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Caenorhabditis elegans is a very important model organism in life sciences. C. elegans has been widely used in research on life sciences, especially in drug screening and the mechanism of drugs, thanks to some of their prominent characteristics, including a short life,short generation cycle, and easy culture and observation. Aging is a complex process, which is the result of multiple factors. There are mainly three types of anti-aging signal pathways in C. elegans, including insulin-insulin-like growth factor-1 signal pathway, diet-restricted signaling pathway and mitochondrial respiratory chain/ATP synthesis pathway. In this paper, we reviewed the aging models based on the above three signaling pathways and the progress in anti-aging drugs based on the above aging models. In addition, a number of C. elegans models of aging-related neurodegenerative diseases can be obtained by using transgenic or chemical mutagenesis. Thus, this paper reviewed the transgenic models of C. elegans associated with neurodegenerative diseases, including theα-synuclein transgenic model of Parkinson disease, theβ-amyloid deposition model of Alzheimer disease, and the polyQ of Huntington disease, and summa?rized the effective drugs based on the above disease models. This review will provide reference for the study of C. elegans in the future screening of anti-aging drugs and drug screening for the prevention and treatment of neurodegenerative diseases.
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Objective To analyse the CT radiation dose statistically using the standardized radiation-dose-structured report (RDSR) of digital imaging and communications in medicine (DICOM). Methods Using the self-designed software, 1230 RDSR files about CT examination were obtained searching on the picture archiving and communication system ( PACS ) . The patient dose database was established by combination of the extracted relevant information with the scanned sites. The patients were divided into adult group (over 10 years) and child groups (0-1 year, 1-5 years, 5-10 years) according to the age. The average volume CT dose index ( CTDIvol ) and dose length product ( DLP) of all scans were recorded respectively, and then the effective dose ( E) was estimated. The DLP value at 75% quantile was calculated and compared with the diagnostic reference level ( DRL) . Results In adult group, CTDIvol and DLP values were moderately and positively correlated ( r=0?41 ) , the highest E was observed in upper abdominal enhanced scan, and the DLP value at 75% quantile was 60% higher than DRL. In child group, their CTDIvol in group of 5-10 years was greater than that in groups of 0-1 and 1-5 years ( t=2?42, 2?04, P<0?05);the DLP value was slightly and positively correlated with the age (r=0?16), while E was moderately and negatively correlated with the age ( r = -0?48 ) . Conclusions It is a simple and efficient method to use RDSR to obtain the radiation doses of patients. With the popularization of the new equipment and the application of regionalized medical platform, RDSR would become the main tool for the dosimetric level surveying and individual dose recording.
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Objective To evaluate the feasibility of chest digital tomosynthesis(DTS)for lung lesion screening by comparing the effective dose of chest DTS with chest digital radiography(DR),low-dose MSCT and MSCT examinations.Methods The Fluke lung/chest phantom underwent posterior-anterior (PA),left lateral(LAT)chest DR and DTS with automatic exposure control technique.Using RTI DoseGuard and WinODS,the dose area product(DAP)and effective dose of PA,LAT and total DTS were calculated.CareDose technique was used for MSCT and low-dose MSCT scans,the dose length products (DLP)was acquired.According to the DLP to E(k)conversion coefficient in ICRP 103,the effective dose of low-dose MSCT and MSCT were calculated.Paired t test was used for comparison of the mean effective dose of DTS,DR and low-dose MSCT.Results The mean effective dose was 0.1 3 mSv for chest DR and 0.11 mSv for DTS examination.The mean effective dose of low-dose MSCT and MSCT scans were 1.13 mSv and 6.38 mSv.The effective dose of chest DTS was comparable to that of chest DR,and was approximately 1/10 and 1/60 times lower than that of low-dose MSCT and MSCT scans.There was no statistical difference between chest DTS and DR(t =3.514,P ＞0.01),and there was a significant difference between chest DTS and low-dose MSCT(t =178.769,P ＜0.01).Conclusion DTS is a new X-ray tomography which has the advantage of low radiation dosage in chest examination for lung lesion screening comparing with low-dose MSCT.
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Objective To investigate radiation dose to the patients undergoing interventional radiology and make radiation risk assessment.Methods Data was collected on 198 instances of 10 interventional radiology procedures by using Philips Allura Xper FD20 DSA, which was equipped with the transparent ionization chamber system in compliance with IEC 60601-2.Patient peak skin dose and effective dose were estimated.Results Cumulative fluoroscopy time was 2.1 - 80.9 min, and number of images monitored for PSD were above 1 Gy and 79 cases monitored for E were above 20 mSv.Conclusions Substantial number of cases exceeded the dose threshold for erythema.Due attention should be paid to radiation protection of patients.
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Objective To study the development of medical imaging in Shandong province and identify existing problems. Methods 378 secondary hospitals and above were surveyed with questionnaires and other means for a general picture of their radiology departments. The survey covered medical imaging examinations, human resources and equipment configurations. Results The recent five years have found a rapid growth of a variety of medical imaging examinations, digital imaging in dominance, high-end equipments as the mainstream, sufficient staffing, shortage of high-level talents in these hospitals. Conclusion The medical imaging examinations should be regarded as justified and reasonable, the competence of hospital staff should be upgraded, and operation of medical imaging examinations should be normalized.
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Objective To evaluate diagnostic accuracy of image interpretation using viewboxes at different luminance with ALVIM statistical phantom (TRG).Methods A digital film of TRG image was obtained by exposing the phantom of TRG with Kodak DR 3000 using proper parameter.Viewboxes with three different luminance were selected from those used in daily work.The film of TRG was evaluated with these viewboxes of three different luminance by three different radiologists with experience of five,eight and sixteen years respectively.A grade scale of 5 was used to evaluate each row of signal and noise.According to the results and formula,the probabilities of true-positive [P (S/s)],false-positive [P (S/n)] and true answer(Pdet) were obtained. Results The three kinds of luminance used in viewboxes were: (3489 ± 256),(2231 ± 220),(816 ± 168) cd/m2.When the average luminance of viewbox was 3489 cd/m2,Pdet of 0.6,0.7,0.8 mm in bone substitute was 0.558±0.009,0.788±0.008,0.813±0.006,Pdet of0.9,1.0,1.2 mm in muscle substitute was 0.663 ± 0.010,0.750 ± 0.008,0.933 ± 0.005 ; When the average luminance of viewbox was 2231 cd/m2 ,Pdet of 0.6,0.7,0.8 mm in bone substitute was 0.525 ± 0.013,0.713 ± 0.013,0.775 ± 0.016,Pdet of 0.9,1.0,1.2 mm in muscle substitute was 0.613 ± 0.019,0.650 ± 0.013,0.850±0.019 ;When the average luminance of viewbox was 816 cd/m2 ,Pdet of 0.6,0.7,0.8 mm in bone substitute was 0.475 ± 0.022,0.550 ± 0.018,0.688±0.020,Pdet of 0.9,1.0,1.2 mm in muscle substitute was 0.550 ± 0.025,0.575 ± 0.021,0.725 ± 0.016. Viewboxes of different luminance were compared to one another by paired t-test.The results of comparison all had significant statistical differences (t = 5.057 and 4.681 ,P <0.05).Conclusions The image displayed by viewboxes at different luminance had significant influence on image interpretation. The higher the luminace of viewbox,the richer the information displayed,and the higher the accuracy of diagnosis.
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Objective To investigate the value of MSCT in evaluating pulmonary functional changes in silicosis.Methods 56 cases of silicosis and 10 healthy people(as control group) underwent inspiratory and expiratory MSCT scans and pulmonary functional test one week later.The CT findings including silicotic nodules,large opacity,emphysema,reticular opacities,bronchiectasis and air trapping were recorded and graded subjectively on CT images.Air retention and emphysema were quantified using the software of Pulmo.CT scores were correlated with spirometric findings by using spearman rank correlative analysis in comparison with pulmonary functional index.Results The scores of CT features except for reticular shadows were of significant difference between silicotic group and control group,but not between simple silicotic group and complex silicotic group.The scores of air retention and emphysema on CT were significantly negative correlation.The reticular shadows were of positive correlation with FEF 75%,FEF 50% and FEV1,but on correlation with FEV1/FVC.There were no correlation between the scores of silicotic nodules,bronchiectasis,large shadows and pulmonary functional test.There was obvious correlation between air retention,the scores of emphysema on CT and the index of pulmonary function in obstruction of small airway.Conclusion MSCT is of important value in evaluating the damage of pulmonary function in silicosis.