scholarly journals Heavy Ion Minibeam Therapy: Side Effects in Normal Brain

Cancers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 6207
Author(s):  
John G. Eley ◽  
Catherine B. Haga ◽  
Asaf Keller ◽  
Ellis M. Lazenby ◽  
Charles Raver ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Heavy Ions ◽  
Heavy Ion ◽  
Normal Brain ◽  
Circular Array ◽  
Behavioral Testing ◽  
Juvenile Rats ◽  
Apparent Reduction ◽  
Circular Beam ◽  
Immunohistochemical Studies

The purpose of this work was to investigate whether minibeam therapy with heavy ions might offer improvements of the therapeutic ratio for the treatment of human brain cancers. To assess neurotoxicity, we irradiated normal juvenile rats using 120 MeV lithium-7 ions at an absorbed integral dose of 20 Gy. Beams were configured either as a solid parallel circular beam or as an array of planar parallel minibeams having 300-micron width and 1-mm center-to-center spacing within a circular array. We followed animals for 6 months after treatment and utilized behavioral testing and immunohistochemical studies to investigate the resulting cognitive impairment and chronic pathologic changes. We found both solid-beam therapy and minibeam therapy to result in cognitive impairment compared with sham controls, with no apparent reduction in neurotoxicity using heavy ion minibeams instead of solid beams under the conditions of this study.

scholarly journals A fiber-deprived diet causes cognitive impairment and hippocampal microglia-mediated synaptic loss through the gut microbiota and metabolites

Microbiome ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Hongli Shi ◽  
Xing Ge ◽  
Xi Ma ◽  
Mingxuan Zheng ◽  
Xiaoying Cui ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Gut Microbiota ◽  
Neurodegenerative Diseases ◽  
Dietary Fiber ◽  
Brain Aging ◽  
Synaptic Proteins ◽  
Aging Brain ◽  
Normal Brain ◽  
Fiber Intake ◽  
Synaptic Ultrastructure

Abstract Background Cognitive impairment, an increasing mental health issue, is a core feature of the aging brain and neurodegenerative diseases. Industrialized nations especially, have experienced a marked decrease in dietary fiber intake, but the potential mechanism linking low fiber intake and cognitive impairment is poorly understood. Emerging research reported that the diversity of gut microbiota in Western populations is significantly reduced. However, it is unknown whether a fiber-deficient diet (which alters gut microbiota) could impair cognition and brain functional elements through the gut-brain axis. Results In this study, a mouse model of long-term (15 weeks) dietary fiber deficiency (FD) was used to mimic a sustained low fiber intake in humans. We found that FD mice showed impaired cognition, including deficits in object location memory, temporal order memory, and the ability to perform daily living activities. The hippocampal synaptic ultrastructure was damaged in FD mice, characterized by widened synaptic clefts and thinned postsynaptic densities. A hippocampal proteomic analysis further identified a deficit of CaMKIId and its associated synaptic proteins (including GAP43 and SV2C) in the FD mice, along with neuroinflammation and microglial engulfment of synapses. The FD mice also exhibited gut microbiota dysbiosis (decreased Bacteroidetes and increased Proteobacteria), which was significantly associated with the cognitive deficits. Of note, a rapid differentiating microbiota change was observed in the mice with a short-term FD diet (7 days) before cognitive impairment, highlighting a possible causal impact of the gut microbiota profile on cognitive outcomes. Moreover, the FD diet compromised the intestinal barrier and reduced short-chain fatty acid (SCFA) production. We exploit these findings for SCFA receptor knockout mice and oral SCFA supplementation that verified SCFA playing a critical role linking the altered gut microbiota and cognitive impairment. Conclusions This study, for the first time, reports that a fiber-deprived diet leads to cognitive impairment through altering the gut microbiota-hippocampal axis, which is pathologically distinct from normal brain aging. These findings alert the adverse impact of dietary fiber deficiency on brain function, and highlight an increase in fiber intake as a nutritional strategy to reduce the risk of developing diet-associated cognitive decline and neurodegenerative diseases.

Cognitive impairment persists at least 1 year after juvenile rats are treated with methotrexate

2022 ◽  
pp. 108939
Author(s):  
Jing Wen ◽  
Chadni Patel ◽  
Frank Diglio ◽  
Kayla Baker ◽  
Gregory Marshall ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Juvenile Rats

scholarly journals UV core dimming in coronal streamer belt and the projection effects

2019 ◽  
Vol 623 ◽  
pp. A95 ◽  
Author(s):  
L. Abbo ◽  
S. Giordano ◽  
L. Ofman
Keyword(s):  
Magnetic Structure ◽  
Heavy Ions ◽  
Solar Minimum ◽  
Heavy Ion ◽  
Spectral Lines ◽  
Slow Solar Wind ◽  
Physical Parameters ◽  
Streamer Belt ◽  
Coronal Streamer ◽  
Tilted Dipole

During solar minimum activity, the coronal structure is dominated by a tilted streamer belt, associated with the sources of the slow solar wind. It is known that some UV coronal spectral observations show a quite evident core dimming in heavy ions emission in quiescent streamers. In this paper, our purpose is to investigate this phenomenon by comparing observed and simulated UV coronal ion spectral line intensities. First, we computed the emissivities and the intensities of HI Lyα and OVI spectral lines starting from the physical parameters of a time-dependent 3D three-fluid MHD model of the coronal streamer belt. The model is applied to a tilted dipole (10°) solar minimum magnetic structure. Next, we compared the results obtained from the model in the extended corona (from 1.5 to 4 R⊙) to the UV spectroscopic data from the Ultraviolet Coronagraph Spectrometer (UVCS) onboard SOHO during the minimum of solar activity (1996). We investigate the line-of-sight integration and projection effects in the UV spectroscopic observations, disentangled by the 3D multifluid model. The results demonstrate that the core dimming in heavy ions is produced by the physical processes included in the model (i.e., combination of the effects of heavy ion gravitational settling, and energy exchange of the preferentially heated heavy ions through the interaction with electrons and protons) but it is visible only in some cases where the magnetic structure is simple, such as a (tilted) dipole.

scholarly journals Stopping power of heavy ions in strongly coupled plasmas

1995 ◽  
Vol 13 (2) ◽  
pp. 311-319 ◽  
Author(s):  
G. Zwicknagel ◽  
C. Toepffer ◽  
P.-G. Reinhard
Keyword(s):  
Heavy Ions ◽  
Weak Coupling ◽  
Heavy Ion ◽  
Stopping Power ◽  
Electron Cooling ◽  
Strongly Coupled ◽  
Electron Plasmas ◽  
Coupling Behavior ◽  
Ion Storage ◽  
Coupled Plasmas

We investigate the stopping power of heavy ions in strongly coupled electron plasmas by performing molecular dynamics (MD) computer simulations. A comparison with conventional weak coupling theories shows that these fail in describing the stopping power at low ion velocities and strong coupling. Then nonlinear screening effects become important and this causes a change in the dependence of the stopping power on the ion charge Zp at low ion velocities. From the MD simulation, we find the stopping power to behave like ZP1.43 instead of the weak coupling behavior Zp2 ln(const/Zp). Similar results were recently obtained by experiments in connection with electron cooling at heavy ion storage rings.

scholarly journals Heavy Ion Acceleration at J-PARC

2018 ◽  
Vol 171 ◽  
pp. 21002
Author(s):  
Susumu SATO
Keyword(s):  
High Intensity ◽  
Heavy Ions ◽  
Particle Production ◽  
Heavy Ion ◽  
Proton Accelerator ◽  
Chiral Property ◽  
Region I ◽  
Particle Momentum ◽  
Low Mass ◽  
Frontier Studies

J-PARC, the Japan Proton Accelerator Research Complex, is an accelerator, which provides a high-intensity proton beam. Recently as a very attractive project, the acceleration of heavy ions produced by supplementary ion sources, called J-PARC-HI, is seriously contemplated by domestic as well as international communities. The planned facility would accelerate heavy ions up to U92+ with a beam energy 20 AGeV ([see formula in PDF] of 6.2 AGeV). The highlight of the J-PARC-HI project is its very high beam rate up to ~1011 Hz, which will enable the study of very rare events. Taking advantage of this high intensity, J-PARC-HI will carry out frontier studies of new and rare observables in this energy region: (i) nuclear medium modification of chiral property of vector mesons through low-mass di-lepton signal, (ii) QCD critical pointcharacterization through event-by-event fluctuation signals of particle production, (iii) systematic measurements related to the equation of state through collective flow signal or two-particle momentum correlation signal, or (iv) the search of hyper nuclei with multi strangeness including or exceeding S = 3. The current plan of J-PARC-HI aims to carrying out the first experimental measurements in 2025.

scholarly journals Outflowing protons and heavy ions as a source for the sub-keV ring current

2009 ◽  
Vol 27 (2) ◽  
pp. 839-849 ◽  
Author(s):  
T. T. Giang ◽  
M. Hamrin ◽  
M. Yamauchi ◽  
R. Lundin ◽  
H. Nilsson ◽  
...  
Keyword(s):  
Heavy Ions ◽  
Ring Current ◽  
Particle Interaction ◽  
Heavy Ion ◽  
Local Times ◽  
Cluster Data ◽  
Abstract Data ◽  
Low Altitude ◽  
Field Lines ◽  
Different Characteristics

Abstract. Data from the Cluster CIS instrument have been used for studying proton and heavy ion (O+ and He+) characteristics of the sub-keV ring current. Thirteen events with dispersed heavy ions (O+ and He+) were identified out of two years (2001 and 2002) of Cluster data. All events took place during rather geomagnetically quiet periods. Three of those events have been investigated in detail: 21 August 2001, 26 November 2001 and 20 February 2002. These events were chosen from varying magnetic local times (MLT), and they showed different characteristics. In this article, we discuss the potential source for sub-keV ring current ions. We show that: (1) outflows of terrestrial sub-keV ions are supplied to the ring current also during quiet geomagnetic conditions; (2) the composition of the outflow implies an origin that covers an altitude interval from the low-altitude ionosphere to the plasmasphere, and (3) terrestrial ions are moving upward along magnetic field lines, at times forming narrow collimated beams, but frequently also as broad beams. Over time, the ion beams are expected to gradually become isotropised as a result of wave-particle interaction, eventually taking the form of isotropic drifting sub-keV ion signatures. We argue that the sub-keV energy-time dispersed signatures originate from field-aligned terrestrial ion energising and outflow, which may occur at all local times and persist also during quiet times.

scholarly journals Chondrotoxicity and Toxicokinetics of Sparfloxacin in Juvenile Rats

1998 ◽  
Vol 42 (6) ◽  
pp. 1470-1475 ◽  
Author(s):  
Ralf Stahlmann ◽  
Uta Zippel ◽  
Christian Förster ◽  
Rudolf Schwabe ◽  
Mehdi Shakibaei ◽  
...  
Keyword(s):  
Body Weight ◽  
Oral Dose ◽  
Knee Joint ◽  
Species Differences ◽  
Joint Cartilage ◽  
Juvenile Rats ◽  
Cartilage Lesions ◽  
Old Rats ◽  
Immunohistochemical Studies ◽  
Oral Doses

ABSTRACT Sparfloxacin is a fluoroquinolone with improved antibacterial activity against gram-positive pathogens. Like other quinolones, use of this drug is contraindicated in children and adolescents because of its potential chondrotoxicity in juveniles. We performed histological and immunohistochemical studies on the knee joint cartilage in 5-week-old rats after treatment with 600 or 1,800 mg of sparfloxacin/kg of body weight. Treatment with single or multiple oral doses of 600 mg of sparfloxacin/kg was not sufficient to induce joint cartilage lesions. However, five of eight rats treated with a single oral dose of 1,800 mg of sparfloxacin/kg of body weight showed typical cartilage lesions in the femoral part of the knee joint. The concentrations of the drug in plasma measured 0.25, 0.75, 1.5, 3, 6, 12, and 24 h after the administration of an oral dose of 600 mg of sparfloxacin/kg were 6.3 ± 1.8, 9.2 ± 1.7, 9.6 ± 2.7, 13.0 ± 1.8, 12.3 ± 1.6, 3.4 ± 0.4, and 0.30 ± 0.20 mg/liter, respectively (mean ± standard deviation [SD];n = 5 to 6 per group). The concentrations in plasma measured 0.75, 1.5, 3, 6, 24, and 48 h after the administration of an oral dose of 1,800 mg of sparfloxacin/kg were 10.9 ± 1.5, 15.9 ± 1.6, 19.1 ± 1.7, 14.9 ± 3.1, 4.1 ± 0.6, and 0.46 ± 0.37 mg/liter, respectively (mean ± SD;n = 3 to 4 per group). The concentrations of sparfloxacin in joint cartilage were significantly higher at all time points studied (114.8 ± 80, 99.4 ± 31.5, 84.9 ± 16.8, 44.4 ± 13.9, and 14.2 ± 4.8 mg of sparfloxacin/kg at 1.5, 3, 6, 24, and 48 h after the administration of 1,800 mg/kg, respectively). The range of concentrations in bone were similar to the range of concentrations in cartilage (peak, 115 ± 12 mg/kg after 3 h). Our data indicate that chondrotoxic doses of sparfloxacin in juvenile rats are approximately 300 times higher than the doses of sparfloxacin used therapeutically (1,800 versus approximately 6 mg/kg of body weight), but due to species differences in kinetics, concentrations in plasma differ by a factor of only approximately 15. More data on quinolone concentrations in cartilage from animals and humans could provide a better basis for a reasonable risk assessment.

scholarly journals Experimental investigation of ion beam transport in laser initiated plasma channels

2002 ◽  
Vol 20 (4) ◽  
pp. 559-563 ◽  
Author(s):  
D. PENACHE ◽  
C. NIEMANN ◽  
A. TAUSCHWITZ ◽  
R. KNOBLOCH ◽  
S. NEFF ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Heavy Ions ◽  
Plasma Channel ◽  
Ion Beam ◽  
Heavy Ion ◽  
High Current ◽  
Beam Transport ◽  
Electrode Gap ◽  
Discharge Gap ◽  
The Magnetic Field

The aim of the presented experiments is to study the transport of a heavy ion beam in a high-current plasma channel. The discharge is initiated in NH3 gas at pressures between 2 and 20 mbar by a line-tuned CO2 laser. A stable discharge over the entire electrode gap (0.5 m) was achieved for currents up to 60 kA. Concerning the ion beam transport, the magnetic field distribution inside the plasma channel has to be known. The ion-optical properties of the plasma channel have been investigated using different species of heavy ions (C, Ni, Au, U) with 11.4 MeV/u during six runs at the Gesellschaft für Schwerionenforschungs-UNILAC linear accelerator. The high magnetic field allowed the accomplishment of one complete betatron oscillation along the discharge channel. The results obtained up to now are very promising and suggest that, by scaling the discharge gap to longer distances, the beam transport over several meters is possible with negligible losses.

Membrane architecture with ion-conducting channels through swift heavy ion induced graft copolymerization

2017 ◽  
Vol 5 (47) ◽  
pp. 24826-24835 ◽  
Author(s):  
V. Sproll ◽  
M. Handl ◽  
R. Hiesgen ◽  
K. A. Friedrich ◽  
T. J. Schmidt ◽  
...  
Keyword(s):  
Polymer Film ◽  
Heavy Ions ◽  
Graft Copolymerization ◽  
Heavy Ion ◽  
Proton Conducting ◽  
Swift Heavy Ions ◽  
Swift Heavy Ion ◽  
Ion Conducting ◽  
Subsequent Modification ◽  
Membrane Architecture

Swift heavy ions create tracks of activated material in a polymer film for subsequent modification to form proton conducting channels.

Effect of Cascade Remnants on Freely Migrating Defects in Cu -1 % Au Alloys

1995 ◽  
Vol 396 ◽  
Author(s):  
A. Iwase ◽  
L. E. Rehn ◽  
P. M. Baldo ◽  
L. Funk
Keyword(s):  
Heavy Ions ◽  
Ion Irradiation ◽  
Ion Beam ◽  
Heavy Ion ◽  
The Other ◽  
Inert Gas ◽  
Heavy Ion Irradiation ◽  
Simultaneous Irradiation ◽  
Radiation Induced ◽  
Cu Ions

AbstractThe effects of cascade remnants on Freely Migrating Defects (FMD) were studied by measuring Radiation-Induced Segregation (RIS) in Cu-l%Au at 400°C during simultaneous irradiation with 1.5-MeV He and (400-800)-keV heavy ions (Ne, Ar or Cu). The large RIS observed during 1.5-MeV He-only irradiation was dramatically suppressed under simultaneous heavy ion irradiation. For Cu simultaneous irradiation, the suppression disappeared immediately after the Cu irradiation ceased, while for simultaneous inert gas (Ne or Ar) irradiation, the suppression persisted after the ion beam was turned off. These results demonstrate that the displacement cascades created by heavy ions introduce additional annihilation sites, which reduce the steady-state FMD concentrations. As the cascade remnants produced by Cu ions are thermally unstable at 400°C, the RIS suppression occurs only during simultaneous irradiation. On the other hand, the inert gas atoms which accumulate in the specimen apparently stabilize the cascade remnants, allowing the suppression to persist.

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