training data range. By adding stress predicted by the Arrhenius‐type model considering compensation of strain and characteristic points (critical stress, peak stress, and steady–state stress) to neural network model's inputs, the integrated model can result in accurate prediction for hot deformation behavior of Nb–Ti micro alloyed steel, showing more promising potential for industrial application.
Impact of additives on mechanical and barrier properties of starch‐based films plasticized with deep eutectic solvents
Authors: Zdanowicz Magdalena , Johansson Caisa
Published: June 2017

The aim of this work was to prepare starch‐based films plasticized with two and three‐component deep eutectic solvents (DES) in the presence of different additives: aluminosilicates (sodium and calcium montmorillonite), microcrystalline cellulose, and tannin; and to investigate their influence on mechanical and barrier properties of the films. Mutual interactions between polysaccharide matrix, plasticizer, and additive were investigated by Fourier transform infrared (FTIR) spectroscopy. Two types of starches were used: native potato starch (TPS) and hydroxypropylated, oxidized potato starch (HOPS). The two‐component DES CC:G consisted of choline chloride (CC) and glycerol (G), whereas the three‐component DES with crosslinking activity CCit:U:G, included choline citrate (CCit), urea (U), and glycerol. For the TPS/CCit:U:G films an improvement of the mechanical and barrier properties was obtained after introduction of additives, whereas for TPS/CC:G only a slight decrease in water vapor transmission rate was observed, without any significant improvement in mechanical properties. Moreover, the mechanical test results, FTIR spectra, and the oxygen transmission rate values revealed that the clays interacted with plasticizer components, thereby hindering crosslinking reactions between plasticizer and starch.
A fast heuristic optimization algorithm for measurement placement in distribution system state estimation
Authors: Jiao Runhai , Li Yuying , Wang Yi , Lin Biying
Published: June 2017

An accurate, real‐time estimation of the states of a power distribution system is highly desirable but hard to achieve because of the complexity of the network and the relative inefficiency of the measuring system. To increase the efficiency, this paper analyzes the mathematical relationship between the measurement errors and estimation errors of the state vector using the classic weighted least square method. Then a heuristic algorithm is proposed to improve the accuracy by optimizing the deployment of the real‐time measuring points, which is based on the deterministic factors of the measuring points/branches over the system state. The basic implementation starts with an initial measurement set and replaces the least important branches in the set with the most important branches outside the set using iterative optimization. The algorithm was tested in the IEEE 14‐bus and 33‐bus distribution systems and achieved 50% increase in accuracy at much lower computational cost compared with exhaustive search. Moreover, the proposed algorithm has also been compared with representative and widely used evolution algorithms such as particle swarm optimization and quantum‐behaved particle swarm optimization. This comparison shows that our method can achieve stable and comparable accuracy with a speed at least 10 times higher. The performance of our method can be even better with increasing network size. © 2017 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Bioprocess engineering to produce 9-(nonanoyloxy) nonanoic acid by a recombinant Corynebacterium glutamicum-based biocatalyst
Authors: Kim Hyeonsoo , Park Soohyun , Cho Sukhyeong , Yang Jeongmo , Jeong Kijun , Park Jinbyung , Lee Jinwon
Published: June 2017

Here, Corynebacterium glutamicum ATCC13032 expressing Baeyer–Villiger monooxygenase from Pseudomonas putida KT2440 was designed to produce 9-(nonanoyloxy) nonanoic acid from 10-ketostearic acid. Diverse parameters including cultivation and reaction temperatures, type of detergent, and pH were found to improve biotransformation efficiency. The optimal temperature of cultivation for the production of 9-(nonanoyloxy) nonanoic acid from 10-ketostearic acid using whole cells of recombinant C. glutamicum was 15 °C, but the reaction temperature was optimal at 30 °C. Enhanced conversion efficiency was obtained by supplying 0.05 g/L of Tween 80 at pH 7.5. Under these optimal conditions, recombinant C. glutamicum produced 0.28 mM of 9-(nonanoyloxy) nonanoic acid with a 75.6% (mol/mol) conversion yield in 2 h. This is the first report on the biotransformation of 10-ketostearic acid to 9-(nonanoyloxy) nonanoic acid with a recombinant whole-cell C. glutamicum-based biocatalyst and the results demonstrate the feasibility of using C. glutamicum as a whole-cell biocatalyst.
The ‘modern’ management of rats: British agricultural science in farm and field during the twentieth century
Authors: SAYER KAREN
Published: June 2017

During the period from 1919 to 1970, rat killing was ‘modernized’: official, scientific, commercial, agricultural and county advisers sought ‘rat control’. Scientific expertise on rat parasites and rat control circulated internationally. The risks posed to human health through plague, as traced by researchers who were already expert on the third pandemic, led in the UK to the Rats and Mice (Destruction) Act 1919; and the United Nations Conference on Food and Agriculture, at Hot Springs, Virginia, USA, 1943 informed its replacement, the Prevention of Damage by Pests Act 1949. Anticoagulants such as Warfarin developed in the USA at first sold widely in the UK, then later British research on resistance informed subsequent American research. This UK application of international policy and science paralleled the emergence of an official case at Parliamentary level for the national, multidisciplinary and multi-agency approach to rats. Within the UK, animal ecologists under Charles Elton mapped rats in the emergent field of population studies; and new forms of economic costing at MAFF quantified the damage done to farm buildings and machinery and the consumption, soiling and contamination of food, seed and fodder in store. Yet nineteenth-century rat catchers already had an excellent and long-established grasp of rat behaviour, a necessity in either taking or executing their subjects. Though characterized as inefficient, picturesque and craft-based, that vernacular knowledge was reproduced and formalized in the twentieth century through empirical research and evidence-based practice, shaped by experiences at the intersection of human demand, the interests of the (wild and domesticated) animals that humans have preferred, and the endeavours of the rat.
Burns associated with e-cigarette batteries: A case series and literature review
Authors: Harshman Jamie , Vojvodic Miliana , Rogers Alan D.
Published: June 2017

Electronic cigarettes, often referred to ase-cigarettes, have established a considerable market in North America over the last decade. In parallel to this trend, there has been a surge of e-cigarette battery explosions reported in the general media. Given the growing number of such events, acute care physicians should recognize the associated risks and injury patterns and initiate appropriate treatment. This report presents two cases of burn injuries from e-cigarette battery explosions requiring surgical management. The accompanying comprehensive literature review highlights the emerging importance of e-cigarettes as an aetiology of burn injury.
How Did Arius Learn from Asterius? On the Relationship between the Thalia and the Syntagmation
Authors: DELCOGLIANO MARK
Published: June 2017

In the De decretis Athanasius claims that Arius ‘copied’ and ‘learned’ from Asterius. This study explores how this could have happened by arguing that in the writing of his Thalia Arius was influenced by Asterius’ Syntagmation. Besides complicating the literary and theological relationship between Arius and Asterius, this reconstruction provides the clearest evidence for the new perspective on Arius which has emerged in recent revisionist scholarship, and which argues that he is best understood as embedded within a theological tradition and as a catalysing participant in its efforts to articulate a theological vision. By dating the Syntagmation to about 322 and the Thalia to about 323 this study also gives qualified support to Rowan Williams's dating of some pre-Nicene events and discredits a recent attempt to position Asterius as having had a formative influence on Arius.
A century of monetary reform in South-East Europe: from political autonomy to the gold standard, 1815–1910
Authors: Morys Matthias
Published: June 2017

This article documents and analyses monetary reform in Bulgaria, Greece, Serbia and Romania from 1815 (Serbian autonomy within the Ottoman Empire) to 1910, when Greece became the last country in the region to join the gold standard. It explains the five key steps towards monetary reform which the four countries took in the same chronological order, and asks why national coinage and the foundation of a bank of note issue came late in the reform process. The South-East European countries tried to emulate West European prototypes, yet economic backwardness meant such institutions were often different from the outset, remained short-lived or both.
A new hemostatic device utilizing a novel transmission structure for delivery of adrenaline and microwave energy at 5.8 GHz
Authors: Preston Shaun C. , White Malcolm , Saunders Brian , Tsiamoulos Zacharias , Hancock Christoper P.
Published: June 2017

A novel transmission line structure has been developed to facilitate the delivery of both adrenaline and microwave energy to achieve hemostasis. A proximal end impedance transformer and radiative tip have been designed and manufactured to provide good match between the novel hollow transmission line and the microwave source and tissue, respectively. Further consideration of the challenges and problems encountered along with evidence of successful microwave energy delivery at 5.8 GHz into porcine liver model providing a controlled and focused coagulation zone of approximately 5 mm.
Monitoring Wind in Portugal’s Mountains Down to Microscales
Authors: Fernando Harindra , Lundquist Julie , Oncley Steven
Published: June 2017

Researchers are now gathered for the Perdigão field campaign, an effort to study wind flow physics at scales down to tens of meters. The effort should help engineers harness wind energy in Europe.
Disease-linked connexin26 S17F promotes volar skin abnormalities and mild wound healing defects in mice
Authors: Press Eric , Alaga Katanya C , Barr Kevin , Shao Qing , Bosen Felicitas , Willecke Klaus , Laird Dale W
Published: June 2017

Several mutant mice have been generated to model connexin (Cx)-linked skin diseases; however, the role of connexins in skin maintenance and during wound healing remains to be fully elucidated. Here we generated a novel, viable, and fertile mouse (Cx26CK14-S17F/+) with the keratitis-ichthyosis-deafness mutant (Cx26S17F) driven by the cytokeratin 14 promoter. This mutant mouse mirrors several Cx26-linked human skin pathologies suggesting that the etiology of Cx26-linked skin disease indeed stems from epidermal expression of the Cx26 mutant. Cx26CK14-S17F/+ foot pad epidermis formed severe palmoplantar keratoderma, which expressed elevated levels of Cx26 and filaggrin. Primary keratinocytes isolated from Cx26CK14-S17F/+ neonates exhibited reduced gap junctional intercellular communication and migration. Furthermore, Cx26CK14-S17F/+ mouse skin wound closure was normal but repaired epidermis appeared hyperplastic with elevated expression of cytokeratin 6. Taken together, we suggest that the Cx26S17F mutant disturbs keratinocyte differentiation and epidermal remodeling following wound closure. We further posit that Cx26 contributes to epidermal homeostasis by regulating keratinocyte differentiation, and that mice harboring a disease-linked Cx26 mutant display epidermal abnormalities yet retain most wound healing properties.
Cystatin C as a potential therapeutic mediator against Parkinson’s disease via VEGF-induced angiogenesis and enhanced neuronal autophagy in neurovascular units
Authors: Zou Jing , Chen Zhaoyu , Wei Xiaobo , Chen Zhigang , Fu Yongmei , Yang Xiaoyan , Chen Dan , Wang Rui , Jenner Peter , Lu Jia-Hong , Li Min , Zhang Zhuohua , Tang Beisha , Jin Kunlin , Wang Qing
Published: June 2017

Cystatin C (CYS C, Cst3) is an endogenous cysteine protease inhibitor that plays neuroprotective roles in neurodegenerative diseases. We aimed to explore the association of CYS C with Parkinson’s disease (PD) models and investigate its involvement in the role of neurovascular units (NVUs) in PD neuro-pathogenesis. We used A53T α-synuclein (SNCA) transgenic mice and 6-hydroxydopamine-lesioned DAergic PC12 cells as experimental PD models to investigate the mechanisms behind this association. The injections of CYS C were administered to the right substantia nigra (SN) of A53T SNCA transgenic mice to measure the effects of CYS C in transgenic A53T SNCA mice. To explore the angiogenesis in vivo and in vitro, we used the chick embryo chorioallantoic membrane (CAM) assay and tube formation (TF) assay. We found that CYS C has a neuroprotective effect in this in vivo PD model. We observed increased VEGF, NURR1 and autophagy markers LC3B and decreased SNCA and apoptosis marker cleaved CASP3 in different brain regions of CYS C-treated A53T SNCA transgenic mice. In vitro, we observed that CYS C-induced VEGF, a secreted protein, attenuated 6-OHDA-lesioned DAergic PC12 cell degeneration by regulating p-PKC-α/p-ERK1/2-Nurr1 signaling and inducing autophagy. VEGF-mediated angiogenesis was markedly enhanced in the conditioned media of 6-OHDA-lesioned PC12 cells with CYS C-overexpression, whereas blockage of autophagy in CYS C-overexpressing PC12 cells significantly downregulated VEGF expression and the associated angiogenesis. Our data indicate that CYS C displays dual neuronal–vascular functions, promoting PC12 cell survival and angiogenesis via regulating the level of secreted VEGF in NVUs. Our study provides evidence that may aid in the development of an alternative approach for the treatment of PD through modulation of CYS C-mediated neuronal-vascular pathways.
Neuronal population coding of perceived and memorized visual features in the lateral prefrontal cortex
Authors: Mendoza-Halliday Diego , Martinez-Trujillo Julio C.
Published: June 2017

The primate lateral prefrontal cortex (LPFC) encodes visual stimulus features while they are perceived and while they are maintained in working memory. However, it remains unclear whether perceived and memorized features are encoded by the same or different neurons and population activity patterns. Here we record LPFC neuronal activity while monkeys perceive the motion direction of a stimulus that remains visually available, or memorize the direction if the stimulus disappears. We find neurons with a wide variety of combinations of coding strength for perceived and memorized directions: some neurons encode both to similar degrees while others preferentially or exclusively encode either one. Reading out the combined activity of all neurons, a machine-learning algorithm reliably decode the motion direction and determine whether it is perceived or memorized. Our results indicate that a functionally diverse population of LPFC neurons provides a substrate for discriminating between perceptual and mnemonic representations of visual features.
A robot for high yield electrophysiology and morphology of single neurons in vivo
Authors: Li Lu , Ouellette Benjamin , Stoy William A. , Garren Emma J. , Daigle Tanya L. , Forest Craig R. , Koch Christof , Zeng Hongkui
Published: June 2017

Single-cell characterization and perturbation of neurons provides knowledge critical to addressing fundamental neuroscience questions including the structure–function relationship and neuronal cell-type classification. Here we report a robot for efficiently performing in vivo single-cell experiments in deep brain tissues optically difficult to access. This robot automates blind (non-visually guided) single-cell electroporation (SCE) and extracellular electrophysiology, and can be used to characterize neuronal morphological and physiological properties of, and/or manipulate genetic/chemical contents via delivering extraneous materials (for example, genes) into single neurons in vivo. Tested in the mouse brain, our robot successfully reveals the full morphology of single-infragranular neurons recorded in multiple neocortical regions, as well as deep brain structures such as hippocampal CA3, with high efficiency. Our robot thus can greatly facilitate the study of in vivo full morphology and electrophysiology of single neurons in the brain.
Simple and scalable growth of AgCl nanorods by plasma-assisted strain relaxation on flexible polymer substrates
Authors: Park Jae Yong , Lee Illhwan , Ham Juyoung , Gim Seungo , Lee Jong-Lam
Published: June 2017

Implementing nanostructures on plastic film is indispensable for highly efficient flexible optoelectronic devices. However, due to the thermal and chemical fragility of plastic, nanostructuring approaches are limited to indirect transfer with low throughput. Here, we fabricate single-crystal AgCl nanorods by using a Cl2 plasma on Ag-coated polyimide. Cl radicals react with Ag to form AgCl nanorods. The AgCl is subjected to compressive strain at its interface with the Ag film because of the larger lattice constant of AgCl compared to Ag. To minimize strain energy, the AgCl nanorods grow in the [200] direction. The epitaxial relationship between AgCl (200) and Ag (111) induces a strain, which leads to a strain gradient at the periphery of AgCl nanorods. The gradient causes a strain-induced diffusion of Ag atoms to accelerate the nanorod growth. Nanorods grown for 45 s exhibit superior haze up to 100% and luminance of optical device increased by up to 33%.
The microprotein Minion controls cell fusion and muscle formation
Authors: Zhang Qiao , Vashisht Ajay A. , O’Rourke Jason , Corbel Stéphane Y , Moran Rita , Romero Angelica , Miraglia Loren , Zhang Jia , Durrant Eric , Schmedt Christian , Sampath Srinath C. , Sampath Srihari C.
Published: June 2017

Although recent evidence has pointed to the existence of small open reading frame (smORF)-encoded microproteins in mammals, their function remains to be determined. Skeletal muscle development requires fusion of mononuclear progenitors to form multinucleated myotubes, a critical but poorly understood process. Here we report the identification of Minion (microprotein inducer of fusion), a smORF encoding an essential skeletal muscle specific microprotein. Myogenic progenitors lacking Minion differentiate normally but fail to form syncytial myotubes, and Minion-deficient mice die perinatally and demonstrate a marked reduction in fused muscle fibres. The fusogenic activity of Minion is conserved in the human orthologue, and co-expression of Minion and the transmembrane protein Myomaker is sufficient to induce cellular fusion accompanied by rapid cytoskeletal rearrangement, even in non-muscle cells. These findings establish Minion as a novel microprotein required for muscle development, and define a two-component programme for the induction of mammalian cell fusion. Moreover, these data also significantly expand the known functions of smORF-encoded microproteins.
Giant barocaloric effect in the ferroic organic-inorganic hybrid [TPrA][Mn(dca)3] perovskite under easily accessible pressures
Authors: Bermúdez-García Juan M. , Sánchez-Andújar Manuel , Castro-García Socorro , López-Beceiro Jorge , Artiaga Ramón , Señarís-Rodríguez María A.
Published: June 2017

The fast growing family of organic–inorganic hybrid compounds has recently been attracting increased attention owing to the remarkable functional properties (magnetic, multiferroic, optoelectronic, photovoltaic) displayed by some of its members. Here we show that these compounds can also have great potential in the until now unexplored field of solid-state cooling by presenting giant barocaloric effects near room temperature already under easily accessible pressures in the hybrid perovskite [TPrA][Mn(dca)3] (TPrA: tetrapropylammonium, dca: dicyanamide). Moreover, we propose that this will not be an isolated example for such an extraordinary behaviour as many other organic–inorganic hybrids (metal-organic frameworks and coordination polymers) exhibit the basic ingredients to display large caloric effects which can be very sensitive to pressure and other external stimuli. These findings open up new horizons and great opportunities for both organic–inorganic hybrids and for solid-state cooling technologies.
Thermal annihilation of photo-induced radicals following dynamic nuclear polarization to produce transportable frozen hyperpolarized 13C-substrates
Authors: Capozzi Andrea , Cheng Tian , Boero Giovanni , Roussel Christophe , Comment Arnaud
Published: June 2017

Hyperpolarization via dynamic nuclear polarization (DNP) is pivotal for boosting magnetic resonance imaging (MRI) sensitivity and dissolution DNP can be used to perform in vivo real-time 13C MRI. The type of applications is however limited by the relatively fast decay time of the hyperpolarized spin state together with the constraint of having to polarize the 13C spins in a dedicated apparatus nearby but separated from the MRI magnet. We herein demonstrate that by polarizing 13C with photo-induced radicals, which can be subsequently annihilated using a thermalization process that maintains the sample temperature below its melting point, hyperpolarized 13C-substrates can be extracted from the DNP apparatus in the solid form, while maintaining the enhanced 13C polarization. The melting procedure necessary to transform the frozen solid into an injectable solution containing the hyperpolarized 13C-substrates can therefore be performed ex situ, up to several hours after extraction and storage of the polarized solid.
The Effects of e-interventions on the Medical Outcomes of Hemodialysis Patients: A Retrospective Matched Patient Cohort Study
Authors: Jenq Chang-Chyi , Hung Cheng-Chieh , Juan Kuo-Chang , Hsu Kuang-Hung
Published: June 2017

Aggressively applying e-interventions in the health care industry has become a global trend to improve the quality of medical care. The present retrospective study evaluated the effect of electronic information systems on the quality of medical care provide to hemodialysis (HD) patients. In total, 600 patients (300 patients each in the e-intervention and non-e-intervention groups, were matched for sex, age, HD duration, diabetes, and hypertension) receiving HD at the study institute for four years were included in this study. The e-intervention group had significantly fewer hospitalization days than the non-e-intervention group. Cox regression analysis demonstrated that the non-e-intervention group had a significantly higher mortality rate than the e-intervention group. Stratified analysis revealed significant differences between the e-intervention and non-e-intervention groups in their serum albumin levels, urea reduction ratios, and cardiothoracic ratios at 1-year follow-up. The patients in the e-intervention group had a significantly higher HD blood flow rate, fewer hospitalization days and a lower 4-year all-cause mortality rate than those in the non-e-intervention group. The implementation of the e-intervention improved patient outcomes, but additional studies are required to evaluate the cost effectiveness of such implementations.
Formation Mechanism for 2015/16 Super El Niño
Authors: Chen Lin , Li Tim , Wang Bin , Wang Lu
Published: June 2017

The extreme El Niño (EN) events in 1997/98 and 1982/83, referred to as super EN, exerted remarkable global influence. A super EN was anticipated on the way in early 2014 but failed to materialize toward the end of 2014. Whilst the scientific community was still puzzling about the cause of the aborted EN event in 2014, the remnants of the decaying warming in late 2014 unexpectedly reignited since February 2015 and grew into a super EN by the end of 2015. Understanding the onset mechanism of the 2015 EN event and its differences from past super EN events is crucial for improving EN prediction in a changing climate. Our observational analyses and modeling studies demonstrate that the principal difference between the 2015 EN and the past super ENs lies in exceptionally strong and consecutive occurrence of westerly wind burst events that turned around unfavorable ocean thermocline conditions in tropical western Pacific in early 2015, reigniting rapidly the surface warming in the eastern Pacific. By August the sea surface temperature anomalies reached a critical amplitude similar to that of the past super ENs; positive atmosphere-ocean feedbacks further amplify this warm episode into a super EN by the end of 2015.
A highly conserved sequence of the viral TAP inhibitor ICP47 is required for freezing of the peptide transport cycle
Authors: Matschulla Tony , Berry Richard , Gerke Carolin , Döring Marius , Busch Julia , Paijo Jennifer , Kalinke Ulrich , Momburg Frank , Hengel Hartmut , Halenius Anne
Published: June 2017

The transporter associated with antigen processing (TAP) translocates antigenic peptides into the endoplasmic reticulum (ER) lumen for loading onto MHC class I molecules. This is a key step in the control of viral infections through CD8+ T-cells. The herpes simplex virus type-1 encodes an 88 amino acid long species-specific TAP inhibitor, ICP47, that functions as a high affinity competitor for the peptide binding site on TAP. It has previously been suggested that the inhibitory function of ICP47 resides within the N-terminal region (residues 1–35). Here we show that mutation of the highly conserved50PLL52motif within the central region of ICP47 attenuates its inhibitory capacity. Taking advantage of the human cytomegalovirus-encoded TAP inhibitor US6 as a luminal sensor for conformational changes of TAP, we demonstrated that the50PLL52motif is essential for freezing of the TAP conformation. Moreover, hierarchical functional interaction sites on TAP dependent on50PLL52could be defined using a comprehensive set of human-rat TAP chimeras. This data broadens our understanding of the molecular mechanism underpinning TAP inhibition by ICP47, to include the50PLL52sequence as a stabilizer that tethers the TAP-ICP47 complex in an inward-facing conformation.
Cdc6 contributes to abrogating the G1 checkpoint under hypoxic conditions in HPV E7 expressing cells
Authors: Chen Hanxiang , Zhang Qishu , Qiao Lijun , Fan Xueli , Zhang Weifang , Zhao Weiming , Chen Jason J.
Published: June 2017

The human papillomavirus (HPV) plays a central role in cervical carcinogenesis and its oncogene E7 is essential in this process. We showed here that E7 abrogated the G1 cell cycle checkpoint under hypoxia and analyzed key cell cycle related proteins for their potential role in this process. To further explore the mechanism by which E7 bypasses hypoxia-induced G1 arrest, we applied a proteomic approach and used mass spectrometry to search for proteins that are differentially expressed in E7 expressing cells under hypoxia. Among differentially expressed proteins identified, Cdc6 is a DNA replication initiation factor and exhibits oncogenic activities when overexpressed. We have recently demonstrated that Cdc6 was required for E7-induced re-replication. Significantly, here we showed that Cdc6 played a role in E7-mediated G1 checkpoint abrogation under hypoxic condition, and the function could possibly be independent from its role in DNA replication initiation. This study uncovered a new function of Cdc6 in regulating cell cycle progression and has important implications in HPV-associated cancers.
Dynamic Triple-Mode Sorption and Outgassing in Materials
Authors: Sharma Hom N. , Harley Stephen J. , Sun Yunwei , Glascoe Elizabeth A.
Published: June 2017

Moisture uptake and outgassing can be detrimental to a system by altering the chemical and mechanical properties of materials within the system over time. In this work, we conducted isotherm experiments to investigate dynamic moisture sorption and desorption in markedly different materials, i.e., a polymeric material, Sylgard-184 and a ceramic aluminosilicate material, Zircar RS-1200, at different temperatures (30 °C–70 °C) by varying the water activity (0.0–0.90). Sylgard-184 showed a linear sorption and outgassing behavior with no-hysteresis over the entire temperature and water activity range considered here. Whereas, the sorption and outgassing of Zircar RS-1200 was highly non-linear with significant hysteresis, especially at higher water activities, at all temperatures considered here. The type of hysteresis suggested the presence of mesopores in Zircar RS-1200, whereas the lack of hysteresis in Sylgard-184 indicates that it has a nonporous structure. A diffusion model coupled with a dynamic, triple-mode sorption (Langmuir, Henry, and pooling modes) model employed in this study matched our experimental data very well and provides mechanistic insight into the processes. Our triple-mode sorption model was adaptive enough to (1) model these distinctly different materials and (2) predict sorption and outgassing under conditions that are distinctly different from the parameterization experiments.
Biogeography of Amazon birds: rivers limit species composition, but not areas of endemism
Authors: Oliveira Ubirajara , Vasconcelos Marcelo F. , Santos Adalberto J.
Published: June 2017

Amazonian rivers are usually suggested as dispersal barriers, limiting biogeographic units. This is evident in a widely accepted Areas of Endemism (AoEs) hypothesis proposed for Amazonian birds. We empirically test this hypothesis based on quantitative analyses of species distribution. We compiled a database of bird species and subspecies distribution records, and used this dataset to identify AoEs through three different methods. Our results show that the currently accepted Amazonian AoEs are not consistent with areas identified, which were generally congruent among datasets and methods. Some Amazonian rivers represent limits of AoEs, but these areas are not congruent with those previously proposed. However, spatial variation in species composition is correlated with largest Amazonian rivers. Overall, the previously proposed Amazonian AoEs are not consistent with the evidence from bird distribution. However, the fact that major rivers coincide with breaks in species composition suggest they can act as dispersal barriers, though not necessarily for all bird taxa. This scenario indicates a more complex picture of the Amazonian bird distribution than previously imagined.
Paradoxical puborectalis syndrome on diffusion-weighted imaging: a retrospective study of 72 cases
Authors: Liu Guiqin , Cui Zhe , Dai Yongming , Yao Qiuying , Xu Jianrong , Wu Guangyu
Published: June 2017

This study aimed to evaluate the application value of diffusion-weighted imaging (DWI) for assessing paradoxical puborectalis syndrome (PPS) in patients with obstructive defecation syndrome (ODS). The medical records of 72 ODS patients who underwent magnetic resonance (MR)-DWI and MR-defecography were retrospectively reviewed. The differences in the apparent diffusion coefficients (ADCs) and the thickness of the right and left branches of the puborectalis muscles between the PPS(+) and PPS(−) groups were compared. In addition, the absolute within-patient differences between the right and left branches (ADC, thickness) were compared between the two groups. The absolute difference in ADCs (right branch - left branch) was significantly different between the two groups. Regardless of whether the ADC was acquired through single-ROI (0.10 ± 0.08 vs 0.23 ± 0.18, P = 0.000) or multi-ROI (0.16 ± 0.14 vs 0.27 ± 0.17, P = 0.009) analysis, the PPS(+) patients displayed a lower absolute ADC difference than did the PPS(−) patients. However, there was no statistically significant difference in the ADC value, thickness or the absolute difference in thickness between the two groups. These findings suggest that DWI may have value in quantitatively assessing the puborectalis muscle in ODS patients, whereas the value of puborectalis thickness in such aspect needs further study.
Low genetic diversity and potential inbreeding in an isolated population of alder buckthorn (Frangula alnus) following a founder effect
Authors: Finlay Caroline M. V. , Bradley Caroline R. , Preston S. Jane , Provan Jim
Published: June 2017

Alder buckthorn (Frangula alnus) is one of Ireland’s rarest tree species, and in Northern Ireland the species is now restricted to a single population in Peatlands Park, Co. Armagh numberingca. 140 mature trees. Genotyping of 95% of the trees at nine nuclear microsatellite loci revealed that levels of genetic diversity within this population were generally lower than those reported from larger populations in Spain. Analysis of six chloroplast microsatellite loci revealed no variation. The level ofFISwas significantly higher than that in the Spanish populations, as well as in other populations across Europe, potentially indicating inbreeding. Spatial autocorrelation analysis indicated some evidence of fine-scale genetic structuring, most likely due to limited seed dispersal, but the overall level of differentiation between subpopulations was low, indicating high levels of gene flow, probably due to cross-pollination by bees. Our results are consistent with a gradual population expansion from a limited number of individuals. We suggest that more immediate conservation efforts might be best focused on ensuring suitable habitat for the continued recovery of this isolated population.
PH-Dependent Enantioselectivity of D-amino Acid Oxidase in Aqueous Solution
Authors: Liu Qingju , Chen Li , Zhang Zhikun , Du Bibai , Xiao Yating , Yang Kunhao , Gong Lingling , Wu Li , Li Xiangjun , He Yujian
Published: June 2017

D-amino acid oxidases (DAAO) are stereospecific enzymes which are generally almost inactive towards L-enantiomer in neutral solution when L-, D-amino acids are supplied as substrates. In this paper, the D-amino acid oxidase can catalytic oxidize L-amino acids by modulating pH of aqueous solution. With L-Pro as substrate, the catalytic rate (kcat) and the affinity (Km) of DAAO were 6.71 s−1 and 33 mM at pH 8.0, respectively, suggesting that optimal pH condition enhanced the activity of DAAO towards L-Pro. Similar results were obtained when L-Ala (pH 9.8), L-Arg (pH 6.5), L-Phe (pH 9.0), L-Thr (pH 9.4), and L-Val (pH 8.5) were catalyzed by DAAO at various pH values. The racemization of the L-amino acids was not found by capillary electrophoresis analysis during oxidation, and quantification analysis of L-amino acids before and after catalytic reaction was performed, which confirmed that the modulation of enantioselectivity of DAAO resulted from the oxidation of L-amino acids rather than D-amino acids by changing pH. A mechanistic model was proposed to explain enhanced activity of DAAO towards L-amino acids under optimal pH condition.