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https://www.readbyqxmd.com/read/28636792/mtf-and-dqe-enhancement-using-an-apodized-aperture-x-ray-detector-design
#1
Tomi F Nano, Terenz Escartin, Elina Ismailova, Karim S Karim, Jan Lindstrȍm, Ho Kyung Kim, Ian A Cunningham
PURPOSE: Acquisition of high-quality x-ray images using low patient exposures requires detectors with high detective quantum efficiency (DQE). We describe a novel apodized-aperture pixel (AAP) design that increases high-frequency modulation transfer function (MTF) and DQE values. The AAP design makes a separation of physical sensor elements from image pixels by using very small sensor elements (e.g. 0.010-0.025 mm) to synthesize desired larger image pixels (e.g. 0.1-0.2 mm). METHODS: A cascaded systems model of signal and noise propagation is developed to describe the benefits of the AAP approach in terms of the MTF, Wiener noise power spectrum (NPS) and DQE...
June 21, 2017: Medical Physics
https://www.readbyqxmd.com/read/28636567/invariant-wide-bandgaps-in-honeycomb-monolayer-and-single-walled-nanotubes-of-iib-vi-semiconductors
#2
Xiaoxuan Ma, Jun Hu, Bicai Pan
Search for low-dimensional materials with unique electronic properties is important for the development of electronic devices in nano scale. Through systematic first-principles calculations, we found that the band gaps of the two-dimensional honeycomb monolayers and one-dimensional single-walled nanotubes of IIB-VI semiconductors (ZnO, CdO, ZnS and CdS) are nearly chirality-independent and weakly diameter-dependent. Based on analysis of the electronic structures, it was found that the conduction band minimum is contributed by the spherically symmetric $s$ orbitals of cations and the valence band maximum is dominated by the in-plane d<sub>xy</sub>-p<sub>y</sub> and d<sub>x<sup>2</sup>-y<sup>2</sup></sub>-p<sub>x</sub> hybridizations...
June 21, 2017: Nanotechnology
https://www.readbyqxmd.com/read/28636246/stretchable-electrochemical-sensor-for-inducing-and-monitoring-cell-mechanotransduction-in-real-time
#3
Yan-Ling Liu, Yu Qin, Zi-He Jin, Xue-Bo Hu, Miao-Miao Chen, Rong Liu, Christian Amatore, Wei-Hua Huang
Existing methods offer little direct and real-time information about stretch-triggered biochemical responses during cell mechanotransduction. Herein, we report a novel stretchable electrochemical sensor that takes advantage of a hierarchical percolation network of carbon nanotubes and gold nanotubes (CNTs- Au NTs). This hybrid nano-structure provides the sensor with excellent time-reproducible mechanical and electrochemical performances while granting very good cellular compatibility, making it perfectly apt to induce and monitor simultaneously transient biochemical signals...
June 21, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28635947/in-situ-dynamic-observations-of-perovskite-crystallisation-and-microstructure-evolution-intermediated-from-pbi6-4-cage-nanoparticles
#4
Qin Hu, Lichen Zhao, Jiang Wu, Ke Gao, Deying Luo, Yufeng Jiang, Ziyi Zhang, Chenhui Zhu, Eric Schaible, Alexander Hexemer, Cheng Wang, Yi Liu, Wei Zhang, Michael Grätzel, Feng Liu, Thomas P Russell, Rui Zhu, Qihuang Gong
Hybrid lead halide perovskites have emerged as high-performance photovoltaic materials with their extraordinary optoelectronic properties. In particular, the remarkable device efficiency is strongly influenced by the perovskite crystallinity and the film morphology. Here, we investigate the perovskites crystallisation kinetics and growth mechanism in real time from liquid precursor continually to the final uniform film. We utilize some advanced in situ characterisation techniques including synchrotron-based grazing incident X-ray diffraction to observe crystal structure and chemical transition of perovskites...
June 21, 2017: Nature Communications
https://www.readbyqxmd.com/read/28634732/engineering-poly-lactic-co-glycolic-acid-plga-micro-and-nano-carriers-for-controlled-delivery-of-17%C3%AE-estradiol
#5
Alesia V Prakapenka, Heather A Bimonte-Nelson, Rachael W Sirianni
With menopause, circulating levels of 17β-estradiol (E2) markedly decrease. E2-based hormone therapy is prescribed to alleviate symptoms associated with menopause. E2 is also recognized for its beneficial effects in the central nervous system (CNS), such as enhanced cognitive function following abrupt hormonal loss associated with ovariectomy. For women with an intact uterus, an opposing progestogen component is required to decrease the risk of developing endometrial hyperplasia. While adding an opposing progestogen attenuates these detrimental effects on the uterus, it can attenuate the beneficial effects of E2 in the CNS...
June 20, 2017: Annals of Biomedical Engineering
https://www.readbyqxmd.com/read/28634611/micro-and-nano-patterned-conductive-graphene-peg-hybrid-scaffolds-for-cardiac-tissue-engineering
#6
Alec S T Smith, Hyok Yoo, Hyunjung Yi, Eun Hyun Ahn, Justin H Lee, Guozheng Shao, Ekaterina Nagornyak, Michael A Laflamme, Charles E Murry, Deok-Ho Kim
A lack of electrical conductivity and structural organization in currently available biomaterial scaffolds limits their utility for generating physiologically representative models of functional cardiac tissue. Here we report on the development of scalable, graphene-functionalized topographies with anisotropic electrical conductivity for engineering the structural and functional phenotypes of macroscopic cardiac tissue constructs. Guided by anisotropic electroconductive and topographic cues, the tissue constructs displayed structural property enhancement in myofibrils and sarcomeres, and exhibited significant increases in the expression of cell-cell coupling and calcium handling proteins, as well as in action potential duration and peak calcium release...
June 21, 2017: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/28634139/ocular-disposition-of-ciprofloxacin-from-topical-pegylated-nanostructured-lipid-carriers-effect-of-molecular-weight-and-density-of-poly-ethylene-glycol
#7
Sai Prachetan Balguri, Goutham R Adelli, Karthik Yadav Janga, Prakash Bhagav, Soumyajit Majumdar
Ciprofloxacin (CIP) is an antibacterial agent prescribed for the treatment of ocular infections. The objective of the present project is to investigate the effect of surface PEG functionalization of the Nano structured lipid carriers (NLCs) on formulation stability, ocular penetration and distribution. CIP NLCs were tested with different molecular weight (poly ethylene glycol) PEGs ranging from (2K to 20K) grafted onto the phospholipid and with different chain lengths (14-18 carbons) of phospholipids derivatized with PEG-2K...
June 17, 2017: International Journal of Pharmaceutics
https://www.readbyqxmd.com/read/28633851/nano-fe3o4-peg-succinic-anhydride-a-novel-and-efficient-catalyst-for-the-synthesis-of-benzoxanthenes-under-ultrasonic-irradiation
#8
Javad Safaei-Ghomi, Fahime Eshteghal
In this paper, we reported the successful synthesis of Fe3O4/polyethyleneglycol (PEG)/succinic anhydride nanocatalyst. The catalyst was fully characterized by scanning electronic microscopy (SEM), vibrating sample magnetometer (VSM), X-ray diffraction (XRD), thermal gravimetric analysis (TGA), dynamic laser scattering (DLS) and FT-IR spectroscopy. Fe3O4/PEG/succinic anhydride nanocatalyst as an efficient and green catalyst has been used for the synthesis of benzoxanthenes by the three-component condensation reaction of aldehydes, 2-hydroxynaphthalene-1,4-dione and 2-naphthol or dimedone under ultrasonic irradiation...
September 2017: Ultrasonics Sonochemistry
https://www.readbyqxmd.com/read/28633850/stabilization-of-nano-structured-zno-particles-onto-the-surface-of-cotton-fibers-using-different-surfactants-and-their-antimicrobial-activity
#9
Issa M El-Nahhal, Abdelraouf A Elmanama, Nizam M El Ashgar, Nadia Amara, Mohamed Selmane, Mohamed M Chehimi
ZnO NPs were prepared and deposited onto cotton fibers via ultrasound irradiation successfully. Different surfactants (SDS, HY, CTAB, TX-100) have been used to stabilize, homogenize the coated ZnO NPs and control their shape and size as encapsulated species. The use of surfactants has improved the durability of ZnO NPs and decreased its leaching in particular SDS. The small mean crystallite size for ZnO particles due to the use of surfactants is the main reason for decreasing the leached of ZnO particles from cotton substrate...
September 2017: Ultrasonics Sonochemistry
https://www.readbyqxmd.com/read/28633846/aqueous-norfloxacin-sonocatalytic-degradation-with-multilayer-flower-like-zno-in-the-presence-of-peroxydisulfate
#10
Shou-Bo Hu, Liang Li, Meng-Yu Luo, Ya-Feng Yun, Chang-Tang Chang
Multilayer ZnO nanoflowers were synthesized through a simple precipitation method and characterized by field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), X-ray photoelectron spectra (XPS) and nitrogen absorption-desorption techniques. The FE-SEM images show the integrated morphology of an individual flower-like ZnO nanostructure, which is made of nano-platelets with uniform thickness (20-30nm). The average pore size and Brunauer-Emmet-Teller (BET) surface area of the as-synthesized ZnO were 27...
September 2017: Ultrasonics Sonochemistry
https://www.readbyqxmd.com/read/28633812/sonochemical-synthesis-of-a-new-cobalt-ii-complex-crystal-structure-thermal-behavior-hirshfeld-surface-analysis-and-its-usage-as-precursor-for-preparation-of-coo-co3o4-nanoparticles
#11
Morteza Montazerozohori, Ardavan Masoudiasl, Sara Farokhiyani, Shiva Joohari, Patrick McArdle
A bidentate Schiff base ligand and its nano-structured cobalt(II) complex were synthesized under ultrasound irradiation and then their structures were identified by physical and spectral techniques SEM and XRD techniques were used to confirm the nanostructure character of the complex. Single crystal X-ray diffraction analysis showed that the complex crystallizes in the triclinic system with space group of P1¯ and two crystallographically independent molecules participate in its asymmetric unit. In the structure of complex, cobalt center is four-coordinated by two iminic nitrogens of bidentate Schiff base ligand and two bromide anions in a distorted tetrahedral geometry...
September 2017: Ultrasonics Sonochemistry
https://www.readbyqxmd.com/read/28633520/ion-selective-nanosensor-for-photoacoustic-and-fluorescence-imaging-of-potassium
#12
Chang Heon Lee, Jeff Folz, Wuliang Zhang, Janggun Jo, Joel W Y Tan, Xueding Wang, Raoul Kopelman
Ion-selective optodes (ISOs), the optical analog of ion-selective electrodes, have played an increasingly important role in chemical and biochemical analysis. Here we extend this technique to ion-selective photo-acoustic optodes (ISPAOs) that serve at the same time as fluorescence-based ISOs, and apply it specifically to potassium (K+). Notably, the potassium ion is one of the most abundant cations in biological systems, involved in numerous physiological and pathological processes. Furthermore, it has been recently reported that the presence of abnormal extracellular potassium concentrations in tumors suppresses the immune responses and thus suppresses immunotherapy...
June 21, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28631921/direct-electron-beam-writing-of-silver-based-nanostructures
#13
Katja Hoeflich, Jakub Jurczyk, Yucheng Zhang, Marcos Vinicius Puydinger Dos Santos, Maximilian Goetz, Carlos Guerra-Nunez, James P Best, Czesław Kapusta, Ivo Utke
Direct writing utilizing a focused electron beam constitutes an interesting alternative to resist based techniques, as it allows for precise and flexible growth onto any conductive substrate in a single-step process. One important challenge, however, is the identification of appropriate precursors which allow for deposition of the material of choice e.g. for envisaged applications in nano-optics. In this regard the coinage metal silver is of particular interest since it shows a relatively high plasma frequency, and thus, excellent plasmonic properties in the visible range...
June 20, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28631683/-the-clinical-and-bacteriological-study-of-the-effectiveness-of-the-application-of-silver-nanoparticle-for-the-treatment-of-tuberculosis
#14
B B Uraskulova, A O Gyusan
The objective of the present study was to evaluate the expediency of the application of nano-scale silver preparations, argovit-C and vitargol, differing in concentration for the treatment of tuberculosis of the upper respiratory tract. The study was carried out based at the Karachaevo-Cherkessian TB dispensary. It has been demonstrated that the 3.3% solution of argovit-C possessed of the 100% bactericidal activity with respect to the medically-resistant mycobacteria at both maximum and minimal concentrations of isoniazid...
2017: Vestnik Otorinolaringologii
https://www.readbyqxmd.com/read/28631471/great-disparity-in-photoluminesence-quantum-yields-of-colloidal-cspbbr3-nanocrystals-with-varied-shape-the-effect-of-crystal-lattice-strain
#15
Jiangtao Zhao, Mei Liu, Li Fang, Shenlong Jiang, Jingtian Zhou, Huaiyi Ding, Hongwen Huang, Wen Wen, Zhenlin Luo, Qun Zhang, Xiaoping Wang, Chen Gao
Understanding the big discrepancy in the photoluminesence quantum yields (PLQY) of nano-scale colloidal materials with varied morphologies is of great significance to its property optimization and functional application. In this work, using different shaped CsPbBr3 nanocrystals with same fabrication processes as model, quantitative synchrotron radiation x-ray diffraction analysis reveals the increasing trend in lattice strain values of the nanocrystals: nanocube, nanoplate, nanowire. Further, transient spectroscopic measurements reveals a same trend in the defect quantities of these nanocrystals...
June 20, 2017: Journal of Physical Chemistry Letters
https://www.readbyqxmd.com/read/28631375/3d-mimicry-of-native-tissue-fiber-architecture-guides-tendon-derived-cells-and-adipose-stem-cells-into-artificial-tendon-constructs
#16
Mariana Laranjeira, Rui M A Domingues, Raquel Costa-Almeida, Rui L Reis, Manuela E Gomes
Tendon and ligament (T/L) function is intrinsically related with their unique hierarchically and anisotropically organized extracellular matrix. Their natural healing capacity is, however, limited. Here, continuous and aligned electrospun nanofiber threads (CANT) based on synthetic/natural polymer blends mechanically reinforced with cellulose nanocrystals are produced to replicate the nanoscale collagen fibrils grouped into microscale collagen fibers that compose the native T/L. CANT are then incrementally assembled into 3D hierarchical scaffolds, resulting in woven constructions, which simultaneously mimic T/L nano-to-macro architecture, nanotopography, and nonlinear biomechanical behavior...
June 20, 2017: Small
https://www.readbyqxmd.com/read/28630667/evaluation-of-radical-scavenging-system-in-amoeba-chaos-carolinense-during-nutrient-deprivation
#17
Yuru Deng, Edlyn Li-Hui Lee, Ketpin Chong, Zakaria A Almsherqi
The frequent appearance of non-lamellar membrane arrangements such as cubic membranes (CMs) in cells under stressed or pathological conditions points to an intrinsic cellular response mechanism. CM represents highly curved, three-dimensional nano-periodic structures that correspond to mathematically well-defined triply periodic minimal surfaces. Specifically, cellular membrane may transform into CM organization in response to pathological, inflammatory and oxidative stress conditions. CM organization, thus, may provide an advantage to cope with various types of stress...
August 6, 2017: Interface Focus
https://www.readbyqxmd.com/read/28630474/nanoassembly-routes-stimulate-conflicting-antibody-quantity-and-quality-for-transmission-blocking-malaria-vaccines
#18
Darren B Leneghan, Kazutoyo Miura, Iona J Taylor, Yuanyuan Li, Jing Jin, Karl D Brune, Martin F Bachmann, Mark Howarth, Carole A Long, Sumi Biswas
Vaccine development efforts have recently focused on enabling strong immune responses to poorly immunogenic antigens, via display on multimerisation scaffolds or virus like particles (VLPs). Typically such studies demonstrate improved antibody titer comparing monomeric and nano-arrayed antigen. There are many such studies and scaffold technologies, but minimal side-by-side evaluation of platforms for both the amount and efficacy of antibodies induced. Here we present direct comparison of three leading platforms displaying the promising malaria transmission-blocking vaccine (TBV) target Pfs25...
June 19, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28630465/changes-in-pore-structure-of-coal-caused-by-coal-to-gas-bioconversion
#19
Rui Zhang, Shimin Liu, Jitendra Bahadur, Derek Elsworth, Yi Wang, Guanglong Hu, Yanna Liang
Microbial enhanced coalbed methane (ME-CBM) recovery is critically examined as a viable technology for natural gas recovery from coalbed methane (CBM) reservoirs. Since the majority of gas-in-place (GIP) is stored as an adsorbed phase in fine pores of coal matrix, the nano-pore structure directly influences gas storage and transport properties. Only limited studies have quantified the alteration of the nano-pore structure due to ME-CBM treatment. This study examines the evolution of the pore structure using a combination of small angle X-ray scattering (SAXS), low-pressure N2 and CO2 adsorption (LPGA) and high-pressure methane adsorption methods...
June 19, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28630342/autoantibody-profiling-on-a-plasmonic-nano-gold-chip-for-the-early-detection-of-hypertensive-heart-disease
#20
Xiaoyang Li, Tatiana Kuznetsova, Nicholas Cauwenberghs, Matthew Wheeler, Holden Maecker, Joseph C Wu, Francois Haddad, Hongjie Dai
The role of autoimmunity in cardiovascular (CV) diseases has been increasingly recognized. Autoimmunity is most commonly examined by the levels of circulating autoantibodies in clinical practices. Measurement of autoantibodies remains, however, challenging because of the deficiency of reproducible, sensitive, and standardized assays. The lack of multiplexed assays also limits the potential to identify a CV-specific autoantibody profile. To overcome these challenges, we developed a nanotechnology-based plasmonic gold chip for autoantibody profiling...
June 19, 2017: Proceedings of the National Academy of Sciences of the United States of America
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