keyword
MENU ▼
Read by QxMD icon Read
search

Helium

keyword
https://www.readbyqxmd.com/read/28209015/boron-neutron-capture-therapy-a-literature-review
#1
REVIEW
Kavitaa Nedunchezhian, Nalini Aswath, Manigandan Thiruppathy, Sarumathi Thirugnanamurthy
Boron Neutron Capture Therapy (BNCT) is a radiation science which is emerging as a hopeful tool in treating cancer, by selectively concentrating boron compounds in tumour cells and then subjecting the tumour cells to epithermal neutron beam radiation. BNCT bestows upon the nuclear reaction that occurs when Boron-10, a stable isotope, is irradiated with low-energy thermal neutrons to yield α particles (Helium-4) and recoiling lithium-7 nuclei. A large number of 10 Boron (10B) atoms have to be localized on or within neoplastic cells for BNCT to be effective, and an adequate number of thermal neutrons have to be absorbed by the 10B atoms to maintain a lethal 10B (n, α) lithium-7 reaction...
December 2016: Journal of Clinical and Diagnostic Research: JCDR
https://www.readbyqxmd.com/read/28206822/the-effect-of-high-dose-ionizing-radiation-on-the-astrobiological-model-lichen-circinaria-gyrosa
#2
Rosa de la Torre, Ana Zélia Miller, Beatriz Cubero, M Luisa Martín-Cerezo, Marina Raguse, Joachim Meeßen
The lichen Circinaria gyrosa is an astrobiological model defined by its high capacity of resistance to space conditions and to a simulated martian environment. Therefore, it became part of the currently operated BIOMEX experiment on board the International Space Station and the recent STARLIFE campaign to study the effects of four types of space-relevant ionizing radiation. The samples were irradiated with helium and iron ions at doses up to 2 kGy, with X-rays at doses up to 5 kGy and with γ rays at doses from 6 to 113 kGy...
February 2017: Astrobiology
https://www.readbyqxmd.com/read/28206820/tolerance-to-x-rays-and-heavy-ions-fe-he-in-the-tardigrade-richtersius-coronifer-and-the-bdelloid-rotifer-mniobia-russeola
#3
K Ingemar Jönsson, Andrzej Wojcik
The aim of this study was to analyze tolerance to heavy ions in desiccated animals of the eutardigrade Richtersius coronifer and the bdelloid rotifer Mniobia russeola within the STARLIFE project. Both species were exposed to iron (Fe) and helium (He) ions at the Heavy Ion Medical Accelerator in Chiba (HIMAC) in Chiba, Japan, and to X-rays at the German Aerospace Center (DLR) in Cologne, Germany. Results show no effect of Fe and He on viability up to 7 days post-rehydration in both R. coronifer and M. russeola, while X-rays tended to reduce viability in R...
February 2017: Astrobiology
https://www.readbyqxmd.com/read/28203657/presence-of-peierls-pairing-and-absence-of-insulator-to-metal-transition-in-vo2-a-a-structure-property-relationship-study
#4
S R Popuri, A Artemenko, R Decourt, A Villesuzanne, M Pollet
Layered vanadium oxides have been extensively explored due to their interesting metal-insulator transitions and energy conversion/storage applications. In the present study, we have successfully synthesized VO2 (A) polymorph powder samples by a single-step hydrothermal synthesis process and consolidated them using spark plasma sintering. The structural and electronic properties of VO2 (A) are measured over a large temperature range from liquid helium, across the structural transition (400-440 K) and up to 500 K...
February 16, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28202960/chemistry-helium-succumbs-to-pressure
#5
(no author information available yet)
No abstract text is available yet for this article.
February 15, 2017: Nature
https://www.readbyqxmd.com/read/28195125/morphologies-of-tungsten-nanotendrils-grown-under-helium-exposure
#6
Kun Wang, R P Doerner, M J Baldwin, F W Meyer, M E Bannister, Amith Darbal, Robert Stroud, Chad M Parish
Nanotendril "fuzz" will grow under He bombardment under tokamak-relevant conditions on tungsten plasma-facing materials in a magnetic fusion energy device. We have grown tungsten nanotendrils at low (50 eV) and high (12 keV) He bombardment energy, in the range 900-1000 °C, and characterized them using electron microscopy. Low energy tendrils are finer (~22 nm diameter) than high-energy tendrils (~176 nm diameter), and low-energy tendrils have a smoother surface than high-energy tendrils. Cavities were omnipresent and typically ~5-10 nm in size...
February 14, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28193025/application-of-the-uranium-helium-chronometer-to-the-analysis-of-nuclear-forensic-materials
#7
Sean D Gates, William S Cassata
Radiochronometers are used to constrain the manufacturing and processing history of actinide materials for nuclear forensic investigations. This paper describes U-He ages and He diffusion kinetics obtained from a metallic, highly enriched uranium sample. The average U-He age is 8% older than the known casting date, which indicates that excess He is present and is likely due to incomplete degassing of pre-existing He during the casting process. Although the U-He age is older than expected, the accuracy is comparable to other chronometers that have been applied to this material...
December 20, 2016: Analytical Chemistry
https://www.readbyqxmd.com/read/28186113/strain-gated-bilayer-molybdenum-disulfide-field-effect-transistor-with-edge-contacts
#8
Yu Chai, Shanshan Su, Dong Yan, Mihrimah Ozkan, Roger Lake, Cengiz S Ozkan
Silicon nitride stress capping layer is an industry proven technique for increasing electron mobility and drive currents in n-channel silicon MOSFETs. Herein, the strain induced by silicon nitride is firstly characterized through the changes in photoluminescence and Raman spectra of a bare bilayer MoS2 (Molybdenum disulfide). To make an analogy of the strain-gated silicon MOSFET, strain is exerted to a bilayer MoS2 field effect transistor (FET) through deposition of a silicon nitride stress liner that warps both the gate and the source-drain area...
February 10, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28167262/humidity-affects-the-morphology-of-particles-emitted-from-beclomethasone-dipropionate-pressurized-metered-dose-inhalers
#9
James W Ivey, Pallavi Bhambri, Tanya K Church, David A Lewis, Mark T McDermott, Shereen Elbayomy, Warren H Finlay, Reinhard Vehring
The effects of propellant type, cosolvent content, and air humidity on the morphology and solid phase of the particles produced from solution pressurized metered dose inhalers containing the corticosteroid beclomethasone dipropionate were investigated. The active ingredient was dissolved in the HFA propellants 134a and 227ea with varying levels of the cosolvent ethanol and filled into pressurized metered dose inhalers. Inhalers were actuated into an evaporation chamber under controlled temperature and humidity conditions and sampled using a single nozzle, single stage inertial impactor...
February 3, 2017: International Journal of Pharmaceutics
https://www.readbyqxmd.com/read/28166539/primordial-helium-entrained-by-the-hottest-mantle-plumes
#10
M G Jackson, J G Konter, T W Becker
Helium isotopes provide an important tool for tracing early-Earth, primordial reservoirs that have survived in the planet's interior. Volcanic hotspot lavas, like those erupted at Hawaii and Iceland, can host rare, high (3)He/(4)He isotopic ratios (up to 50 times the present atmospheric ratio, Ra) compared to the lower (3)He/(4)He ratios identified in mid-ocean-ridge basalts that form by melting the upper mantle (about 8Ra; ref. 5). A long-standing hypothesis maintains that the high-(3)He/(4)He domain resides in the deep mantle, beneath the upper mantle sampled by mid-ocean-ridge basalts, and that buoyantly upwelling plumes from the deep mantle transport high-(3)He/(4)He material to the shallow mantle beneath plume-fed hotspots...
February 6, 2017: Nature
https://www.readbyqxmd.com/read/28166407/optical-nanoscopy-of-high-tc-cuprate-nanoconstriction-devices-patterned-by-helium-ion-beams
#11
A Gozar, N E Litombe, Jennifer E Hoffman, I Božović
Helium ion beams (HIB) focused to subnanometer scales have emerged as powerful tools for high-resolution imaging as well as nanoscale lithography, ion milling, or deposition [ Ward et al. J. Vac. Sci. Technol. B 2006 , 24 , 2871 ; Hlawacek et al. J. Vac. Sci. Technol. B 2014 , 32 , 02081 ; Alkemade et al. Appl. Phys. A 2014 , 117 , 1727 ]. Quantifying irradiation effects is an essential step toward reliable device fabrication, but most of the depth profiling information is provided by computer simulations rather than the experiment [ Zeigler et al...
February 10, 2017: Nano Letters
https://www.readbyqxmd.com/read/28163937/a-narrowing-diagnosis-a-rare-cause-of-adult-croup-and-literature-review
#12
Jayshil J Patel, Emily Kitchin, Kurt Pfeifer
Croup or laryngotracheitis is rare in adults. We present a case of an otherwise healthy young woman that presented in the winter with 3 days of increasing dyspnea, cough, and fever. She was hemodynamically stable but was found to have a barking cough, paradoxical abdominal breathing, and stridor. Chest radiograph revealed subglottic narrowing. Respiratory viral nucleic acid amplification testing was positive for respiratory syncytial virus. The patient was treated with nebulized epinephrine, dexamethasone, and a helium-oxygen mixture...
2017: Case Reports in Critical Care
https://www.readbyqxmd.com/read/28157200/revisiting-metallization-boundary-of-warm-dense-helium-in-a-wide-%C3%AF-t-regime-from-ab-initio-study
#13
Wei Zhang, Zhiguo Li, Zhijian Fu, Jiayu Dai, Qifeng Chen, Lingcang Cai
The knowledge of the metallization of warm dense helium has important implications for understanding the thermal histories, stellar structure and magnetic field environment of giant planets. However, it is also a pendent scientific topic. For a revisiting into the properties of warm dense helium, we performed extensive quantum Langevin molecular dynamic simulations and electronic structure calculations to study helium over a very wide range of density (ρ = 1~24 g/cm(3)) and temperature (T = 10~160 kK)...
February 3, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28155914/evolutionary-clade-affects-resistance-of-clostridium-difficile-spores-to-cold-atmospheric-plasma
#14
Mairéad Connor, Padrig B Flynn, Derek J Fairley, Nikki Marks, Panagiotis Manesiotis, William G Graham, Brendan F Gilmore, John W McGrath
Clostridium difficile is a spore forming bacterium and the leading cause of colitis and antibiotic associated diarrhoea in the developed world. Spores produced by C. difficile are robust and can remain viable for months, leading to prolonged healthcare-associated outbreaks with high mortality. Exposure of C. difficile spores to a novel, non-thermal atmospheric pressure gas plasma was assessed. Factors affecting sporicidal efficacy, including percentage of oxygen in the helium carrier gas admixture, and the effect on spores from different strains representing the five evolutionary C...
February 3, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28152309/reaction-of-o-3-p-with-c3h6-yield-of-the-reaction-products-as-a-function-of-temperature
#15
Yuri Bedjanian, Julien Morin
Reaction of oxygen atoms with propene is an important step in combustion processes particularly affecting the profiles of intermediate species and flame speed. The relative importance of different pathways of this multichannel reaction at different temperatures represents significant theoretical interest and is essential for modeling combustion systems. In the present work, we report the first experimental investigation of the products of the O((3)P) + C3H6 reaction over an extended temperature range (298-905 K)...
February 16, 2017: Journal of Physical Chemistry. A
https://www.readbyqxmd.com/read/28147678/high-pressure-gas-flow-storage-and-displacement-in-fractured-rock-experimental-setup-development-and-application
#16
M Hadi Mosleh, M Turner, M Sedighi, P J Vardon
This paper presents the design, development, and application of a laboratory setup for the experimental investigations of gas flow and reactions in a fractured rock. The laboratory facility comprises (i) a high pressure manometric sorption apparatus, where equilibrium and kinetic phenomena of adsorption and desorption can be examined, (ii) a high pressure triaxial core flooding system where the chemical reactive transport properties or processes can be explored, and (iii) an ancillary system including pure and mixed gas supply and analysis units...
January 2017: Review of Scientific Instruments
https://www.readbyqxmd.com/read/28147675/note-a-simple-detection-method-for-helium-droplet-spectroscopy-experiments
#17
Brandon J Thomas, Barbara A Harruff-Miller, William K Lewis
Helium droplet methods are currently established as a premier experimental technique for the production and spectroscopic study of novel clusters and complexes. Unfortunately, some of the essential equipment required to perform the experiments, such as the detector used to monitor photon-induced depletion of the helium droplet beam, can be relatively large, complex, and expensive. Most often this detector is a quadrupole mass spectrometer (QMS). In this report, we describe the development and evaluation of an extremely simple, straightforward, small, and inexpensive droplet beam detector for use in helium droplet spectroscopy experiments and compare its performance to that of a QMS by recording the infrared spectra of helium droplets doped with either (13)CO2 or CD4...
January 2017: Review of Scientific Instruments
https://www.readbyqxmd.com/read/28147653/a-high-signal-to-noise-ratio-passive-near-field-microscope-equipped-with-a-helium-free-cryostat
#18
Kuan-Ting Lin, Susumu Komiyama, Sunmi Kim, Ken-Ichi Kawamura, Yusuke Kajihara
We have developed a passive long-wavelength infrared (LWIR) scattering-type scanning near-field optical microscope (s-SNOM) installed in a helium-free mechanically cooled cryostat, which facilitates cooling of an LWIR detector and optical elements to 4.5 K. To reduce mechanical vibration propagation from a compressor unit, we have introduced a metal bellows damper and a helium gas damper. These dampers ensure the performance of the s-SNOM to be free from mechanical vibration. Furthermore, we have introduced a solid immersion lens to improve the confocal microscope performance...
January 2017: Review of Scientific Instruments
https://www.readbyqxmd.com/read/28147643/an-in-situ-synchrotron-xas-methodology-for-surface-analysis-under-high-temperature-pressure-and-shear
#19
A Dorgham, A Neville, K Ignatyev, F Mosselmans, A Morina
The complex tribochemical nature of lubricated tribological contacts is inaccessible in real time without altering their initial state. To overcome this issue, a new design of a pin-on-disc tribological apparatus was developed and combined with synchrotron X-ray absorption spectroscopy (XAS). Using the designed apparatus, it is possible to study in situ the transient decomposition reactions of various oil additives on different surfaces under a wide range of realistic operating conditions of contact pressure (1...
January 2017: Review of Scientific Instruments
https://www.readbyqxmd.com/read/28147633/a-low-power-miniaturized-dielectric-barrier-discharge-based-atmospheric-pressure-plasma-jet
#20
G Divya Deepak, N K Joshi, Dharmendra Kumar Pal, Ram Prakash
In this paper, a dielectric barrier discharge plasma based atmospheric pressure plasma jet has been generated in a floating helix and floating end ring electrode configuration using argon and helium gases. This configuration is subjected to a range of supply frequencies (10-25 kHz) and supply voltages (2-6 kV) at a fixed rate of gas flow rate (i.e., 1 l/min). The electrical characterization of the plasma jet has been carried out using a high voltage probe and current transformer. The current-voltage characteristics have been analyzed, and the consumed power has been estimated at different applied combinations for optimum power consumption at maximum jet length...
January 2017: Review of Scientific Instruments
keyword
keyword
110671
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"