Objective:To measure CT linearity and evaluate if it would show linear relationship between coefficient and attenuation.Methods:The Catphan phantom was used to measure CT linearity in 18 computed tomography equipments,and the results were calculated.Results:(1)The CT linearity were qualified in 14 equipment but 4.Conclusion:(1)There are many factors which affect CT linearity.The artifact will be produced if the CT linearity is unqualified.(2)CT linearity must be calibrated periodically to assure the stability of the CT linearity and to make for the accurate diagnoses.

Objective To investigate the Ring Artifact Location Algorithm based on edge detection to eliminate the ring artifact.Methods The Sobel operator was used to extract the ring edge,and then an algorithm,which combined scan line searching with line fitting,was applied to determining the ring center and its size.Finally the linear interpolation algorithm was used to get rid of the ring artifact.Results This method was very effective to eliminate the ring artifact of both phantom and clinical images.Conclusion This algorithm is faster and more effective than the usual one and its speed and accuracy are improved.

Objective:To measure CT linearity and evaluate if it would show linear relationship between coefficient and attenuation.Methods:The Catphan phantom was used to measure CT linearity in 18 computed tomography equipments,and the results were calculated.Results:(1)The CT linearity were qualified in 14 equipment but 4.Conclusion:(1)There are many factors which affect CT linearity.The artifact will be produced if the CT linearity is unqualified.(2)CT linearity must be calibrated periodically to assure the stability of the CT linearity and to make for the accurate diagnoses.

Objective To investigate the influence of physiological motions on three-dimensional (3D) CT images and the rules of motion artifacts.Methods A mathematical model of motion artifact was set up based on the principle of spiral scanning, hereby the geometrical distortion of 3D image was analyzed.Experiments were carried out with home-made phantoms on a CT scanner.Results The details of 3D images with trivial distortion were legible under static condition.On the contrary, distinct distortion occured under moving condition, and its degree increased with the pitch and motion period. The 3D images were varied with difference of the motion initial phases.Conclusion The distortion of 3D-CT image depends on the motion characters of scanned objects and scanning parameters such as pitch and slice thickness.

80%)as a calcium supplement.Methods Weanling SD rats(21 days after birth,n=50)were fed with low calcium forage for 10 days,then were divided into 5 groups randomly with 10 rats in each group,half male and half female.GroupⅠwas control group fed on low calcium forage.GroupⅡ~Ⅲ were fed on low calcium with L-lactic acid calcium.Group Ⅳ~Ⅴ were fed on low calcium forage with ultramicro-mussel shell powder.The experiment period was 4 weeks.The indices were including the eventual weight and length of the rats,the calcium absorption rate of calcium supplement,the concentrations of serum calcium,serum phosphorus,bone calcium,skeletal muscle calcium,myocardial calcium,hemocyte calcium,liver calcium,kidney calcium and the activity of alkaline phosphatase were assessed.Results The effect of ultramicro-mussel shell powder group was similar to L-lactic acid calcium.Conclusion The ultramicro-mussel shell powder can be well absorbed and utilized,and it can be used as a calcium supplement.

ObjectiveTo investigate the effect of ivabradine， an inhibitor of peripheral HCN channel， on remifentanil-induced hyperalgesia in mice. MethodsThe model of remifentanil-induced hyperalgesia was established by intravenously infusing remifentanil 2 μg/（kg·min） for 1 h through tail vein of adult male C57/BL6 mice. To observe the effect of ivabradine on remifentanil induced hyperalgesia， ivabradine （5 mg/kg） was injected subcutaneously 30 minutes before remifentanil infusion. Forty mice were equally and randomly divided into 4 groups： saline group， remifentanil group， remifentanil + vehicle group and remifentanil + ivabradine group. In each group， six mice were used to test mechanical and thermal pain thresholds at 24 h before （baseline） and on 1 d， 3 d， 5 d after remifentanil or saline infusion. Four mice of each group were used to detected c-Fos positive cell in spinal dorsal horn by immunofluorescence on 1 d after remifentanil or saline infusion. ResultsCompared with the saline group， a significant decrease in mechanical or thermal threshold was observed on 1 d and 3 d after remifentanil infusion （P<0.001）， and the number of c-Fos positive neurons in the lumbar dorsal horn increased significantly （P<0.001）. Compared with vehicle group， subcutaneous injection of ivabradine effectively inhibited remifentanil induced hyperalgesia （P<0.001） and blocked the increase of c-Fos positive neurons in the lumbar dorsal horn on 1 d following remifentanil treatment （P<0.001）. ConclusionsIvabradine could effectively prevent remifentanil-induced hyperalgesia in mice. The possible mechanism underlying this effect is that ivabradine suppresses the enhanced peripheral nociceptive input onto spinal cord neurons.

ObjectiveThis study aims to explore the effect of ultrasound-guided superficial parasternal intercostal plane block on the quality of recovery and postoperative analgesia in patients undergoing sternotomy cardiac surgery. MethodsA total of 64 patients undergoing sternotomy cardiac surgery were selected for this study. They were randomly divided into two groups： one group received a superficial parasternal intercostal plane block with ropivacaine （the ropivacaine group）， while the other was given normal saline （the normal saline group）. The primary outcome was the Quality of Recovery-15 （QoR-15） score on postoperative day 1 in both groups， accompanied by a comparative analysis of the pain score and opioid usage. ResultsCompared with the normal saline group， the ropivacaine group exhibited a significantly higher QoR-15 score on postoperative day 1［（89.60±13.24） vs （81.18±12.78）， P=0.012］. The numerical rating scale at rest was significantly lower［（3.03±0.72） vs （4.26±0.93）， P<0.001］， and the numerical rating scale during coughing was also significantly reduced ［（4.40±0.89） vs （5.44±1.05）， P<0.001］. Concurrently， the cumulative morphine equivalent consumption during the initial 24 h postoperatively was significantly lower in patients who were administered the ropivacaine ［14.15 （4.95～30.00） mg vs 40.50 （19.25～68.18） mg， P=0.002］， and there was also a notable decrease in the rescue analgesia ［0.00 （0.00～0.00） mg vs 0.00 （0.00～100.00） mg， P=0.007］. ConclusionUltrasound-guided superficial parasternal intercostal plane block can significantly enhance the overall quality of recovery in patients undergoing sternotomy cardiac surgery on postoperative day 1. The technique contributes to improved postoperative analgesic effects and a reduction in opioid usage， thereby facilitating early postoperative recovery.

OBJECTIVE: To study the effect of nano-cerium oxide on the early development of zebrafish embryos. METHODS: The well-developed zebrafish embryos were randomly divided into the control group and the 50, 100, 200, 400 and 800 mg/L dose groups, with 40 embryos in each group. The dose groups were treated with nano-cerium oxide at the corresponding mass concentration for 5 days. The control group received no treatment. The death and malformation of embryos were observed. The heart rate of zebrafish embryos was recorded using confocol microscope. The protein expression of microtubule-associated protein 1 light chain 3(LC3) and cleaved Caspase-3 and were observed by Western blot technology. RESULTS: The death and embryonic malformation rate of zebrafish embryos increased with the increase of doses, showing statistical significance(P<0.01). The heart rate of the 800 mg/L dose group was decreased compared with the control group [(77±8) vs(93±4) beats/min, P<0.01]. There was no statistical significant difference in LC3-Ⅱ protein expression in each groups(P>0.05). The cleaved Caspase-3 protein expression increased in all dose groups compared with the control group(P<0.05). The cleaved Caspase-3 protein expression in the 200 mg/L dose group was higher than that in the 50 mg/L dose group(P<0.05). CONCLUSION: The nano-cerium oxide may induce cell apoptosis, causing toxic effect in early development of zebrafish embryos.