bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimal Design and Control Strategy of a Novel 2-DOF Micromanipulator
Authors: Li Yangmin , Wu Zhigang , Zhao Xinhua
Published: March 2013

A kind of novel 2-DOF micromanipulator is designed and analysed based on the two scales of level amplifier principle, which adopts the flexure hinge to replace the traditional hinge. The kinematics, static and dynamic modelling are established, and the input stiffness and actual amplification ratios are calculated. Meanwhile, the finite element analysis (FEA) is applied in order to validate the calculation by using ANSYS software. Then, the theoretical, calculated and simulated values diagrams are compared. Thereafter, the stress and the natural frequency of the stage are also analysed to optimize the platform dimensions. Parasitic motion values are calculated and analysed, and their values are compared in a diagram. The Particle Swarm Optimization (POS) is applied to design and optimize the structure parameters, and finally the optimal structure parameters are obtained and the values of parameters are used by the finite element model (FEM). In addition, a dynamic equation and a suitable control flow chart are designed for the mechanism, and the control strategy is proposed accordingly. Finally, the simulation analysis of the stage control adopting the MATLAB software is performed.
Towards Behavior Control for Evolutionary Robot Based on RL with ENN
Authors: Yang Jingan , Zhuang Yanbin , Li Chunguang
Published: March 2013

This paper proposes a behavior-switching control strategy of an evolutionary robot based on Artificial Neural Network (ANN) and genetic algorithm (GA). This method is able not only to construct the reinforcement learning models for autonomous robots and evolutionary robot modules that control behaviors and reinforcement learning environments, and but also to perform the behavior-switching control and obstacle avoidance of an evolutionary robot in the unpredictable environments with the static and moving obstacles by combining ANN and GA.

The experimental results have demonstrated that our method can perform the decision-making strategy and parameter setup optimization of ANN and GA by learning and can effectively escape from a trap of local minima, avoid motion deadlock status of humanoid soccer robotic agents, and reduce the oscillation of the planned trajectory among the multiple obstacles by crossover and mutation. We have successfully applied some results of the proposed algorithm to our simulation humanoid robotic soccer team CIT3D which won the 1st prize of RoboCup Championship and ChinaOpen2010 and the 2nd place of the official RoboCup World Championship on 5-11, July 2011 in Istanbul, Turkey.

In comparison with the conventional behavior network and the adaptive behavior method, our algorithm simplified the genetic encoding complexity, improved the convergence rate ρ and the network performance.
An On-Line Path Planner for Industrial Manipulators
Authors: Padula Fabrizio , Perdereau Veronique
Published: March 2013

In this paper, an on-line path planner for an industrial manipulator is presented. The proposed control architecture is capable of driving the manipulator in its environment while avoiding collisions. Potential fields are used in order to control the joint velocities in such a way that the robot avoids the obstacles. We also propose a new weighted pseudoinverse matrix that improves the manipulator capability of finding feasible paths to move around obstacles and pass through narrow corridors without relying on the manipulator dynamic model. The proposed technique fits to both redundant and non-redundant manipulators. Experimental results show the effectiveness of the proposed solution.
Adaptive Human Control Gains during Precision Grip
Authors: Engeberg Erik D.
Published: March 2013

Eight human test subjects attempted to track a desired position trajectory with an instrumented manipulandum (MN). The test subjects used the MN with three different levels of stiffness. A transfer function was developed to represent the human application of a precision grip from the data when the test subjects initially displaced the MN so as to learn the position mapping from the MN onto the display. Another transfer function was formed from the data of the remainder of the experiments, after significant displacement of the MN occurred. Both of these transfer functions accurately modelled the system dynamics for a portion of the experiments, but neither was accurate for the duration of the experiments because the human grip dynamics changed while learning the position mapping. Thus, an adaptive system model was developed to describe the learning process of the human test subjects as they displaced the MN in order to gain knowledge of the position mapping. The adaptive system model was subsequently validated following comparison with the human test subject data. An examination of the average absolute error between the position predicted by the adaptive model and the actual experimental data yielded an overall average error of 0.34mm for all three levels of stiffness.
Robot Emotion and Performance Regulation Based on HMM
Authors: Xin Liu , Lun Xie , Zhi-liang Wang , Dong-mei Fu
Published: March 2013

This paper discusses the transference process of emotional states driven by psychological energy in the active field state space and also builds a robot expression model based on the Hidden Marov Models(HMM). Facial expressions and behaviours are two important channels for human-robot interaction. Robot performance based on a static emotional state cannot vividly display dynamic and complex emotional transference. Building a real-time emotional interactive model is a critical part of robot expression. First, the attenuating emotional state space is defined and the state transfer probability is acquired. Secondly, the emotional expression model based on the HMM is proposed and the performance transference probability is calculated. Finally, this model is verified by a 15 degrees of freedom robot platform. Moreover, the interactive effects are analysed by a statistical algorithm. The experimental results demonstrate that the emotional expression model can acquire an expressive performance and remove the mechanized interactive mode when compared to traditional algorithms.
Evaluating the Intellectual Capital of Technology Transfer and Learning Public Services
Authors: Grimaldi Michele , Hanandi Musadaq
Published: March 2013

Since the rise of the knowledge-based economy, many worldwide companies have begun to deal with different frameworks to manage and evaluate the performance of intellectual capital, especially in the area of knowledge management services. This paper presents a novel conceptual model aiming to support management in evaluating and prioritizing their intellectual capital competitive core competences. Based on the analytic hierarchy process, the model analyses interdependences among intellectual capital elements and determines the impacts of core competences on organizational performance. To validate the model, it is empirically applied in the Technology Transfer Unit of the Italian national agency for new technologies, energy and economic development.
Temperature-Dependent Sellmeier Equation for Refractive Index of 1.0 mol % Mg-Doped Stoichiometric Lithium Tantalate
Authors: Lim Hwan Hong , Kurimura Sunao , Katagai Toshio , Shoji Ichiro
Published: March 2013

Mg-doped stoichiometric lithium tantalate (SLT) is a promising material in high power generation, due to its high thermal conductivity. The accuracy of the temperature-dependent Sellmeier equation for Mg-doped SLT is important for designing high-power-frequency converters. We propose a temperature-dependent Sellmeier equation for the extraordinary refractive index of 1.0 mol % Mg-doped SLT. The equation is fitted with measured data in the first-order quasi-phase-matched (QPM) second harmonic generation (SHG) and optical parametric oscillation (OPO) with the fundamental and pump wavelengths being both 1.064 µm and previously published data [Jpn. J. Appl. Phys. 41 (2002) 465] of SLT. The equation allows us to predict accurate QPM periods in the range of 0.5–4 µm wavelength and in temperature range of 30–170 °C.
Thermodynamic Analysis of Coherently Grown GaAsN/Ge: Effects of Different Gaseous Sources
Authors: Kawano Jun , Kangawa Yoshihiro , Yayama Tomoe , Kakimoto Koichi , Koukitu Akinori
Published: March 2013

Thermodynamic analysis of coherently grown GaAs1-x
N
x
on Ge with low N content was performed to determine the relationship between solid composition and growth conditions. In this study, a new algorithm for the simulation code, which is applicable to wider combinations of gaseous sources than the traditional algorithm, was developed to determine the influence of different gaseous sources on N incorporation. Using this code, here we successfully compared two cases: one is a system using trimethylgallium (TMG), AsH3, and NH3, and the other uses dimethylhydrazine (DMHy) instead of NH3. It was found that the optimal N/As ratio of input gas in the system using DMHy was much lower than that using NH3. This shows that the newly developed algorithm could be a useful tool for analyzing the N incorporation during the vapor growth of GaAs1-x
N
x
.
Chemical Gradient of Contact Hole Latent Image Created in Chemically Amplified Extreme Ultraviolet Resists
Authors: Kozawa Takahiro , Hirayama Taku
Published: March 2013

A contact hole pattern as well as a line-and-space pattern is a basic element for the fabrication of semiconductor devices. The critical dimension uniformity and edge roughness of contact hole patterns are critical issues for extreme ultraviolet (EUV) lithography. In this study, the quality of the latent images of contact hole patterns was investigated in terms of the chemical gradient using a simulation on the basis of the reaction mechanisms of chemically amplified EUV resists. The latent image formation of contact hole patterns was compared with that of line-and-space patterns. The latent image quality of contact hole patterns was significantly lower than that of line-and-space patterns. To obtain the same latent image quality as line-and-space patterns, the exposure dose should be increased 1.4±0.1 times. Similarly to the line-and-space patterns, the increase of acid generator concentration and effective reaction radius is effective for the enhancement of latent image quality. For the enhancement of latent image quality of contact hole patterns, the enhancement of the effective reaction radius is more effective in a low exposure dose region than a high exposure dose region.
Fabrication and Evaluation of Thin-Film Spiral-Antenna-Coupled VOx Microbolometer by Metal–Organic Decomposition
Authors: Son Le Ngoc , Tachiki Takashi , Uchida Takashi
Published: March 2013

A VO
x
microbolometer coupled with thin-film spiral antenna was fabricated on a fused-quartz substrate by metal–organic decomposition (MOD). The size of the bolometer was 1 ×52 µm2, and the antenna was designed for operating at 75–110 GHz. The DC sensitivity and responsivity of the bolometer were 540 W-1 and 124 V/W at the bias current of 0.5 mA under the irradiation of a 94 GHz electromagnetic wave, respectively. These values were over one order higher than those of the Bi microbolometer, which is conventionally utilized as a detector in terahertz and infrared regions. The antenna-coupled VO
x
microbolometer with a high responsivity was realized by MOD.
Fabrication of Silicon Microchannel for Transport of Bacterial Cells by Ar/F2 Vapor Etching Process
Authors: Matsutani Akihiro , Takada Ayako
Published: March 2013

We fabricated a Si based microchannel without cover plates by an Ar/F2 vapor etching process. In the Ar/F2 vapor etching process, the Si substrate was etched in proportion to the etching time with good controllability. We succeeded in the transport of Escherichia coli cells in the microchannel. In addition, we fabricated a Si-based two-step microchannel without cover plates by Ar/F2 vapor etching and Cl2-based inductively coupled plasma (ICP) etching processes. The proposed microchannel would be useful for the separation of bacterial cells according to size.
Special Education History, Current Status and Future: India
Authors: Antony Pavan John
Published: March 2013

Education of all children in public schools, including those with disabilities, continues to be an unresolved issue in many countries around the globe. While education of all children is mandated by law and considered a basic human right in many countries, the current status of implementation varies. India, for example, is an ancient country that adopted several laws and policies for its citizens with disabilities after gaining independence from British rule. Today, India legally requires the education of all children in schools; however, despite this, millions of children with disabilities continue to remain out of school or receive little or no education. This paper discusses the special education history, legal system, current status and future for people with disabilities in India.
Laser‐ and Optical‐Based Techniques for the Detection of ExplosivesUpdate based on the original article by David L. Monts, Jagdish P. Singh and Gary M. Boudreaux,Encyclopedia of Analytical Chemistry, © 2000, John Wiley & Sons, Ltd
Authors: Hummel R. , Dubroca T.
Published: March 2013

A wide variety of optical‐ and laser‐based techniques have been and are currently being investigated as means of identifying and characterizing explosive materials. These efforts are hampered by the very low volatility of explosive compounds at room temperature and their tendency to ignite at higher temperatures where their vapor pressures are beginning to reach a regime where the species can be readily detected. Traditional, condensed‐phase absorption spectroscopy (both infrared (IR) and ultraviolet/ visible (UV/VIS)) requires larger samples than are frequently available and, although useful as confirmatory techniques, do not provide signatures that enable unique identification of species. The choice of nontraditional techniques for analysis of explosive materials is dependent upon the amount of sample available, the sample matrix, and sample‐imposed constraints upon the measurement. Raman spectroscopy can identify and quantify condensed phase explosive materials, but the detection limit depends upon substrate, excitation wavelength, and illumination area: limits of detection (LODs) vary from 0.05 ng for 2,4,6‐trinitrotoluene (TNT) on glass to 10 µg for nitroglycerin (NG) on silica gel. The other detection techniques considered require volatilization of either the explosive compound itself or more often of characteristic decomposition products, such as NO, NO2, or N2O. Using IR irradiation, researchers have demonstrated that photoacoustic spectroscopy (PAS) has detection limits ranging from 0.55 ppb (parts per billion) for vapor‐phase NG with 9 mm excitation to 220 ppm (parts per million) for vaporphase 2,4‐dinitrotoluene (DNT) with 6‐µm excitation. IR laser differential absorption detection of dissociation products NO, NO2, and/or N2O can achieve detection limits of a few picograms. Laser‐induced fluorescence (LIF) detection of the photofragments (typically NO) of explosive compounds yields detection limits in the tens to hundreds of ppb (by weight) range. Low LODs can be achieved using ion detection techniques: resonance‐enhanced multiphoton ionization (REMPI) spectrometry is capable of LODs for detecting vapor‐phase explosives compounds in the hundredths to tens of ppb range; ion mobility spectrometry (IMS) has vapor‐phase detection limits for common explosive compounds of typically 200 pg, but for some species can be significantly lower: for example, 1 pg for TNT.
Nanoparticles in Foods, Determination of
Authors: Blasco Cristina , Picó Yolanda
Published: March 2013

This article discusses the state of the art in the identification and determination of nanoparticles in food. It is of utmost importance to determine, in addition to the particle‐size distribution, the chemical composition as well as the physical and chemical properties of the nanomaterials within the sample. After a brief description of what nanomaterials are and how to classify them, sources and routes of nanomaterials to food are discussed. The article then follows the debate on legislative consideration, which has emerged very recently. Its main aim is to deliver information on how nanomaterials are determined in food because of the number of challenges that arise when analyzing food and beverages for nanomaterials. No single technique can provide all relevant information. Therefore, a range of analytical techniques is required for detection and characterization of nanomaterials in foods. The principles of the techniques together with their advantages and drawbacks, and reported applications concerning nanoparticles or related nanocompounds are discussed.
Duty to Warn
Authors: Stankowski Joy
Published: March 2013

In law, duty to warn states that a party may be held liable for damages sustained to a second party, if the first party had an opportunity to warn the second, and failed to do so. This concept was applied to mental health practitioners in the landmark California Supreme Court case,Tarasoff v. Regents(hereafter known asTarasoff I), which established the duty of a therapist to warn foreseeable victims of patients. In the rehearing of Tarasoff I in 1976 (hereafter known asTarasoff), the court clarified that the duty was to protect, with warning a possible victim being one way of discharging this duty. For the past four decades, both therapists and courts have wrestled with the implications of the Tarasoff duty. In the United States, the majority of states have adopted Tarasoff‐like statutes, with various interpretations and limitations. Canada and the United Kingdom have also considered Tarasoff‐like statues, but to date, have mostly relied on an unlegislated concept that public protection typically supersedes patient confidentiality. This article examines the history of duty to protect, before and after Tarasoff, controversies surrounding this duty, and current trends.
Genomics and Behavioral Evidence
Authors: Bernet William
Published: March 2013

This article summarizes the history and current status of testimony regarding behavioral genetics and genomics. Depending on the case specifics, testimony regarding a person's genetic makeup may constitute evidence of a particular psychiatric diagnosis, may simply support the diagnosis in a general way, or may help explain the person's behavior. In criminal trials, testimony regarding behavioral genomics—including gene and environment interactions—is most likely to be relevant as mitigation in sentencing hearings. Ordinarily, genotyping a defendant is only one part of a comprehensive psychiatric and psychological forensic evaluation.
Arab World Psychology
Authors: Ibrahim Abdel‐Sattar
Published: March 2013

The phrase “Arab world” refers to the Middle Eastern Arab countries from Morocco to the Arabian Gulf . Arab societies are highly diverse and consist of heterogeneous psychosocial systems based on ethnic, regional, socioeconomic, and national identities. Despite differences among the nations and regions of the Arab world, there are broad commonalities in religion, language, and psychosocial trends that are all part of the shared cultural heritage.
Impact of Relevance and Distraction on Driving Performance and Visual Attention in a Simulated Driving Environment
Authors: Garrison Teena M. , Williams Carrick C.
Published: March 2013

Previous demonstrations of the impact of cellular phone conversations on visual attention when driving have primarily focused on attention to stimuli that are not relevant to driving. In contrast, we used a driving simulator and eye tracking to examine attention allocation across driving‐relevant and driving‐irrelevant items in the environment depending on whether drivers were distracted. Performance measures indicated that distraction negatively impacted vehicle control. However, driving relevance and the presence of distraction did not interact, suggesting that participants responded to potential hazards similarly in driving‐only and distraction conditions. In contrast, eye movement results indicated an interaction between distraction and relevance. Drivers attended more to driving‐relevant objects, and these objects showed smaller decrements in number of gazes in the distraction condition, compared with less relevant items. Even under distraction conditions, experienced drivers continued to attend to potential hazards, allocating less attention to billboards and roadway signage. Copyright © 2013 John Wiley & Sons, Ltd.
Weaverbird: Topological Mesh Editing for Architects
Authors: Piacentino Giulio
Published: March 2013

Design and computation consultant Giulio Piacentino is the developer of WeaverBird. Here he describes how the plug‐in ‘gives architects more geometric control and allows them to create complex surface structures that join in orderly ways, yet in arbitrary configurations’.
Synergy of Pickering Emulsion and Sol‐Gel Process for the Construction of an Efficient, Recyclable Enzyme Cascade System
Authors: Shi Jiafu , Wang Xiaoli , Zhang Wenyan , Jiang Zhongyi , Liang Yanpeng , Zhu Yuanyuan , Zhang Chunhong
Published: March 2013

An efficient, easily recyclable enzyme cascade system based on nanoparticle‐stabilized capsules (NPSCs) is constructed through a synergy of a Pickering emulsion and sol‐gel process. Specifically, oligodopa‐coated titania nanoparticles (biomimetic titania) containing the first enzyme (FateDH) are synthesized through a bioadhesion‐assisted biomimetic mineralization approach. The biomimetic titania is then spontaneously assembled at the interface between the oil phase (hexadecane/butyl titanate (BuTi) mixture) and water phase during the formation of Pickering emulsions. The sol‐gel process of BuTi can produce not only butanol for assisting the formation of Pickering emulsions but also titania gel particles (sol‐gel titania) for cross‐linking the biomimetic titania through catechol‐titanium chelating. The NPSCs obtained, which contain the first enzyme, conjugate the second enzyme (FaldDH) onto the surface for constructing the enzyme cascade system. The system exhibits high activity and stability, particularly, superior recyclability for conversion of CO2 into formaldehyde. In detail, the system shows a formaldehyde yield of 50.0%, and can quickly float onto the air/water interface soon after stopping the agitation of reaction mixtures, which ensures that the formaldehyde yield keeps almost unaltered after 10 times recycling. This study will be useful for facile construction of a wealth of catalytic systems with efficient, recyclable attributes.
Preparation of Iron Networks Hosted in Porous Alumina with Tunable Negative Permittivity and Permeability
Authors: Shi Zhi‐cheng , Fan Run‐hua , Yan Ke‐lan , Sun Kai , Zhang Meng , Wang Cheng‐guo , Liu Xiang‐fa , Zhang Xi‐hua
Published: March 2013

Random composites of iron particles hosted in porous alumina were prepared from a facile impregnation‐reduction process. Interestingly, when the iron content exceeds the percolation threshold, the interconnection of iron particles results in the formation of iron networks. The composites then change from capacitive to inductive and the conductive mechanism changes from hopping conduction to metal‐like conduction. The negative permittivity was attributed to the plasma oscillation of delocalized electrons in iron networks, while the negative permeability could be ascribed to the strong diamagnetic response of current loops in iron networks. The negative permittivity behavior of the iron/alumina composite was analyzed using Drude model. Additionally, the fitting results indicated that the effective plasma frequency of the iron/alumina composite is much lower than bulk iron. Further investigations show that, the iron content and reduction temperature can easily tune the amplitude and frequency ranges of the negative permittivity and permeability. Moreover, the negative permittivity region and the negative permeability region can be pushed to the same frequency region by adjusting the iron content and reduction temperature. The impregnation‐reduction process opens a new way for the realization of tunable negative permittivity and permeability in random composites, and has great potential for the preparation of new types of double negative materials.
Graphene/SiO2/p‐GaN Diodes: An Advanced Economical Alternative for Electrically Tunable Light Emitters
Authors: Chang Che‐Wei , Tan Wei‐Chun , Lu Meng‐Lin , Pan Tai‐Chun , Yang Ying‐Jay , Chen Yang‐Fang
Published: March 2013

Advanced materials that combine novel functionality and ease of applicability are central to the development of light‐emitting diodes (LEDs), which is of ever increasing commercial importance. Here a new metal‐insulator‐semiconductor (MIS) LED structure that combines economical fabrication with novel device properties is reported. The presented MIS‐LED consists of a graphene electrode on p‐GaN substrate separated by an insulating SiO2 layer. It is found that the MIS‐LED possesses a unique tunability of the electroluminescence spectra depending on the bias conditions. Tunnel injection from graphene into the p‐GaN can explain the difference in luminescence spectra under forward and reverse bias. The demonstrated MIS‐LED expands the use of graphene and also possibly allows the direct integration of light emitters with other circuit elements.
Visualizing MOF Mixed Matrix Membranes at the Nanoscale: Towards Structure‐Performance Relationships in CO2/CH4 Separation Over NH2‐MIL‐53(Al)@PI
Authors: Rodenas Tania , van Dalen Marion , García‐Pérez Elena , Serra‐Crespo Pablo , Zornoza Beatriz , Kapteijn Freek , Gascon Jorge
Published: March 2013

Mixed matrix membranes (MMMs) composed of metal organic framework (MOF) fillers embedded in a polymeric matrix represent a promising alternative for CO2 removal from natural gas and biogas. Here, MMMs based on NH2‐MIL‐53(Al) MOF and polyimide are successfully synthesized with MOF loadings up to 25 wt% and different thicknesses. At 308 K and ΔP = 3 bar, the incorporation of the MOF filler enhances CO2 permeability with respect to membranes based on the neat polymer, while preserving the relatively high separation factor. The rate of solvent evaporation after membrane casting proves key for the final configuration and dispersion of the MOF in the membrane. Fast solvent removal favours the contraction of the MOF structure to its narrow pore framework configuration, resulting in enhanced separation factor and, particularly, CO2 permeability. The study reveals an excellent filler‐polymer contact, with ca. 0.11% void volume fraction, for membranes based on the amino‐functionalized MOF, even at high filler loadings (25 wt%). By providing precise and quantitative insight into key structural features at the nanoscale range, the approach provides feedback to the membrane casting process and therefore it represents an important advancement towards the rational design of mixed matrix membranes with enhanced structural features and separation performance.
Stretching‐Induced Growth of PEDOT‐Rich Cores: A New Mechanism for Strain‐Dependent Resistivity Change in PEDOT:PSS Films
Authors: Lee Yoo‐Yong , Lee Ji‐Hoon , Cho Ju‐Young , Kim Na‐Rae , Nam Dae‐Hyun , Choi In‐Suk , Nam Ki Tae , Joo Young‐Chang
Published: March 2013

It remains a fundamental challenge in the development of stretchable electronics to understand how mechanical strain changes the electrical properties of materials. Although the piezoresistive behavior of poly(3,4‐ethylene‐ dioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) has been observed, its intrinsic origin is not yet fully understood because there are many extrinsic contributing factors and an experimental platform with which to assess such behavior has not been established. Here, systematic analysis shows that the matching Poisson's ratio and elastic modulus between PEDOT:PSS films and their underlying substrates is important in decoupling the factors that affect the material's piezoresistivity, allowing for tunable resistivity. Based on such a fundamental understanding, the conductivity of PEDOT:PSS can be controlled to be invariant and decrease as a function of applied tensile stress. Furthermore, a linear response of the resistivity with respect to mechanical strains of up to 60%, which has never before been realized, is shown. The irreversible conductivity enhancement is primarily caused by the coalescence‐induced growth of conductive PEDOT‐rich cores.
Near‐Infrared SERS Nanoprobes with Plasmonic Au/Ag Hollow‐Shell Assemblies for In Vivo Multiplex Detection
Authors: Kang Homan , Jeong Sinyoung , Park Younggeun , Yim Joonhyuk , Jun Bong‐Hyun , Kyeong San , Yang Jin‐Kyoung , Kim Gunsung , Hong SoonGweon , Lee Luke P. , Kim Jong‐Ho , Lee Ho‐Young , Jeong Dae Hong , Lee Yoon‐Sik
Published: March 2013

For the effective application of surface‐enhanced Raman scattering (SERS) nanoprobes for in vivo targeting, the tissue transparency of the probe signals should be as high as it can be in order to increase detection sensitivity and signal reproducibility. Here, near‐infrared (NIR)‐sensitive SERS nanoprobes (NIR SERS dots) are demonstrated for in vivo multiplex detection. The NIR SERS dots consist of plasmonic Au/Ag hollow‐shell (HS) assemblies on the surface of silica nanospheres and simple aromatic Raman labels. The diameter of the HS interior is adjusted from 3 to 11 nm by varying the amount of Au3+ added, which results in a red‐shift of the plasmonic extinction of the Au/Ag nanoparticles toward the NIR (700–900 nm). The red‐shifted plasmonic extinction of NIR SERS dots causes enhanced SERS signals in the NIR optical window where endogenous tissue absorption coefficients are more than two orders of magnitude lower than those for ultraviolet and visible light. The signals from NIR SERS dots are detectable from 8‐mm deep in animal tissues. Three kinds of NIR SERS dots, which are injected into live animal tissues, produce strong SERS signals from deep tissues without spectral overlap, demonstrating their potential for in vivo multiplex detection of specific target molecules.
μHall Chip for Sensitive Detection of Bacteria
Authors: Issadore David , Chung Hyun Jung , Chung Jaehoon , Budin Ghyslain , Weissleder Ralph , Lee Hakho
Published: March 2013

Sensitive, rapid and phenotype‐specific enumeration of pathogens is essential for the diagnosis of infectious disease, monitoring of food chains, and for defense against bioterrorism. Microbiological culture and genotyping, techniques that sensitively and selectively detect bacteria in laboratory settings, have limited application in clinical environments due to high cost, slow response times, and the need for specially trained staff and laboratory infrastructure. To address these challenges, we developed a microfluidic chip‐based micro‐Hall (μHall) platform capable of measuring single, magnetically tagged bacteria directly in clinical specimens with minimal sample processing. We demonstrated the clinical utility of the μHall chip by enumerating Gram‐positive bacteria. The overall detection limit of the system was similar to that of culture tests (∼10 bacteria), but the assay time was 50‐times faster. This low‐cost, single‐cell analytical technique is especially well‐suited to diagnose infectious diseases in resource‐limited clinical settings.
In Vivo Treatment of Propionibacterium acnes Infection with Liposomal Lauric Acids
Authors: Pornpattananangkul Dissaya , Fu Victoria , Thamphiwatana Soracha , Zhang Li , Chen Michael , Vecchio James , Gao Weiwei , Huang Chun‐Ming , Zhang Liangfang
Published: March 2013

Propionibacterium acnes (P. acnes) is a Gram‐positive bacterium strongly associated with acne infection. While many antimicrobial agents have been used in clinic to treat acne infection by targeting P. acnes, these existing anti‐acne agents usually produce considerable side effects. Herein, the development and evaluation of liposomal lauric acids (LipoLA) is reported as a new, effective and safe therapeutic agent for the treatment of acne infection. By incorporating lauric acids into the lipid bilayer of liposomes, it is observed that the resulting LipoLA readily fuse with bacterial membranes, causing effective killing of P. acnes by disrupting bacterial membrane structures. Using a mouse ear model, we demonstrated that the bactericidal property of LipoLA against P. acne is well preserved at physiological conditions. Topically applying LipoLA in a gel form onto the infectious sites leads to eradication of P. acnes bacteria in vivo. Further skin toxicity studies show that LipoLA does not induce acute toxicity to normal mouse skin, while benzoyl peroxide and salicylic acid, the two most popular over‐the‐counter acne medications, generate moderate to severe skin irritation within 24 h. These results suggest that LipoLA hold a high therapeutic potential for the treatment of acne infection and other P. acnes related diseases.
Organocatalytic Asymmetric Michael Addition/Carbon‐Carbon Bond Cleavage of Trifluoromethyl α‐Fluorinated gem‐Diols to Nitroolefins
Authors: Saidalimu Ibrayim , Fang Xiang , Lv Wenwen , Yang Xueyan , He Xiaopeng , Zhang Jingyuan , Wu Fanhong
Published: March 2013

A new organocatalytic asymmetric Michael addition reaction by cleavage of carbon‐carbon bonds through a mild release of trifluoroacetate has been developed. The reported method generates the decarboxylated γ‐nitro‐α‐fluorocarbonyl products with excellent enantioselectivies (up to 98% ee) and good diastereoselectivies (up to 20:1 dr).
Lipase/Acetamide‐Catalyzed Carbon‐Carbon Bond Formations: A Mechanistic View
Authors: Chen Xiao‐Yang , Chen Guo‐Jun , Wang Jun‐Liang , Wu Qi , Lin Xian‐Fu
Published: March 2013

A lipase B from Candida antarctica (CALB)/acetamide‐catalyzed Michael addition of less‐activated ketones and aromatic nitroolefins has been developed, which is particularly interesting because neither CALB nor acetamide can independently catalyze the reaction to any appreciable extent. This co‐catalyst system was applicable to the Michael additions of cyclic and acyclic ketones to a series of aromatic and heteroaromatic nitroolefins. Hydrogen bonds between acetamide and cyclohexanone were confirmed for the observed activation by experimental facts, and new mechanistic insights into CALB/acetamide co‐catalysis are presented.
A New Henry/Michael/Retro‐Henry/Henry Domino Sequence Promoted by Bifunctional Organocatalysts
Authors: Quintavalla Arianna , Lombardo Marco , Sanap Shrihari P. , Trombini Claudio
Published: March 2013

A highly stereoselective route to densely functionalized cyclohexanes is described, via a Cinchona‐based bifunctional organocatalyzed Henry/Michael/retro‐Henry/Henry domino reaction. The peculiar stereoconvergent mechanism allows the creation of up to four contiguous stereocenters in a highly stereodefined manner starting from both achiral aldehydes and racemic nitro alcohols. The simple and efficient protocol can be exploited to synthesize a wide range of substrates and also useful bioactive molecules.
Accelerated Zincations for an Efficient and Mild Functionalization of Aromatics and Heterocycles
Authors: Unsinn Andreas , Wunderlich Stefan H. , Knochel Paul
Published: March 2013

An improved process for the preparation of aromatic and heteroaromatic diorganozinc reagents and their subsequent reaction with electrophiles is presented. The new method, featuring the use of a 2,2,6,6‐tetramethylpiperidyl (TMP) magnesium base in the presence of zinc chloride (ZnCl2), is superior to the previous methods, which require the preparation of zinc bases. Specifically, the shorter reaction times under mild conditions provide an easier and more practical process, while the use of only a slight excess of the amide allows the isolation of products in high yields. These improvements are particularly significant for the large‐scale preparation of organozincs and their subsequent reactions. Remarkably, beside the high kinetic activity, a wide range of functional groups is tolerated and sensitive heteroaromatics can easily be converted into the corresponding organometallic reagents and reacted with various electrophiles.
Donor–Acceptor Shape Matching Drives Performance in Photovoltaics
Authors: Schiros Theanne , Kladnik Gregor , Prezzi Deborah , Ferretti Andrea , Olivieri Giorgia , Cossaro Albano , Floreano Luca , Verdini Alberto , Schenck Christine , Cox Marshall , Gorodetsky Alon A. , Plunkett Kyle , Delongchamp Dean , Nuckolls Colin , Morgante Alberto , Cvetko Dean , Kymissis Ioannis
Published: March 2013

While the demonstrated power conversion efficiency of organic photovoltaics (OPVs) now exceeds 10%, new design rules are required to tailor interfaces at the molecular level for optimal exciton dissociation and charge transport in higher efficiency devices. We show that molecular shape‐complementarity between donors and acceptors can drive performance in OPV devices. Using core hole clock (CHC) X‐ray spectroscopy and density functional theory (DFT), we compare the electronic coupling, assembly, and charge transfer rates at the interface between C60 acceptors and flat‐ or contorted‐hexabenzocorone (HBC) donors. The HBC donors have similar optoelectronic properties but differ in molecular contortion and shape matching to the fullerene acceptors. We show that shape‐complementarity drives self‐assembly of an intermixed morphology with a donor/acceptor (D/A) ball‐and‐socket interface, which enables faster electron transfer from HBC to C60. The supramolecular assembly and faster electron transfer rates in the shape complementary heterojunction lead to a larger active volume and enhanced exciton dissociation rate. This work provides fundamental mechanistic insights on the improved efficiency of organic photovoltaic devices that incorporate these concave/convex D/A materials.
Investigation of Quinquethiophene Derivatives with Different End Groups for High Open Circuit Voltage Solar Cells
Authors: Long Guankui , Wan Xiangjian , Kan Bin , Liu Yongsheng , He Guangrui , Li Zhi , Zhang Yawei , Zhang Yi , Zhang Qian , Zhang Mingtao , Chen Yongsheng
Published: March 2013

Three quinquethiophene derivatives with different end groups of octyl 2‐cyanoacetate (DCAO5T), 3‐ethylrhodanine (DERHD5T) and 2H‐indene‐1,3‐dione (DIN5T) are synthesized in order to obtain higher open circuit voltage (Voc) than their septithiophene analogs. The photovoltaic performance of these three molecules as donors and fullerene derivatives as the acceptors in bulk heterojunction solar cells are studied by using the simple solution spin‐coating fabrication process. Among them, DERHD5T shows Voc as high as 1.08 volt and power conversion efficiency of 4.63% under AM 1.5G irradiation (100 mW cm−2). The reasons for the high Voc were investigated by the theoretical simulations and consistent results have been obtained in comparison with experimental measurements.
Investigation ofNRXN1deletions: Clinical and molecular characterization
Authors: Dabell Mindy Preston , Rosenfeld Jill A. , Bader Patricia , Escobar Luis F. , El‐Khechen Dima , Vallee Stephanie E. , Dinulos Mary Beth Palko , Curry Cynthia , Fisher Jamie , Tervo Raymond , Hannibal Mark C. , Siefkas Kiana , Wyatt Philip R. , Hughes Lauren , Smith Rosemarie , Ellingwood Sara , Lacassie Yves , Stroud Tracy , Farrell Sandra A. , Sanchez‐Lara Pedro A. , Randolph Linda M. , Niyazov Dmitriy , Stevens Cathy A. , Schoonveld Cheri , Skidmore David , MacKay Sara , Miles Judith H. , Moodley Manikum , Huillet Adam , Neill Nicholas J. , Ellison Jay W. , Ballif Blake C. , Shaffer Lisa G.
Published: March 2013

Deletions at 2p16.3 involving exons ofNRXN1are associated with susceptibility for autism and schizophrenia, and similar deletions have been identified in individuals with developmental delay and dysmorphic features. We have identified 34 probands with exonicNRXN1deletions following referral for clinical microarray‐based comparative genomic hybridization. To more firmly establish the full phenotypic spectrum associated with exonicNRXN1deletions, we report the clinical features of 27 individuals withNRXN1deletions, who represent 23 of these 34 families. The frequency of exonicNRXN1deletions among our postnatally diagnosed patients (0.11%) is significantly higher than the frequency among reported controls (0.02%;P = 6.08 × 10−7), supporting a role for these deletions in the development of abnormal phenotypes. Generally, most individuals withNRXN1exonic deletions have developmental delay (particularly speech), abnormal behaviors, and mild dysmorphic features. In our cohort, autism spectrum disorders were diagnosed in 43% (10/23), and 16% (4/25) had epilepsy. The presence ofNRXN1deletions in normal parents and siblings suggests reduced penetrance and/or variable expressivity, which may be influenced by genetic, environmental, and/or stochastic factors. The pathogenicity of these deletions may also be affected by the location of the deletion within the gene. Counseling should appropriately represent this spectrum of possibilities when discussing recurrence risks or expectations for a child found to have a deletion inNRXN1. © 2013 Wiley Periodicals, Inc.
A patient with de novo 0.45 Mb deletion of 2p16.1: The role of BCL11A, PAPOLG, REL, and FLJ16341 in the 2p15‐p16.1 microdeletion syndrome
Authors: Hancarova Miroslava , Simandlova Martina , Drabova Jana , Mannik Katrin , Kurg Ants , Sedlacek Zdenek
Published: March 2013

The 2p15‐p16.1 microdeletion syndrome is a novel, rare disorder characterized by developmental delay, intellectual disability, microcephaly, growth retardation, facial abnormalities, and other medical problems. We report here on an 11‐year‐old female showing clinical features consistent with the syndrome and carrying a de novo 0.45 Mb long deletion of the paternally derived 2p16.1 allele. The deleted region contains only three protein‐coding RefSeq genes, BCL11A, PAPOLG, and REL, and one long non‐coding RNA gene FLJ16341. Based on close phenotypic similarities with six reported patients showing typical clinical features of the syndrome, we propose that the critical region can be narrowed down further, and that these brain expressed genes can be considered candidates for the features seen in this microdeletion syndrome. © 2013 Wiley Periodicals, Inc.
Synthesis of Pyrroles, Indoles, and Carbazoles through Transition‐Metal‐Catalyzed CH Functionalization
Authors: Yoshikai Naohiko , Wei Ye
Published: March 2013

Pyrroles, indoles, and carbazoles are among the most important families of nitrogen‐containing heterocycles that occur frequently in natural products, pharmaceuticals, agrochemicals, and other functional molecules. Consequently, improved syntheses of these compounds continue to interest synthetic chemists. This Focus Review describes recent advances in synthetic methods for producing these privileged heterocycles that feature transition‐metal‐catalyzed CH activation approaches. Because of the common five‐membered pyrrole core, some of the CH activation approaches are applicable to two or more of the pyrrole, indole, and carbazole skeletons. The reactions discussed here not only serve as atom‐ and step‐economical alternatives to the existing synthetic methods, but also show the latest developments in organometallic chemistry and homogeneous catalysis.
Levodopa gains psychostimulant‐like properties after nigral dopaminergic loss
Authors: Engeln Michel , Fasano Stefania , Ahmed Serge H. , Cador Martine , Baekelandt Veerle , Bezard Erwan , Fernagut Pierre‐Olivier
Published: March 2013

Dopamine dysregulation syndrome shares some core behavioral features with psychostimulant addiction, suggesting that dopamine replacement therapy can acquire psychostimulantlike properties in some patients with Parkinson disease (PD). We here report strong experimental evidence supporting this hypothesis in an α‐synuclein rat model of PD. Although levodopa had no effect in controls, it acquired 2 prominent psychostimulantlike properties in Parkinsonian rats: (1) it produced intense reward on its own and in parallel (2) decreased interest in other nondrug reward. These 2 effects may combine to explain the addictive use of levodopa after loss of midbrain dopamine neurons in some PD patients. Ann Neurol 2013;74:140–144
Response surface predictions of the viscoelastic properties of vapor‐grown carbon nanofiber/vinyl ester nanocomposites
Authors: Nouranian Sasan , Lacy Thomas E. , Toghiani Hossein , Pittman Charles U. , L. DuBien Janice
Published: March 2013

A full factorial design of experiments and response surface methodology were used to investigate the effects of formulation, processing, and operating temperature on the viscoelastic properties of vapor‐grown carbon nanofiber (VGCNF)/vinyl ester (VE) nanocomposites. Factors included VGCNF type (pristine, oxidized), use of a dispersing agent (DA) (no, yes), mixing method (ultrasonication, high‐shear mixing, and a combination of both), VGCNF weight fraction (0.00, 0.25, 0.50, 0.75, and 1.00 parts per hundred parts resin (phr)), and temperature (30, 60, 90, and 120°C). Response surface models (RSMs) for predicting storage and loss moduli were developed, which explicitly account for the effect of complex interactions between nanocomposite design factors and operating temperature on resultant composite properties; such influences would be impossible to assess using traditional single‐factor experiments. Nanocomposite storage moduli were maximized over the entire temperature range (∼20% increase over neat VE) by using high‐shear mixing and oxidized VGCNFs with DA or equivalently by employing pristine VGCNFs without DA at ∼0.40 phr of VGCNFs. Ultrasonication yielded the highest loss modulus at ∼0.25 phr of VGCNFs. The RSMs developed in this investigation may be used to design VGCNF‐enhanced VE matrices with optimal storage and loss moduli for automotive structural applications. Moreover, a similar approach may be used to tailor the mechanical, thermal, and electrical properties of nanomaterials over a range of anticipated operating environments. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Characterization and modeling of the moisture diffusion behavior of natural fibers
Authors: Célino Amandine , Fréour Sylvain , Jacquemin Frédéric , Casari Pascal
Published: March 2013

Natural fibers have good properties to be used as reinforcement in composite materials. The main issue is their hydrophilic behavior. So we propose here to investigate the diffusion phenomenon in such fibres. First, a brief characterization of four vegetal fibers has been achieved. We show that all fibers have a similar composition and structure despite their different origin. Then, their moisture diffusive behavior was investigated. The samples were submitted to hygro‐thermal aging either in total water immersion at room temperature or in an environmental chamber at 80% relative humidity and 23°C. Various predictive models were used to simulate experimental curves. Results show that all fibers exhibit a similar diffusive behavior in a same environment. In immersion, specimens show anomalous absorption kinetics and Langmuir theory actually describes very well the diffusion kinetics in such conditions, whereas the same fibers follow a Fickian diffusion when they are exposed to vapor during relative humidity aging. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013