Objective To compare the dosimetric differences between helical tomotherapy (HT) and volume-modulated arc therapy (VMAT) in the treatment of upper thoracic esophageal carcinoma (UTEC).Methods A total of 10 patients with UTEC were randomly selected.HT plan and double-arc VMAT plan were designed and optimized for each patient.The prescription dose was 50 Gy/30 fractions for gross target volume (GTV), 66 Gy/30 fractions for planned target volume (PTV).The dose distribution and conformal index (CI), homogeneity index (HI) of target volume, the D1％, D5％, Dg5％, D99％, and dose of organ at risk (OAR) were analyzed by using the dose volume histogram (DVH).The monitor units and delivery time were also evaluated.Results For GTV and PTV, the D99％ of HT plans were slightly higher than those of VMAT plans (t =4.476, 3.756, P ＜ 0.05) , but no significant differences in D1％ , D5％ , D95％ , HI and CI (P ＞ 0.05) were found.The V10, V15, V20 and mean lung dose (MLD) to the total-lung of HT plans were all significantly lower than those of VMAT plans (t =-3.369,-4.824, -4.869,-3.657, P ＜ 0.05).There were no significant differences for V5, V30 and Dmax of cord (P ＞ 0.05).The monitor units and delivery time of VMAT plans were significantly lower than those of HT plans (t =13.970, 7.982, P ＜ 0.05).Conclusions Both HT and VMAT are appropriate for esophageal cancer radiotherapy.HT significantly reduces the radiation dose of the total-lung, while VMAT has obvious advantages in efficiency.

Objective To investigate clinical significance and function of microRNA-106b (miR-106b) in retinoblastoma tissues and cells.Methods We detected miR-106b expression in 51 samples of thyroid cancer and the adjacent non-tumor tissues using qRT-PCR.The expression of miR-106b was altered by corresponding vectors in thyroid cancer cells,and then BrdU cell proliferation and flow cytometry assay were performed to examine the proliferation and apoptosis of thyroid cancer cells.Results The expression of miR-106b in thyroid cancer tissues was significantly lower than that in normal tumor-adjacent tissues (0.36±0.029 vs 0.98±0.034,P＝ 0.004).MiR-106b expression in tumor tissues was significantly associated with tumor size and tumor number.MiR-106b was obviously inhibited by miR-106b inhibitor in PTC-I cells (0.96±0.025 vs 0.29±0.032,P＝0.001),and inhibition of miR-106b resulted in significantly increased proliferation (89.33±5.67 vs 136.67±10.33,P＝0.03) and decreased apoptosis (16.33±3.20 vs 7.67±2.45,P＝0.04).On the contrast,over-expression of miR-106b using miR-106b mimics led to significantly decreased proliferation (98.00±4.65 vs 76.33±2.87,P＝0.03) and increased apoptosis (22.54±2.13 vs 32.45±4.34,P＝0.04).Conclusions Decreased expression of miR-106b is correlated with the adverse clinicopathological features of thyroid cancer.MiR-106b can inhibit cell proliferation and apoptosis of thyroid cancer cells,suggesting miR-106b plays a suppressive role in development and progression of thyroid cancer.

Objective To evaluate the dosimetric characteristics of helical tomotherapy (HT),intensity-modulated radiation therapy (IMRT) and three-dimensional conformal radiation therapy (3D-CRT) for postoperative radiotherapy of rectal cancer.Methods Ten male patients with stage Ⅱ or Ⅲ middle or low position rectal cancer were selected retrospectively.All of the 10 patients underwent Dixon surgery and CT simulation orientation.The target volumes and normal organs were drawn in the CT images and the plans for HT,IMRT and 3D-CRT were designed.The prescribed dose was given 50 Gy in 25 fractions,covering at least 95％ of the planning target volume.Results All plans met the needs of the prescribed doses.The HT and IMRT plans met the needs of dose limit to organs at risk,however,the 3D-CRT plans failed to do that.The conformity indexes of HT,IMRT and 3D-CRT plans were 0.86,0.82 and 0.62,respectively (F =206.81,P ＜ 0.001),and the homogeneity indexes were 0.001,0.157,and 0.205,respectively (x2 =15.8,P ＜ 0.001).The 3D-CRT plans had larger volumes than the HT plans and IMRT plans in the high-dose regions such as pelvic V50,bladder V40,bowel V50 and femoral head D5 (P ＜ 0.05),but the differences between the HT plans and IMRT plans were not statistically significant (P ＞0.05).The V15 value of bowel of HT plans were higher than those of the IMRT and 3D-CRT plans (71.1％ vs.63.3％ and 67.7％,respectively).However,there was no significantly difference.Conclusions All of the HT,IMRT and 3D-CRT plans are able to meet the prescription dose requirement of the target regions of rectal cancer.The HT plans show the best dose homogeneity and target conformity,followed by the IMRT plans,and then the 3D-CRT plans.The HT plans meet the needs of all OARs slightly better than the IMRT plans.3D-CRT plans are simple and practical with poor protective ability toward the OARs.

The core pathogenesis of membranous nephropathy is spleen-kidney depletion and dampness-stasis blocking collaterals， in which spleen-kidney depletion runs through the whole process of membranous nephropathy. Spleen and kidney depletion often occurs in the early stage of membranous nephropathy， accompanied by the progression of the disease and the stagnation of deficiency and qi， which leads to the obstruction of kidney collaterals by patho-logical products such as phlegm， blood stasis and water-dampness， and then the formation of stasis obstruction in kidney collaterals over time. Huangqi （Radix Astragali） as an important herb for supplementing spleen and boosting kidney can be used to fortify spleen， consolidate kidney and generate essence， and to boost qi， expel blood and unblock collaterals when treating membranous nephropathy. With combined medicinals， it can dispel and remove wind， astringe， store and consolidate essence， unblock stagnation and remove excess， strengthen efficiency and supplement deficiency， raise yang and lift the sunken. Besides， it is emphasized that caution should be taken against the drawbacks that excessive sweet may constrain the stomach， and the sweet and the warm may assist heat in the treatment of membranous nephropathy. The degree at which the spleen is supplemented and the kidney boosted should be chosen properly， and the medication contraindications should be cautioned.

Objective:To develope and analyze and optimize the performance of some kinds of environmentally friendly flexible X-ray protective materials in attempt to tackle the various environmental and high energy consumption problems in the development of traditional medical X-ray protective clothing.Methods:The Monte Carlo program was used to establish a simplified model of medical X-ray tube. The aim was to carry out numerical simulation and prediction of the shielding materials′ performance against X-ray, prepare the flexible X-ray shielding materials through experiments and test and verify the their shielding performances The development and optimization path was also obtained by comparing the result between simulation and experiment.Results:Bi was the preferred alternative to toxic Pb elements, while W was able to compensate for weak X-ray absorption zone of Bi. The shielding efficiency of the composite material doped with 25% Bi+ 25% W was able to reach 77.8% and 66.3% at 80 and 120 kV p tube voltages, respectively. Conclusions:With both the selection of elements and the optimization of functional particles, the combination of W and Bi is an economical, environmentally friendly, and efficient shielding way within the energy range of medical diagnostic X-rays. The numerical simulation helps reduce experimental costs, shorten the research period, and improve the design efficiency of X-ray shielding materials.

Rift Valley fever (RVF) is an acute, febrile zoonotic disease that is caused by the RVF virus (RVFV). RVF is mainly prevalent on the Arabian Peninsula, the African continent, and several islands in the Indian Ocean near southeast Africa. RVFV has been classified by the World Organisation for Animal Health (OIE) as a category A pathogen. To avoid biological safety concerns associated with use of the pathogen in RVFV neutralization assays, the present study investigated and established an RVFV pseudovirus-based neutralization assay. This study used the human immunodeficiency virus (HIV) lentiviral packaging system and RVFV structural proteins to successfully construct RVFV pseudoviruses. Electron microscopy observation and western blotting indicated that the size, structure, and shape of the packaged pseudoviruses were notably similar to those of HIV lentiviral vectors. Infection inhibition assay results showed that an antibody against RVFV inhibited the infective ability of the RVFV pseudoviruses, and an antibody neutralization assay for RVFV detection was then established. This study has successfully established a neutralization assay based on RVFV pseudoviruses and demonstrated that this method can be used to effectively evaluate antibody neutralization.
Africa ; Animals ; Blotting, Western ; HIV ; Indian Ocean ; Islands ; Methods ; Microscopy, Electron ; Product Packaging ; Rift Valley fever virus ; Rift Valley Fever ; Zoonoses

Objective:To evaluate the effectiveness of interventional treatment for neonatal critical pulmonary stenosis(NCPS).Methods:Clinical data of 12 neonates with NCPS who received percutaneous balloon pulmonary valvuloplasty (PBPV) from January 2016 to December 2019 in Department of Cardiology, Shenzhen Children′s Hospital were summarized and analyzed.The collected data included transthoracic echocardiography (TTE), percutaneous oxygen saturation (SPO 2), relevant data on interventional surgery, and follow-up results. Results:All 12 neonates with NCPS received PBPV successfully.The postoperative pressure difference between the right ventricle and the pulmonary artery ranged from 8 to 35 mmHg[(20±7) mmHg, 1 mmHg=0.133 kPa]. The postoperative SPO 2 ranged from 74%-100%[(93.0±5.9)%]. Three neonates with NCPS received Blalock-Taussig (B-T) shunt.One neonate with NCPS developed supraventricular tachycardia during the operation.There was no death for these 12 neonates with NCPS. Conclusions:Interventional treatment of neonates with NCPS could achieve a better effect and be employed as the first treatment option.Some neonates with NCPS would require cardiac B-T shunt or patent ductus arteriosus stent implantation.

Chiral drugs are closely related to the safety and effectiveness of drug use. Most dihydropyridine drugs have chiral carbon atoms, which are used as racemes and produce stereoselective disposal characteristics after entering the body, and may affect the safety and effectiveness of drugs. Therefore, based on the chiral resolution and pharmacokinetic characteristics of this class of drugs, the selection rules of chiral HPLC and CE methods and in vivo analysis applications of this class of drugs in recent years were reviewed. The stereoselective pharmacokinetics of this class of drugs were listed and compared. It was found that some of these drugs had obvious differences in stereoselective pharmacokinetics, and the pharmacokinetics and toxicity in vivo were also different.

The segmentation of organs at risk is an important part of radiotherapy. The current method of manual segmentation depends on the knowledge and experience of physicians, which is very time-consuming and difficult to ensure the accuracy, consistency and repeatability. Therefore, a deep convolutional neural network (DCNN) is proposed for the automatic and accurate segmentation of head and neck organs at risk. The data of 496 patients with nasopharyngeal carcinoma were reviewed. Among them, 376 cases were randomly selected for training set, 60 cases for validation set and 60 cases for test set. Using the three-dimensional (3D) U-NET DCNN, combined with two loss functions of Dice Loss and Generalized Dice Loss, the automatic segmentation neural network model for the head and neck organs at risk was trained. The evaluation parameters are Dice similarity coefficient and Jaccard distance. The average Dice Similarity coefficient of the 19 organs at risk was 0.91, and the Jaccard distance was 0.15. The results demonstrate that 3D U-NET DCNN combined with Dice Loss function can be better applied to automatic segmentation of head and neck organs at risk.