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The diverse thermophilic strains of Thermoanaerobacter, serving as unique platforms with a broad range of application in biofuels and chemicals, have received wide attention from scholars and practitioners. Although biochemical experiments and genome sequences have been reported for a variety of Thermoanaerobacter strains, an efficient genetic manipulation system remains to be established for revealing the biosynthetic pathways of Thermoanaerobacter. In line with this demand, the clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated (Cas) systems for editing, regulating and targeting genomes have been well developed in thermophiles. Here, we reviewed and discussed the current status, associated challenges, and future perspectives of the construction of thermostable CRISPR/Cas9 genome editing systems for some representative Thermoanaerobacter species. The establishment, optimization, and application of thermostable CRISPR/Cas genome editing systems would potentially provide a foundation for further genetic modification of thermophilic bacteria.
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Bacteria/genetics , CRISPR-Cas Systems/genetics , Gene Editing , GenomeABSTRACT
Objective:To explore the accurate display method of the local structure of small CT nodules in lung.Methods:Close the automatic radiation dose adjustment technique. Keep the thickness of the phantom was 2 mm, the interval between the phantom layers was 2 mm, the pitch was 1, and the reconstructed convoluted nucleus was B80s. Group A controlled the scanning matrix FOV to be 500 mm×500 mm, 400 mm×400 mm, 300 mm×300 mm, 200 mm×200 mm and 100 mm×100 mm, while group B controlled the scanning matrix FOV to be 500 mm×500 mm. Use these parameters to scan the catphan 500 phantom, a routine chest CT conditioned scanning quality control model. The original data raw data were used to reconstruct the FOV to be 400 mm×400 mm, 300 mm×300 mm, 200 mm×200 mm and 100 mm×100 mm under the scanning FOV to be 500 mm×500 mm. All other conditions are consistent. Observe the high contrast resolution module of Catphan 500 phantom, and compare the line logarithms of two groups of images under different scanning FOV or different reconstruction FOV. Thirty-five patients with small pulmonary nodules from February 2018 to March 2018 of the Second Affiliated Hospital of Zhejiang University Medical College were retrospectively collected. The raw data were used to reconstruct the images. The FOV was 320 mm×320 mm in the conventional reconstruction group and 100 mm×100 mm in the local magnification reconstruction group. The subjective score data of the two groups were compared by using rank-sum test.Results:When catphan 500 phantom was used, the number of lines in group A and group B increased gradually with the decreasing of FOV. The subjective score of local magnification reconstruction group (4.77±0.35) was higher than that of conventional reconstruction group (3.86±0.50) and the difference was statistically significant ( Z=-5.763, P<0.05). Conclusion:Local magnification and reconstruction of high-resolution CT images can achieve the same image quality as local magnification, local magnification and reconstruction of image quality is significantly better than simple image magnification.
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Objective@#To explore the accurate display method of the local structure of small CT nodules in lung.@*Methods@#Close the automatic radiation dose adjustment technique. Keep the thickness of the phantom was 2 mm, the interval between the phantom layers was 2 mm, the pitch was 1, and the reconstructed convoluted nucleus was B80s. Group A controlled the scanning matrix FOV to be 500 mm×500 mm, 400 mm×400 mm, 300 mm×300 mm, 200 mm×200 mm and 100 mm×100 mm, while group B controlled the scanning matrix FOV to be 500 mm×500 mm. Use these parameters to scan the catphan 500 phantom, a routine chest CT conditioned scanning quality control model. The original data raw data were used to reconstruct the FOV to be 400 mm×400 mm, 300 mm×300 mm, 200 mm×200 mm and 100 mm×100 mm under the scanning FOV to be 500 mm×500 mm. All other conditions are consistent. Observe the high contrast resolution module of Catphan 500 phantom, and compare the line logarithms of two groups of images under different scanning FOV or different reconstruction FOV. Thirty-five patients with small pulmonary nodules from February 2018 to March 2018 of the Second Affiliated Hospital of Zhejiang University Medical College were retrospectively collected. The raw data were used to reconstruct the images. The FOV was 320 mm×320 mm in the conventional reconstruction group and 100 mm×100 mm in the local magnification reconstruction group. The subjective score data of the two groups were compared by using rank-sum test.@*Results@#When catphan 500 phantom was used, the number of lines in group A and group B increased gradually with the decreasing of FOV. The subjective score of local magnification reconstruction group (4.77±0.35) was higher than that of conventional reconstruction group (3.86±0.50) and the difference was statistically significant (Z=-5.763, P<0.05).@*Conclusion@#Local magnification and reconstruction of high-resolution CT images can achieve the same image quality as local magnification, local magnification and reconstruction of image quality is significantly better than simple image magnification.
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Objective To evaluate and compare the radiation dose and image quality of the new generation of whole body mobile CT (BodyTom CT) with commonly used fixed CT.Methods The image quality was evaluated with CATPHAN 500 performance test body model.The radiation dose was measured by conventional 100 mm pen ionization chamber and PMMA body phantom and head phantom (head diameter 160 mm,phantom diameter 320 rm and width 140 mm).Results The spatial and contrast resolution of BodyTom CT images were similar to two kinds of fixed CT(P ＞ 0.05).The CNR of image with BodyTom CT decreased by about 20％:In head scan mode,significantly lower than that with Philps 64 slice CT and Toshiba 320 slice CT (with soft,t =-4.82,-6.98,P ＜ 0.05;with standard,t =-20.60,-20.09,P ＜0.05);in body scan mode,significantly lower than that with Philps 64 slice CT and Toshiba 320 slice CT (with soft,t =-5.67,-12.82,P ＜ 0.05;with standard,t =-3.39,-9.18,P ＜ 0.05;with sharp,t =-3.88,-3.21,P ＜0.05).The radiation dose with BodyTom CT was significantly higher than that with fixed CT:in body model,22.97％ than that with Philps 64(t=9.48,P＜0.05),29.6％ than that with Toshiba 320 slice CT(t =11.66,P ＜0.05);in head model,29.76％ than that with Philps 64 slice CT(t=23.44,P＜0.05),33.22％ than that with Toshiba 320 slice CT(t=23.11,P＜0.05).Conclusions The radiation dose with mobile CT was over 20％ higher than that with routine multi-row CT while with the similar image quality.
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Objective To analyze the sites of CT scan and radiation dose to children, and to compare the dose difference between children and others aged above 14 years with the dose-monitoring software in a single scan. Methods A total of 125147 cases undergoing CT scans were selected from Jan 1 to Dec 31, 2016, including 542 in children group and 124605 in patients group aged above 14 years. Based on the self-designed CT dose of real-time detection and management software, the scan sites and the composition of the scanning dose were recorded and compared between children and patients aged above 14 years in a single scan. Results Head (39. 67%) and extremities (36. 90%) were the primary CT scan sites in children. Abdominal (20. 77%) and limbs (48. 87%) constituted the main part of effective dose to children. In children group, the average single DLP gradually increased with age ( Z =21. 42, P <0. 05). The mean DLP was (567. 38 ± 433. 03) mGy·cm and average effective dose (5. 58 ± 5. 45) mSv in children group, significantly lower than that in patients aged above[14 years (737. 75 ± 172. 40) mGy· cm and (11. 07 ± 2. 59) mSv, Z= -3. 74,-4. 12, P<0. 05]. DLPs in patients aged above 14 years were higher than or equal to those in children group, with a few exceptions of neck and limbs with higher values(Z= -2. 04、 -3. 97, P<0. 05). Effective doses in children were higher than or equal to those in the group aged above 14 years(Z= -3. 03, -3. 11, -4. 12,P<0. 05), with an exception of chest with higher value. Conclusions Although the parameters of CT scan and dose control were optimized to some extent in children, radiation protection on children still needs to be paid attention for due to the radiosensitivity of children. CT scanning on children should be more careful.
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Objective To study the impacts of different tube voltage and different noise index(NI) guided automatic tube current modulation on the image quality and radiation dose in cerebrovascular imaging and determine the optimal scanning condition. Methods PH3 angiographic CT head phantom was used for head CTA examination. Scanning protocols: all the scanning objectives were divided into three groups according to the different tube voltages of 80, 100 and 120 kV. Each group applied certain tube current(300,400 mA)and automatic tube current modulation technique with NI from 3 to 10 to perform head CTA. There were 30 scanning proposals with different parameter combinations of tube voltage and tube current. The radiation dose [ CT dose index volume (CTDIvol), dose length product (DLP) and effective dose (ED)], objective indicators of images(CT value of the blood vessels and its noise, CT value of brain tissue and its noise, signal-to-noise ratio , contrast-to-noise ratio) and the subjective scores of the five cerebrovascular segments were recorded. Differences of CT value of the blood vessels and its noise, CT value of brain tissue and its noise, signal-to-noise ratio and contrast-to-noise ratio between different tube voltages and tube currents were analyzed by One-Way ANOVA. Results When the tube voltage was certain, the CTDIvol, DLP and ED were all dropped while NI was increased from 3 to 10. Compared with group(120 kV, 300 mA), CTDIvol of group with 100 kV, 300 mA decreased 35.32%(12.22/34.59), CTDIvol of group(100 kV, NI=6) decreased 46.72%(16.16/34.59). Compared with group(100 kV, 300 mA), CTDIvol of group (100 kV, NI=6) decreased 17.61%(3.94/22.37). When the tube voltage was certain and the tube current and NI were not certain, there is no statistical difference (P>0.05) between CT values of blood vessel and brain, while blood vessel noise, noise of brain, SNR and CNR showed statistical difference (P<0.05). When tube current and NI were certain while tube voltage was varied, all objective indicators discussed above all exhibited statistical difference (P<0.05). SNR and CNR of group(100 kV, NI=6) were higher than group(120 kV, 300 mA) with 6.31%(2.69/42.66)and 7.18%(2.64/36.78), respectively. The tube voltage, NI and tube current had no effect on the subjective scores of first and second grade vessel but greater impact on the fourth and fifth grade vessel. Conclusion In the head CTA scanning, combined the use of NI 6 guided automatic adjustment tube current and low tube voltage(100 kV)technique not only can get better image quality but also significantly decreased the radiation dose.
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Objective To study the impacts of different tube voltage and different noise index(NI) guided automatic tube current modulation on the image quality and radiation dose in cerebrovascular imaging and determine the optimal scanning condition. Methods PH3 angiographic CT head phantom was used for head CTA examination. Scanning protocols: all the scanning objectives were divided into three groups according to the different tube voltages of 80, 100 and 120 kV. Each group applied certain tube current(300,400 mA)and automatic tube current modulation technique with NI from 3 to 10 to perform head CTA. There were 30 scanning proposals with different parameter combinations of tube voltage and tube current. The radiation dose [ CT dose index volume (CTDIvol), dose length product (DLP) and effective dose (ED)], objective indicators of images(CT value of the blood vessels and its noise, CT value of brain tissue and its noise, signal-to-noise ratio , contrast-to-noise ratio) and the subjective scores of the five cerebrovascular segments were recorded. Differences of CT value of the blood vessels and its noise, CT value of brain tissue and its noise, signal-to-noise ratio and contrast-to-noise ratio between different tube voltages and tube currents were analyzed by One-Way ANOVA. Results When the tube voltage was certain, the CTDIvol, DLP and ED were all dropped while NI was increased from 3 to 10. Compared with group(120 kV, 300 mA), CTDIvol of group with 100 kV, 300 mA decreased 35.32%(12.22/34.59), CTDIvol of group(100 kV, NI=6) decreased 46.72%(16.16/34.59). Compared with group(100 kV, 300 mA), CTDIvol of group (100 kV, NI=6) decreased 17.61%(3.94/22.37). When the tube voltage was certain and the tube current and NI were not certain, there is no statistical difference (P>0.05) between CT values of blood vessel and brain, while blood vessel noise, noise of brain, SNR and CNR showed statistical difference (P<0.05). When tube current and NI were certain while tube voltage was varied, all objective indicators discussed above all exhibited statistical difference (P<0.05). SNR and CNR of group(100 kV, NI=6) were higher than group(120 kV, 300 mA) with 6.31%(2.69/42.66)and 7.18%(2.64/36.78), respectively. The tube voltage, NI and tube current had no effect on the subjective scores of first and second grade vessel but greater impact on the fourth and fifth grade vessel. Conclusion In the head CTA scanning, combined the use of NI 6 guided automatic adjustment tube current and low tube voltage(100 kV)technique not only can get better image quality but also significantly decreased the radiation dose.
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BACKGROUND:Transformation growth factor-β(TGF-β) and brain-derived neurotrophic factor (BDNF) are the main regulatory factors in the process of spinal cord injury. There are many researches for TGF-βand BDNF pathogenesis in the spinal cord injury, but the regulation of Ginsenoside Rg1 intervention on TGF-βand BDNF in the spinal cord injury is rarely reported. OBJECTIVE:To observe the effect of Ginsenoside Rg1 intervention on TGF-βand BDNF expression at themolecular protein levels, and to study the protection effect of Ginsenoside Rg1 on the spinal cord and nerve function after spinal cord injury. METHODS:Experimental rats were randomly divided into blank control group, model group and Ginsenoside Rg1 group. In the model and Ginsenoside Rg1 groups, spinal cord injury model was established with the impact method in rats. In the Ginsenoside Rg1 group, rats were intraperitoneal y injected with 10 mg/kg Ginsenoside Rg1 24 hours after modeling, once per day, for 14 days. Rats in the blank control and model groups were injected with equal saline. RESULTS AND CONCLUSION:Compared with the control group, serum malondialdehyde levels increased, the content of superoxide dismutase decreased, TGF-βexpression levels in spinal cord tissue increased, and BDNF expression levels decreased in the model and Ginsenoside Rg1 groups. Compared with the model group, serum malondialdehyde levels decreased, the content of superoxide dismutase increased, TGF-βexpression levels in spinal cord tissue decreased, and BDNF expression levels increased in the Ginsenoside Rg1 group. Ginsenoside Rg1 can protect the injury spinal cord in rats after spinal cord injury.
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BACKGROUND:Chinese herb extracts can restore and protect the nervous system of rats through intervention of neural stem cels. OBJECTIVE:To explore the role of ginsenosides Rg1 in the proliferation and protection of neural stem cels. METHOD:Sprague-Dawley rats at pregnant 19 days were dissected to take out fetal rats, and then the hippocampal tissues from fetal rats were isolated to extract neural stem cels. Neural stem cels were co-cultured with DMEM/F12 medium containing 50 g/L ginsenosides Rg1 as intervention group, with DMEM/F12 medium as blank control group, and with DMEM/F12 containing 0.64% phenol as positive control group, respectively. MTT assay was used to detect the proliferation of neural stem cels in each group, and western blot method to detect the protein expression of brain-derived neurotrophic factor and transforming growth factor-β in neural stem cels. RESULTS AND CONCLUSION:Rat neural stem cels were round single cels with clear border at early period after isolation but at 2 days after inoculation, the cels were adherent and aggregated into smal cel spheres. Compared with the blank control group, the proliferative rate of neural stem cels was significantly increased in the ginsenosides Rg1 group (P < 0.05), but decreased in the positive control group (P < 0.05). Compared with the blank control group, in the ginsenosides Rg1 group, the expression of brain-derived neurotrophic factor was elevated, and the expression of transforming growth factor-β was reduced, indicating ginsenosides Rg1 has a certain effect to promote the proliferation of neural stem cels as wel as to protect the neural stem cels.
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Objective To explore the prognostic effect of fluid-attenuated inversion recovery imaging vascular hyperintensity (FVH)on intravenous thrombolysis of acute ischemic stroke.Methods We retrospectively reviewed the clinical and imaging data of intravenous thrombolytic patients with acute anterior circulation infarction admitted from May 2009 to December 2013.The presence of FVH was evaluated,and its associations with reperfusion and clinical outcome after thrombolysis were assessed.Results Ninety-three patients were analyzed.FVH was detectable in 55 (59.1％) cases.Patients with FVH had higher NIHSS scores (11.8 ± 6.0 vs 7.2 ± 4.5,P ＜ 0.01),larger initial DWI lesions (5.5 ml vs 2.0 ml,Z =-3.030,P=0.002) and perfusion lesions (42.0 ml vs 3.0 ml,Z=-6.104,P =0.005),compared with those without FVH.The history of hyperlipidemia (OR =0.264,95％ CI 0.07-0.90,P =0.048) and proximal large vessel occlusion(OR =48.874,95％ CI 11.6-205.924,P ＜ 0.01) were independently associated with the presence of FVH.The presence of FVH independently predicted the poor neurological outcome at 3 months (OR =4.143,95 ％ CI 1.440-11.919,P =0.008).However,early reperfusion was associated with favorable outcome in patients with FVH after intravenous thrombolysis (OR =8.500,95％ CI 1.964-36.790,P =0.004).Conclusions The presence of FVH is associated with proximal large vessel occlusion,which predicts poor outcome in patients with intravenous thrombolysis.However,early reperfusion among patients with FVH can improve the outcome.
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Objective To evaluate Alberta stroke programme early CT score on diffusion-weighted imaging (DWI-ASPECTS)and clot burden score on MR angiography (MRA-CBS)in predicting hemorrhagic transformation(HT) in acute anterior circulation cerebral infarction after thrombolysis in diffusion-weighted imaging Alberta stroke program.Methods A total of 37 consecutive patients with acute anterior circulation cerebral infarction were treated with thrombolysis.The clinical information , score of DWI-ASPECTS before thrombolysis , score of MRA-CBS before thrombolysis and images of enhanced gradient echo T 2*-weighted angiographywithin ( ESWAN) 24 hours before and after thrombolysis were all collected.The interval between onset and the two MRI scans were recorded respectively.We identified HT according to the images of ESWAN scanned after thrombolysis , and divided patients into 2 groups:with HT(14 cases) and without HT (23 cases).Differences of clinical data and imaging indicators between the two groups were compared by using Fisher′s exact test and Wilcoxon rank sum test.Logistic regression analysis was performed by taking HT as the dependent variable , and the scores of NIHSS , DWI-ASPECTS and MRA-CBS at admission were taken as independent variables.The variables which were statistically significant in logistic regression analysis were enrolled in receiver operating characteristic analysis.Results In HT group, the scores of NIHSS, DWI-ASPECTS and MRA-CBS were 15.00 ±5.30, 6.00(4.75,7.00) and 7.00(0.75,8.50) respectively.In the other group without HT, these scores were 7.00 ±4.80, 9.00(8.00,10.00)and 10.00(6.00,10.00) respectively.Compared with patients without HT , patients with HT had a higher baseline NIHSS score ( Z=-3.72,P<0.01), a lower DWI-ASPECTS (Z=-4.13,P<0.01) and a lower MRA-CBS (Z=-2.00, P<0.05).Logistic regression analysis showed that the scores of DWI-ASPECTS ( OR 0.42,95%CI 0.21-0.87,P <0.05 ) and NIHSS ( OR 1.22, 95%CI 1.00-1.48, P <0.05 ) at baseline predicted HT development independently.Receiver operating characteristic analysis showed that the optimal cut -off point of DWI-ASPECTS to predict the development of HT was≤7.Its sensitivity, specificity and area under ROC curve were 92.9%, 78.3% and 0.902 respectively ( P<0.01 ).Conclusions ASPECTS on DWI is of great value in predicting HT after thrombolysis in acute cerebral infarction.CBS on MRA can provide additional information for predicting HT.
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According to the investigation about the current ability of military hospitals to cope with bioterrorism , we suggest that military hospitals improve the capability for bioterrorism response based on the research above by satisfying mission requirements , combining peacetime with wartime , carrying out crisis management , classifying response and cooperating with local sectors .
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Objectives Through analyzing the published scientific papers from 2001 to 2010 by the professionals of the 31 provincial Center for Disease Control and Prevention in China,offer reference for making plan about scientific research,disciplinary areas,personnel training.Methods Literature quantitative analysis and health statistics methods were used to analyze these papers.Results The professionals in 31 provincial CDC published a total of 22079 papers,Zhejiang 1669(7.56％),Guangxi 1579 (7.15 ％),Jiangsu 1410 (6.39 ％) are the top 3 provinces.The ratio of published papers in Zhonghua medical journal among all the papers are 1366(6.19％),the first three provinces Tianjinlll (13.67％).Beijing160 (13.57％).Shaanxi34 (10.59％).Average papers published by the eastern,central and western regions are 1131,452,444,eastern above western regions (P =0.0065.P =0.0028).Conclusion In recent ten years,the quantity and quality of papers published by the professionals of provincial CDC in China were improved.The unbalanced development exist among eastern,central and western regions,But the majority CDC's papers should be strengthened further.
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Objective To investigate the impact of the pretreatment perfusion weighted imaging (PWI)-diffusion weighted imaging (DWI) mismatch on reperfusion and early neurological improvement after intravenous thrombolysis in acute ischemic stroke.Methods We retrospectively reviewed our collected clinical,laboratory,and radiologic data in patients receiving intravenous recombinant tissue plasminogen activator therapy,who had performed multimodal MRI in both pretreatment and 24 h post-treatment in our hospital..The target mismatch of PWI-DWI was defined as a PWI lesion that was 10 ml or more and 120％ or more of the DWI lesion,with DWI lesion less than 70 ml and PWI lesion less than 140 ml.The smalllesion was defined as a DWI and PWI volume both less than 10 ml.The others were termed non-target mismatch.Reperfusion required a 30％ or greater reduction in PWI lesion volume on the 24-hour follow-up scar.The early neurological improvement was defined as the patients with an NIHSS score of 0 to 4 or 6-point or greater improvement at 7 days.Results Among 45 patients analyzed,19(41％) patients presented target mismatch,of which 8 patients were treated over 4.5 h.The rate of reperfusion and early neurological improvement after thrombolysis in target mismatch group were both significantly increased comparing with non-target mismatch group( 16/19 vs 5/12,x2 =6.092,P ＜0.05 and 13/19 vs 2/12,x2 =7.888,P ＜ 0.05,respectively ),although the recanalization rate demonstrated no significant difference between two groups.The pooled OR for reperfusion was 6.4(95％ CI 1.156-35.437,P =0.034),and the pooled OR for favorable clinical response was 21.7 ( 95％ CI 2.234-210.110,P =0.008 ) in target mismatch patients.Among the target mismatch group,13/16 of patients with reperfusion had early neurological improvement,while no patients without reperfusion had neurological improvement.The rate of recanalization,reperfusion and neurological improvement after thrombolysis demonstrated no significant difference between target mismatch group treated within 4.5 h and beyond 4.5 h.Conclusion Patients with target mismatch profile before thrombolysis had a high reperfusion rate and were prone to get early neurological improvement,indicating that the evaluation of PWI-DWI mismatch may facilitate the selection of patients who may benefit from thrombolysis beyond the time window.
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Objective To study the cumulative radiation dose of multiple trauma patients during their hospitalization and to analyze the dose influece factors.Methods The DLP for CT and DR were retrospectively collected from the patients during June,2009 and April,2011 at a university affiliated hospital.The cumulative radiation doses were calculated by summing typical effective doses of the anatomic regions scanned.Results The cumulative radiation doses of 113 patients were collected.The maximum,minimum and the mean values of cumulative effective doses were 153.3,16.48 mSv and(52.3 ± 26.6) mSv.Conclusions Multiple trauma patients have high cumulative radiation exposure.Therefore,the management of cumulative radiation doses should be enhanced.To establish the individualized radiation exposure archives will be helpful for the clinicians and technicians to make decision wheather to image again and how to select the imaging parameters.
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Attempting to use nonlinear spatiotemporal Lyapunov exponent to characterize fMRI brain functional connectivity of anxiety disease patients, we adopted the methods of nonlinear spatiotemporal Lyapunov exponent and linear correlation coefficients to analyses fMRI datum of 11 anxiety disease patients and 11 healthy volunteers, respectively. The results show that there are significant normalized variance exponent (NVE) differences in Inferior Frontal Gyrus (rIFG) and Medial Frontal Gyrus (MFG) between the two groups (P<0.01). And correlation coefficients shows significant differences (P<0.05). The spatial-temporal Lyapunov exponent method had higher sensitivity than the correlation coefficient method in the characterization of functional connectivity; Anxiety disease patients have abnormal functional connectivity in rIFG and MFG during our experiment.
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Adult , Female , Humans , Male , Middle Aged , Anxiety Disorders , Brain Mapping , Methods , Case-Control Studies , Magnetic Resonance Imaging , Methods , Nonlinear DynamicsABSTRACT
Objective To investigate the radiation doses for the patients undergoing interventional radiology and to analyze the dose - influencing factors.MethodsThe clinical data of 461 patients undergoing interventional radiology,including cerebral angiography ( CEA ),cerebral aneurysm embolism ( CAE ),superselective hepatic arterial chemoembolization ( SHAG ),coronary angiography ( COA ),percutaneous intracoronary stent implantation ( PIS1 ),cardiac radiofrequency catheter ablation ( RFCA ),and permanent cardiac pacemaker implantation(PCPI) were collected to observe the cumulative air kerma (CAK),dose area product (DAP),and fluoroscopy time,and effective dose was estimated using the conversion factors.Results The effective doses for CEA,CAE,SHAG,COA,PISI,RFCA,and PCPI were (0.33 ±0.20),(0.49 ±0.35),(6.92 ±4.19),(0.76 ±0.91),(2.35 ± 1.47),(0.50 ±0.74),and (0.67 ±0.70) Sv,respectively.In 126 of the 416 patients (26%),the effective doses were greater than 1 Sv,and the effective doses of 10 person-times were greater than 10 Sv,all of which were observed in the patients undergoing SHAG.The CAK values for CEA,CAE,SHAG,COA,PISI,RFCA,and PCPIwere (0.55 ±0.43),(1.34 ± 1.11),(0.95 ±0.57),(0.32 ±0.31),(0.91 ±0.33),(0.16 ±0.22),and (0.15 ±0.14) Gy,respectively.The CAK values were greater than 1 Gy in 59 of the 461 patients ( 12.8% ),greater than 2 Gy in 11 cases (2.4%) ,and greater than 3 Gy in 1 CEA cases and 1 CEA case,respectively.Conclusions There is a wide variation range in radiation dose for different procedures.As most interventional radiology procedure can result in clinically significant radiation dose to the patient,stricter dose control should be carried out.
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Objective To explore the optimum exposure factors in digital chest radiography.Methods Chest phantom was exposed under auto exposure control model with 73, 90, 125kV and S200,400,800 plus or minor 4 micro-adjust for each sensitivity grade. Meanwhile dose area product (DAP) was recorded and the value of IQFinv was analyzed automatically by Artinis CDRAD Analyzer 1.1. Ten volunteers were exposed with 73 kV, S800 - 2; 90 kV, S800 + 2 and 125 kV, S400 + 2. Two radiologists evaluated and scored image quality. Statistical analysis was performed using one way ANOVA test by SPSS 12. 0. Results ( 1 ) The quality scores of volunteers' images obtained with three combinations of exposure factors were 2. 7 ± 0. 5 for 73 kV group, 2. 9 ± 0. 3 for 90 kV group and 2. 8 ± 0. 4 for 125 kV group. The difference among them was not statistically significant ( F = 0. 587, P ＞ 0. 05 ). Whereas the DAP values were (29. 1 ± 7.9) mGy · cm2 for 73 kV group, ( 30. 5 ± 4. 5 ) mGy ·cm2 for 90 kV group and (40. 4 ±7.6) mGy · cm2 for 125 kV group, with statistically significant difference among them ( F = 9. 803, P ＜0. 01 ). (2) In all three kV conditions, DAP value of phantom declined when sensitivity increased. There was a difference of DAP value by 11％ between two successive sensitivity grades. Under the condition of same sensitivity, DAP value changed with kV in the following order: 73 kV ＞90 kV ＞ 125 kV. (3) The value of IQFinv decreased when sensitivity increased. Under the condition of same sensitivity, IQFinv changed with kV as follow: 73 kV ＞90 kV ＞ 125 kV. Conclusion The combination of exposure factors of 90 kV and S800 + 2-S800 +4 is optimum for digital chest radiography.
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Objective To investigate the reproducibility and influencing factors of relative quantification of phosphorus metabolites with two-dimensional chemical shift imaging (2D CSI) in rabbit liver. Methods Using 2D CSI MRS, 500 ml phosphate (NaH2PO4) solution phantom with 0. 05 mol/E concentration and one healthy rabbit were scanned 30 times respectively in one day and rescanned 30 times in the next day, and the stability of MR scanner and reproducibility of within-run and between-days in the same individual were analyzed. Each of thirty rabbits was scanned and rescanned one time respectively in different days, and the reproducibility of between-days in one group was analyzed. The data were statistically analyzed with t tests. Results (1) Phosphate solution phantom had a good reproducibility of within-run with the coefficient variation (CV) of 4. 92% and 5. 12% respectively in different two days. No significant change of phosphorus metabolites was detected in between-days, which was 16. 68 ± 0. 82 and 16. 56 ± 0. 85 respectively(t = 0. 665, P > 0. 05 ). (2) The CV of metabolites in one healthy rabbit ranged from 8. 04% to 34. 13%. Among the metabolites, β-ATP had the best reproducibility with the CV less than 10%. PME was 0. 88 ± 0. 28 and 0. 88 ± 0. 30, PDE was 4. 35 ± 0. 66 and 4. 35 ± 0, 66, Pi was 0. 95 ± 0.30 and 0.97±0.28, α-ATP was 5.58±0.60 and 5.61±0.61, β-ATP was 2.70±0.22 and 2.71± 0. 22, γ-ATP was 2. 20±0. 63 and 2. 18±0.44 respectively, no significant changes of metabolites were detected in between-days( P >0. 05 ). (3) The CV of metabolites in 30 healthy rabbits ranged from 8.48% to 36. 21%. Among the metabelites, β-ATP had the best reproducibility with CV less than 10%. PME was 0. 84 ± 0. 30 and 0. 79 ± 0. 28, PDE was 4. 29 ± 0.72 and 3.94 ± 0. 84, Pi was 0. 91 ± 0. 28 and 0. 92 ± 0. 31, α-ATP was 5.65±0. 66 and 5. 36±0. 60, β-ATP was 2. 71±0. 23 and 2. 66±0. 25, γ-ATP was 2. 07±0. 29 and 1.99±0. 37 respectively, no significant changes of metabolites were detected in between-days (P > 0. 05). Conclusions The relative quantification of hepatic β-ATP may be most reliable among the phosphorus metabolites for rabbit liver because of its good reproducibility and small CV. The quantification of phosphorus metabolites by 31p MRS with 2D CSI in rabbit liver is affected by many factors.
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Objective To examine loss of heterozygosity (LOH) and microsatellite instability (MSI) of locus D8S532 on chromosome 8 and their influence on the expression of sFRP1 in the hepatocellular carcinoma (HCCs), which may provide an experimental evidence for clarifying the mechanism of sFRP1 gene and tumor development. Methods DNA was extracted from formalin-fixed paraffin-embedded tissues. Polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) and ordinary silver stain were used to study LOH and MSI of locus D8S532. Envision immunohistochemistry, Leica-Qwin computerized imaging system and Image-Pro PluS (IPP) version 4.5 professional imaging analysis software were used to assess the expression of sFRP1. Results The detection rates of LOH and MSI of locus D8S532 in the 36 specimens of HCC were 11.11% and 8.33% respectively. The down-regulation of sFRP1 was observed in 31 of 36 HCCs (86.11%) compared with non-carcinoma liver tissues, and the positive rate of sFRP1 protein of the HCCs was 52.78%( 19/36 ). The frequency of LOH was lower in the cases with positive expression of sFRP1 protein than those negative (0 vs 23.53%, P <0.05). Conclusion It was a common phenomenon that expression of sFRP1 protein is negative or low in Chinese with HCCs. The genetic instability of sFRP1 gene was one of causes, which lead to HCCs. LOH may play a major role in negative expression of sFRP1.