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Objective To measure the peripheral dose distributions of the mobile head cone beam computed tomography (CBCT) and evaluate the impact of CBCT on the surrounding personnel and environment, and provide data support for clinical radiation protection management. Methods Combined with the structural characteristics of CBCT, AT1123 was used in the direction of 0° (counterclockwise), 45°, 90°, 135°, 180°, 225°, 270° and 315° in front of CBCT to measure the ambient dose equivalent rate of 30 cm, 80 cm and 130 cm away from the ground when the equipment was normally out of the beam, and the boundary of the temporary control area was drawn. At the same time, the dose level behind the lead screen 1 m away from the external surface of the equipment was measured and analyzed. Results The dose field around CBCT was symmetrically distributed with the dividing line of 0° and 180°, and the radiation dose level of 5.5 m in the direction of 0°, 3.5 m in the direction of 45°, 0.5 m in the direction of 90° and within 1.0 m in the direction of 180° (inside the "spoon" type) was higher than 2.5 μSv/h. The radiation dose levels of CT aperture 0° (straight forward), 45° and 315° behind the lead screen 1 m away from the equipment surface were 0.37 μSv/h, 0.22 μSv/h and 0.54 μSv/h, respectively. Conclusion The results show that the radiation dose around the mobile head cone beam CT is in a low dose level, the distribution of the dose field can provide necessary reference for the administrative and medical personnel to strengthen the radiation safety management. At the same time, it is suggested that lead screens should be set up in the clinical use of mobile CT to ensure the health and safety of the surrounding people and the environment.
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Aim: To investigate the in vitro release behavior and pharmacokinetic characteristics of quercetinloaded mixed micelles composed of Pluronic P123/ Poloxamer 188 in rats. Methods: Polymer micelles were prepared by the thin-film hydration method. The quercetin release rate of quercetin mixed micelles was investigated by dynamic membrane dialysis technique in the physiological saline contained 1% Tween-80. The drug release curves were drawn. The results were evaluated by DD Solver. Ultra performance liquid chromatography (UPLC) method was employed to measure the plasma concentration of quercetin in rats after tail intravenous administration. The plasma concentration-time curves were drawn, and the pharmacokinetic parameters were calculated with PK Solver. Results: The entrapment efficiency (EE%) and loading efficiency (DL%) of mixed micelles was (94. 25 ± 2. 13)% and (8.61 ± 0. 18)%, respectively. The quercetin release rate of quercetin mixed micelles in the physiological saline contained 1% Tween-80 was (52.90 ± 1.08)%. The quercetin mixed micelles could be described by Higuchi model and expressed by the equation; F = 6. 735 t0.5 (Rsqr-adj = 0. 960 4, AlC = 75. 584 0). T1/2β, AUC0.4 and MRT0-inf of quercetin mixed micelles were calculated to be 1.2,1.5 and 2. 4 times of free quercetin, respectively. Conclusions: The quercetin-loaded mixed micelles have high entrapment efficiency and loading efficiency, which can improve the release behavior in vitro, prolong the time of quercetin, and significantly enhance the fraction of bioavailability of quercetin in rats.
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Objective@#To explore the effects of surgical technique of single one-stage posterior C1-2 screw rod fixation of Chiari malformation (CM) associated with occipitalization and without atlantoaxial dislocation.@*Methods@#A total of 23 patients with CM treated between January 2014 and October 2015 in Department of Neurosurgery of Chinese People′s Liberation Army General Hospital were retrospective reviewed. All of them were diagnosis with CM associated with occipitalization and without atlantoaxial dislocation, including 8 males and 15 females, aging from 11 to 57 years (mean (35.5±10.52) years). Single one-stage posterior C1-2 screw rod fixation with bone grafting fusion was performed. Operation time and intraoperative blood loss were recorded. Japanese Orthopaedic Association (JOA) scores and Odom rating were used to evaluate the clinical effects at pre- and post-operative. Regression of the cerebellar tonsillar was measured by MRI. The results were analyzed by paired samples t test.@*Results@#Twenty-three patients were implanted screws successfully, the vertebral artery injury and cerebrospinal fluid leakage were not found. The mean operation time was (172.7±19.9) minutes, the intraoperative blood loss was (153.9±49.3) ml. Compared to preoperative, the JOA score increased (13.7±1.6 vs. 11.5±1.4) and the tonsillar herniation decreased ((0.8±0.6)cm vs. (1.9±0.6) cm) in the last follow-up, there were statistical difference (t=13.386, P<0.01; t=17.995, P<0.01). The results of the postoperative Odom grading were as follows: 6 cases were perfect (26.1%), 13 cases were good (56.5%), 4 cases were moderate (17.4%) and no case was poor.No signs of instrument loosen or screw broken was noticed. 100% bony fusion rate was achieved. The follow-up time was 6 to 23 months (mean (10.5±3.2) months). One case developed internal fixator related discomfort, the symptom was relieved by internal fixator removal surgery performed 4 months after the operation when osseous fusion had already been achieved. No new neurologic symptoms were observed in other 22 patients.@*Conclusions@#The results of the study substantiates the effectiveness of single one-stage posterior fixation strategy for CM, which is associated with occipitalization and without atlantoaxial dislocation. This technique could be an alternative choice for this type of CM.
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It review the structure-function relationship of natural anthraquinone derivatives from Radix et Rhizoma Rhei. The anthraquinone derivatives had many identical activities because they have the identical mother nucleus; but the strength of their activities were different, because they have different substitution groups. The anthraquinone derivatives shown the obvious structure-function relationship in many respects, such as antioxygenation, antibiosis, anticancer, the influence of immunity and so on.