During excitation and demagnetization phase for the superconducting magnet, in dual-active-bridge (DAB) converter based power supply, a dc bias may occur in high-frequency transformer and thus lead to the faults. In this paper, an improved transient extend-phase-shift (TEPS) control strategy is proposed to suppress the dc bias without any additional hardware. Unlike the traditional extend-phase-shift (EPS) strategy, the voltages of the transformer are asymmetrical for half a period after changing phase-shift and then remain symmetrical. This makes it take half a switching period for the current of transformer to reach the steady state, and then eliminates the dc bias. The experiment verifies the performance on dc bias suppression. This method provides a good theoretical and experimental basis for the EPS DAB DC-DC converter to realize the optimal control for excitation and demagnetization system in high-field superconducting magnet power supply (SMPS).

Study objective: To determine the safety and effectiveness of ultrasound-guided paracervical nerve blocks for the painless treatment of patients with cervical cancer post-implantation. Design: Single-center randomized controlled trial. Setting: Fourth Hospital of Hebei Medical University (July 2023 to October 2023). Trial number: ChiCTR2300071580 [https://clin.larvol.com/trial-detail/ChiCTR2300071580]. Patients: Eighty patients with cervical cancer underwent post-implantation treatment. Interventions: Patients receiving and not receiving paracervical nerve blocks (Groups T and C, respectively) were randomly allocated. Measurements: Primary measures included visual analog scale (VAS) scores and patient body movement scores at various stages, including vaginal speculum placement (T1), applicator/needle insertion (T2), treatment administration following connection of the treatment tube (T3), needle withdrawal and hemostasis (T4), and willingness to receive further treatment. The secondary observation indices in this study included the operation time, incidence of hypoxemia, occurrence of nausea and vomiting, adverse events related to the circulatory system, patient satisfaction score, operator satisfaction score, and operation duration required by patients with an Alderte score of ≥ 9. Main results: Forty patients each were randomly allocated into Groups T and C. The VAS scores did not differ significantly between the two groups at T1. However, at T3 and T4, the VAS scores of Group T was significantly lower than that of Group C. No significant difference was observed in the body movement scores between the two groups at T1 and T3. However, the body movement score of Group T was significantly lower than that of Group C (P < 0.001) at T2 and T4. Group T showed higher postoperative satisfaction and willingness to receive further treatment compared to that of Group C. Conclusions: Ultrasound-guided paracervical nerve block effectively reduced the pain scores in patients with cervical cancer undergoing post-implantation treatment and enhanced their inclination to undergo further treatment.

Background: The goal of anesthesia in patients with hypertrophic obstructive cardiomyopathy (HOCM) is to reduce the risk of left ventricular outflow tract obstruction triggered by anesthetics. Remimazolam is a newly developed anesthetic that has been reported to have superior hemodynamic stability. There have been no reports on the completion of non-cardiac surgery with remimazolam in patients with HOCM. Methods: Here we report the case of a 49-year-old man diagnosed with hypertrophic obstructive cardiomyopathy who underwent resection of colon cancer with remimazolam and remifentanil anesthesia. A bolus 0.3 mg/kg remimazolam was administered for anesthesia induction, and then adjusted to 2 mg/kg/h to maintain anesthesia. Set the pain threshold index to 50 to auto-control the infusion speed of remifentanil. Results: No hypotension occurred during anesthesia, and norepinephrine was not administered. After conversion to open surgery, the patient’s blood pressure elevated and reduced with urapidil and esmolol. Conclusion: In this patient with HOCM, remimazolam and remifentanil provided adequate anesthesia for induction and maintenance to complete the right hemicolectomy.

Background: Bronchial blockers (BBs) manage airways during thoracoscopic lobectomy and isolate lungs by occluding the bronchus at the surgical site. However, intraoperative malpositioning remains a concern. We compared the performance of a new double-cuff BB (DcBB) with an additional cuff near the end of a single-cuff BB (ScBB) with that of ScBBs during thoracoscopic lobectomy. Methods: This single-center, randomized, parallel, controlled clinical study enrolled 80 patients undergoing thoracoscopic lobectomy for lung cancer at Nanpi People’s Hospital. The patients were randomized into two groups (n = 40 each); DcBB (DcBB used during one-lung ventilation) and ScBB (ScBB used during one-lung ventilation). The primary outcomes were the incidence and number of BB malpositioning. Secondary outcomes time for BB placement and positioning, surgical duration, hypoxemia, incidence of adverse cardiovascular events, grades of lung collapse, surgeon satisfaction, tracheal wall damage assessed during bronchoscopy, contamination rates of the non-surgical lung lobe on the surgical site determined by bronchoscopy, radiographic incidence of pulmonary infiltration on postoperative day 1, and intraoperative blood gas values. Results: The incidence of malpositioning was significantly lower in the DcBB than the ScBB group (7.5% vs . 30%, P = 0.02). The incidence of malposition was significantly lower in the DcBB cohort (P = 0.002). However, positioning the DcBB required more time (32.28 ± 5.37 vs . 19.90 ± 4.16 sec, P < 0.001). Other secondary outcomes did not differ significantly. Conclusions: In patients undergoing thoracoscopic lobectomy, the DcBB was associated with a lower incidence of malposition than the ScBB. The DcBB did not increase tracheal wall injury or cause significant adverse hemodynamic effects, and therefore may serve as a promising optional device for airway management during thoracoscopic lobectomy, particularly in clinical scenarios requiring high placement stability. Trial registration: the Chinese Clinical Trial Registry ChiCTR2400086472