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Open Access Publications from the University of California

Scholarly Works (3 results)

  • Thesis
  • Peer Reviewed
UC Irvine Electronic Theses and Dissertations (2023)

A system was constructed for measuring magnetic field in 3D space and determining the position and orientation of magnets. Measurements were performed with a Hall-effect Gaussmeter attached to a 3-axis cartesian robot, capable of measuring magnetic fields of ±2 Tesla at spatial increments of as little as 8.75 µm within a working volume of 325mm by 290mm by 100mm. An algorithm was developed for the localization of magnets with known properties based on nonlinear optimization techniques. The Nelder-Mead simplex algorithm and Levenberg-Marquardt nonlinear least-squares algorithm were tested for detection of Neodymium-Iron-Boron magnets. Nelder-Mead performed the best, with a positional error of 2.21mm and orientation error of up to 22.4 degrees.

    Cover page: Position and Orientation Detection of Magnetic Objects Using Optimization Techniques
    • Article
    LBL Publications (1985)
      Cover page: Commercial-Sector Conservation Technologies
      • Article
      • Peer Reviewed
      UC San Francisco Previously Published Works (2016)

      Background

      Merkel-cell carcinoma is an aggressive skin cancer that is linked to exposure to ultraviolet light and the Merkel-cell polyomavirus (MCPyV). Advanced Merkel-cell carcinoma often responds to chemotherapy, but responses are transient. Blocking the programmed death 1 (PD-1) immune inhibitory pathway is of interest, because these tumors often express PD-L1, and MCPyV-specific T cells express PD-1.

      Methods

      In this multicenter, phase 2, noncontrolled study, we assigned adults with advanced Merkel-cell carcinoma who had received no previous systemic therapy to receive pembrolizumab (anti-PD-1) at a dose of 2 mg per kilogram of body weight every 3 weeks. The primary end point was the objective response rate according to Response Evaluation Criteria in Solid Tumors, version 1.1. Efficacy was correlated with tumor viral status, as assessed by serologic and immunohistochemical testing.

      Results

      A total of 26 patients received at least one dose of pembrolizumab. The objective response rate among the 25 patients with at least one evaluation during treatment was 56% (95% confidence interval [CI], 35 to 76); 4 patients had a complete response, and 10 had a partial response. With a median follow-up of 33 weeks (range, 7 to 53), relapses occurred in 2 of the 14 patients who had had a response (14%). The response duration ranged from at least 2.2 months to at least 9.7 months. The rate of progression-free survival at 6 months was 67% (95% CI, 49 to 86). A total of 17 of the 26 patients (65%) had virus-positive tumors. The response rate was 62% among patients with MCPyV-positive tumors (10 of 16 patients) and 44% among those with virus-negative tumors (4 of 9 patients). Drug-related grade 3 or 4 adverse events occurred in 15% of the patients.

      Conclusions

      In this study, first-line therapy with pembrolizumab in patients with advanced Merkel-cell carcinoma was associated with an objective response rate of 56%. Responses were observed in patients with virus-positive tumors and those with virus-negative tumors. (Funded by the National Cancer Institute and Merck; ClinicalTrials.gov number, NCT02267603.).
        Cover page: PD-1 Blockade with Pembrolizumab in Advanced Merkel-Cell Carcinoma
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