Cusaci Matei - Academia.edu (original) (raw)

Papers by Cusaci Matei

Laser Physics, 2013

ABSTRACT In recent years there has been a large increase in the areas related to developments in ... more ABSTRACT In recent years there has been a large increase in the areas related to developments in the prevention of diseases, especially in explaining the role of oxidative stress. Lipid peroxidation and oxidative stress contributes to morbidity in hemodialysis (HD) patients. It is therefore relevant to analyze the impact of oxidative stress and its related species (ethylene) immediately after dialysis treatment in order to prevent trauma in the renal failure of elderly patients. In this paper we describe recent progress in laser photoacoustic spectroscopy detection of ethylene in renal failure patients. We have found that HD treatment increases ethylene concentration in the exhaled breath of elderly patients and may intensify oxidative stress.

AIP Conference …, 2011

A chi2 minimization algorithm has been developed to extract sub-sampling-time information from di... more A chi2 minimization algorithm has been developed to extract sub-sampling-time information from digitized waveforms, to be used to instrument the future Versatile Array of Neutron Detectors at Low energies. The algorithm performance has been characterized with a fast Arbitrary Function Generator, obtaining time resolution better than 1 ns for signals of amplitudes between 50 mV and 1V, with negligible walk

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2012

ABSTRACT The properties of a novel p-terphenyl neutron detector have been investigated using phot... more ABSTRACT The properties of a novel p-terphenyl neutron detector have been investigated using photon sources and neutrons from a time tagged 252Cf(sf) source. The electron light output scale has been calibrated by comparing the measured detector response to a Monte Carlo generated spectrum folded with a resolution function. Proton light output and efficiency functions have been determined in the energy range 0.8 < En < 4 MeV using the 252Cf(sf) source. The efficiency of the detector has been calculated by comparing the experimental 252Cf(sf) neutron energy spectrum to the Mannhart evaluation. A NE213- equivalent neutron detector has been used to cross-check our method and results. The results show that the p-terphenyl crystal has better energy resolution, increased proton light output and neutron efficiency when compared to a similar size NE213-equivalent neutron detector.

Magnetic …, 1997

The results of an initial study on the feasibility of using the phosphonium analog of choline to ... more The results of an initial study on the feasibility of using the phosphonium analog of choline to follow the metabolism of phosphatidylcholine in tumors in vivo using 31P NMR are reported. C3HIHe mice bearing a mammary carcinoma tumor on the foot pad were fed a choline-free diet supplemented with the phosphonium analog of choline. Metabolites of this compound, including the phosphonium analogs of phosphatidylcholine, phosphocholine, glycerophosphocholine, and betaine were observed noninvasively in vivo in tumors by 31P NMR after 2-3 weeks of feeding. Clearance of these phosphonium-labeled metabolites from tumors was measured after a change to a choline-containing diet. Significant decreases were seen in the levels of the analogs of betaine (P < 0.003) and phosphatidylcholine (P < 0.004) by Day 4. A significant increase in the level of authentic phosphocholine (P < 0.003) occurred over the same time period.

Applied Physics B, 2011

ABSTRACT The application of laser photoacoustic spectroscopy (LPAS) for fast and precise measurem... more ABSTRACT The application of laser photoacoustic spectroscopy (LPAS) for fast and precise measurements of breath biomarkers has opened up new promises for monitoring and diagnostics in recent years, especially because breath test is a non-invasive method, safe, rapid and acceptable to patients. Our study involved assessment of breath ethylene and breath ammonia levels in patients with renal failure receiving haemodialysis (HD) treatment. Breath samples from healthy subjects and from patients with renal failure were collected using chemically inert aluminized bags and were subsequently analyzed using the LPAS technique. We have found out that the composition of exhaled breath in patients with renal failure contains not only ethylene, but also ammonia and gives valuable information for determining efficacy and endpoint of HD. Analysis of ethylene and ammonia traces from the human breath may provide insight into severity of oxidative stress and metabolic disturbances and may ensure optimal therapy and prevention of pathology at patients on continuous HD.

Bulletin of the American …, 2010

The Versatile Array of Neutron Detectors at Low Energies (VANDLE) is being developed to study the... more The Versatile Array of Neutron Detectors at Low Energies (VANDLE) is being developed to study the properties of unstable nuclei via (d,n) reactions and beta-delayed neutron emission. It is composed of scintillator bars of two sizes, 60 cm and 2 m, coupled to photomultiplier tubes. Twenty of ...

Physical review …, 2006

Radiative-particle capture into the first excited, J 0 state of 16 O at 6.049 MeV excitation ener... more Radiative-particle capture into the first excited, J 0 state of 16 O at 6.049 MeV excitation energy has rarely been discussed as contributing to the 12 C; 16 O reaction cross section due to experimental difficulties in observing this transition. We report here measurements of this radiative capture in 12 C; 16 O for center-of-mass energies of E 2:22 MeV to 5.42 MeV at the DRAGON recoil separator. To determine cross sections, the acceptance of the recoil separator has been simulated in GEANT as well as measured directly. The transition strength between resonances has been identified in R-matrix fits as resulting both from E2 contributions as well as E1 radiative capture. Details of the extrapolation of the total cross section to low energies are then discussed [S 6:0 300 25 16 ÿ15 keV b] showing that this transition is likely the most important cascade contribution for 12 C; 16 O.

The (p,alpha) reactions on T=1/2 nuclei like ^23Na, ^27Al, ^31P, and ^35Cl, and the competing (p,... more The (p,alpha) reactions on T=1/2 nuclei like ^23Na, ^27Al, ^31P, and ^35Cl, and the competing (p,gamma) reactions are important for understanding the reaction flow to heavier elements in the rp-process. Previous rate calculations of the ^31P(p,alpha)^28Si reaction were based on indirect information gained from studies of the ^31P(^3He,d)^28S reaction [1]. At ORNL, we measured the energy and strength of the

... JC Blackmon M. Matos (LSU). RL Kozub J. Rogers DJ Sissom (TTU). Reaction cycles in explosive ... more ... JC Blackmon M. Matos (LSU). RL Kozub J. Rogers DJ Sissom (TTU). Reaction cycles in explosive hydrogen burning in novae and X-ray bursts influence both the energy generation and the processing of material to higher masses. ...

... University). C. Matei (Oak Ridge Associated Universities). BH Moazen (University of Tennessee... more ... University). C. Matei (Oak Ridge Associated Universities). BH Moazen (University of Tennessee Knoxville). CD Nesaraja (Oak Ridge National Laboratory). PD O'Malley (Rutgers University). SD Pain (Oak Ridge National Laboratory). WA Peters (Rutgers University). ...

Low-energy resonances in 31P(p, α 28Si and 35Cl(p, α)32S were studied directly in order to gain a... more Low-energy resonances in 31P(p, α 28Si and 35Cl(p, α)32S were studied directly in order to gain a better understanding of reaction cycling in the Si-Ar region in novae. New resonance strengths at E c.m. = 600 and 622 keV in 31P(p, α)28Si were measured (ωγ p, α = (2.2#x00B1;0.7) × 10−2 eV and ωγ p, α = (0.99±0.08) eV, respectively)

... KA Chipps,1 DW Bardayan,2 KY Chae,3,4 JA Cizewski,5 RL Kozub,6 JF Liang,2 C. Matei,7 PD O&#x2... more ... KA Chipps,1 DW Bardayan,2 KY Chae,3,4 JA Cizewski,5 RL Kozub,6 JF Liang,2 C. Matei,7 PD O'Malley,5 SD Pain,2 WA Peters,5 ST Pittman,3 and MS Smith2 1Physics Department, Colorado School of Mines, Golden, Colorado 80401 ... [6] N. de Sereville et al., PoS (NIC XI) 212 ...

DW Bardayan 1, PD O'Malley 2, JC Blackmon 3, KY Chae 4, KA Chipps 5, JA Cizewski 2, R. Hatar... more DW Bardayan 1, PD O'Malley 2, JC Blackmon 3, KY Chae 4, KA Chipps 5, JA Cizewski 2, R. Hatarik 2, KL Jones 4, RL Kozub 6, C. Matei 7, BH Moazen 4, CD Nesaraja 1, SD Pain 1, S. Paulauskas 4, WA Peters 2, ST Pittman 4, KT Schmitt 4, JF Shriner, Jr. 6, and MS Smith 1

The Ne18(alpha,p)Na21 reaction plays a crucial role in the (alpha,p) process, which leads to the ... more The Ne18(alpha,p)Na21 reaction plays a crucial role in the (alpha,p) process, which leads to the rapid proton capture process in x-ray bursts. The reaction rate depends upon properties of Mg22 levels above the alpha threshold at 8.14 MeV. Despite recent studies of these levels, only the excitation energies are known for most with no constraints on the spins. We have

Laser Physics, 2013

ABSTRACT In recent years there has been a large increase in the areas related to developments in ... more ABSTRACT In recent years there has been a large increase in the areas related to developments in the prevention of diseases, especially in explaining the role of oxidative stress. Lipid peroxidation and oxidative stress contributes to morbidity in hemodialysis (HD) patients. It is therefore relevant to analyze the impact of oxidative stress and its related species (ethylene) immediately after dialysis treatment in order to prevent trauma in the renal failure of elderly patients. In this paper we describe recent progress in laser photoacoustic spectroscopy detection of ethylene in renal failure patients. We have found that HD treatment increases ethylene concentration in the exhaled breath of elderly patients and may intensify oxidative stress.

AIP Conference …, 2011

A chi2 minimization algorithm has been developed to extract sub-sampling-time information from di... more A chi2 minimization algorithm has been developed to extract sub-sampling-time information from digitized waveforms, to be used to instrument the future Versatile Array of Neutron Detectors at Low energies. The algorithm performance has been characterized with a fast Arbitrary Function Generator, obtaining time resolution better than 1 ns for signals of amplitudes between 50 mV and 1V, with negligible walk

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2012

ABSTRACT The properties of a novel p-terphenyl neutron detector have been investigated using phot... more ABSTRACT The properties of a novel p-terphenyl neutron detector have been investigated using photon sources and neutrons from a time tagged 252Cf(sf) source. The electron light output scale has been calibrated by comparing the measured detector response to a Monte Carlo generated spectrum folded with a resolution function. Proton light output and efficiency functions have been determined in the energy range 0.8 &lt; En &lt; 4 MeV using the 252Cf(sf) source. The efficiency of the detector has been calculated by comparing the experimental 252Cf(sf) neutron energy spectrum to the Mannhart evaluation. A NE213- equivalent neutron detector has been used to cross-check our method and results. The results show that the p-terphenyl crystal has better energy resolution, increased proton light output and neutron efficiency when compared to a similar size NE213-equivalent neutron detector.

Magnetic …, 1997

The results of an initial study on the feasibility of using the phosphonium analog of choline to ... more The results of an initial study on the feasibility of using the phosphonium analog of choline to follow the metabolism of phosphatidylcholine in tumors in vivo using 31P NMR are reported. C3HIHe mice bearing a mammary carcinoma tumor on the foot pad were fed a choline-free diet supplemented with the phosphonium analog of choline. Metabolites of this compound, including the phosphonium analogs of phosphatidylcholine, phosphocholine, glycerophosphocholine, and betaine were observed noninvasively in vivo in tumors by 31P NMR after 2-3 weeks of feeding. Clearance of these phosphonium-labeled metabolites from tumors was measured after a change to a choline-containing diet. Significant decreases were seen in the levels of the analogs of betaine (P < 0.003) and phosphatidylcholine (P < 0.004) by Day 4. A significant increase in the level of authentic phosphocholine (P < 0.003) occurred over the same time period.

Applied Physics B, 2011

ABSTRACT The application of laser photoacoustic spectroscopy (LPAS) for fast and precise measurem... more ABSTRACT The application of laser photoacoustic spectroscopy (LPAS) for fast and precise measurements of breath biomarkers has opened up new promises for monitoring and diagnostics in recent years, especially because breath test is a non-invasive method, safe, rapid and acceptable to patients. Our study involved assessment of breath ethylene and breath ammonia levels in patients with renal failure receiving haemodialysis (HD) treatment. Breath samples from healthy subjects and from patients with renal failure were collected using chemically inert aluminized bags and were subsequently analyzed using the LPAS technique. We have found out that the composition of exhaled breath in patients with renal failure contains not only ethylene, but also ammonia and gives valuable information for determining efficacy and endpoint of HD. Analysis of ethylene and ammonia traces from the human breath may provide insight into severity of oxidative stress and metabolic disturbances and may ensure optimal therapy and prevention of pathology at patients on continuous HD.

Bulletin of the American …, 2010

The Versatile Array of Neutron Detectors at Low Energies (VANDLE) is being developed to study the... more The Versatile Array of Neutron Detectors at Low Energies (VANDLE) is being developed to study the properties of unstable nuclei via (d,n) reactions and beta-delayed neutron emission. It is composed of scintillator bars of two sizes, 60 cm and 2 m, coupled to photomultiplier tubes. Twenty of ...

Physical review …, 2006

Radiative-particle capture into the first excited, J 0 state of 16 O at 6.049 MeV excitation ener... more Radiative-particle capture into the first excited, J 0 state of 16 O at 6.049 MeV excitation energy has rarely been discussed as contributing to the 12 C; 16 O reaction cross section due to experimental difficulties in observing this transition. We report here measurements of this radiative capture in 12 C; 16 O for center-of-mass energies of E 2:22 MeV to 5.42 MeV at the DRAGON recoil separator. To determine cross sections, the acceptance of the recoil separator has been simulated in GEANT as well as measured directly. The transition strength between resonances has been identified in R-matrix fits as resulting both from E2 contributions as well as E1 radiative capture. Details of the extrapolation of the total cross section to low energies are then discussed [S 6:0 300 25 16 ÿ15 keV b] showing that this transition is likely the most important cascade contribution for 12 C; 16 O.

The (p,alpha) reactions on T=1/2 nuclei like ^23Na, ^27Al, ^31P, and ^35Cl, and the competing (p,... more The (p,alpha) reactions on T=1/2 nuclei like ^23Na, ^27Al, ^31P, and ^35Cl, and the competing (p,gamma) reactions are important for understanding the reaction flow to heavier elements in the rp-process. Previous rate calculations of the ^31P(p,alpha)^28Si reaction were based on indirect information gained from studies of the ^31P(^3He,d)^28S reaction [1]. At ORNL, we measured the energy and strength of the

... JC Blackmon M. Matos (LSU). RL Kozub J. Rogers DJ Sissom (TTU). Reaction cycles in explosive ... more ... JC Blackmon M. Matos (LSU). RL Kozub J. Rogers DJ Sissom (TTU). Reaction cycles in explosive hydrogen burning in novae and X-ray bursts influence both the energy generation and the processing of material to higher masses. ...

... University). C. Matei (Oak Ridge Associated Universities). BH Moazen (University of Tennessee... more ... University). C. Matei (Oak Ridge Associated Universities). BH Moazen (University of Tennessee Knoxville). CD Nesaraja (Oak Ridge National Laboratory). PD O'Malley (Rutgers University). SD Pain (Oak Ridge National Laboratory). WA Peters (Rutgers University). ...

Low-energy resonances in 31P(p, α 28Si and 35Cl(p, α)32S were studied directly in order to gain a... more Low-energy resonances in 31P(p, α 28Si and 35Cl(p, α)32S were studied directly in order to gain a better understanding of reaction cycling in the Si-Ar region in novae. New resonance strengths at E c.m. = 600 and 622 keV in 31P(p, α)28Si were measured (ωγ p, α = (2.2#x00B1;0.7) × 10−2 eV and ωγ p, α = (0.99±0.08) eV, respectively)

... KA Chipps,1 DW Bardayan,2 KY Chae,3,4 JA Cizewski,5 RL Kozub,6 JF Liang,2 C. Matei,7 PD O&#x2... more ... KA Chipps,1 DW Bardayan,2 KY Chae,3,4 JA Cizewski,5 RL Kozub,6 JF Liang,2 C. Matei,7 PD O'Malley,5 SD Pain,2 WA Peters,5 ST Pittman,3 and MS Smith2 1Physics Department, Colorado School of Mines, Golden, Colorado 80401 ... [6] N. de Sereville et al., PoS (NIC XI) 212 ...

DW Bardayan 1, PD O'Malley 2, JC Blackmon 3, KY Chae 4, KA Chipps 5, JA Cizewski 2, R. Hatar... more DW Bardayan 1, PD O'Malley 2, JC Blackmon 3, KY Chae 4, KA Chipps 5, JA Cizewski 2, R. Hatarik 2, KL Jones 4, RL Kozub 6, C. Matei 7, BH Moazen 4, CD Nesaraja 1, SD Pain 1, S. Paulauskas 4, WA Peters 2, ST Pittman 4, KT Schmitt 4, JF Shriner, Jr. 6, and MS Smith 1

The Ne18(alpha,p)Na21 reaction plays a crucial role in the (alpha,p) process, which leads to the ... more The Ne18(alpha,p)Na21 reaction plays a crucial role in the (alpha,p) process, which leads to the rapid proton capture process in x-ray bursts. The reaction rate depends upon properties of Mg22 levels above the alpha threshold at 8.14 MeV. Despite recent studies of these levels, only the excitation energies are known for most with no constraints on the spins. We have