scholarly journals Soman hydrolysis catalysed by hypochlorite ions

2021 ◽  
Vol 267 ◽  
pp. 02043
Author(s):  
Mengxue Xu ◽  
Hongpeng Zhang ◽  
Haiyan Zhu ◽  
Lianyuan Wang ◽  
Chaohua Zhou
Keyword(s):  
Rate Constant ◽  
Half Life ◽  
Nerve Agents ◽  
Free Base ◽  
Relevant Research ◽  
Ethanesulfonic Acid

Sarin (GB) and soman (GD) are severely toxic nerve agents that react slowly in water, resulting in long-term poisoning of the water and a serious threat to personnel. Some ions can catalyse GB and GD hydrolysis in water; the relevant research for GB is detailed, whereas that for GD is relatively less so. In this paper, GD hydrolysis catalysed by hypochlorite (ClO−) ions was studied via kinetic experiments. A fluorite-ion-specific electrode was used to monitor F− ions produced, allowing the rate constant and half-life of the GD hydrolysis to be calculated. The results showed that ClO− ions promote GD hydrolysis well; the higher the concentration of ClO−, the faster the GD was hydrolysed. In NaClO solution at pH 8.0 with 3.22×10–3 M ClO− ions, the half-life of GD hydrolysis was 82.5 s, about 875 times shorter than that in water at pH 8.0. The rate constant for catalysis of GD hydrolysis by ClO- ions ++(kc1o−)++ was 2.6 M−1 s−1, about one quarter the value of ++koh− ++but over 1500 times greater than kB and ++kPO4,++ with B representing N-2-hydroxyethylpiperazine-N’-2-ethanesulfonic acid present as a free base; this result indicated that ClO− ions catalyse GD hydrolysis well.

Adipose tissue triglyceride turnover, de novo lipogenesis, and cell proliferation in humans measured with 2H2O

2004 ◽  
Vol 286 (4) ◽  
pp. E577-E588 ◽  
Author(s):  
A. Strawford ◽  
F. Antelo ◽  
M. Christiansen ◽  
M. K. Hellerstein
Keyword(s):  
Cell Proliferation ◽  
Adipose Tissue ◽  
Half Life ◽  
De Novo ◽  
Human Subjects ◽  
De Novo Lipogenesis ◽  
Gas Chromatography Mass Spectrometry ◽  
Distribution Analysis ◽  
Mass Isotopomer Distribution Analysis

The turnover of adipose tissue components (lipids and cells) and the pathways of adipose lipid deposition have been difficult to measure in humans. We apply here a 2H2O long-term labeling technique for concurrent measurement of adipose-triglyceride (TG) turnover, cell (DNA) proliferation, and de novo lipogenesis (DNL). Healthy subjects drank 2H2O (70 ml/day) for 5-9 wk. Subcutaneous adipose tissue aspirates were taken (gluteal, thigh, and flank depots). Deuterium incorporation into TG glycerol (representing all-source TG synthesis), TG palmitate (representing DNL, by mass isotopomer distribution analysis), and DNA (representing cell proliferation) was measured by gas chromatography-mass spectrometry. Subjects tolerated the protocol well, and body 2H2O enrichments were stable. Mean TG-glycerol fractional synthesis was 0.12 (i.e., 12%) with a range of 0.03-0.32 after 5 wk and 0.20 (range 0.08-0.49) after 9 wk (TG half-life 200-270 days). Label decay measurements 5-8 mo after discontinuing 2H2O gave similar turnover estimates. Net lipolysis (TG turnover) was 50-60 g/day. DNL contribution to adipose-TG was 0.04 after 9 wk, representing ∼20% of newly deposited TG. Cell proliferation was 0.10-0.17 after 9 wk (half-life 240-425 days). In summary, long-term 2H2O administration to human subjects allows measurement of the dynamics of adipose tissue components. Turnover of all elements is slow, and DNL contributes ∼20% of new TG.

scholarly journals Effect of Short-term and Long-term Lithium Treatment on Uptake and Retention of 10dine-131 in Rat Thyroid

1988 ◽  
Vol 41 (3) ◽  
pp. 387 ◽  
Author(s):  
D Dhawan ◽  
RR Sharma ◽  
R Sharma ◽  
RJ Dash
Keyword(s):  
Half Life ◽  
Standard Dose ◽  
Lithium Treatment ◽  
Lithium Carbonate ◽  
Thyroid Uptake ◽  
Male Wistar Rats ◽  
Significant Change ◽  
Pelleted Diet ◽  
Rat Thyroid

No significant change occurred in the uptake by the thyroid of male Wistar rats of a standard dose of carrier-free 1311 administered intraperitoneally and its retention by the thyroid, as measured by biological and effective half-life, after feeding these rats a powdered pelleted diet containing lithium carbonate (I . I g per kg of diet) for 7 days. However, continuing this diet for 10 days inhibited thyroid uptake and increased the retention of 131 I. Uptake remained suppressed for up to 4 months after lithium treatment and continuing this treatment for 6 months did not result in any significant change in 1311 uptake by the thryoid. Lithium treatment for 10 days increased the biological and effective half-life of 13l I in the thyroid and this increase continued for the 6 months treatment period. The dose of 13l I delivered to the thyroid was significantly lower after 10 days and I month of lithium treatment but there was no change in this dose after 2 and 4 months of treatment. However, there was a significant increase after 6 months.

scholarly journals LONG-TERM SELECTION RESPONSE FOR 12-DAY LITTER WEIGHT IN MICE

Genetics ◽  
1972 ◽  
Vol 72 (1) ◽  
pp. 129-142
Author(s):  
E J Eisen
Keyword(s):  
Body Weight ◽  
Genetic Correlation ◽  
Half Life ◽  
Selection Process ◽  
Selection Response ◽  
Exponential Model ◽  
Correlated Response ◽  
Term Selection ◽  
Litter Weight

ABSTRACT Long-term selection for increased 12-day litter weight in two replicate lines (W2, W3) of mice resulted in an apparent selection limit at about 17 generations. Quadratic polynomial and exponential models were fitted to the data in order to estimate the plateaued response and half-life of the selection process. Using the polynomial results, the half-life estimates were 4.5 and 8.6 generations for W2 and W3, respectively. The plateaued responses were 5.1 and 5.8 g which, when expressed in phenotypic standard deviation units, became 1.1 and 1.3. The exponential model provides similar estimates. A negative association between 12-day litter weight and fitness was not considered to be an adequate explanation for the plateau since there was no decrease in fertility of the selected lines. Evidence that exhaustion of genetic variability was not the cause of the plateau came from the immediate response to reverse selection. It was proposed that the plateau may be due to a negative genetic correlation between direct and maternal genetic effects, which would be expected to occur after many generations of selection. There were positive correlated responses in both replicates for adult body weight, which was in agreement with the positive genetic correlation between preweaning and postweaning body weight. The expected positive correlated response for number born was realized in only one of the replicates.

Observation of a radical intermediate in the one electron oxidation of 5-methyl-1-thia-5-azacyclooctane by •Br2−

1984 ◽  
Vol 62 (9) ◽  
pp. 1874-1876 ◽  
Author(s):  
Warren Kenneth Musker ◽  
Parminder S. Surdhar ◽  
Rizwan Ahmad ◽  
David A. Armstrong
Keyword(s):  
Aqueous Solution ◽  
Rate Constant ◽  
Half Life ◽  
Cation Radical ◽  
Order Rate Constant ◽  
Type Structure ◽  
Radical Intermediate ◽  
Text Type ◽  
First Order ◽  
The One

The one electron oxidant •Br2− reacts with 5-methyl-1-thia-5-azacyclooctane (4) in aqueous solution at high pH with an overall rate constant of ~2 × 108 M s−1. The radical intermediate produced has a broad maximum at 500 nm with ε = 2400 M−1 cm−1 and at pH 10 decays with a first order rate constant of 2.3 ± 0.3 × 104 s−1, first half-life of 30 ± 5 μs. Its characteristics do not correspond to those of the [Formula: see text] species reported by Asmus and co-workers. The species appears to be the same as the cation radical reported earlier in the one electron oxidation of 4 in acetonitrile. This species is considered to have an [Formula: see text] type structure, which provides transannular stabilization.

scholarly journals Pharmacokinetics of human chorionic gonadotropin after i.m. administration in goats (Capra hircus)

Reproduction ◽  
2012 ◽  
Vol 144 (1) ◽  
pp. 77-81 ◽  
Author(s):  
M Saleh ◽  
M Shahin ◽  
W Wuttke ◽  
M Gauly ◽  
W Holtz
Keyword(s):  
Rate Constant ◽  
Chorionic Gonadotropin ◽  
Human Chorionic Gonadotropin ◽  
Half Life ◽  
Absorption Rate ◽  
Elimination Rate ◽  
Elimination Rate Constant ◽  
Capra Hircus ◽  
Absorption Rate Constant ◽  
Biological Half Life

The present investigation addresses the pharmacokinetics of human chorionic gonadotropin (hCG), intramuscularly (i.m.) administered to goats. Nine pluriparous does of the Boer goat breed, 2–6 years of age and weighing 45–60 kg, were administered 500 IU hCG (2 ml Chorulon) deep into the thigh musculature 18 h after superovulatory FSH treatment. Blood samples were drawn from the jugular vein at 2 h intervals for the first 24 h, at 6 h intervals until 42 h, and at 12 h intervals until 114 h after administration. After centrifugation, plasma hCG concentrations were determined by electrochemiluminescence immunoassay. Pharmacokinetical parameters were as follows: lag time, 0.4 (s.e.m. 0.1) h; absorption rate constant, 0.34 (s.e.m. 0.002) h; absorption half-life, 2.7 (s.e.m. 0.5) h; elimination rate constant, 0.02 (s.e.m. 0.002) h; biological half-life, 39.4 (s.e.m. 5.1) h; and apparent volume of distribution, 16.9 (s.e.m. 4.3) l. The plasma hCG profile was characterized by an absorption phase of 11.6 (s.e.m. 1.8) h and an elimination phase of 70.0 (s.e.m. 9.8) h, with considerable individual variation in bioavailability and pharmacokinetical parameters. Biological half-life was negatively correlated (P<0.05) with peak concentration (r=−0.76), absorption rate constant (r=−0.78), and elimination rate constant (r=−0.87). The results indicate that after rapid absorption, hCG remains in the circulation for an extended period. This has to be taken into account when assessing the stimulatory response to hCG treatment on an ovarian level.

Abstract 034: Characterization of A Novel Maternally Restricted Pro-angiogenic Therapeutic for Preeclampsia

Hypertension ◽  
2016 ◽  
Vol 68 (suppl_1) ◽  
Author(s):  
William H Stewart ◽  
Eric George ◽  
Gene L Bidwell ◽  
Heather Chapman ◽  
Fakhri Mahdi ◽  
...  
Keyword(s):  
Endothelial Dysfunction ◽  
Half Life ◽  
Plasma Concentrations ◽  
Subcutaneous Administration ◽  
Chronic Administration ◽  
Health Concern ◽  
Pathogenic Factors ◽  
Clearance Kinetics

Background: Preeclampsia is a major obstetrical health concern, affecting 5-8% of all pregnancies. Hallmarked by hypertension and endothelial dysfunction the origin of the disease remains obscure, though it is generally accepted that placental insufficiency/ischemia is a central cause. In response, the placenta secretes pathogenic factors, in particular the anti-angiogenic protein sFlt-1. Currently, there is no effective therapy for the management of the preeclampsia patient. We have recently produced a novel synthetic peptide based on placental growth factor (PlGF) which is maternally restricted by fusion to the synthetic carrier elastin like polypeptide (ELP). Here, we describe its in vivo pharmacokinetics and biodistribution. Methods: Fluorescently labeled ELP-PLGF was administered i.v. and blood sampled serially to determine clearance kinetics. Long-term pharmacokinetics and biodistribution was performed after subcutaneous administration of labeled peptide. Measurements were made on serially drawn blood, and in the whole animal by in vivo imaging. Results: ELP-PlGF exhibited markedly more favorable pharmacokinetics than the normal half life of PlGF, with a terminal half-life of ~10 hours as opposed to ~30 minutes for PlGF alone. Chronic administration found highest levels accumulating in placenta and kidney (two favorable targets for preeclampsia) and liver. A single subcutaneous administration at 100mg/kg resulted in sustained therapeutic plasma concentrations for over 10 days. Conclusion: These data demonstrate that ELP-PlGF has favorable pharmacokinetic and biodistribution profiles. Previous data suggest ELP-PlGF directly antagonizes sFlt-1 in culture. Future studies to assess the in vivo effectiveness of ELP-PlGF in managing placental ischemia induced hypertension and endothelial dysfunction are currently in progress. Acknowledgment: This work was supported by NIH grants R0121527 (GLB), T32HL105324 (OCL), P01HL51971, P20GM104357 (EMG), and R00HL116774 (EMG)

Development of a Guinea Pig Model for Low-Dose, Long-Term Exposure to Organophosphorus Nerve Agents

2004 ◽  
Vol 14 (3) ◽  
pp. 183-194 ◽  
Author(s):  
Chessley R. Atchison ◽  
Robert E. Sheridan ◽  
Steven M. Duniho ◽  
Tsung-Ming Shih
Keyword(s):  
Guinea Pig ◽  
Low Dose ◽  
Nerve Agents ◽  
Pig Model ◽  
Organophosphorus Nerve Agents ◽  
Guinea Pig Model

scholarly journals Facile incorporation of technetium into magnetite, magnesioferrite, and hematite by formation of ferrous nitrate in situ: precursors to iron oxide nuclear waste forms

2018 ◽  
Vol 47 (30) ◽  
pp. 10229-10239 ◽  
Author(s):  
Wayne W. Lukens ◽  
Sarah A. Saslow
Keyword(s):  
Iron Oxide ◽  
Fission Product ◽  
Nuclear Waste ◽  
Half Life ◽  
Fission Yield ◽  
Waste Forms ◽  
Nuclear Waste Forms

The fission product, 99Tc, presents significant challenges to the long-term disposal of nuclear waste due to its long half-life, high fission yield, and to the environmental mobility of pertechnetate (TcO4−), the stable Tc species in aerobic environments.

Pharmacokinetics of Intermittent Intraperitoneal Cefazolin in Continuous Ambulatory Peritoneal Dialysis Patients

1999 ◽  
Vol 19 (1) ◽  
pp. 65-70 ◽  
Author(s):  
Harold J. Manley ◽  
George R. Bailie ◽  
Rupesh D. Asher ◽  
George Eisele ◽  
Reginald F. Frye
Keyword(s):  
Body Weight ◽  
Peritoneal Dialysis ◽  
Continuous Ambulatory Peritoneal Dialysis ◽  
Rate Constant ◽  
Half Life ◽  
Elimination Rate ◽  
Pharmacokinetic Parameters ◽  
Number Of Patients ◽  
The Mean ◽  
Concentration Levels

Objective To investigate the pharmacokinetic parameters of intermittent intraperitoneal (IP) cefazolin, and recommend a cefazolin dosing regimen in continuous ambulatory peritoneal dialysis (CAPD) patients. Design Prospective nonrandomized open study. Setting CAPD outpatient clinic in Albany, New York. Patients Seven volunteer CAPD patients without peritonitis. Three of the patients were nonanuric while 4 were anuric. Interventions Cefazolin (15 mg/kg total body weight) was given to each patient during the first peritoneal exchange. Blood and dialysate samples were collected at times 0, 0.5, 1, 2, 3, 6 (end of the first antibiotic-containing dwell), 24, and 48 hours after the administration of IP cefazolin. Urine samples were collected in nonanuric patients over the study period. Results The mean ± SD amount of cefazolin dose absorbed from the dialysate after the 6-hour dwell was 69.7% ± 8.0% of the administered dose. The cefazolin absorption rate constant from dialysate to serum was 0.21 ± 0.1 /hr (absorption half-life 3.5 ± 0.8 hr). The mean serum concentrations reached at 24 and 48 hours were 52.4 ± 3.7 mg/L and 30.3 ± 5.9 mg/L, respectively. The mean dialysate cefazolin concentrations reached at 24 and 48 hours were 15.1 ± 3.4 mg/L and 7.9 ± 1.4 mg/L, respectively. The cefazolin serum elimination rate constant was 0.02 ± 0.01 /hr (elimination half-life 31.5 ± 8.8 hr). The total cefazolin body clearance was 3.4 ± 0.6 mL/min. In the 3 nonanuric patients the mean renal clearance of cefazolin was 0.6 ± 0.4 mL/min. The peritoneal clearance of cefazolin was 1.0 ± 0.3 mL/min. The systemic volume of distribution of cefazolin was 0.2 ± 0.05 L/kg. No statistical difference was detected in pharmacokinetic parameters between anuric and nonanuric patients, although this may be due to the small number of patients in each group. Conclusion A single daily dose of cefazolin dosed at 15 mg/kg actual body weight in CAPD patients is effective in achieving serum concentration levels greater than the minimum inhibitory concentration for sensitive organisms over 48 hours, and dialysate concentration levels over 24 hours. Caution is warranted in extrapolation of dosing recommendations to patients who maintain a significant degree of residual renal function.

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