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Mingyang Shang, Bing Han, Chibiao Ding, Jili Sun, Tao Zhang, Lijia Huang, Dadi Meng
Spotlight synthetic aperture radar (SAR) is a proven technique, which can provide high-resolution images as compared to those produced by traditional stripmap SAR. This paper addresses a high-resolution SAR focusing experiment based on Gaofen-3 satellite (GF-3) staring data with about 55 cm azimuth resolution and 240 MHz range bandwidth. In staring spotlight (ST) mode, the antenna always illuminates the same scene on the ground, which can extend the synthetic aperture. Based on a two-step processing algorithm, some special aspects such as curved-orbit model error correction, stop-and-go correction, and antenna pattern demodulation must be considered in image focusing...
March 22, 2018: Sensors
Yiting Yu, Wenli Li, Haoyong Li, Muyuan Li, Weizheng Yuan
Planar super-oscillation lenses (SOLs) can fulfill super-resolution focusing and nanoscopic imaging in the far field without the contribution of evanescent waves. Nevertheless, the existing deviations between the design and experimental results have been seldomly investigated, leaving the practical applications of SOLs unpredictable and uncontrollable. In this paper, some application-oriented issues are taken into consideration, such as the inevitable fabrication errors and the size effect of the designed SOLs, with the aim of providing an engineering reference to elaborately customize the demanded focusing light field...
March 22, 2018: Nanomaterials
Seokho Kim, Do Hyoung Kim, Jinho Choi, Hojin Lee, Sun-Young Kim, Jung Woon Park, Dong Hyuk Park
We report the growth and nanoscale luminescence characteristics of 8-hydroxyquinolinato aluminum (Alq₃) with a crystalline hexagonal column morphology. Pristine Alq₃ nanoparticles (NPs) were prepared using a conventional reprecipitation method. Crystal hexagonal columns of Alq₃ were grown by using a surfactant-assisted self-assembly technique as an adjunct to the aforementioned reprecipitation method. The formation and structural properties of the crystalline and non-crystalline Alq₃ NPs were analyzed with scanning electron microscopy and X-ray diffraction...
March 22, 2018: Materials
Srinivasan Ramakrishnan, Beejan Asady, Roberto Docampo
Membrane contact sites are regions of close apposition between two organelles, typically less than 30 nanometers apart, that facilitate transfer of biomolecules. The presence of contact sites has been demonstrated in yeast, plants, and mammalian cells. Here, we investigated the presence of such contact sites in Trypanosoma brucei . In mammalian cells, endoplasmic reticulum-mitochondria contact sites facilitate mitochondrial uptake of Ca2+ released by the ER-located inositol 1,4,5-trisphosphate receptor (InsP₃R)...
March 22, 2018: Pathogens
Melissa Preissner, Rhiannon P Murrie, Isaac Pinar, Freda Werdiger, Richard P Carnibella, Graeme R Zosky, Andreas Fouras, Stephen Dubsky
We have developed an X-ray imaging system for <i>in vivo</i> four-dimensional computed tomography (4DCT) of small animals for pre-clinical lung investigations. Our customized laboratory facility is capable of high resolution <i>in vivo</i> imaging at high frame rates. Characterization using phantoms demonstrate a spatial resolution of slightly below 50 μm at imaging rates of 30 Hz, and the ability to quantify material density differences of at least 3%...
March 22, 2018: Physics in Medicine and Biology
Soo Young Yun, Young Jin Heo, Hae Woong Jeong, Jin Wook Baek, Hye Jung Choo, Jung Hwa Seo, Sung Tae Kim, Ji Young Lee, Sung Chul Jin
Background Acute ischemic stroke (AIS) more frequently develops in patients with intracranial vertebral artery dissection (VAD) than extracranial VAD, and is associated with possible poor clinical outcomes. The aim of this study is to compare high-resolution magnetic resonance imaging (HR-MRI) findings and clinical features of VAD with and without AIS. Methods Twenty-nine lesions from 27 patients (15 male and 12 female patients; age range = 28-73 years) who underwent diffusion MRI and 3T HR-MRI within seven days were included...
January 1, 2018: Neuroradiology Journal
Bianca Abreu Dos Santos de Oliveira, Elenir Rose Jardim Cury Pontes, Teresa Cristina Abranches Rosa
INTRODUCTION: Patients in intensive care status are in nutritional threat and frequently present innutrition, therefore monitoring the nutritional offer becomes indispensable. AIM: To purpose a control and monitoring form of enteral nutritional therapy and to evaluate its resoluteness. METHODS: Observational, analytical and retrospective study performed in intensive care patients receiving an enteral diet exclusively and/or associated with the oral/parenteral route, from January to April 2015 and from January to April 2016...
January 10, 2018: Nutrición Hospitalaria: Organo Oficial de la Sociedad Española de Nutrición Parenteral y Enteral
Junjian Chen, Meng Gao, Lin Wang, Shiwu Li, Jingcai He, Anjun Qin, Li Ren, Yingjun Wang, Ben Zhong Tang
Multi-drug resistant bacterial infection has become one of the most serious threats to human health. Antimicrobial peptides (AMPs) have been identified as potential alternatives to antibiotics owing to their excellent bactericidal activity. However, the complicated bactericidal mechanism of AMPs is still poorly understood. Fluorescence imaging has many advantages in terms of dynamic monitoring, easy operation, and high sensitivity. In this study, we developed an aggregation-induced emission (AIE)-active probe AMP-2HBT by decorating of the antimicrobial peptide HHC36 (KRWWKWWRR) with an AIEgen of 2-(2-hydroxyphenyl)benzothiazole (HBT)...
March 22, 2018: ACS Applied Materials & Interfaces
Kfir Kuchuk, Uri Sivan
Hydration interaction shapes biomolecules and is a dominant inter-molecular force. Mapping the hydration patterns of biomolecules is therefore essential for understanding molecular processes in biology. Numerous studies have been devoted to this challenge but current methods cannot map the hydration of single biomolecules, let alone under physiological conditions. Here, we show that FM-AFM can fill this gap and generate 3D hydration maps of single DNA molecules under near-physiological conditions. Additionally, we present real space images of DNA in which the double helix is resolved with unprecedented resolution, clearly revealing individual phosphate groups along the DNA backbone...
March 22, 2018: Nano Letters
Laura M Higgins, Vidya Ganapathy, Harini Kantamneni, Xinyu Zhao, Yang Sheng, Mei-Chee Tan, Charles M Roth, Richard E Riman, Prabhas V Moghe, Mark C Pierce
Rare-earth-doped nanocomposites have appealing optical properties for use as biomedical contrast agents, but few systems exist for imaging these materials. We describe the design and characterization of (i) a preclinical system for whole animal in vivo imaging and (ii) an integrated optical coherence tomography/confocal microscopy system for high-resolution imaging of ex vivo tissues. We demonstrate these systems by administering erbium-doped nanocomposites to a murine model of metastatic breast cancer. Short-wave infrared emissions were detected in vivo and in whole organ imaging ex vivo...
March 2018: Journal of Biomedical Optics
Brittany L Daughtry, Shawn L Chavez
The use of time-lapse microscopic imaging has proven to be a powerful tool for the study of mitotic divisions and other cellular processes across diverse species and cell types. Although time-lapse monitoring (TLM) of human preimplantation development was first introduced to the in vitro fertilization (IVF) community several decades ago, it was not until relatively recently that TLM systems were commercialized for clinical embryology purposes. Traditionally, human IVF embryos are assessed by successful progression and morphology under a stereomicroscope at distinct time points prior to selection for transfer...
2018: Methods in Molecular Biology
Martin Poot
The highly complex structural genome variations chromothripsis, chromoanasynthesis, and chromoplexy are subsumed under the term chromoanagenesis, which means chromosome rebirth. Precipitated by numerous DNA double-strand breaks, they differ in number of and distances between breakpoints, associated copy number variations, order and orientation of segments, and flanking sequences at joining points. Results from patients with the autosomal dominant cancer susceptibility disorder Li-Fraumeni syndrome implicated somatic TP53 mutations in chromothripsis...
2018: Methods in Molecular Biology
Clint L Makino, Teresa Duda, Alexandre Pertzev, Rameshwar K Sharma
Our ability to see is based on the activity of retinal rod and cone photoreceptors. Rods function when there is very little light, while cones operate at higher light levels. Photon absorption by rhodopsin activates a biochemical cascade that converts photic energy into a change in the membrane potential of the cell by decreasing the levels of a second messenger, cGMP, that control the gating of cation channels. But just as important as the activation of the cascade are the shut-off and recovery processes. The timing of shutoff and recovery ultimately affects sensitivity, temporal resolution and even the capacity for counting single photons...
2018: Methods in Molecular Biology
Yoko Miura
Retinal pigment epithelium (RPE), a monolayer of epithelial cells located between the neural retina and the choroid, plays a significant role in the maintenance of retinal function. Its in vivo imaging is still technically challenging in human eye. With the mouse eye, there is a possibility to look into the RPE through the sclera using two-photon microscopy (TPM). TPM is a two photon-excited nonlinear fluorescence microscopy that enables the observation of deep tissues up to several hundred micrometers. Since the simultaneous absorption of two photons occurs only at the focal plane, spatial resolution of the TPM is quite high, such that pinhole as used in a confocal microscope is not necessary...
2018: Methods in Molecular Biology
Shang Wang, Irina V Larina
The oviduct (or fallopian tube) serves as the site where a number of major reproductive events occur for the start of a new life in mammals. Understanding the oviduct physiology is essential to uncover hidden mechanisms of the human reproduction and its disorders, yet the current analysis of the oviduct that is largely limited to in vitro imaging is a significant technical hurdle. To overcome this barrier, we have recently developed in vivo approaches based on optical coherence tomography for structural and functional imaging of the mouse oviduct...
2018: Methods in Molecular Biology
Yu-Qing Zhou, Lindsay S Cahill, John G Sled
Genetically engineered mice have been widely used for studying cardiovascular development, physiology and diseases. In the past decade, high frequency ultrasound imaging technology has been significantly advanced and applied to observe the cardiovascular structure, function, and blood flow dynamics with high spatial and temporal resolution in mice. This noninvasive imaging approach has made possible longitudinal studies of the mouse embryo/fetus in utero. In this chapter, we describe detailed methods for: (1) the assessment of the structure, function, and flow dynamics of the developing heart of the mouse embryo during middle gestation (E10...
2018: Methods in Molecular Biology
Jeffrey Lambe, Olwen C Murphy, Shiv Saidha
PURPOSE OF REVIEW: With the recognition that neurodegeneration represents the principal substrate of disability in multiple sclerosis (MS), there has been increased strives towards identifying biomarkers for accurately quantifying and tracking neurodegeneration during the disease course. The retina provides an opportune "window" into the central nervous system (CNS) in MS, with retinal changes in MS reflecting not only local, but also global aspects of neurodegeneration and inflammation operative in the disease...
March 21, 2018: Current Treatment Options in Neurology
Antonio Merolli, Stephanie Fung, N Sanjeeva Murthy, E Thomas Pashuck, Yong Mao, Xiaohuan Wu, Joseph A M Steele, Daniel Martin, Prabhas V Moghe, Timothy Bromage, Joachim Kohn
Osteoclasts are large multinucleated giant cells that actively resorb bone during the physiological bone turnover (BTO), which is the continuous cycle of bone resorption (by osteoclasts) followed by new bone formation (by osteoblasts). Osteoclasts secrete chemotactic signals to recruit cells for regeneration of vasculature and bone. We hypothesize that a biomaterial that attracts osteoclasts and re-establishes BTO will induce a better healing response than currently used bone graft materials. While the majority of bone regeneration efforts have focused on maximizing bone deposition, the novelty in this approach is the focus on stimulating osteoclastic resorption as the starter for BTO and its concurrent new vascularized bone formation...
March 21, 2018: Journal of Materials Science. Materials in Medicine
Torsten C Schmidt
Water analysis has been an important area since the beginning of analytical chemistry. The focus though has shifted substantially: from minerals and the main constituents of water in the time of Carl Remigius Fresenius to a multitude of, in particular, organic compounds at concentrations down to the sub-nanogram per liter level nowadays. This was possible only because of numerous innovations in instrumentation in recent decades, drivers of which are briefly discussed. In addition to the high demands on sensitivity, high throughput by automation and short analysis times are major requirements...
March 21, 2018: Analytical and Bioanalytical Chemistry
Shishu Zhang, Na Zhang, Yan Zhao, Ting Cheng, Xiaobo Li, Rui Feng, Hua Xu, Zhirong Liu, Jin Zhang, Lianming Tong
Two-dimensional (2D) layered materials have attracted tremendous attention and led to a prosperous development in both fundamental investigation and device applications in various fields, such as nanoelectronics, flexible devices, sustainable energy and catalysts. The precise characterization of the structure and properties of 2D materials is in urgent need. Raman scattering spectroscopy is one of the most popular characterization tools that is convenient, rapid and non-invasive. It provides information on both the lattice structure from the frequency of phonon modes and the electronic band structure through the intensity due to electronic resonance Raman scattering...
March 22, 2018: Chemical Society Reviews
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