Effect of Energy and Dose on Transient-Enhanced Diffusion and Defect Microstructure in Low Energy High Dose As+ Implanted Si

1996 ◽  
Vol 439 ◽  
Author(s):  
V. Krishnamoorthy ◽  
D. Venables ◽  
K. Moeller ◽  
K. S. Jones ◽  
B. Freer
Keyword(s):  
Point Defects ◽  
Surface Recombination ◽  
High Dose ◽  
Enhanced Diffusion ◽  
Projected Range ◽  
Diffusion Enhancement ◽  
Defect Microstructures ◽  
Dose Dependent ◽  
Higher Doses ◽  
Defect Microstructure

Abstract(001) CZ silicon wafers were implanted with arsenic (As+) at energies of 10–50keV to doses of 2x 1014 to 5x1015/cm2. All implants were amorphizing in nature. The samples were annealed at 700°C for 16hrs. The resultant defect microstructures were analyzed by XTEM and PTEM and the As profiles were analyzed by SIMS. The As profiles showed significantly enhanced diffusion in all of the annealed specimens. The diffusion enhancement was both energy and dose dependent. The lowest dose implant/annealed samples did not show As clustering which translated to a lack of defects at the projected range. At higher doses, however, projected range defects were clearly observed, presumably due to interstitials generated during As clustering. The extent of enhancement in diffusion and its relation to the defect microstructure is explained by a combination of factors including surface recombination of point defects, As precipitation, As clustering and end of range damage.

Effect of Energy and Dose on Transient-Enhanced Diffusion and Defect Microstructure in Low Energy High Dose As+ Implanted Si

1996 ◽  
Vol 438 ◽  
Author(s):  
V. Krishnamoorthy ◽  
D. Venables ◽  
K. Moeller ◽  
K. S. Jones ◽  
B. Freer
Keyword(s):  
Point Defects ◽  
Surface Recombination ◽  
High Dose ◽  
Enhanced Diffusion ◽  
Projected Range ◽  
Diffusion Enhancement ◽  
Defect Microstructures ◽  
Dose Dependent ◽  
Higher Doses ◽  
Defect Microstructure

Abstract(001) CZ silicon wafers were implanted with arsenic (As+) at energies of 10–50keV to doses of 2×1014 to 5×1015/cm2. All implants were amorphizing in nature. The samples were annealed at 700°C for 16hrs. The resultant defect microstructures were analyzed by XTEM and PTEM and the As profiles were analyzed by SIMS. The As profiles showed significantly enhanced diffusion in all of the annealed specimens. The diffusion enhancement was both energy and dose dependent. The lowest dose implant/annealed samples did not show As clustering which translated to a lack of defects at the projected range. At higher doses, however, projected range defects were clearly observed, presumably due to interstitials generated during As clustering. The extent of enhancement in diffusion and its relation to the defect microstructure is explained by a combination of factors including surface recombination of point defects, As precipitation, As clustering and end of range damage.

scholarly journals Dose-dependent Effects of Smoked Cannabis on Capsaicin-induced Pain and Hyperalgesia in Healthy Volunteers

2007 ◽  
Vol 107 (5) ◽  
pp. 785-796 ◽  
Author(s):  
Mark Wallace ◽  
Gery Schulteis ◽  
J Hampton Atkinson ◽  
Tanya Wolfson ◽  
Deborah Lazzaretto ◽  
...  
Keyword(s):  
Healthy Volunteers ◽  
Drug Exposure ◽  
Pain Perception ◽  
Experimental Pain ◽  
High Dose ◽  
Significant Difference ◽  
Pain State ◽  
Double Blinded ◽  
Dose Dependent ◽  
Higher Doses

Background Although the preclinical literature suggests that cannabinoids produce antinociception and antihyperalgesic effects, efficacy in the human pain state remains unclear. Using a human experimental pain model, the authors hypothesized that inhaled cannabis would reduce the pain and hyperalgesia induced by intradermal capsaicin. Methods In a randomized, double-blinded, placebo-controlled, crossover trial in 15 healthy volunteers, the authors evaluated concentration-response effects of low-, medium-, and high-dose smoked cannabis (respectively 2%, 4%, and 8% 9-delta-tetrahydrocannabinol by weight) on pain and cutaneous hyperalgesia induced by intradermal capsaicin. Capsaicin was injected into opposite forearms 5 and 45 min after drug exposure, and pain, hyperalgesia, tetrahydrocannabinol plasma levels, and side effects were assessed. Results Five minutes after cannabis exposure, there was no effect on capsaicin-induced pain at any dose. By 45 min after cannabis exposure, however, there was a significant decrease in capsaicin-induced pain with the medium dose and a significant increase in capsaicin-induced pain with the high dose. There was no effect seen with the low dose, nor was there an effect on the area of hyperalgesia at any dose. Significant negative correlations between pain perception and plasma delta-9-tetrahydrocannabinol levels were found after adjusting for the overall dose effects. There was no significant difference in performance on the neuropsychological tests. Conclusions This study suggests that there is a window of modest analgesia for smoked cannabis, with lower doses decreasing pain and higher doses increasing pain.

Transient enhanced diffusion and defect microstructure in high dose, low energy As+ implanted Si

1998 ◽  
Vol 84 (11) ◽  
pp. 5997-6002 ◽  
Author(s):  
V. Krishnamoorthy ◽  
K. Moller ◽  
K. S. Jones ◽  
D. Venables ◽  
J. Jackson ◽  
...  
Keyword(s):  
Low Energy ◽  
High Dose ◽  
Enhanced Diffusion ◽  
Transient Enhanced Diffusion ◽  
Defect Microstructure

scholarly journals Tumor-Shed Antigen Affects Antibody Tumor Targeting: Comparison of Two 89Zr-Labeled Antibodies Directed against Shed or Nonshed Antigens

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Jae-Ho Lee ◽  
Heejung Kim ◽  
Zhengsheng Yao ◽  
Lawrence P. Szajek ◽  
Luigi Grasso ◽  
...  
Keyword(s):  
Half Life ◽  
Tumor Targeting ◽  
High Dose ◽  
Distribution Profile ◽  
Tumor Penetration ◽  
Lewis Y Antigen ◽  
Tumor Periphery ◽  
Ideal System ◽  
Dose Dependent ◽  
Higher Doses

We investigated the effect of shed antigen mesothelin on the tumor uptake of amatuximab, a therapeutic anti-mesothelin mAb clinically tested in mesothelioma patients. The B3 mAb targeting a nonshed antigen was also analyzed for comparison. The mouse model implanted with A431/H9 tumor, which expresses both shed mesothelin and nonshed Lewis-Y antigen, provided an ideal system to compare the biodistribution and PET imaging profiles of the two mAbs. Our study demonstrated that the tumor and organ uptakes of 89Zr-B3 were dose-independent when 3 doses, 2, 15, and 60 μg B3, were compared at 24 h after injection. In contrast, tumor and organ uptakes of 89Zr-amatuximab were dose-dependent, whereby a high dose (60 μg) was needed to achieve tumor targeting comparable to the low dose (2 μg) of 89Zr-B3, suggesting that shed mesothelin may affect amatuximab tumor targeting as well as serum half-life. The autoradiography analysis showed that the distribution of 89Zr-B3 was nonuniform with the radioactivity primarily localized at the tumor periphery independent of the B3 dose. However, the autoradiography analysis for 89Zr-amatuximab showed dose-dependent distribution profiles of the radiolabel; at 10 μg dose, the radiolabel penetrated toward the tumor core with its activity comparable to that at the tumor periphery, whereas at 60 μg dose, the distribution profile became similar to those of 89Zr-B3. These results suggest that shed antigen in blood may act as a decoy requiring higher doses of mAb to improve serum half-life as well as tumor targeting. Systemic mAb concentration should be at a severalfold molar excess to the shed Ag in blood to overcome the hepatic processing of mAb-Ag complexes. On the other hand, mAb concentration should remain lower than the shed Ag concentration in the tumor ECS to maximize tumor penetration by passing binding site barriers.

Production of GexSi1−x, and SiC Films on Si Substrates Using Particle-Beam Technologies

1992 ◽  
Vol 281 ◽  
Author(s):  
V. A. Kagadey ◽  
O. B. Ladizhensky ◽  
N. I. Lebedeva ◽  
E. N. Matin ◽  
D. I. Proskurovsky ◽  
...  
Keyword(s):  
Electron Beam ◽  
Point Defects ◽  
Particle Beam ◽  
High Dose ◽  
Si Substrate ◽  
Enhanced Diffusion ◽  
Si Substrates ◽  
Prolonged Annealing ◽  
Sic Films ◽  
High Dose Implantation

ABSTRACTThe paper presents the results of preliminary experiments on the production of GexSi1−x/Si structures using deposition of a thin Ge film on a Si substrate, implantation of Si ions and rapid electron-beam annealing. The conditions under which monocrystalline layers form have been found. It is supposed that the large depth of Ge penetration into Si is due to enhanced diffusion of Ge conditioned by the high density of point defects in the doped Si. It has been established that high-dose implantation of C ions into Si and subsequent electron beam annealing result in the formation of a monocrystalline layer of the SiC phase in the case of pulsed (∼0.7 μs) heating and liquid-phase recrystallisation and a polycrystalline SiC layer in the case of prolonged annealing.

lmmunotoxicological Investigation of SCMF, a New Pyrethroid Pesticide in Mice

1994 ◽  
Vol 13 (5) ◽  
pp. 337-343 ◽  
Author(s):  
Olga Siroki ◽  
L. Institoris ◽  
E. Tatar ◽  
I. Desi
Keyword(s):  
Oral Treatment ◽  
Dose Range ◽  
High Dose ◽  
Experimental Conditions ◽  
Cell Content ◽  
Pyrethroid Pesticide ◽  
Dose Dependent Decrease ◽  
Dose Dependent ◽  
Higher Doses ◽  
Femoral Bone Marrow

The toxicity of a new pyrethroid pesticide Supercypermethrin Forte (SCMF) was studied in male CFLP mice using classic toxicological (body weight, organ weights) and haematological (white blood cell count, haematocrit, nucleated cell content of femoral bone marrow) methods and immune function tests (PFC assay, DTH reaction). Four weeks of oral treatment in a 5 days per week system at doses of 1/10, 1/20, or 1/40 x LD50 did not cause evaluable changes in the measured parameters. When single calculated LD20, LD10, or LD5 doses of SCMF were administered on different days before termination to different groups of mice the two higher doses caused a time- and dose-dependent decrease in the splenic PCF number, Apart from some temporary toxic signs and an increase of haematocrit at the top dose the other examined parameters did not show evaluable changes. Under these experimental conditions toxic changes appeared only at the high dose range and, of those applied, the PFC assay proved to be the most sensitive method for detecting the toxicity of SCMF.

The Embryotoxic and Immunodepressive Effects of Gossypol

1986 ◽  
Vol 14 (03n04) ◽  
pp. 110-115 ◽  
Author(s):  
G.M. Sein ◽  
M. Phil
Keyword(s):  
Parent Compound ◽  
Lymphocyte Transformation ◽  
Immunological Response ◽  
High Dose ◽  
Intragastric Administration ◽  
Humoral Immune ◽  
Pregnant Mice ◽  
Dose Levels ◽  
Dose Dependent ◽  
Higher Doses

The effects of gossypol acetic on pregnancy, embryofoetal development and on some selected parameters of immunological response in mice were studied. Daily intragastric administration of gossypol (50 or 75 mg/kg/day) during day 1-15 of gestation in mice produced a dose-dependent embroyocidal effect (37.8% and 94.5% respectively) of non-viable foetuses. There was a significant reduction in foetal bodyweight when pregnant mice were treated with gossypol, although no foetal abnormalities were observed. Lymphocyte transformation induced by mitogen concanavalin A, was not inhibited by pretreatment with gossypol (25, 50 or 75 mg/kg/day) for 10 weeks. However, both plaque-forming cells to sheep red blood cell immunisation and the total spleen cell population were significantly depressed by higher doses (50 or 75 mg/kg/day) of gossypol. The results of the present study indicate that gossypol is not teratogenic, but exerts embryocidal and a selective depression humoral immune response at high dose levels (50 or 75 mg/kg/day). It is not clear, whether the dose-dependent embryocidal and/or immunodepressive effects of gossypol are mediated by the parent compound or its metabolites, or whether these findings have any clinical relevance.

The Role of Vacancies and Interstitials in Transient Enhanced Diffusion of Arsenic Implanted into Silicon

1997 ◽  
Vol 469 ◽  
Author(s):  
D. Venables ◽  
V. Krishnamoorthy ◽  
H.- J. Gossmann ◽  
A. Lilak ◽  
K. S. Jones ◽  
...  
Keyword(s):  
Fermi Level ◽  
Point Defect ◽  
Boron Diffusion ◽  
Direct Role ◽  
Enhanced Diffusion ◽  
Projected Range ◽  
Transient Enhanced Diffusion ◽  
Diffusion Enhancement ◽  
Recombination Centers

ABSTRACTBoron and antimony doped superlattices (DSLs) were implanted with arsenic at 40 keV to doses of 2×1014 cm−2, 5×1015 cm−2 and 2×1016 cm−2. Increasing the arsenic dose above 5×1015 cm−2 resulted in a reduction in the extent of arsenic transient enhanced diffusion (TED) following annealing at 700°C, 16 hr. Concurrent with this reduction in TED was a reduction in the number of free interstitials beyond the end-of-range, as measured by the boron diffusion enhancement in the doped superlattices. No enhancement in antimony diffusivity was observed in this region, indicating that vacancies play no direct role in the diffusion of arsenic in this region, although an indirect role for vacancies as recombination centers for mobile interstitials is not precluded by these experiments. We conclude that interstitials dominate arsenic diffusion in the end-of-range region and beyond. Interpretation of the DSL data in the projected range region is complicated by Fermi level and segregation effects and no definitive conclusion can be reached about the point defect populations in this region.

Investigation of Lateral and Vertical Profiles Enhanced by Implantation

1995 ◽  
Vol 396 ◽  
Author(s):  
A. Mineji ◽  
K. Hamada ◽  
S. Saito
Keyword(s):  
Point Defects ◽  
Diffusion Control ◽  
High Dose ◽  
Vertical Profiles ◽  
Junction Depth ◽  
Shallow Junction ◽  
Enhanced Diffusion ◽  
Junction Formation ◽  
D Region ◽  
High Dose Implantation

AbstractIn shallow junction formation with junction depth below 0.1μm, enhanced diffusion control is essential. The purpose of this paper is to investigate the B enhanced diffusion by point defects, introduced by high dose implantation with amorphization. Ge ions were implanted to induce amorphization within the S/D region of pMOS. These results were compared with that of the B enhanced diffusion by point defects, induced by Si+ implant with non-amorphization. These results suggest that the B enhanced diffusion in lateral profiles is much smaller, compared with that in vertical profiles, when point defects were introduced by amorphization.

scholarly journals A dose-dependent plasma signature of the safety and immunogenicity of the rVSV-Ebola vaccine in Europe and Africa

2017 ◽  
Vol 9 (385) ◽  
pp. eaaj1701 ◽  
Author(s):  
Angela Huttner ◽  
Christophe Combescure ◽  
Stéphane Grillet ◽  
Mariëlle C. Haks ◽  
Edwin Quinten ◽  
...  
Keyword(s):  
Critical Role ◽  
Vaccine Dose ◽  
High Dose ◽  
Vaccine Response ◽  
African Countries ◽  
Tnf Α ◽  
Vesicular Stomatitis ◽  
Dose Dependent ◽  
Higher Doses ◽  
Site Pain

The 2014–2015 Ebola epidemic affected several African countries, claiming more than 11,000 lives and leaving thousands with ongoing sequelae. Safe and effective vaccines could prevent or limit future outbreaks. The recombinant vesicular stomatitis virus–vectored Zaire Ebola (rVSV-ZEBOV) vaccine has shown marked immunogenicity and efficacy in humans but is reactogenic at higher doses. To understand its effects, we examined plasma samples from 115 healthy volunteers from Geneva who received low-dose (LD) or high-dose (HD) vaccine or placebo. Fifteen plasma chemokines/cytokines were assessed at baseline and on days 1, 2 to 3, and 7 after injection. Significant increases in monocyte-mediated MCP-1/CCL2, MIP-1β/CCL4, IL-6, TNF-α, IL-1Ra, and IL-10 occurred on day 1. A signature explaining 68% of cytokine/chemokine vaccine-response variability was identified. Its score was higher in HD versus LD vaccinees and was associated positively with vaccine viremia and negatively with cytopenia. It was higher in vaccinees with injection-site pain, fever, myalgia, chills, and headache; higher scores reflected increasing severity. In contrast, HD vaccinees who subsequently developed arthritis had lower day 1 scores than other HD vaccinees. Vaccine dose did not influence the signature despite its influence on specific outcomes. The Geneva-derived signature associated strongly (ρ = 0.97) with that of a cohort of 75 vaccinees from a parallel trial in Lambaréné, Gabon. Its score in Geneva HD vaccinees with subsequent arthritis was significantly lower than that in Lambaréné HD vaccinees, none of whom experienced arthritis. This signature, which reveals monocytes’ critical role in rVSV-ZEBOV immunogenicity and safety across doses and continents, should prove useful in assessments of other vaccines.

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