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H Nakajima, T Morimoto, Y Okigawa, T Yamada, Y Ikuta, K Kawahara, H Ago, T Okazaki
The distribution of defects and dislocations in graphene layers has become a very important concern with regard to the electrical and electronic transport properties of device applications. Although several experiments have shown the influence of defects on the electrical properties of graphene, these studies were limited to measuring microscopic areas because of their long measurement times. Here, we successfully imaged various local defects in a large area of chemical vapor deposition graphene within a reasonable amount of time by using lock-in thermography (LIT)...
February 2019: Science Advances
Omer Wagner, Moty Schultz, Eitan Edri, Rinat Meir, Eran Barnoy, Amihai Meiri, Hagay Shpaisman, Eli Sloutskin, Zeev Zalevsky
Gold nanoparticles are widely exploited in phototherapy. Owing to their biocompatibility and their strong visible-light surface plasmonic resonance, these particles also serve as contrast agents for cell image enhancement and super-resolved imaging. Yet, their optical signal is still insufficiently strong for many important real-life applications. Also, the differentiation between adjacent nanoparticles is usually limited by the optical resolution and the orientations of non-spherical particles are unknown...
February 7, 2019: Scientific Reports
Panagis D Samolis, Michelle Y Sander
Imaging of the phase output of a lock-in amplifier in mid-infrared photothermal vibrational microscopy is demonstrated for the first time in combination with nonlinear demodulation. In general, thermal blurring and heat transport phenomena contribute to the resolution and sensitivity of mid-infrared photothermal imaging. For heterogeneous samples with multiple absorbing features, if imaged in a spectral regime of comparable absorption with their embedding medium, it is demonstrated that differentiation with high contrast is achieved in complementary imaging of the phase signal obtained from a lock-in amplifier compared to standard imaging of the photothermal amplitude signal...
February 4, 2019: Optics Express
Cody A Cushing, Hee Yeon Im, Reginald B Adams, Noreen Ward, Kestutis Kveraga
Human faces evolved to signal emotions, with their meaning contextualized by eye gaze. For instance, a fearful expression paired with averted gaze clearly signals both presence of threat and its probable location. Conversely, direct gaze paired with facial fear leaves the source of the fear-evoking threat ambiguous. Given that visual perception occurs in parallel streams with different processing emphases, our goal was to test a recently developed hypothesis that clear and ambiguous threat cues would differentially engage the magnocellular (M) and parvocellular (P) pathways, respectively...
February 5, 2019: Social Cognitive and Affective Neuroscience
Sumit Kumar, Michele Merelli, Wojciech Danowski, Petra Rudolf, Ben L Feringa, Ryan C Chiechi
This paper describes the reversible chemical locking of sypiropyran switches bound to metallic surfaces to enable the encoding of nonvolatile information. Data are encoded spatially by selectively locking the spiropyran moieties in their merocyanine form using a combination of exposure to acid and UV light. Without exposure to acid, the merocyanine form spontaneously converts back to the spiropyran form. Bits are resolved by defining the regions of the monolayer that are exposed to acid, using a "soft punchcard" fabricated from a silicone elastomer...
February 5, 2019: Advanced Materials
Yunxi Ye, Liwei Zhao, Shuanggang Hu, Ajuan Liang, Yongsheng Li, Qixin Zhuang, Guorong Tao, Jinlou Gu
Hypochlorous acid (HClO), as one of the reactive oxygen species, plays a key role in a variety of physiological and pathological processes, while its accurate and specific in vitro monitoring remains a profound challenge. Herein, a novel luminescent metal-organic framework with high chemical stability has been designed for the specific detection of intracellular ClO-. The specificity was realized by the size-selective effect of MOF-801 with an ultra-small aperture, which can inhibit the entry of large-sized interferents into the cages of MOFs...
February 5, 2019: Dalton Transactions: An International Journal of Inorganic Chemistry
Riccardo Borgani, David B Haviland
We present an alternative approach to pump-probe spectroscopy for measuring fast charge dynamics with an atomic force microscope (AFM). Our approach is based on coherent multifrequency lock-in measurement of the intermodulation between a mechanical drive and an optical or electrical excitation. In response to the excitation, the charge dynamics of the sample is reconstructed by fitting a theoretical model to the measured frequency spectrum of the electrostatic force near resonance of the AFM cantilever. We discuss the time resolution, which in theory is limited only by the measurement time, but in practice is of order 1 ns for standard cantilevers and imaging speeds...
January 2019: Review of Scientific Instruments
Magen Ellen Francis, Morgan Leslie King, Alyson Ann Kelvin
The influenza virus-host interaction is a classic arms race. The recurrent and evolving nature of the influenza virus family allows a single host to be infected several times. Locked in co-evolution, recurrent influenza virus infection elicits continual refinement of the host immune system. Here we give historical context of circulating influenza viruses to understand how the individual immune history is mirrored by the history of influenza virus circulation. Original Antigenic Sin was first proposed as the negative influence of the host's first influenza virus infection on the next and Imprinting modernizes Antigenic Sin incorporating both positive and negative outcomes...
January 30, 2019: Viruses
Chang-Hee Han, Yong-Wook Kim, Do Yeon Kim, Seung Hyun Kim, Zoran Nenadic, Chang-Hwan Im
BACKGROUND: Brain-computer interfaces (BCIs) have demonstrated the potential to provide paralyzed individuals with new means of communication, but an electroencephalography (EEG)-based endogenous BCI has never been successfully used for communication with a patient in a completely locked-in state (CLIS). METHODS: In this study, we investigated the possibility of using an EEG-based endogenous BCI paradigm for online binary communication by a patient in CLIS. A female patient in CLIS participated in this study...
January 30, 2019: Journal of Neuroengineering and Rehabilitation
Miguel Tovar, Sundar Hengoju, Thomas Weber, Lisa Mahler, Mahipal Choudhary, Tino Becker, Martin Roth
High-speed multi-wavelength fluorescence measurements are of paramount importance in microfluidic analytics. However, multicolor detection requires an intricate arrangement of multiple detectors and meticulously aligned filters and dichroic beamsplitters that counteract the simplicity, versatility and low cost of microfluidic approaches. In order to break free from the restrictions of optical set-up complexity, we introduce a simpler single-sensor setup based on laser frequency modulation and frequency-division multiplexing (FDM)...
January 28, 2019: Analytical Chemistry
Marco Cummaudo, Annalisa Cappella, Francesca Giacomini, Caterina Raffone, Nicholas Màrquez-Grant, Cristina Cattaneo
In recent years, several studies have focused on species discrimination of bone fragments by histological analysis. According to literature, the most consistent distinguishing features are Haversian canal and Haversian system areas. Nonetheless, there is a consistent overlap between human and non-human secondary osteon dimensions. One of the features that have never been analyzed for the purpose of species discrimination is the osteocyte lacuna, a small oblong cavity in which the osteocyte is locked in. The aim of this study is to verify whether there are significant quantitative differences between human and pig lacunae within secondary osteons with similar areas...
January 24, 2019: International Journal of Legal Medicine
Kai Ito, Hideki Endo
We compared the temporomandibular joint structure between species of the order Carnivora and investigated its variation among family lineages. We also investigated the effect of the masticatory muscle physiological cross-sectional area (PCSA) on temporomandibular joint structure. The masticatory muscle is composed of multiple muscles, which contract in different directions and exert pressure on the temporomandibular joint. We investigated the effect of the ratio of each muscle's PCSA-an indicator of muscle force-and muscle size relative to body size on temporomandibular joint structure...
January 22, 2019: Journal of Veterinary Medical Science
Ather Akhlaq, Brian McKinstry, Aziz Sheikh
INTRODUCTION: Due to the many advantages of open source software (OSS), including reduced cost of licensing, more flexibility in terms of customisation and redistribution, better quality and no vendor lock-in, OSS in healthcare is increasingly gaining importance. Various open source health information technologies (OS-HITs) are continuously being designed and developed for different areas of healthcare to increase organisational efficiencies and quality of care at minimum costs. The objective of this scoping review is to identify the kinds of existing OS-HITs, their characteristics (e...
December 31, 2018: Journal of Innovation in Health Informatics
Hong-Jun Ma, Lin-Xing Xu, Guang-Hong Yang
This paper studies the fault-tolerant control (FTC) problem for unknown affine nonlinear systems with actuators faults. The considered types of faults are stuck (lock-in-place), loss-in-effectiveness (LIE), and bias, under which a part of the actuators is disabled. The objective is to find the remaining (not fully LIE) actuators, and manipulate them to obtain the best achievable performance in real time. First, considering that the best achievable performance is determined by the remaining actuators, a set of basic policies is predesigned with multiple levels of performances for different groups of activated actuators...
January 17, 2019: IEEE Transactions on Cybernetics
Wenjiao Xiao, Qiuyi Fu, Yi Zhao, Li Zhang, Qiming Yue, Li Hai, Li Guo, Yong Wu
In this study, a novel brain targeting ascorbic acid (AA) derivative with "lock-in" function was designed and synthesized as a liposome ligand to prepare novel liposomes to achieve the effective delivery of drug formulations to brain via glucose transporter 1 (GLUT1 ) and the Na+ -dependent vitamin C transporter (SVCT2 ). The liposome was prepared and characterized in terms of the particle size, zeta potential, encapsulation efficiency, release profile, stability, hemolysis and cell cytotoxicity. The preliminary evaluation in vivo demonstrated that the AA-thiamine disulfide system (TDS)-coated liposome had an improved targeting ability and significantly increased the brain concentration of docetaxel (DTX) as compared to the naked docetaxel, the non-coated and the AA-coated liposomes...
January 17, 2019: Chemistry and Physics of Lipids
Shubham Dodia, Damodar Reddy Edla, Annushree Bablani, Dharavath Ramesh, Venkatanareshbabu Kuppili
BACKGROUND: Brain-computer interface (BCI) is a combination of hardware and software that provides a non-muscular channel to send various messages and commands to the outside world and control external devices such as computers. BCI helps severely disabled patients having neuromuscular injuries, locked-in syndrome (LiS) to lead their life as a normal person to the best extent possible. There are various applications of BCI not only in the field of medicine but also in entertainment, lie detection, gaming etc...
January 17, 2019: Journal of Neuroscience Methods
N J J van Hoof, S E T Ter Huurne, J Gómez Rivas, A Halpin
We demonstrate a novel method for measuring terahertz (THz) photoconductivity of semiconductors on length scales smaller than the diffraction limit at THz frequencies. This method is based on a near-field microscope that measures the transmission of a THz pulse through the semiconductor following photoexcitation by an ultrafast laser pulse. Combining back-excitation of the sample using a Dove prism, and a dual lock-in detection scheme, our microscope design offers a flexible platform for near-field time-resolved THz time-domain spectroscopy, using fluences available to typical laser oscillators...
November 26, 2018: Optics Express
Courtney Benjamin Wolk, Amelia E Van Pelt, Shari Jager-Hyman, Brian K Ahmedani, John E Zeber, Joel A Fein, Gregory K Brown, Courtney A Gregor, Adina Lieberman, Rinad S Beidas
Importance: The rate of youth suicide has increased steadily over the past several decades due, in part, to an increase in suicide by firearm. Implementation of evidence-based approaches to increase safe firearm storage practices are important for reducing youth suicide. Objective: To assess the needs of stakeholders who would be affected by implementing an evidence-based approach to firearm safety promotion-Firearm Safety Check, which includes screening for the presence of firearms in the home, brief motivational interviewing-informed counseling regarding safe firearm storage, and provision of free firearm locks-in pediatric primary care settings...
November 2, 2018: JAMA network open
Baozhu Lu, Darius H Torchinsky
We describe a novel scheme of detecting rotational anisotropy-second harmonic generation (RA-SHG) signals using a lock-in amplifier referenced to a fast scanning RASHG apparatus. The method directly measures the nth harmonics of the scanning frequency corresponding to SHG signal components of Cn symmetry that appear in a Fourier series expansion of a general RA-SHG signal. GaAs was used as a test sample allowing comparison of point-by-point averaging with the lock-in based method. When divided by the C∞ signal component, the lock-in detected data allowed for both self-referenced determination of ratios of Cn components of up to 1 part in 104 and significantly more sensitive measurement of the relative amount of different Cn components when compared with conventional methods...
December 10, 2018: Optics Express
Richard K Burt, Roumen Balabanov, Joachim Burman, Basil Sharrack, John A Snowden, Maria Carolina Oliveira, Jan Fagius, John Rose, Flavia Nelson, Amilton Antunes Barreira, Kristina Carlson, Xiaoqiang Han, Daniela Moraes, Amy Morgan, Kathleen Quigley, Kimberly Yaung, Regan Buckley, Carri Alldredge, Allison Clendenan, Michelle A Calvario, Jacquelyn Henry, Borko Jovanovic, Irene B Helenowski
Importance: Hematopoietic stem cell transplantation (HSCT) represents a potentially useful approach to slow or prevent progressive disability in relapsing-remitting multiple sclerosis (MS). Objective: To compare the effect of nonmyeloablative HSCT vs disease-modifying therapy (DMT) on disease progression. Design, Setting, and Participants: Between September 20, 2005, and July 7, 2016, a total of 110 patients with relapsing-remitting MS, at least 2 relapses while receiving DMT in the prior year, and an Expanded Disability Status Scale (EDSS; score range, 0-10 [10 = worst neurologic disability]) score of 2...
January 15, 2019: JAMA: the Journal of the American Medical Association
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