14 research outputs found
Self-Isolated Dual-Mode High-Pass Birdcage RF Coil for Proton and Sodium MR Imaging at 7 T MRI
This study presents the feasibility of a dual-mode high-pass birdcage RF coil to acquire MR images at both 1H and 23Na frequencies at ultra-high-field MR scanner, 7 T. A dual-mode circuit (DMC) in the dual-mode birdcage (DMBC) RF coil operates at two frequencies, addressing the limitations of sensitivity reduction and isolation between two frequencies as in traditional dual-tuned RF coil. Finite-difference time-domain (FDTD) based electromagnetic (EM) simulations were performed to verify the RF coil at each frequency on the three-dimensional human head model. The DMBC RF coil resonated at proton (1H) and sodium (23Na) frequencies, and also single-tuned high-pass birdcage RF coils were constructed for both 1H and 23Na frequencies. The bench test performance of the RF coils was evaluated using network analysis parameters, including the measurement of scattering parameters (S-parameters) and quality factors (Q-factors). Q-factor of the DMBC coil at 1H port was 10.2% lower than that of 1H single-tuned birdcage (STBC) coil, with a modest SNR reduction of 6.5%. Similarly, the Q-factor for the DMBC coil at 23Na port was 12.3% less than that of 23Na STBC coil, and the SNR showed a minimal reduction of 5.4%. Utilizing the DMBC coil, promising 1H and 23Na MR images were acquired compared to those by using STBC coils. In conclusion, deploying a DMBC 1H/23Na coil has been demonstrated to overcome traditional constraints associated with dual-tuned RF coils, achieving this with only nominal signal attenuation across both nuclei operational frequencies
Reading Single DNA with DNA Polymerase Followed by Atomic Force Microscopy
The importance of DNA sequencing in the life sciences and personalized medicine is continually increasing. Single-molecule sequencing methods have been developed to analyze DNA directly without the need for amplification. Here, we present a new approach to sequencing single DNA molecules using atomic force microscopy (AFM). In our approach, four surface conjugated nucleotides were examined sequentially with a DNA polymerase immobilized AFM tip. By observing the specific rupture events upon examination of a matching nucleotide, we could determine the template base bound in the polymerase's active site. The subsequent incorporation of the complementary base in solution enabled the next base to be read. Additionally, we observed that the DNA polymerase could incorporate the surface-conjugated dGTP when the applied force was controlled by employing the force-clamp mode.X1114Ysciescopu
Left anterior descending artery dissection with retrograde aortic dissection during percutaneous coronary intervention: a case report
Retrograde catheter-induced coronary artery dissection during percutaneous coronary intervention is an exceedingly rare occurrence, and the likelihood of it extending into the aorta is even more uncommon. Typically, surgical treatment involves aortic root replacement combined with coronary artery bypass grafting. However, in this particular case, a meticulous approach was employed. By carefully guiding wires into the true lumens and placing stents in the proximal left main and left anterior descending arteries, the immediate complications were averted by obstructing the retrograde flow in the false lumen. Subsequently, an off-pump coronary artery bypass was performed using the left internal mammary artery to the left anterior descending artery, without the need to manipulate the aorta. This approach resulted in a short operation time and the absence of any other complications
Uniportal video-assisted thoracoscopic anatomical resection of the right anterior pulmonary segment in a 10-year-old child with congenital pulmonary airway malformation
Abstract Congenital pulmonary airway malformation (CPAM) is a very rare phenomenon subject to malignant transformation that requires surgical resection. In an asymptomatic 10-year-old girl, we identified a single cystic and consolidated lesion on computed tomography. This incidental finding was confined to anterior segment of lung in right upper lobe (RUL). Uniportal video-assisted thoracoscopic surgery (VATS) served to successfully achieve anterior segmentectomy, without chest tube placement. The surgical specimen confirmed features of CPAM, also showing acute and chronic inflammation with abscess formation. Once the surgical mainstay for such lesions, open lobectomy is now under challenge by thoracoscopic technique, port-reduction methods, and a lung-preserving strategy. Herein, we have shown uniportal VATS anatomical resection of right anterior pulmonary segment to be a viable option for a 10-year-old child with CPAM confined to a single lung segment
Lobectomy versus Sublobar Resection in Non-Lepidic Small-Sized Non-Small Cell Lung Cancer
Background: Recently, many surgeons have chosen sublobar resection for the curative treatment of lung tu-mors with ground-glass opacity, which is a hallmark of lepidic lung cancer. The purpose of this study was to evaluate the oncological results of sublobar resection for non-lepidic lung cancer in comparison with lobectomy. Methods: We conducted a retrospective chart review of 328 patients with clinical N0 non-small cell lung cancer sized ≤2 cm who underwent curative surgical resection from January 2009 to December 2014. The patients were classified on the basis of their lesions into non-lepidic and lepidic groups. The sur-vival rates following lobectomy and sublobar resection were compared within each of these 2 groups. Results: The non-lepidic group contained a total of 191 patients. The 5-year recurrence-free survival rate was not significantly different between patients who received sublobar resection or lobectomy in the non-lepidic group (80.1% vs. 79.2%, p=0.822) or in the lepidic group (100% vs. 97.4%, p=0.283). Multivariate analysis indicated that only lymphatic invasion was a significant risk factor for recurrence in the non-lepidic group. Sublobar resection was not a risk factor for recurrence in the non-lepidic group. Conclusion: The oncological outcomes of sublobar resection and lobectomy in small-sized non-small cell lung cancer did not significantly differ according to histological type
Nonintubated Uniportal Video-Assisted Thoracoscopic Surgery: A Single-Center Experience
Background: We report our surgical technique for nonintubated uniportal video-assisted thoracoscopic surgery (VATS) pulmonary resection and early postoperative outcomes at a single center. Methods: Between January and July 2017, 40 consecutive patients underwent nonintubated uniportal VATS pulmonary resection. Multilevel intercostal nerve block was performed using local anesthesia in all patients, and an intrathoracic vagal blockade was performed in 35 patients (87.5%). Results: Twenty-nine procedures (72.5%) were performed in patients with lung cancer (21 lobectomies, 6 segmentectomies, and 2 wedge resections), and 11 (27.5%) in patients with pulmonary metastases, benign lung disease, or pleural disease. The mean anesthesia time was 166.8 minutes, and the mean operative duration was 125.9 minutes. The mean postoperative chest tube duration was 3.2 days, and the mean hospital stay was 5.8 days. There were 3 conversions (7.5%) to intubation due to intraoperative hypoxemia and 1 conversion (2.5%) to multiportal VATS due to injury of the segmental artery. There were 7 complications (17.5%), including 3 cases of prolonged air leak, 2 cases of chylothorax, 1 case of pleural effusion, and 1 case of pneumonia. There was no in-hospital mortality. Conclusion: Nonintubated uniportal VATS appears to be a feasible and valid surgical option, depending on the surgeon’s experience, for appropriately selected patients
Finite Element Simulations of a Slump during the 2017 ML5.4 Pohang, South Korea, Earthquake
During the 2017 local magnitude (ML) 5.4 Pohang, South Korea, Earthquake, a slump occurred on a natural slope with a fill which is located 3 km East from the earthquake epicenter. Notably, conjugated reverse faults cutting the Quaternary sediments near the ground surface were found in the vicinity of the slope toe through a trench survey. In addition, a maximum uplift of ground surface at the slope toe was measured about 1.0 m through the LiDAR image processing technique. This paper investigates the influences of the fill soil on top of the natural slope and the ground shaking on triggering the slump through finite element simulations. Three slope models are considered. Model A is a slope with a fill soil and a fault near the toe. Model B is a slope with the fill and without the fault, and Model C is a slope with the fault and without the fill. Acceleration time series available from the seismograph 8.17 km North of the epicenter are applied to the bottom of the three slope models as input motions. The numerical simulations for Models A and B predicted upward vertical displacements at the slope toe, showing good agreement with the uplift observed from the field. The vertical displacements for Models A and B were similar, implying the existence of the fault did not affect the triggering of slump. Model C does not produce any considerable amount of displacements, which implies a significant role of the fill soil in triggering the slump