1,104 research outputs found
Observation of beta decay of In-115 to the first excited level of Sn-115
In the context of the LENS R&D solar neutrino project, the gamma spectrum of
a sample of metallic indium was measured using a single experimental setup of 4
HP-Ge detectors located underground at the Gran Sasso National Laboratories
(LNGS), Italy. A gamma line at the energy (497.48 +/- 0.21) keV was found that
is not present in the background spectrum and that can be identified as a gamma
quantum following the beta decay of In-115 to the first excited state of Sn-115
(9/2+ --> 3/2+). This decay channel of In-115, which is reported here for the
first time, has an extremely low Q-value, Q = (2 +/- 4) keV, and has a much
lower probability than the well-known ground state-ground state transition,
being the branching ratio b = (1.18 +/- 0.31) 10^-6. This could be the beta
decay with the lowest known Q-value. The limit on charge non-conserving beta
decay of In-115 is set at 90% C.L. as tau > 4.1 10^20 y.Comment: 19 pages, 5 figures, 2 table
Differential Responses of Targeted Lung Redox Enzymes to Rat Exposure to 60 or 85% Oxygen
Rat exposure to 60% O2 (hyper-60) or 85% O2 (hyper-85) for 7 days confers susceptibility or tolerance, respectively, of the otherwise lethal effects of exposure to 100% O2. The objective of this study was to determine whether activities of the antioxidant cytosolic enzyme NAD(P)H:quinone oxidoreductase 1 (NQO1) and mitochondrial complex III are differentially altered in hyper-60 and hyper-85 lungs. Duroquinone (DQ), an NQO1 substrate, or its hydroquinone (DQH2), a complex III substrate, was infused into the arterial inflow of isolated, perfused lungs, and the venous efflux rates of DQH2 and DQ were measured. Based on inhibitor effects and kinetic modeling, capacities of NQO1-mediated DQ reduction (Vmax1) and complex III-mediated DQH2 oxidation (Vmax2) increased by ∼140 and ∼180% in hyper-85 lungs, respectively, compared with rates in lungs of rats exposed to room air (normoxic). In hyper-60 lungs, Vmax1 increased by ∼80%, with no effect on Vmax2. Additional studies revealed that mitochondrial complex I activity in hyper-60 and hyper-85 lung tissue homogenates was ∼50% lower than in normoxic lung homogenates, whereas mitochondrial complex IV activity was ∼90% higher in only hyper-85 lung tissue homogenates. Thus NQO1 activity increased in both hyper-60 and hyper-85 lungs, whereas complex III activity increased in hyper-85 lungs only. This increase, along with the increase in complex IV activity, may counter the effects the depression in complex I activity might have on tissue mitochondrial function and/or reactive oxygen species production and may be important to the tolerance of 100% O2 observed in hyper-85 rats
Distribution of Capillary Transit Times in Isolated Lungs of Oxygen-Tolerant Rats
Rats pre-exposed to 85% O2 for 5–7 days tolerate the otherwise lethal effects of 100% O2. The objective was to evaluate the effect of rat exposure to 85% O2 for 7 days on lung capillary mean transit time (t¯c) and distribution of capillary transit times (h c(t)). This information is important for subsequent evaluation of the effect of this hyperoxia model on the redox metabolic functions of the pulmonary capillary endothelium. The venous concentration vs. time outflow curves of fluorescein isothiocyanate labeled dextran (FITC-dex), an intravascular indicator, and coenzyme Q1 hydroquinone (CoQ1H2), a compound which rapidly equilibrates between blood and tissue on passage through the pulmonary circulation, were measured following their bolus injection into the pulmonary artery of isolated perfused lungs from rats exposed to room air (normoxic) or 85% O2 for 7 days (hyperoxic). The moments (mean transit time and variance) of the measured FITC-dex and CoQ1H2 outflow curves were determined for each lung, and were then used in a mathematical model [Audi et al. J. Appl. Physiol. 77: 332–351, 1994] to estimate t¯c and the relative dispersion (RDc) of h c(t). Data analysis reveals that exposure to hyperoxia decreases lung t¯c by 42% and increases RDc, a measure h c(t) heterogeneity, by 40%
In vivo Detection of Hyperoxia-induced Pulmonary Endothelial Cell Death Using \u3csup\u3e99m\u3c/sup\u3eTc-Duramycin
Introduction 99mTc-duramycin, DU, is a SPECT biomarker of tissue injury identifying cell death. The objective of this study is to investigate the potential of DU imaging to quantify capillary endothelial cell death in rat lung injury resulting from hyperoxia exposure as a model of acute lung injury. Methods Rats were exposed to room air (normoxic) or \u3e 98% O2 for 48 or 60 hours. DU was injected i.v. in anesthetized rats, scintigraphy images were acquired at steady-state, and lung DU uptake was quantified from the images. Post-mortem, the lungs were removed for histological studies. Sequential lung sections were immunostained for caspase activation and endothelial and epithelial cells. Results Lung DU uptake increased significantly (p \u3c 0.001) by 39% and 146% in 48-hr and 60-hr exposed rats, respectively, compared to normoxic rats. There was strong correlation (r2 = 0.82, p = 0.005) between lung DU uptake and the number of cleaved caspase 3 (CC3) positive cells, and endothelial cells accounted for more than 50% of CC3 positive cells in the hyperoxic lungs. Histology revealed preserved lung morphology through 48 hours. By 60 hours there was evidence of edema, and modest neutrophilic infiltrate. Conclusions Rat lung DU uptake in vivo increased after just 48 hours of \u3e 98% O2 exposure, prior to the onset of any substantial evidence of lung injury. These results suggest that apoptotic endothelial cells are the primary contributors to the enhanced DU lung uptake, and support the utility of DU imaging for detecting early endothelial cell death in vivo
Optical Imaging of Lipopolysaccharide-induced Oxidative Stress in Acute Lung Injury from Hyperoxia and Sepsis
Reactive oxygen species (ROS) have been implicated in the pathogenesis of many acute and chronic pulmonary disorders such as acute lung injury (ALI) in adults and bronchopulmonary dysplasia (BPD) in premature infants. Bacterial infection and oxygen toxicity, which result in pulmonary vascular endothelial injury, contribute to impaired vascular growth and alveolar simplification seen in the lungs of premature infants with BPD. Hyperoxia induces ALI, reduces cell proliferation, causes DNA damage and promotes cell death by causing mitochondrial dysfunction. The objective of this study was to use an optical imaging technique to evaluate the variations in fluorescence intensities of the auto-fluorescent mitochondrial metabolic coenzymes, NADH and FAD in four different groups of rats. The ratio of these fluorescence signals (NADH/FAD), referred to as NADH redox ratio (NADH RR) has been used as an indicator of tissue metabolism in injuries. Here, we investigated whether the changes in metabolic state can be used as a marker of oxidative stress caused by hyperoxia and bacterial lipopolysaccharide (LPS) exposure in neonatal rat lungs. We examined the tissue redox states of lungs from four groups of rat pups: normoxic (21% O2) pups, hyperoxic (90% O2) pups, pups treated with LPS (normoxic + LPS), and pups treated with LPS and hyperoxia (hyperoxic + LPS). Our results show that hyperoxia oxidized the respiratory chain as reflected by a ~ 31% decrease in lung tissue NADH RR as compared to that for normoxic lungs. LPS treatment alone or with hyperoxia had no significant effect on lung tissue NADH RR as compared to that for normoxic or hyperoxic lungs, respectively. Thus, NADH RR serves as a quantitative marker of oxidative stress level in lung injury caused by two clinically important conditions: hyperoxia and LPS exposure
Beta decay of 115-In to the first excited level of 115-Sn: Potential outcome for neutrino mass
Recent observation of beta decay of 115-In to the first excited level of
115-Sn with an extremely low Q_beta value (Q_beta ~ 1 keV) could be used to set
a limit on neutrino mass. To give restriction potentially competitive with
those extracted from experiments with 3-H (~2 eV) and 187-Re (~15 eV), atomic
mass difference between 115-In and 115-Sn and energy of the first 115-Sn level
should be remeasured with higher accuracy (possibly of the order of ~1 eV).Comment: 9 pages, 3 figures; talk at the NANP'05 Conferenc
PEMBUATAN SISTEM INFORMASI MANAJEMEN PADA ORGANISASI EXCELLENT LEADER TRAINING
ELT (Excellent Leader Training) merupakan organisasi berfokus pada pelatihan kepemimpinan. ELT sendiri sudah menjangkau hampir seluruh indonesia akan tetapi ELT masih belum memiliki sistem yang mengatur data mereka dengan, sehingga yang terjadi adalah banyak data yang menjadi tidak akurat. Rekam jejak member yang pernah menjadi panitia atau peserta pun tidak tersimpan dengan baik. Hal ini menyusahkan administrator jika memerlukan informasi tersebut. Tujuan peneilitian ini adalah untuk membangun sebuah sistem informasi manajemen yang dapat memudahkan administrator maupun member untuk dapat melihat data rekam jejak setiap member dan menjadikan data tersebut akurat. Di sisi lain, sistem ini akan menangani banyak informasi dan informasi tersebut akan lebih mudah tersampaikan kepada member, sehingga member pun tidak kebingungan dalam mencari informasi
PEMBUATAN SISTEM INFORMASI MANAJEMEN PADA ORGANISASI EXCELLENT LEADER TRAINING
ELT (Excellent Leader Training) merupakan organisasi berfokus pada pelatihan kepemimpinan. ELT sendiri sudah menjangkau hampir seluruh indonesia akan tetapi ELT masih belum memiliki sistem yang mengatur data mereka dengan, sehingga yang terjadi adalah banyak data yang menjadi tidak akurat. Rekam jejak member yang pernah menjadi panitia atau peserta pun tidak tersimpan dengan baik. Hal ini menyusahkan administrator jika memerlukan informasi tersebut. Tujuan peneilitian ini adalah untuk membangun sebuah sistem informasi manajemen yang dapat memudahkan administrator maupun member untuk dapat melihat data rekam jejak setiap member dan menjadikan data tersebut akurat. Di sisi lain, sistem ini akan menangani banyak informasi dan informasi tersebut akan lebih mudah tersampaikan kepada member, sehingga member pun tidak kebingungan dalam mencari informasi
PEMBUATAN SISTEM INFORMASI MANAJEMEN PADA ORGANISASI EXCELLENT LEADER TRAINING
ELT (Excellent Leader Training) merupakan organisasi berfokus pada pelatihan kepemimpinan. ELT sendiri sudah menjangkau hampir seluruh indonesia akan tetapi ELT masih belum memiliki sistem yang mengatur data mereka dengan, sehingga yang terjadi adalah banyak data yang menjadi tidak akurat. Rekam jejak member yang pernah menjadi panitia atau peserta pun tidak tersimpan dengan baik. Hal ini menyusahkan administrator jika memerlukan informasi tersebut. Tujuan peneilitian ini adalah untuk membangun sebuah sistem informasi manajemen yang dapat memudahkan administrator maupun member untuk dapat melihat data rekam jejak setiap member dan menjadikan data tersebut akurat. Di sisi lain, sistem ini akan menangani banyak informasi dan informasi tersebut akan lebih mudah tersampaikan kepada member, sehingga member pun tidak kebingungan dalam mencari informasi
Biomarkers for Radiation Pneumonitis Using Noninvasive Molecular Imaging
Our goal is to develop minimally invasive biomarkers for predicting radiation-induced lung injury before symptoms develop. Currently, there are no biomarkers that can predict radiation pneumonitis. Radiation damage to the whole lung is a serious risk in nuclear accidents or in radiologic terrorism. Our previous studies have shown that a single dose of 15 Gy of x-rays to the thorax causes severe pneumonitis in rats by 6–8 wk. We have also developed a mitigator for radiation pneumonitis and fibrosis that can be started as late as 5 wk after radiation. Methods: We used 2 functional SPECT probes in vivo in irradiated rat lungs. Regional pulmonary perfusion was measured by injection of 99mTc-macroaggregated albumin. Perfused volume was determined by comparing the volume of distribution of 99mTc-macroaggregated albumin to the anatomic lung volume obtained by small-animal CT. A second probe, 99mTc-labeled Duramycin, which binds to apoptotic cells, was used to measure pulmonary cell death in the same rat model. Results: The perfused volume of lung was decreased by about 25% at 1, 2, and 3 wk after receipt of 15 Gy, and 99mTc-Duramycin uptake was more than doubled at 2 and 3 wk. There was no change in body weight, breathing rate, or lung histology between irradiated and nonirradiated rats at these times. Pulmonary vascular resistance and vascular permeability measured in isolated perfused lungs ex vivo increased at 2 wk after 15 Gy of irradiation. Conclusion: Our results suggest that SPECT biomarkers have the potential to predict radiation injury to the lungs before substantial functional or histologic damage is observed. Early prediction of radiation pneumonitis in time to initiate mitigation will benefit those exposed to radiation in the context of therapy, accidents, or terrorism
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