scholarly journals In-vivo singlet oxygen threshold doses for PDT

2015 ◽  
Vol 4 (1) ◽  
Author(s):  
Timothy C. Zhu ◽  
Michele M. Kim ◽  
Xing Liang ◽  
Jarod C. Finlay ◽  
Theresa M. Busch

AbstractObjective:Dosimetry of singlet oxygen (Material and methods:AnResults:The mean values (standard deviation) of theConclusions:The experimental results of [

Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5109
Author(s):  
Emanuele Rizzuto ◽  
Barbara Peruzzi ◽  
Mariagrazia Giudice ◽  
Enrica Urciuoli ◽  
Erika Pittella ◽  
...  

In this paper, the characterization of the main techniques and transducers employed to measure local and global strains induced by uniaxial loading of murine tibiae is presented. Micro strain gauges and digital image correlation (DIC) were tested to measure local strains, while a moving coil motor-based length transducer was employed to measure relative global shortening. Local strain is the crucial parameter to be measured when dealing with bone cell mechanotransduction, so we characterized these techniques in the experimental conditions known to activate cell mechanosensing in vivo. The experimental tests were performed using tibia samples excised from twenty-two C57BL/6 mice. To evaluate measurement repeatability we computed the standard deviation of ten repetitive compressions to the mean value. This value was lower than 3% for micro strain gauges, and in the range of 7%–10% for DIC and the length transducer. The coefficient of variation, i.e., the standard deviation to the mean value, was about 35% for strain gauges and the length transducer, and about 40% for DIC. These results provided a comprehensive characterization of three methodologies for local and global bone strain measurement, suggesting a possible field of application on the basis of their advantages and limitations.


2009 ◽  
Vol 53 (7) ◽  
pp. 2857-2864 ◽  
Author(s):  
Zheng Ma ◽  
Jiping Wang ◽  
Roger L. Nation ◽  
Jian Li ◽  
John D. Turnidge ◽  
...  

ABSTRACT Nephrotoxicity is an important limitation to the clinical use of colistin against Pseudomonas aeruginosa and other gram-negative pathogens. Previous work reported net tubular reabsorption of colistin by the kidney in vivo, but there is no knowledge of its disposition within the kidney. This study investigated the renal disposition and potential transport mechanisms of colistin in the isolated perfused rat kidney (IPK) model by perfusing with colistin sulfate alone (2 μg/ml) or in the presence of potential inhibitors (tetraethylammonium [TEA], glycine-glycine [Gly-Gly], or hydrochloric acid [HCl]) at three different concentrations. When perfused alone, the renal clearances (CLR) for colistin A and B (the major components of colistin) in control kidneys were constant and low (mean values < 0.05 ml/min throughout the perfusion). The mean clearance ratios [CR, defined as CLR/(f u × GFR), where f u is the fraction of drug unbound in perfusate and GFR is the glomerular filtration rate] were significantly less than 1. It was concluded that there is net tubular reabsorption of colistin, and this exceeded the reabsorption of water. Less than 10% eliminated from perfusate was recovered in urine, suggesting considerable renal accumulation of colistin. The CR values for colistin were significantly increased when perfused with TEA (500 μM), Gly-Gly (833 μM), and HCl (2,500, 5,000, and 10,000 μM). It is proposed that renal reabsorption of colistin may involve organic cation transporters (inhibited by TEA) and peptide transporters (inhibited by Gly-Gly) and that the process is sensitive to the pH of urine.


1963 ◽  
Vol 18 (4) ◽  
pp. 815-817 ◽  
Author(s):  
Earl S. Barker ◽  
Archer P. Crosley ◽  
John K. Clark

Renal respiratory quotient (RQ) has been calculated from data collected in unanesthetized human subjects. In contrast to RQ recently reported on anesthetized dogs, these data do not indicate a mean value greater than 1. Under control conditions in 24 subjects, renal RQ calculated without special corrections averaged 0.88. Correcting for differences in blood flow between renal artery and vein due to urine formation the mean was 0.73, with 95% confidence limits 0.49–0.97. With alkaline urines an additional correction for urinary excretion of CO2 is advised. Excluding procedures known to alkalinize the urine, RQ values were similar in 46 observations after a variety of experimental procedures. Since both numerator and denominator of the ratio involve small differences between large values, small analytical errors can produce large changes indistinguishable from physiologic variation. Therefore mean values rather than individual observations are stressed. While such values in our data appear similar to RQ for other organs and the whole body, they do not preclude considerable anaerobic metabolism. Submitted on August 9, 1962


2002 ◽  
Vol 60 (2A) ◽  
pp. 211-218 ◽  
Author(s):  
Svetlana Agapejev

OBJECTIVES: to propose standardisation of fourth ventricle dimensions and to study its characteristics in neurocysticercosis. METHOD: a control group (CG) constituted by 114 individuals with normal CT, and 80 patients with neurocysticercosis composed the group with neurocysticercosis (GN). Measures of the inner cranial diameter (Cr), fronto-polar distance between both lateral ventricles (FP), antero-posterior (AP) and latero-lateral (LL) fourth ventricle width based the standardisation of six indexes. RESULTS: AP/Cr, AP/LL and AP/FP were the more discriminative indexes, presenting in CG the mean values of 0.063, 0.267 and 0.582, respectively. The indexes in GN had values statistically higher than in CG. From GN, 51patients had increased indexes values above 2 standard deviation of the CG mean. AP/Ll was > or = 1 in 95% of patients with ventricular shunting and in 88% with depression. It also occurred in 73% patients with satisfactory follow-up and in everybody who died. CONCLUSION: AP/Cr, AP/LL and AP/FP may represent fourth ventricle dimensions.


2018 ◽  
Vol 09 (03) ◽  
pp. 298-304 ◽  
Author(s):  
Francis Osita Okpala

ABSTRACT Background: Several attempts (radiographic and nonradiographic) have been made to measure the lumbar lordosis (LL), but the results differ substantially as investigators have used different parameters. Radiography is the gold standard, and the methods include lumbosacral angle (LSA), lumbosacral joint angle (LSJA), Cobb angle, and tangential radiologic assessment of LL (TRALL) angle. The traditional method, the Cobb technique, has a wide range of normal mean values, with a large standard deviation. Using a more reliable radiographic angle will hopefully simply and standardize LL measurement in the diagnosis, treatment, and follow-up of patients. Aim: To compare in normal individuals with fully developed LL the LSA, LSJA, TRALL, and Cobb angles, by determining (a) if any correlation exists between them and (b) the most reliable measures of LL, based on, least (i) number of measurement lines, (ii) range of values, (iii) mean, (iv) standard deviation, and (v) variance. Materials and Methods: The four angles were retrospectively measured in each supine lateral lumbosacral radiograph of 100 males and 100 females, aged 15 years and above. Data were analyzed with IBM SPSS Statistics 23.0 (NY, USA); P < 0.05 was considered statistically significant. Results: No correlation existed between the mean values of the four angles, and in each angle, there was no male-versus-female correlation. LSJA had the best reliability criteria for LL measurement. Conclusion: The mean LSA, LSJA, TRALL, and Cobb angles have no significant Pearson's correlation, and of the four angular measures of LL, LSJA was the most reliable.


1975 ◽  
Vol 26 ◽  
pp. 469
Author(s):  
E. Proverbio ◽  
S. Uras

AbstractIn 1972, Proverbio and Quesada compiled a list of seven homogeneous systems of polar coordinates expressed in tenths of years adopted by different authors. In the paper, the authors try to determine the internal correlation of the different systems of coordinates so as to represent the precision of each series for different frequency ranges. The analysis of the standard deviation of the raw residuals of the differences between the coordinates of each series and the mean values from the smoothed curve of the residuals provided further information about the accuracy of the same series of polar coordinates.


2006 ◽  
Vol 24 (18_suppl) ◽  
pp. 9025-9025
Author(s):  
V. I. Avramis ◽  
E. H. Panosyan ◽  
I. A. Avramis ◽  
F. Dorey ◽  
P. Gaynon

9025 Background: ASNase is an important agent in the treatment of childhood acute lymphoblastic leukemia. Most other chemotherapeutic agents require entry into cells and some variety of activation. ASNase acts unmodulated and totally outside of cells, targeting extracellular ASN and glutamine. Several investigators have described a relationship between ASNase activity and ASN. In vivo, the equilibrium asparagine level depends on the input rate of ASN derived from the nutrients plus the de novo biosynthesis minus its deamination from the serum ASNase activity. Imax is a pharmacodynamic (PD) parameter developed in 1980’s representing the cumulative input of ASN from nutrients and de novo biosynthesis. Of note, glutamine is the amino group source for the synthesis of ASN from aspartate. In Enzyme-substrate relationships a sigmoid relationship exists that reaches a maximum product formation (Imax). We reported a link between Day 14 ASN depletion - not ASNase activity - and response for children with ALL in first marrow relapse (Jarrar et al, 2006). Methods: On CCG-1962, 117 children with standard risk ALL were randomly allocated to native or pegylated ASNase. Relevant PK-PD parameters have been reported (Avramis et al, Blood 2002). ASNase activity was not predictive of EFS. Induction (IND) Day 3 - 24 serum ASN levels were fitted into a PD model and the Imax values were evaluated for 112 patients. Results: The median Imax values were 1E-6 nmoles/ml/min in all 112 (range 2.0E-2 to 1.0E-7) and in the native or PEG-ASNase randomized patients. The mean values were 1.1E-3.1±3E-3 in 112 patients and 1.5E-3±4.0E-3 & 1.1E-3±3.0E-3 nmoles/ml/min in the native or PEG-ASNase randomized patients. We examined EFS by Imax values in lifetable analyses. High Imax values predicted statistically poorer outcome (p<0.00001) with various cut-off values (e.g., Imax ≥1x 10−3 or Imax ≥5 × 10−4 nmoles/ml/min. The effect was similar in the native and pegylated ASNase subsets. ASNase activity was not prognostic. Conclusions: Hence, ASN Imax in serum is a treatment-independent PD prognostic factor in a subset of children with standard risk ALL. Strategies to provide uniform therapeutic effect among patients with differing Imax are under consideration. No significant financial relationships to disclose.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Zahid Hussain Hulio ◽  
Gm Yousufzai ◽  
Wei Jiang

Purpose Pakistan is an energy starving country that needs continuous supply of energy to keep up its economic speed. The aim of this paper is to assess the wind resource and energy potential of Quaidabad site for minimizing the dependence on fuels and improving the environment. Design/methodology/approach The Quaidabad site wind shear coefficient and turbulence intensity factor are investigated. The two-parameter k and c Weibull distribution function is used to analyze the wind speed of site. The standard deviation of the site is also assessed for a period of a year. The wind power density and energy density are assessed for a period of a year. The economic assessment of energy/kWh is investigated for selection of appropriate wind turbine. Findings The mean wind shear coefficient was observed to be 0.2719, 0.2191 and 0.1698 at 20, 40 and 60 m, respectively, for a period of a year. The mean wind speed is found to be 2.961, 3.563, 3.907 and 4.099 m/s at 20, 40, 60 and 80 m, respectively. The mean values of k parameters were observed to be 1.563, 2.092, 2.434 and 2.576 at 20, 40, 60 and 80 m, respectively, for a period of a year. The mean values of c m/s parameter were found to be 3.341, 4.020, 4.408 and 4.625 m/s at 20, 40, 60 and 80 m, respectively, for a period of a year. The major portion of values of standard deviation was found to be in between 0.1 and 2.00 at 20, 40, 60 and 80 m. The wind power density (W/m2) sum total values were observed to be 351, 597, 792 and 923 W/m2 at 20, 40, 60 and 80 m, respectively, for a period of a year. The mean coefficient of variation was found to be 0.161, 0.130, 0.115 and 0.105 at 20, 40, 60 and 80 m, respectively. The sum total energy density was observed to be 1,157, 2,156, 2,970 and 3,778 kWh/m2 at 20, 40, 60 and 80 m, respectively. The economic assessment is showing that wind turbine E has the minimum cost US$0.049/kWh. Originality/value The Quaidabad site is suitable for installing the utility wind turbines for energy generation at the lowest cost.


2011 ◽  
Vol 62 (3) ◽  
pp. 183-189 ◽  
Author(s):  
Kristina A. Szabo ◽  
Colin E. Webber ◽  
Christopher Gordon ◽  
Jonathan D. Adachi ◽  
Richard Tozer ◽  
...  

Purpose The objectives of this study were to utilise the XCT-2000 pQCT scanner to determine the mean values and the reproducibility of in vivo total, trabecular, and cortical volumetric bone measurements at distal and diaphyseal sites of the radius and the tibia, as well as calf muscle and subcutaneous fat areas, in healthy pre- and postmenopausal women. Methods Twenty-nine women (14 premenopausal and 15 postmenopausal) were recruited to participate in this study. Distal and diaphyseal sites of the radius (at 4% and 20% of the length of the radius) and tibia (at 4%, 38%, and 66% of the length of the tibia) were examined. Results The root mean square coefficient of variation for measurements at the distal tibia gave the most favorable reproducibility values for total (1.5%) and trabecular (1.6%) density, whereas the diaphyseal tibia showed the most favorable reproducibility value for cortical density (0.3%). The root mean square coefficients of variation for measurements of muscle and fat cross-sectional areas at the calf were 0.6% and 0.7%, respectively. At the distal tibia, the mean values for total ( P < .05) and trabecular ( P < .01) density were significantly lower in postmenopausal women than in premenopausal women. Conclusions The data presented here indicate that XCT-2000 pQCT scans at the tibia provide highly reproducible measurements of total, cortical, and trabecular bone as well as muscle and fat cross-sectional areas. Furthermore, significant differences in volumetric bone measurements between healthy pre- and postmenopausal women were evident only at the distal tibia, suggesting that this site warrants further study.


1988 ◽  
Vol 65 (1) ◽  
pp. 309-317 ◽  
Author(s):  
M. J. Tobin ◽  
M. J. Mador ◽  
S. M. Guenther ◽  
R. F. Lodato ◽  
M. A. Sackner

Studies of breathing pattern have focused primarily on changes in the mean values of the breathing pattern components, whereas there has been minimal investigation of breath-to-breath variability, which should provide information on the constancy with which respiration is controlled. In this study we examined the variability of breathing pattern both on a breath-to-breath and day-to-day basis by calculating the coefficient of variation (i.e., the standard deviation expressed as a percentage of the mean). By examining breath-to-breath data, we found that the coefficients of variation of tidal volume (VT) and fractional inspiratory time (TI/TT, an index of timing) obtained with an inductive plethysmograph and spirometer were within 1% of each other. Examination of breath-to-breath variability in breathing pattern over a 15-min period in 65 subjects revealed large coefficients of variation, indicating the need to base calculations on a relatively large number of breaths. Less breath-to-breath variability was observed in respiratory frequency [f, 20.8 +/- 11.5% (SD)] and TI/TT (17.9 +/- 6.5%) than in VT (33 +/- 14.9%) and mean inspiratory flow (VT/TI, an index of drive; 31.6 +/- 12.6%; P less than 0.0001). Older subjects (60-81 yr) displayed greater breath-to-breath variability than young subjects (21-50 yr). Use of a mouthpiece did not affect the degree of variability.(ABSTRACT TRUNCATED AT 250 WORDS)


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