scholarly journals Comparison of low energy and medium energy collimators in the quantitative assessment of 123I-MIBG cardiac sympathetic innervation imaging

2021 ◽  
Vol 22 (Supplement_3) ◽  
Author(s):  
I Casans Tormo ◽  
R Ruiz Granell
Keyword(s):  
Image Quality ◽  
Quantitative Assessment ◽  
Sympathetic Innervation ◽  
High Energy ◽  
Mean Difference ◽  
Low Energy ◽  
Medium Energy ◽  
Cardiac Sympathetic Innervation ◽  
Cardiac Uptake ◽  
Planar Images

Abstract Funding Acknowledgements Type of funding sources: Public hospital(s). Main funding source(s): University Clinic Hospital of Valencia Aim The assessment of cardiac sympathetic innervation by 123I-metayodobenzylguanidine (123I-MIBG) has proved useful in patients with heart failure and neurodegenerative disorders. The standard quantification of global cardiac uptake is to obtain the heart to mediastinum (HM) ratio in planar images, while SPECT images provide better evaluation of regional extent of denervated areas. Although low energy (LE) collimator has been widely used in these patients, septal penetration of high-energy photons of 123I could affect image quality and quantification accuracy. We have compared in the same patients the effect of collimator type on image quality and quantitative assessment of HM ratio. Methods In a group of 14 patients (11 men, 57-77 y/o, 66.4 ± 5.6) submitted for cardiac sympathetic study, we obtained successive planar anterior chest images 4h after the IV administration of 10 mCi of 123I-MIBG with a low-energy-high-resolution (LEHR) and a medium-energy (ME) collimators. Images were obtained with the same gammacamera Brightview Philips for 10 min on 256x256 matrix, with 159 Kev photopeak and unchanged patient position. For quantification of HM ratio, we use in each patient the same manual heart ROI and rectangular upper mediastinum ROI in the two acquired images to obtain the corresponding HM ratio. Results The image quality was better in all the patients with ME collimator acquisition than with LEHR collimator acquisition, and the HM ratio showed higher values with ME: 1.65-2.61 (mean 2.15 ± 0.28) than with LEHR: 1.27-1.85 (mean: 1.51 ± 0.18) with a mean difference of 0.64 ± 0.15 (0.38-0.88) between ME and LEHR and a mean ratio LEHR/ME of 0.70 ± 0.04 (0.64-0.79). In 9 patients with HM ratio ≤ 1.60 obtained from LEHR collimator acquisition, the mean difference with HM ratio obtained with ME collimator was 0.61 ± 0.12 and mean ratio LEHR/ME was 0.69 ± 0.03 and in 5 patients with HM ratio(LEHR) >1.60, mean difference with HM ratio(ME) was 0.69 ± 0.19 and mean ratio LEHR/ME was 0.71 ± 0.02. Conclusion Use of a ME collimator provides better image quality than LEHR collimator in planar images and higher values of HM ratio, providing a more accurate quantification of cardiac uptake in the patients submitted for evaluation of cardiac sympathetic innervation by 123I-MIBG, and could also improve the evaluation of regional impairment and extent of denervated areas by SPECT.

scholarly journals Classification and Application of Tight Gas Wells Based on Cluster Analysis

2021 ◽  
Vol 2095 (1) ◽  
pp. 012099
Author(s):  
Zhenhua Cai ◽  
Chuanshuai Zuo ◽  
Jianying Zhu ◽  
Peng Qin ◽  
Baojiang Duan ◽  
...  
Keyword(s):  
Liquid Medium ◽  
High Energy ◽  
Low Energy ◽  
Production Performance ◽  
Tight Gas ◽  
Medium Energy ◽  
Gas Wells ◽  
Gas Field ◽  
Gas Well ◽  
Production Characteristics

Abstract The tight gas field is greatly affected by pressure in the development process. Due to the different production time and formation pressure of each well in the gas field, the production characteristics of the gas well are obviously different. After the gas well sees water, it is impossible to formulate production measures efficiently and accurately. Therefore, by analyzing the production performance characteristics of gas wells, this paper carries out the classification research of tight gas wells, and formulates the corresponding production measures according to the classification results. Taking gas well energy and liquid production intensity as the reference standard of gas well classification, the dynamic parameter indexes characterizing gas well energy and liquid production intensity are established. Gas wells with different production characteristics are divided into six categories by clustering algorithm: high energy-low liquid, high energy-high liquid, medium energy-low liquid, medium energy high-liquid, low energy-low liquid, low energy-high liquid. Then the classification method of tight gas well is formed. In this paper, 50 wells in Linxing block are selected as the research object. The research results show that most of the wells in Linxing block are located in area V, belonging to low energy and low liquid wells. It is recommended to implement intermittent production. The classification based on gas well energy and liquid production intensity are of guiding significance for the formulation of production measures in the Linxing block.

Long-term effect of selection for litter size and feeding programme on the performance of reproductive rabbit does 1. Pregnancy of multiparous does

2006 ◽  
Vol 82 (5) ◽  
pp. 739-750 ◽  
Author(s):  
F. Quevedo ◽  
C. Cervera ◽  
E. Blas ◽  
M. Baselga ◽  
J. J. Pascual
Keyword(s):  
Litter Size ◽  
High Energy ◽  
Term Effect ◽  
Low Energy ◽  
Medium Energy ◽  
Long Term Effect ◽  
Ad Libitum ◽  
Selection For ◽  
Low Energy Diet

AbstractA total of 166 crossbred does were used to study the possible long term effect of two types of crossbred does (H1 v. H2, old and current generations, respectively) from the cross of different generations of lines selected for litter size, the use of a feeding programme based on a low-energy diet during the rearing and the administration of a high-energy diet during reproductive life, on the performance and body condition of multiparous pregnant does. Selection did not affect the live weight (LW) of does at the effective artificial insemination (AI; 4257 g), the LW change (+12·3 g/day) and food intake (172 g dry matter (DM) per day) until the 28th day of pregnancy. However, H2 does showed greater LW losses during the pre-partum period than H1 does (120+g;P<0·05), perhaps related to their higher prolificacy (+1·1 total pups born;P<0·05). H2 does showed a higher perirenal fat thickness (PFT) at first AI (+0·12 mm;P<0·05) than H1 does, these differences disappearing at effective AI. Females given a high-energy reproduction diet showed a lower LW at effective AI than those receiving a medium-energy diet (4210, 4305 g, respectively;P<0·05). However, type of reproduction diet did not affect the LW and PFT changes of pregnancy does, reaching partum with a similar PFT (8·83 v. 8·93 mm) and maintaining the differences in LW. Pregnant does given high-energy diet consumed 20 g DM and 1·4 g digestible protein per day less than does receiving medium-energy diet until the 28th day of pregnancy, but their digestible energy (DE) intake was significantly higher (+78 kJ DE per day;P<0·05). Does given high-energy diet showed a significantly lower litter size at birth (−0·7 pups;P<0·05), although there were no significant differences in the number of pups born alive (9·54 and 9·76 pups for high and medium-energy diets, respectively). Pups from does given high-energy diet were slightly weightier than those from medium-energy diet (+5·4 g;P<0·05). Multiparous pregnant does that received a low-energy diet ad libitum during the rearing period and first pregnancy showed a higher LW at effective AI (+137 g LW;P<0·05) but a lower PFT (−0·26 mm;P<0·05) than those females that received a medium-energy diet restricted during this same period. These differences were maintained at parturition (+142 g LW and −0·20 mm;P<0·05). Feeding programme during rearing affected neither the food intake of multiparous pregnant does until the 28th day of pregnancy, nor the litter size and weight at birth. The interval between parturitions was not affected by the selection for litter size or the reproduction diet received, but was longer for does that received the low-energy diet ad libitum during the rearing period (+2·9 days;P<0·05). In conclusion, rabbit selection programmes by litter size seem to be working well, but high energy reproduction diets, frequently used to cover their higher energy requirements, must be used carefully out of lactation in the long term to avoid a reduction in litter size.

Low energy vs. high energy depositional settings and related sedimentary bodies in early Senenian rudist bearing carbonate shelves (central-southern Italy)

2001 ◽  
Vol 28 (1) ◽  
pp. 37-40 ◽  
Author(s):  
Gabriele Carannante ◽  
A. Laviano ◽  
D. Ruberti ◽  
Lucia Simone ◽  
G. Sirna ◽  
...  
Keyword(s):  
Southern Italy ◽  
High Energy ◽  
Low Energy ◽  
Depositional Settings

Transportation: Fuel Energies

2017 ◽  
Author(s):  
Peter Rez
Keyword(s):  
Energy Density ◽  
Fossil Fuels ◽  
High Energy ◽  
Ease Of Use ◽  
Low Energy ◽  
High Energy Density ◽  
Nuclear Fuels ◽  
Liquid Hydrocarbons ◽  
Transportation Fuel ◽  
Journey Time

Transportation efficiency can be measured in terms of the energy needed to move a person or a tonne of freight over a given distance. For passengers, journey time is important, so an equally useful measure is the product of the energy used and the time taken for the journey. Transportation requires storage of energy. Rechargeable systems such as batteries have very low energy densities as compared to fossil fuels. The highest energy densities come from nuclear fuels, although, because of shielding requirements, these are not practical for most forms of transportation. Liquid hydrocarbons represent a nice compromise between high energy density and ease of use.

scholarly journals Low-Energy Electron Damage to Condensed-Phase DNA and Its Constituents

2021 ◽  
Vol 22 (15) ◽  
pp. 7879
Author(s):  
Yingxia Gao ◽  
Yi Zheng ◽  
Léon Sanche
Keyword(s):  
Condensed Phase ◽  
Genetic Material ◽  
High Energy ◽  
Dna Lesions ◽  
Low Energy ◽  
Experimental Investigations ◽  
Experimental Conditions ◽  
Strand Breaks ◽  
Sequence Of Events ◽  
Wide Range

The complex physical and chemical reactions between the large number of low-energy (0–30 eV) electrons (LEEs) released by high energy radiation interacting with genetic material can lead to the formation of various DNA lesions such as crosslinks, single strand breaks, base modifications, and cleavage, as well as double strand breaks and other cluster damages. When crosslinks and cluster damages cannot be repaired by the cell, they can cause genetic loss of information, mutations, apoptosis, and promote genomic instability. Through the efforts of many research groups in the past two decades, the study of the interaction between LEEs and DNA under different experimental conditions has unveiled some of the main mechanisms responsible for these damages. In the present review, we focus on experimental investigations in the condensed phase that range from fundamental DNA constituents to oligonucleotides, synthetic duplex DNA, and bacterial (i.e., plasmid) DNA. These targets were irradiated either with LEEs from a monoenergetic-electron or photoelectron source, as sub-monolayer, monolayer, or multilayer films and within clusters or water solutions. Each type of experiment is briefly described, and the observed DNA damages are reported, along with the proposed mechanisms. Defining the role of LEEs within the sequence of events leading to radiobiological lesions contributes to our understanding of the action of radiation on living organisms, over a wide range of initial radiation energies. Applications of the interaction of LEEs with DNA to radiotherapy are briefly summarized.

Fabrication of the narrow size nano curcuminoids emulsion by combining phase inversion temperature and ultrasonication: preparation and bioactivity

2021 ◽  
Author(s):  
Quang Hieu Tran ◽  
Thuy Thanh Ho ◽  
Tu Thanh Nguyen
Keyword(s):  
Energy Method ◽  
Phase Inversion ◽  
Curcuma Longa ◽  
High Energy ◽  
Low Energy ◽  
Inversion Temperature ◽  
Comprehensive Study ◽  
Phase Inversion Temperature

A comprehensive study from Curcuma longa to powder nano curcuminoids has been carried out. Combining of both low energy method (Phase Inversion Temperature) and high-energy method (Ultrasonication), a series of...

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