Search

To apply a navigator-based slice tracking method to prospectively compensate the respiratory motion for kidney vessel architecture imaging (VAI).A dual gradient echo (GE)/spin echo (SE) 2D EPI sequence was developed for kidney VAI. A single gradient-echo slice selection and projection readout at the location of the diaphragm along the inferior-superior direction was applied as a navigator. Navigator acquisition and fat suppression were inserted before each transverse imaging slice. Motion information was calculated after exclusion of the signal saturation in the navigator signal caused by imaging slices. The motion information was then directly sent back to the sequence and slice positioning was adjusted in real-time. The whole sequence was applied during a contrast agent pass-through.VAI parametric maps show the structural heterogeneity of the renal vasculature. The respiratory motion from the navigator signal was precisely calculated and slice positioning was changed in real-time based on the motion information. The vibration amplitude of the signal intensity of the liver tissue at the liver-lung interface in the case of prospective motion correction (PMC) on is about 28% of the PMC off case. Compared to the case of PMC off, the coefficient of variation (CoV) was reduced 30% of the case of PMC on.This study demonstrates the feasibility of the motion-compensating technique in kidney VAI. The sequence may improve the evaluation of microvasculature in kidney diseases.

The flooding and drainage of paddy fields has great effects on the transformation of heavy metals, however, the transformation of Cr in basalt-derived paddy soil with high geological background values was less recognized. The typical basalt-derived paddy soil was incubated under alternating redox conditions. The Cr fractions and the dynamics of Fe/N/S/C were examined. The HCl-extractable Cr increased under anaerobic condition and then decreased during aerobic stage. The UV-vis spectra of the supernatant showed that amounts of colloids were released under anaerobic condition, and then re-aggregated during aerobic phase. The scanning transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) revealed that Fe oxides were reduced and became dispersed during anaerobic stage, whereas Fe(II) was oxidized and recrystallized under aerobic condition. Based on these results, a kinetic model was established to further distinguish the relationship between the transformation of Cr and Fe. During anaerobic phase, the reduction of Fe(III) oxides not only directly released the structurally bound Cr, but also enhanced the breakdown of soil aggregation and dissolution of organic matter causing indirect mobilization of Cr. During aerobic phase, the oxidation of Fe(II) and further recrystallization of newly formed Fe(III) oxides might induce the re-aggregation of soil colloids and further incorporation of Cr. In addition, the kinetic model of Cr and Fe transformation was further verified in the pot experiment. The model-based findings demonstrated that the Cr transformation in the basalt-derived paddy soil with high geological background values was highly driven by redox sensitive iron cycling.

This study evaluated the midterm results of endovascular therapy (EVT) for Trans-Atlantic Inter-Society (TASC) II D femoropopliteal lesions in patients with critical limb ischemia (CLI).Fifty seven limbs of 54 patients with CLI due to TASC II D femoropopliteal lesions who underwent EVT at the First Hospital of Hebei Medical University were retrospectively analysed in a single-centre, observational study. The patient characteristics, endovascular procedural details, freedom from target lesion revascularization (TLR), patency rates, ulcer healing rate, and limb salvage rate were accessed.The patients' mean age was 68.2 ± 8.2 years. All patients were treated by EVT. The final technical success rate was 98.2% (56/57). There were 23 cases of pain at rest, 18 cases of ulcer, and 15 cases of gangrene. The median length of the treated segment was 286 ± 42 mm (56/56) and the mean number of stents placed per patient was 2.0 ± 0.8 (49/56). The postoperative ankle-brachial index was significantly higher than that of the preoperative ankle-brachial index (P 0.05). The perioperative complication rate was 10.7% (6/56). The restenosis or occlusion rate was 44.6% (25/56). The estimated rates of freedom from TLR at 1 year, 2 years, and 3 years were 86.8%, 67.0%, and 62.5%, respectively. A univariate analysis showed that predictors of freedom from TLR were the number of runoff vessels, length of the lesion, and complexity of the lesion, while predictors for restenosis or occlusion were the length and the complexity of the lesion. The ulcer healing rate was 93.8%. The limb salvage rates were 76.4%, 74.4%, and 70.9% at 1, 2, and 3 years after treatment, respectively.The midterm outcomes of EVT for TASC II D femoropopliteal lesions in patients with CLI indicated that this treatment approach is safe and effective and is clinically applicable.

The recommendation of the European Society for Vascular Surgery (ESVS) is that vertebral revascularization combined with ipsilateral CEA (carotid endarterectomy) should not be performed in the same operation. ESVS believes that vertebral revascularization combined with ipsilateral CEA increases perioperative death/stroke rates. In our opinion, revascularization of the first segment of vertebral artery (V1) combined with ipsilateral CEA is safe compared to vertebral V1 revascularization in the perioperative period. The purpose of this study is to prove that revascularization of V1 segment of vertebral artery combined with ipsilateral CEA is secure in the perioperative period.We describe our experience with homochronous revascularization of V1 segment of vertebral artery with ipsilateral CEA (group B) and simple revascularization of V1 segment of vertebral artery (group A) in 48 consecutive patients during a 5-year period. O.Y. (Ouyang) incisions were used in both groups. We compare the results of the 2 procedures with aspects of mortality, stroke, morbidity, incident rates of complications, and so on.There was no significant difference between patients in group A and group B in terms of red blood cell reduction, postoperative ventilator using time, postoperative drainage volume, postoperative drainage days, postoperative hospitalize duration, and incident rates of postoperative complications. The postoperative complications include death, stroke, Horner syndrome, vocal paralysis, hypoglossal nerve paralysis, wound hematomas, and lymphatic leakage.Revascularization of vertebral artery combined with ipsilateral CEA should be divided into revascularization of V1 segment of vertebral artery combined with ipsilateral CEA and revascularization of V3 segment of vertebral artery with ipsilateral CEA. Revascularization of V1 segment of vertebral artery combined with ipsilateral CEA is safe; it can be performed for suitable patients who are fit for indications. O.Y. incisions can fully expose the target blood vessels and simplify the procedures without transecting the sternocleidomastoid muscles in operations.

The control precision of thickness and tension is a crucial indicator for evaluating a tandem cold rolling control system. However, the control mode for field application cannot meet the actual quality requirements. Therefore, a distributed model predictive control (DMPC) strategy combined with neighborhood optimization is proposed to decrease the strip thickness deviation and tension change in this paper. First, a cold rolling model describing the relationship among the process parameters is established for the multi-stand cold rolling system. Then, according to the neighborhood optimization theory, the state evolution equation of the output system on each stand is derived. Furthermore, through proper consideration of the input and state information during optimization, optimal control variables are obtained using the proposed performance index to improve the system performance. A series of simulations were carried out with actual rolling data to analyze and validate the capability of the designed control system. The statistical data show that as roll speed disturbance occurs, the thickness and tension deviations can be controlled within respective ranges of 6 × 10