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https://www.readbyqxmd.com/read/28926948/field-emission-from-self-catalyzed-gaas-nanowires
#1
Filippo Giubileo, Antonio Di Bartolomeo, Laura Iemmo, Giuseppe Luongo, Maurizio Passacantando, Eero Koivusalo, Teemu V Hakkarainen, Mircea Guina
We report observations of field emission from self-catalyzed GaAs nanowires grown on Si (111). The measurements were taken inside a scanning electron microscope chamber with a nano-controlled tungsten tip functioning as anode. Experimental data were analyzed in the framework of the Fowler-Nordheim theory. We demonstrate stable current up to 10(-7) A emitted from the tip of single nanowire, with a field enhancement factor β of up to 112 at anode-cathode distance d = 350 nm. A linear dependence of β on the anode-cathode distance was found...
September 16, 2017: Nanomaterials
https://www.readbyqxmd.com/read/28926796/synthesis-thermoluminescence-defect-center-and-dosimetric-characteristics-of-lif-mg-cu-p-si-phosphor
#2
Prince David Preto, Vidyavathy Balraj, Bhushan S Dhabekar, S Watanabe, T K Gundu Rao, Nilo F Cano
LiF:Mg,Cu,P,Si (MCPS), a new tissue equivalent phosphor, was synthesized by solid state method. Powder x-ray diffraction and scanning electron microscope were employed to determine the structural features. The dosimetric characteristics, electron spin resonance (ESR) and defect centers of this newly prepared phosphor were investigated. The MCPS phosphor is highly sensitive when compared with LiF:Mg,Ti and LiF:Mg,Cu,P (MCP), with the TL sensitivity being 35 times and 1.3 times higher respectively. The dosimetric peak occurs at 220°C with a well defined glow curve structure similar to MCP...
August 25, 2017: Applied Radiation and Isotopes
https://www.readbyqxmd.com/read/28926201/effect-of-topical-application-of-black-seed-oil-on-imiquimod-induced-psoriasis-like-lesions-in-the-thin-skin-of-adult-male-albino-rats
#3
Ebtsam F Okasha, Naglaa A Bayomy, Eman Z Abdelaziz
Psoriasis is a chronic inflammatory skin disease that affects about 1-3% of the world's population. Black seed oil, i.e the oil extracted from black seeds (Nigella sativa seeds), possesses a broad spectrum of pharmacological actions including anti-inflammatory, immunostimulatory and antioxidant properties. This study aimed to investigate the effect of black seed oil on imiquimod (IMQ) induced psoriasis-like skin lesions. To this end, 30 male albino rats were divided into three groups: group I, control group; group II, psoriasis-induced group receiving daily topical applications of IMQ cream (5%) on the shaved back skin for 10 consecutive days; and group III, black seed oil group receiving a daily topical dose of black seed oil 5 mg/kg body weight for 10 days after induction of psoriasis...
September 19, 2017: Anatomical Record: Advances in Integrative Anatomy and Evolutionary Biology
https://www.readbyqxmd.com/read/28925099/highly-efficiency-antibacterial-diblock-copolypeptides-based-on-lysine-and-phenylalanine
#4
Xiaokai Su, Xinyu Zhou, Zhengzhong Tan, Chuncai Zhou
A series of amphiphilic diblock copolypeptides (K30 -b-F15 , K30 -b-F30 , and K30 -b-F45 ) were synthesized via N-carboxy-α-amino-anhydride ring-opening polymerization. The copolypeptides had excellent antibacterial efficacy to both Gram positive (S. aureus) and Gram negative (E. coli) bacteria. The minimum inhibitory concentrations (MICs) against E. coli and S. aureus are 8 μg mL(-1) and 2 μg mL(-1) , respectively, lower than most natural and artificial antimicrobial peptides (AMPs). The morphological changes of the bacteria treated with diblock copolypeptides were investigated by transmission electron microscopy; the results proved that the diblock copolypeptides had a similar antibacterial pore-forming mechanism to natural cationic peptides...
September 19, 2017: Biopolymers
https://www.readbyqxmd.com/read/28924671/correlative-fluorescence-super-resolution-localization-microscopy-and-platinum-replica-em-on-unroofed-cells
#5
Kem A Sochacki, Justin W Taraska
Platinum replicas of unroofed mammalian cells can be imaged with a transmission electron microscope (TEM) to produce high contrast, high resolution images of the structure of the cytoplasmic side of a plasma membrane. A complementary approach, super-resolution fluorescence localization microscopy, can be used to localize labeled molecules with better than 20 nm precision in cells. Here, we describe a correlative method that couples these two techniques and produces images where localization microscopy data can be used to highlight specific proteins of interest within the structural context of the platinum replica TEM image...
2017: Methods in Molecular Biology
https://www.readbyqxmd.com/read/28924226/electrically-driven-single-photon-emission-from-an-isolated-single-molecule
#6
Li Zhang, Yun-Jie Yu, Liu-Guo Chen, Yang Luo, Ben Yang, Fan-Fang Kong, Gong Chen, Yang Zhang, Qiang Zhang, Yi Luo, Jin-Long Yang, Zhen-Chao Dong, J G Hou
Electrically driven molecular light emitters are considered to be one of the promising candidates as single-photon sources. However, it is yet to be demonstrated that electrically driven single-photon emission can indeed be generated from an isolated single molecule notwithstanding fluorescence quenching and technical challenges. Here, we report such electrically driven single-photon emission from a well-defined single molecule located inside a precisely controlled nanocavity in a scanning tunneling microscope...
September 18, 2017: Nature Communications
https://www.readbyqxmd.com/read/28924172/multi-characterization-of-licoo2-cathode-films-using-advanced-afm-based-techniques-with-high-resolution
#7
Jiaxiong Wu, Shan Yang, Wei Cai, Zhuanfang Bi, Guangyi Shang, Junen Yao
The thin film Li-ion batteries have been extensively used in micro-electronic devices due to their miniaturization, high capacity density and environmental friendliness, etc. In order to further prolong the lifetime of the film batteries, one of important tasks is to explore the aging mechanisms of the cathode films. In this paper, we especially focused on the multi-characterization of the LiCoO2 film in nanoscale, which is carried out by combining advanced AFM-based techniques with capacity measurement. The surface morphology, contact stiffness as well as surface potential were measured by amplitude modulation-frequency modulation (AM-FM) and kelvin probe force microscope (KPFM), respectively...
September 18, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28923324/regenerating-heart-using-a-novel-compound-and-human-wharton-jelly-mesenchymal-stem-cells
#8
Shahram Rabbani, Masoud Soleimani, Mohammad Imani, Mohammad Sahebjam, Ali Ghiaseddin, Seyed Mahdi Nassiri, Jalil Majd Ardakani, Maryam Tajik Rostami, Arash Jalali, Bahmanshir Mousanassab, Mahsa Kheradmandi, Seyed Hossein Ahmadi Tafti
BACKGROUND: Myocardial infarction is a major problem in health system and most conventional therapy is not led to restoration of the health. Stem cell therapy is a method to regenerate the heart but today appropriate cell source and scaffold selection as extracellular matrix to achieve the best effect is disputing. AIM OF THE STUDY: In this study a combination of human Wharton jelly mesenchymal stem cells (HWJMSCs) with a novel compound consisting polyethylene glycol (PEG), hyaluronic acid and chitosan is presented to heart regeneration...
April 2017: Archives of Medical Research
https://www.readbyqxmd.com/read/28922839/first-description-of-a-new-uncultured-epsilon-sulfur-bacterium-colonizing-marine-mangrove-sediment-in-the-caribbean-thiovulum-sp-strain-karukerense
#9
Olivier Gros
Here, the first description is reported of an epsilon sulfur-oxidizing bacterium from sulfide-rich sediments of marine mangrove in the Caribbean. By transition electron microscopy it was shown that this new strain contains intracytoplasmic large internal sulfur granules, which was confirmed by energy-dispersive X-ray spectroscopy analyses performed using an environmental scanning electron microscope. The sulfur distribution obtained for this sulfur-oxidizing bacterial strain allowed us to conclude that elemental sulfur is formed as an intermediate oxidation product and stored intracellularly...
October 2, 2017: FEMS Microbiology Letters
https://www.readbyqxmd.com/read/28922635/fucoidan-coated-ciprofloxacin-loaded-chitosan-nanoparticles-for-the-treatment-of-intracellular-and-biofilm-infections-of-salmonella
#10
Elbi S, Nimal T R, Rajan V K, Gaurav Baranwal, Raja Biswas, Jayakumar R, Sathianarayanan S
Salmonella infections and their gallstone associated biofilm infections are difficult to treat due to poor penetration of antibiotics into the intracellular compartments of macrophages and within biofilms. Here we developed ciprofloxacin loaded chitosan nanoparticles (cCNPs) and fucoidan (Fu) coated cCNPs (Fu-cCNPs). Characterizations of these nanoparticles were carried out using Dynamic Light Scattering‎, Transmission electron microscopy and Fourier transform infrared spectroscopy. The prepared cCNPs and Fu-cCNPs have the size range of 124±7nm and 320±18nm, respectively...
September 5, 2017: Colloids and Surfaces. B, Biointerfaces
https://www.readbyqxmd.com/read/28922627/distribution-patterns-and-morphology-of-sensilla-on-the-antennae-of-plutella-xylostella-l-a-scanning-and-transmission-electron-microscopic-study
#11
Xi-Zhong Yan, Cai-Ping Deng, Jiao-Xin Xie, Lan-Jun Wu, Xue-Jun Sun, Chi Hao
The antennal morphology, types of antennal sensilla, fine structures and distributions of the sensilla in Plutella xylostella L. (Lepidoptera: Plutellidae) were studied by scanning (SEM) and transmission (TEM) electron microscopy. The antenna, scape, pedicel and flagellum were all longer in males than in females. A total of seventeen types of sensilla were identified on the antennae: trichodea (two subtypes), basiconica, coeloconica (three subtypes), Böhm's bristles (two subtypes), styloconica (two subtypes), squamiformia, auricillica, furcatea (three subtypes), cupuliform organs and terminal sensory pegs...
September 6, 2017: Micron: the International Research and Review Journal for Microscopy
https://www.readbyqxmd.com/read/28922624/quantification-of-voc-emissions-from-paint-spraying-on-a-construction-site-using-solid-phase-microextraction-devices
#12
Wen-Hsi Cheng, Hsiao-Lin Huang, Kang-Shin Chen, Yu-Jen Chang
The objective of this study was to measure the emission of, and personal exposure to workers, volatile organic compound (VOC) during paint spraying on a construction site. Needle trap samplers (NTSs), which are a green solid phase microextraction sampling technology, were used to obtain air samples at a large music exhibition center. The standard active sampling method using charcoal tubes and a personal air pump, Method 1501, was simultaneously utilized at the sampling sites to assess the workers' VOC exposures...
September 18, 2017: Journal of Environmental Science and Health. Part A, Toxic/hazardous Substances & Environmental Engineering
https://www.readbyqxmd.com/read/28922052/applications-of-emerging-transmission-electron-microscopy-technology-in-pcd-research-and-diagnosis
#13
Amelia Shoemark
Primary Ciliary Dyskinesia (PCD) is a heterogeneous genetic condition characterized by dysfunction of motile cilia. Patients suffer from chronic infection and inflammation of the upper and lower respiratory tract. Diagnosis of PCD is confirmed by identification of a hallmark defect of ciliary ultrastructure or by identification of biallelic pathogenic mutations in a known PCD gene. Since the first description of PCD in 1976, assessment of ciliary ultrastructure by transmission electron microscopy (TEM) has been central to diagnosis and research...
September 18, 2017: Ultrastructural Pathology
https://www.readbyqxmd.com/read/28921693/liquid-cell-electron-microscopy-of-adsorbed-polymers
#14
Kandula Hima Nagamanasa, Huan Wang, Steve Granick
Individual macromolecules of polystyrene sulfonate and poly(ethylene oxide) are visualized with nanometer resolution using transmission electron microscopy (TEM) imaging of aqueous solutions with and without added salt, trapped in liquid pockets between creased graphene sheets. Successful imaging with 0.3 s per frame is enabled by the sluggish mobility of the adsorbed molecules. This study finds, validating others, that an advantage of this graphene liquid-cell approach is apparently to retard sample degradation from incident electrons, in addition to minimizing background scattering because graphene windows are atomically thin...
September 18, 2017: Advanced Materials
https://www.readbyqxmd.com/read/28920963/tuning-a-circular-p-n-junction-in-graphene-from-quantum-confinement-to-optical-guiding
#15
Yuhang Jiang, Jinhai Mao, Dean Moldovan, Massoud Ramezani Masir, Guohong Li, Kenji Watanabe, Takashi Taniguchi, Francois M Peeters, Eva Y Andrei
The photon-like propagation of the Dirac electrons in graphene, together with its record-high electronic mobility, can lead to applications based on ultrafast electronic response and low dissipation. However, the chiral nature of the charge carriers that is responsible for the high mobility also makes it difficult to control their motion and prevents electronic switching. Here, we show how to manipulate the charge carriers by using a circular p-n junction whose size can be continuously tuned from the nanometre to the micrometre scale...
September 18, 2017: Nature Nanotechnology
https://www.readbyqxmd.com/read/28920632/acute-cardiotoxicity-induced-by-doxorubicin-in-right-ventricle-is-associated-with-increase-of-oxidative-stress-and-apoptosis-in-rats
#16
N Anghel, H Herman, C Balta, M Rosu, M S Stan, D Nita, A Ivan, Z Galajda, A Ardelean, A Dinischiotu, A Hermenean
Doxorubicin (DOX) is one of the most effective chemotherapeutic agents, but its efficiency is seriously limited by the risk of developing cardiomyopathy. The most recognized cardiotoxic effect is left ventricular (LF) dysfunction, but MRI and echocardiography data demonstrated significant right ventricle (RV) function impairment. In order to clarify this aspect, the present study investigated the potential of DOX to induce acute RV cardiotoxicity at the same time as LV impairment. Rats were intraperitoneally (i...
September 18, 2017: Histology and Histopathology
https://www.readbyqxmd.com/read/28919749/ginsenoside-rg1-nanoparticle-penetrating-the-blood-brain-barrier-to-improve-the-cerebral-function-of-diabetic-rats-complicated-with-cerebral-infarction
#17
Junyi Shen, Zhiming Zhao, Wei Shang, Chunli Liu, Beibei Zhang, Lingjie Zhao, Hui Cai
Diabetic cerebral infarction is with poorer prognosis and high rates of mortality. Ginsenoside Rg1 (Rg1) has a wide variety of therapeutic values for central nervous system (CNS) diseases for the neuron protective effects. However, the blood-brain barrier (BBB) restricts Rg1 in reaching the CNS. In this study, we investigated the therapeutic effects of Rg1 nanoparticle (PHRO, fabricated with γ-PGA, L-PAE (H), Rg1, and OX26 antibody), targeting transferrin receptor, on the diabetes rats complicated with diabetic cerebral infarction in vitro and in vivo...
2017: International Journal of Nanomedicine
https://www.readbyqxmd.com/read/28918765/three-dimensional-3d-nanometrology-based-on-scanning-electron-microscope-sem-stereophotogrammetry
#18
Vipin N Tondare, John S Villarrubia, András E Vlada R
Three-dimensional (3D) reconstruction of a sample surface from scanning electron microscope (SEM) images taken at two perspectives has been known for decades. Nowadays, there exist several commercially available stereophotogrammetry software packages. For testing these software packages, in this study we used Monte Carlo simulated SEM images of virtual samples. A virtual sample is a model in a computer, and its true dimensions are known exactly, which is impossible for real SEM samples due to measurement uncertainty...
September 18, 2017: Microscopy and Microanalysis
https://www.readbyqxmd.com/read/28918375/synthesis-of-fluorescent-dendrimers-with-aggregation-induced-emission-features-through-a-one-pot-multi-component-reaction-and-their-utilization-for-biological-imaging
#19
Weihua Luo, Ruming Jiang, Meiying Liu, Qing Wan, Jianwen Tian, Yuanqing Wen, Qian-Yong Cao, Junfeng Hui, Xiaoyong Zhang, Yen Wei
Hyperbranched polymers have attracted wide research attention owing to their unique topological structure, physicochemical properties and great potential for applications such asadditives, drug delivery, catalysts and nanotechnology. Among these, the polyamidoamine(PAMAM) dendrimers are some of the most important dendrimers. However, the synthesis and biomedical applications of fluorescent PAMAM dendrimers have received only limited attention. In this work, we present a rather effective and convenient approach for synthesis of fluorescent PAMAM dendrimers with aggregation-induced emission (AIE) properties through a one-pot catalyst-free Mannich reaction under rather mild experimental conditions (e...
September 9, 2017: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/28918373/defect-free-surface-modification-methods-for-solubility-tunable-carbon-nanotubes
#20
Hee Dae Lee, Byung Min Yoo, Tae Hoon Lee, Ho Bum Park
Although carbon nanotubes (CNTs) have outstanding physical properties, there are still challenging issues such as poor dispersibility and miscibility between organic polymers and CNTs for polymer nanocomposites. Chemical modifications (e.g., strong acid based oxidation, carboxylation, etc.) can improve dispersion properties and compatibility, but such surface modification methods often lead to damage to the pristine CNT structure and also deteriorate the mechanical properties of CNTs. Here we demonstrate a simple, defect-free and scalable method for well-dispersed CNTs in common organic solvents, using dopamine and amine-terminated polyethylene glycol derivatives...
September 8, 2017: Journal of Colloid and Interface Science
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