[en] Objective: To investigate the effect of Gefitinib on radiosensitivity of human lung adenocarcinoma xenograft in nude mouse. Methods: Human lung adenocarcinoma cell line A549 was used to establish nude mouse xenograft tumor model. The mice were derided into 4 groups: control, irradiation alone, Gefinitib alone and radiation combined with Genifitib. Radiation schedule was 3 fractions of 5 Gy, once daily. Gefitinib was daily administered by gavage at 100 mg/(kg·day^-1) for 14 days. In the combination group, radiotherapy was performed 2 hours after Gefitinib administration. Tumor diameter was measured every other day. Percentage of tumor growth inhibition, growth delay time and regrowth delay time were evaluated. Results: For A549 xenografts in radiation alone, gefitinib alone and combination therapy groups, the percentage of tumor growth inhibition was 22.7%, 12.4% and 38.2%, respectively (F=25.75, P=0.000). Tumor growth delay time was 6.0, 7.8 and 21.6 days, respectively (F=70.49, P=0.000). Tumor regrowth delay time in combination therapy and irradiation alone groups was 23.4 and 10.2 days. (F=174.24, P= 0.000). Sensitizing enhancement ratio of combination group was 1.5 in growth and 1.7 in regrowth. Conclusions: Anti-EGFR therapy enhances the radiosensitivity of human lung adenocarcinoma xenograft in nude mouse. (authors)

[en] The dependences of the flatband voltage shift (ΔV_FB) and the threshold voltage shift (ΔV_TH) in MOS system on the oxide thickness (T_ox) and on total irradiated dose (D) of electron-beam and ⁶⁰Co γ-ray have been studied. It has been found that ΔV_FB ∝ T_ox³, with +10V of gate bias during irradiation for n-Si substrate MOS capacitors; ΔV_TH ∝ T_ox³D^2/3, with 'on' gate bias during irradiation for n- and P-channel MOS transistors; ΔV_TP ∝ T_ox²D^2/3, with 'off' gate bias during irradiation for P-channel MOS transistors. These results are explained by Viswanathan model. According to ∼T_ox³ dependence, the optimization of radiation hardening process for MOS system is also simply discussed

[en] Objective: To evaluate the clinical value of 18floro-deoxyglucose positron emission tomography-CT(¹⁸FDG PET-CT) in the diagnosis of lymph node metastasis from advanced esophageal carcinoma. Methods: A prospective study is performed here to assess whether ¹⁸FDG PET-CT can improve the diagnostic accuracy in lymph node metastasis for patients with advanced esophageal carcinoma. Thirty patients had undergone esophagectomy with extensive lymph node dissection. PET-CT findings were compared with that of CT with pathological finding as the final say. Results: All patients were operated successfully without peri-operative complications. The pathologies] examination confirmed metastasis in 22 patients and 49 out of 243 excised lymph nodes. In CT analysis, the sensitivity was 40.8%, specificity was 96.9%, with a diagnostic accuracy of 85.6%, The positive and negative predictive value was 76.9%, 86.4% respectively; PET-CT resulted in a sensitivity of 93.9%, specificity of 91.2%, accuracy of 91.8%. The positive predictive value was 73.0% and negative predictive value was 98.3 %, The difference of sensitivity (P<0.001 ), accuracy (P<0.05) and negative predictive value between the two radiological modalities was statistically significant (P<0.001). Conclusions: With a high sensitivity and accuracy in the diagnosis of lymph node metastasis, PET-CT appears necessary in preoperative examination for advanced esophageal carcinoma in the hope that surgical treatment be guided by the results of PET-CT, especially for the elder patients with poor pulmonary function or heart or brain complications. Moreover, it could be used as the basis of the conformal radiation therapy planning for inoperable patients. (authors)

[en] Objective: To evaluate the clinical value of 18-fluoro-deoxyglucose positron emission tomography-CT(¹⁸FDG PET-CT) for recurrence and metastasis in treated esophageal carcinoma(EC). Methods: A retrospective study is done on 37 previously treated EC patients who underwent PET-CT scans to detect recurrent or metastatic lesions. The diagnostic accuracy of ¹⁸FDG PET-CT was assessed with the help of pathological finding as well as clinical or' follow-up data. Results: Fourty-six sites of recurrence were finally confirmed in 37 patients by cytology, pathology or follow-up data. The sensitivity, specificity and accuracy of PET-CT in detecting recurrence of all sites were 93.5% (43/46), 76.9% (20/26) and 87.5% (63/72), respectively. Two false-positive findings were found both at the anastomosis and hilar nodes, which caused the decrease in the overall specificity, especially that locally. The analysis of standard uptake value (SUV) demonstrated that patients with recurrence or who died during follow-up had higher SU- Vs compared with the control group. Conclusions: ¹⁸FDG PET-CT is highly effective in detecting recurrence in previously treated EC patients despite the low specificity at local sites. The analysis of stardard uptake value(SUV) provides incremental value in prognosis for this patient cohart. (authors)

[en] Objective: To investigate the imprinting effect of maternal water deprivation during late gestation on fetal and offspring renin-angiotensin system ( RAS) in the rats. Methods: After three days of maternal water deprivation during late gestation, fetal heart, kidney, placenta and body dry, wet weight as well as body and tail length were examined. Both fetal and offspring plasma angiotensin (Ang) II concentrations were measured by radioimmunoassay. Angiotensinogen (ATG) mRNA in the fetal and offspring liver and cardiovascular responses to intravenous injection of Ang II were also determined by real-time PCR. Results: Maternal water deprivation during late gestation significantly decreased heart, kidney, and body dry and wet weight ,the length of the fetal body and tail (P < 0. 05) but placenta (P > 0. 05), and increased fetal plasma Ang II concentration (P < 0. 05). Both fetal and offspring's mRNA of angiotensinogen in liver was significantly increased followed by water deprivation (P < 0. 05). And compared to the control, it significantly increased blood press in response to i. v. Ang II (P < 0. 05). Conclusion: Maternal water deprivation during late gestation has an effect on the heart, kidney and the growth and development of fetals, and changes the RAS of the offspring. These can be related with the ⁱmprinting^effect of diseases in fetal origins. (authors)

[en] Atherosclerotic plaque rupture is the leading cause of mortality in cardiovascular disease. Intravascular ultrasound (IVUS) imaging is a powerful clinical technique that provides real-time cross-sectional images of the arterial wall and atherosclerotic plaques. However, it does not provide sufficient information about the histological composition of plaques to characterize their vulnerability. Arterial wall strain measurements may provide insights into plaque composition and vulnerability, complementing the information directly available in the IVUS echogram. We have developed a method to measure the transverse arterial wall strain tensor in response to luminal pressure change, by registering IVUS images acquired at different pressures. This method has been validated by using IVUS images with simulated motion and IVUS images of a vessel phantom. In this study, we further evaluate the method by assessing the correspondence of the calculated strain distribution and the histological composition of atherosclerotic coronary arteries from Sinclair miniature pigs following 12 months of a high fat diet. The images were acquired in situ using a clinical IVUS system and under computer-controlled pressurization. After image acquisition, the artery segments were fixed for histology to identify plaque components. The strain distributions were aligned with the corresponding histological sections. The stiffness of various components of the lesion, inferred from the wall strain distribution, was consistent with the tissue composition seen in the histological cross-sections. These findings suggest that strain measurements from IVUS are promising for assessing plaque vulnerability.

[en] Intravascular ultrasound (IVUS) elastography is a promising tool for studying atherosclerotic plaque composition and assessing plaque vulnerability. Current IVUS elastography techniques can measure the 1D or 2D strain of the vessel wall using various motion tracking algorithms. Since biological soft tissue tends to deform non-uniformly in 3D, measurement of the complete 3D strain tensor is desirable for more rigorous analysis of arterial wall mechanics. In this paper, we extend our previously developed method of 2D arterial wall strain measurement based on non-rigid image registration into 3D strain measurement. The new technique registers two image volumes acquired from the same vessel segment under different levels of luminal pressure and longitudinal stress. The 3D displacement field obtained from the image registration is used to calculate the local 3D strain tensor. From the 3D strain tensor, radial, circumferential and longitudinal strain distributions can be obtained and displayed. This strain tensor measurement method is validated and evaluated using IVUS images of healthy porcine carotid arteries subjected to a luminal pressure increase and longitudinal stretch. The ability of the algorithm to overcome systematic noise was tested, as well as the consistency of the results under different longitudinal frame resolutions.

[en] Objective: To explore the therapeutic effect of malignant cancer treated with intervention of ⁹⁰Y-lasbelled glass microspheres. Methods: 18 cancer patients with primary tumor located in liver (6 cases), lung (5 cases), cervical lymph node metastases (5 cases), maxillary sinus carcinoma (1 case) and chest wall metastasis (1 case) were included in the study. All patients were confirmed by pathological diagnosis. ⁹⁰Y-lasbelled glass microspheres was injected with or without the help of type-B ultrasonic and CT. Results: Out of 18 cases of patients, 2 cases were CR, 9 cases were PR, 6 cases were SD and one case was PD. 14 cases were showed pain relief and the other 4 cases were no significant relief of pain. Conclusion: This method is effective in the therapy of malignant cancer, and it has great potential for clinical application. (authors)

[en] Highlights: • A new unsteady jet using semi-sinusoid signal is applied to form a flow control method. • The new unsteady jet overcomes the drawbacks of the traditional synthetic jet and increases the efficiency of the drag reduction. • The influence of the control frequency on control efficiency is taken into considerations. • The mechanism of the drag reduction through deviating and stabilizing the shear layers by the unsteady jet is found and interpreted. -- Abstract: A numerical simulation based on the Large eddy simulation method is carried out on the near wake flow behind a 25° slant angle Ahmed body to analyze and establish a new method to control the near wake flow. An active flow control using a new unsteady jet derived from the traditional synthetic jet is applied to reduce the aerodynamic drag. The control devices are distributed along the separation edges on the rear part of the body. Their effects on the near wake and the rear body by influencing the flow topology and the static pressure distribution are examined respectively. The control frequency of the jet as the key forcing parameter is taken into consideration as well. The different actuation set-ups lead to a max drag reduction of up to 13.6%, which demonstrates a good correlation with the static pressure distribution at the rear end of the body.

[en] Objective: To evaluate relation between hypoxia, hypoxic changes detected by ^99mTc-HL91 SPECT and the response to radiotherapy. Methods: Thirty-five patients with pathologically proven non-small cell lung cancer (NSCLC) treated by three-dimensional conformal radiotherapy were entered into the study. All patients were examined by examined by ^99mTc-HL9l SPECT imaging one or two days before radiotherapy. Twenty patients were monitored during radiotherapy(30-40 Gy) and one or two days after radiotherapy. Anterior', posterior and lateral planar images were collected 2 hours, 4 hours and 6 hours after intravenous injection approximately 740 MBq ^99mTc-HL91. Regions of interest(ROIs) were ch awn in the tumor and contralateral position and the radioactivity ratios of tumor to normal(T/N) were calculated. The response to radiotherapy was evaluated by solid tumor' s effect evaluation criterion (WHO) 3-6 months after radiotherapy. The correlations between T/N before radiotherapy, the T/N changes during radiotherapy and the response to radiotherapy were analyzed. Results: The T/N value gradually decreased before, during and after radiotherapy. The average T/N value before, during and after radiotherapy was 1.56±0.19, 1.40±0.12 and 1.29±0.13, respectively (F=10.13, P=0.010). The lower T/N ratio be- fore radiotherapy, the higher the response rate of radiotherapy (P=0.040). The larger change of T/N ratio before and after radiotherapy resulted in higher radiotherapy response, but with no statistical significance (P>0.05). Conclusions: The hypoxia status and hypoxic changes can be observed by HL91 SPECT imaging during radiotherapy which can predict the response to radiotherapy. (authors)