Search

Axial flux permanent magnet machines (AFPM) are popular for applications that benefit from high torque density and an axially compact form factor, such as in-wheel traction drives. Although the radial flux permanent magnet machine (RFPM) and the AFPM work based on the same underlying principle, the differences in their geometry introduce complexities in analysis of the AFPM. In this paper, the different AFPM design variants, their sizing approaches, computationally efficient design optimization techniques, and manufacturing techniques reported in literature are reviewed. In addition to classical AFPM machines, emerging variants and research opportunities with potential to push the boundaries of electric machine technology are reviewed. These include bearingless AFPMs, magnetically geared AFPMs, and combined radial-axial flux machines.

Distribution of the ratio of variant allele frequency to ctDNA fraction of mutations and rearrangements in the AR gene.

Purpose:Comprehensive genomic profiling (CGP) is of increasing value for patients with metastatic castration-resistant prostate cancer (mCRPC). mCRPC tends to metastasize to bone, making tissue biopsies challenging to obtain. We hypothesized CGP of cell-free circulating tumor DNA (ctDNA) could offer a minimally invasive alternative to detect targetable genomic alterations (GA) that inform clinical care.Experimental Design:Using plasma from 3,334 patients with mCRPC (including 1,674 screening samples from TRITON2/3), we evaluated the landscape of GAs detected in ctDNA and assessed concordance with tissue-based CGP.Results:A total of 3,129 patients (94%) had detectable ctDNA with a median ctDNA fraction of 7.5%; BRCA1/2 was mutated in 295 (8.8%). In concordance analysis, 72 of 837 patients had BRCA1/2 mutations detected in tissue, 67 (93%) of which were also identified using ctDNA, including 100% of predicted germline variants. ctDNA harbored some BRCA1/2 alterations not identified by tissue testing, and ctDNA was enriched in therapy resistance alterations, as well as possible clonal hematopoiesis mutations (e.g., in ATM and CHEK2). Potential androgen receptor resistance alterations were detected in 940 of 2,213 patients (42%), including amplifications, polyclonal and compound mutations, rearrangements, and novel deletions in exon 8.Conclusions:Genomic analysis of ctDNA from patients with mCRPC recapitulates the genomic landscape detected in tissue biopsies, with a high level of agreement in detection of BRCA1/2 mutations, but more acquired resistance alterations detected in ctDNA. CGP of ctDNA is a compelling clinical complement to tissue CGP, with reflex to tissue CGP if negative for actionable variants.See related commentary by Hawkey and Armstrong, p. 2961

Positive percent agreement (PPA) between patient-matched cancer tissue and liquid biopsies.

Background The amounts of circulating cell-free DNA (cfDNA) and circulating-tumor DNA (ctDNA) present in peripheral blood liquid biopsies can vary due to preanalytic/analytic variables. In this study, we examined the impact of patient age, sex, stage, and tumor type on cfDNA yield, ctDNA fraction, and estimated ctDNA quantity from a large cohort of clinical liquid biopsy samples. Methods We performed a retrospective analysis of 12 139 consecutive samples received for liquid biopsy (FoundationOne® Liquid) clinical testing. Results Significant differences in both cfDNA yield and estimated ctDNA quantity were observed based on the underlying tumor type that initiated the liquid biopsy analysis and the stage of the patient (P Conclusions In this study, we show that ctDNA quantity varied significantly based on patient age, sex, stage, and tumor type, which could offer an explanation as to why certain liquid biopsy specimens are more likely to fail sequencing or provide clinically meaningful results. In addition, this could affect future clinical decisions on the blood sample volumes required to allow successful liquid biopsy testing.

This paper investigates and compares two popular combined winding configurations for bearingless machines, the multi-phase (MP) and dual-purpose no-voltage (DPNV) windings. Each of these winding configurations has the ability to independently create suspension force and drive torque using the same stator coils. The paper develops analogous bearingless motor force and torque models, space vector equivalent circuits, and a current regulation architecture for each combined winding approach. A comprehensive comparison is made between the two combined winding topologies by using these analogous models and through an experimental study. It is shown that, from a motor design perspective, these combined winding topologies are equivalent for certain design conditions, but that each winding places very different demands upon the drive power electronics. The paper concludes that the optimal choice of winding configuration depends on the machine parameters and the expected loading and drive cycle. When compared in terms of total current stress exerted on the bearingless drive, the MP winding is preferred when over half of the coil current is used to produce torque rather than force. In terms of the drive's volt-ampere rating, the DPNV winding is shown to be advantageous for high operating speeds and low torque values.

This paper investigates combined radial axial magnetic bearing (CRAMB) technology as an enabling component for shafted bearingless motor systems. The unique requirements of high speed bearingless motors designed for significant power levels are used to guide a literature review on CRAMB designs. Fundamental bearing topology aspects are identified and compared. Based on the outcome of this review, a new CRAMB topology is proposed and developed to meet the needs of a bearingless motor. Key features of the proposed design include a three-pole radial force stage (driven by a three-phase motor drive) and utilization of an optimal bias flux that improves radial force density by approximately 15% (improved rotor dynamics). A full design procedure for the new bearing topology is developed and it is shown that compared to a conventional four-pole side-by-side CRAMB, this topology decreases the bearing shaft length and requires two fewer power electronic switches (6 instead of 8). The new bearing is validated via finite element analysis and experimental test results.

The parallel dual-purpose no-voltage (DPNV) winding topology offers appreciable advantages for high speed and significant power bearingless motor designs. Precision current regulation is required to realize the high performance potential of bearingless motors using parallel DPNV windings. The performance of the machine hinges on the ability to decouple the voltage disturbance between the torque and suspension systems at all operating conditions, including high electrical frequencies. Two pathways are investigated to achieve precision actuation: 1) machine design and/or feed-forward control to systematically reduce the voltage disturbance, 2) direct digital design of the current regulator for high-speed operation. Analytical models are constructed which give insight into the root cause of the cross-coupling as a function of the physical winding design. It is shown that all practical machine designs produce some level of voltage disturbance which can be directly eliminated via a feed-forward voltage added to the torque winding current regulator. The state-of-the-art current regulation methods for the parallel DPNV winding are progressed to enable extended operating ranges for the targeted high speed and bandwidth conditions. By codesigning the machine and controls, more optimized designs are possible by trading off torque ripple and force density.

Background: Adult primary retroperitoneal sarcomas (RPSs) are a group of heterogeneous tumors with different histological subtypes. Comprehensive genomic profiling (CGP) analyses have recently provided significant insights into the biology of sarcomas by identifying genomic alterations (GAs) which could benefit from targeted therapies. Methods: RPS were evaluated by CGP using next-generation sequencing of up to 406 cancer-related genes. Tumor mutational burden (TMB) was determined on 0.83 to 1.14 mut/Mb of sequenced DNA. Finally, PD-L1 expression was determined. Results: Overall, 296 cases of primary RPS were analyzed. Liposarcoma (LPS) subtype had more GA/tumor than leiomyosarcoma (LMS) subtypes, with follicular dendritic cell sarcomas harboring the highest and synovial sarcomas the lowest. TP53 and Rb1 alterations were the highest in LMS, and CDK4/6 and MDM2 in LPS. However, both the TMB and targetable GA rates were low across subtypes. PD-L1 immunostaining was low positive in 21% and high positive in 5% of patients, respectively. Conclusions: CGP analysis revealed that potentially actionable genomic targets were rare in our cohort of RPS. Moreover, RPSs seem less likely to respond to immune checkpoint inhibitors based on putative biomarkers status. Nevertheless, genomic stratification according to histological subtypes led to description of GAs that can inform future clinical trials design.

Positive program death-ligand 1 (PD-L1) immunohistochemistry (IHC) is an approved companion diagnostic guiding the use of immune checkpoint inhibitors in uterine cervical carcinoma (CXC). The clinical and genomic features of PD-L1-positive (PD-L1positive) CXC have not been previously described. We reviewed the clinicopathologic and molecular features of 647 CXC cases that were tested using DAKO 22C3 PD-L1 IHC and comprehensive genomic profiling during the course of clinical care. PD-L1positive cases were defined via a combined positive score of ≥ 1. No differences were found in age, genetic ancestry, and HPV status of the PD-L1positive (n = 548) and PD-L1negative disease subset. The PD-L1 positivity rate varied by histologic subtype of CXC with squamous cell carcinoma (SCC) having a PD-L1 positivity rate of 91% (397/437) and usual-type adenocarcinoma’s PD-L1 positivity rate being 60% (35/58). In addition, the PD-L1 positivity rate varied depending on site of the specimen with 89.1% (261/293) positivity rate observed in cervix specimens compared to 25% (2/8) in brain metastases specimens. No significant difference in tumor mutational burden (TMB), microsatellite instability, and CD274 (encoding PD-L1) amplification was observed between PD-L1positive and PD-L1negative CXC subsets. By combining TMB with PD-L1, an additional 17 patients are eligible for pembrolizumab when compared to PD-L1 testing alone. TERT promoter alterations and APOBEC mutational signature were enriched in the PD-L1positive CXC SCC (p = 0.011, and p = 0.004, respectively). Our study reveals important prevalence data on PD-L1 positivity in CXC non-SCC and suggests that further studies in these histologic subtypes are warranted. In addition, we also provide a key framework to guide both specimen selection and future investigations of predictors of immunotherapy response in cervical cancer patients. Lastly, TERT promoter alterations and APOBEC mutational signature may be a biologically unique subset of PD-L1positive CXC SCC.

Background Histiocytic and dendritic cell neoplasms are a diverse group of tumors arising from monocytic or dendritic cell lineage. Whereas the genomic features for Langerhans cell histiocytosis and Erdheim‐Chester disease have been well described, other less common and often aggressive tumors in this broad category remain poorly characterized, and comparison studies across the World Health Organization diagnostic categories are lacking. Methods Tumor samples from a total of 102 patient cases within four major subtypes of malignant histiocytic and dendritic cell neoplasms, including 44 follicular dendritic cell sarcomas (FDCSs), 41 histiocytic sarcomas (HSs), 7 interdigitating dendritic cell sarcomas (IDCSs), and 10 Langerhans cell sarcomas (LCSs), underwent hybridization capture with analysis of up to 406 cancer‐related genes. Results Among the entire cohort of 102 patients, CDKN2A mutations were most frequent across subtypes and made up 32% of cases, followed by TP53 mutations (22%). Mitogen‐activated protein kinase (MAPK) pathway mutations were present and enriched among the malignant histiocytosis (M) group (HS, IDCS, and LCS) but absent in FDCS (72% vs. 0%; p, Histiocytic and dendritic cell neoplasms are a diverse group of tumors arising from the monocytic or dendritic cell lineage. This article presents the molecular characteristics of the four major subtypes of malignant histiocytic and dendritic cell neoplasms, focusing on genomic alterations that could represent therapeutic targets.

Electrification and hybridization of off-highway vehicles have the potential to yield significant fuel savings and air emissions improvements. However, developing the required components to electrify these systems is an extremely challenging task due to high force and power density requirements and highly variable drive cycles. This article investigates a new approach to off-highway vehicle electrification based around a linear piston pump integrated into a linear actuator. The article first reviews linear actuator machine topologies within the context of the charge pump application requirements. A tubular machine topology is optimized for integration with a hydraulic pump and experimentally validated using a prototype machine. A multiphysics simulation framework is developed to simulate the entire charge pump design with a position regulator. An optimized design is proposed with an oscillation frequency of 132 Hz and a total system efficiency (pump and motor) calculated to be 81.3% at full load.

The bearingless version of the induction motor (IM) has unacceptable performance for high speed or significant power applications. This is due to design challenges that are unique to the bearingless IM, including fundamental topology differences, rotor current induced by the suspension field, and a lack of techniques that can rapidly and accurately model the machine. This article presents a complete investigation into the design topology, modeling, and optimization of bearingless IMs to identify high-efficiency, power-dense designs for a high speed industrial compressor system. Key differences in the design of the bearingless IM from that of the classical line-fed IM are explored and an analytic design approach is proposed. A pole-specific rotor and a combined stator winding are used to improve the machine performance. Computationally efficient finite element modeling techniques are proposed and evaluated based on their ability to accurately calculate bearingless IM design performance metrics. An optimization framework is developed around these advancements using the multiobjective evolutionary algorithm based on decomposition. This article exercises this framework to explore the design space of four different slot-pole combination bearingless IMs for a 50 kW, 30 000 r/min compressor. High performance designs are identified that achieve $>96\%$ efficiency with a torque density competitive with high performance servo motors that use contact bearings.

Introduction: Accurate diagnosis, prognosis and treatment of hematologic disorders from both myeloid and lymphoid origin requires assessing somatic mutation status in an increasingly large number of genes. Here we present the results of the assay development and validation of a targeted next generation sequencing panel which provides full exon sequencing of 141 genes associated with myeloid and lymphoid malignancies, as well as the ability to detect clinically relevant copy number alterations (CNAs) and certain sub-gene level CNAs. Methods: Based on review of clinical guidelines, 141 genes including 72 myeloid and 84 lymphoid associated genes were selected. The assay interrogates all coding exons of the 141 genes to detect single nucleotide variants (SNVs) and insertions/deletions (indels). The assay also identifies CNAs in 16 genes, FLT3 internal tandem duplicates (ITDs), and select non-coding pathogenic variants. The custom hybrid capture-based assay utilizes genomic libraries created from 250 ng gDNA extracted from peripheral blood or bone marrow followed by sequencing on Illumina sequencers. Concordance studies were performed on clinical samples previously assessed using an orthogonal NGS-based laboratory developed test for SNVs/Indels or digital multiplexed ligation-dependent probe amplification for CNAs. In addition, analytical sensitivity was assessed using cell line dilution series and specificity by reference samples from Genome in a Bottle (GIAB). Small indels were defined as Results: Interim estimates of positive percentage agreement (PPA) and specificity have been determined for SNV/Indels, FLT3-ITDs, and CNVs, with further testing ongoing. PPA of SNVs was 100% (218/218 SNVs; n = 134 samples). PPA was also 100% for both small indels (21/21; n = 14 samples) and long indels (6/6; n = 6 samples). A dilution series of 8 positive clinical samples at 4 different dilutions showed SNV and small indel detection of 100% at allele frequency (AF) ≥ 3%. Long indel detection was 87.5% at AF ≥ 5%. FLT3-ITD was evaluated with 2 cell line samples at 5 different dilutions with 100% detection at AF ≥ 5%. PPA of CNAs were 95.7% (157/164) in 46 clinical samples. CNA detection was also evaluated with 8 cell line samples at 4 different dilutions showing 92.3% detection at a copy number ratio threshold ± 0.15. A preliminary estimate of specificity was determined using 4 replicates of the GIAB sample, NA12878, and was >99.99% for SNVs and small indels (n=6.9 × 105). Finally, a model for gender classification was created using a training cohort of 70 clinical samples. The performance was evaluated on a test set of 144 clinical samples with 100% PPA (144/144). Conclusions: Taken together, these data demonstrate that the developed NGS assay is a sensitive, specific, and accurate assay with high clinical utility to inform treatment decision making in hematologic malignancies. Citation Format: Grant Hogg, Tong Liu, Helen Cao, Adib Shafi, Ashraf Shabaneh, John Howitt, Amanda Williamson, Rachel Dango, Xiaojun Guan, Heidi Hoffmann, Michael Mooney, John Pruitt, Scott Parker, Stan Letovsky, Li Cai, Eric A. Severson, Shakti Ramkissoon, Anjen Chenn, Marcia Eisenberg, Eyad Almasri, Taylor Jensen. Development of a mutation profiling NGS assay to facilitate clinical decisions in hematologic malignancies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6220.

Purpose: Comprehensive genomic profiling (CGP) is of increasing value for patients with metastatic castration-resistant prostate cancer (mCRPC). mCRPC tends to metastasize to bone, making tissue biopsies challenging to obtain. We hypothesized CGP of cell-free circulating tumor DNA (ctDNA) could offer a minimally invasive alternative to detect targetable genomic alterations (GA) that inform clinical care. Experimental Design: Using plasma from 3,334 patients with mCRPC (including 1,674 screening samples from TRITON2/3), we evaluated the landscape of GAs detected in ctDNA and assessed concordance with tissue-based CGP. Results: A total of 3,129 patients (94%) had detectable ctDNA with a median ctDNA fraction of 7.5%; BRCA1/2 was mutated in 295 (8.8%). In concordance analysis, 72 of 837 patients had BRCA1/2 mutations detected in tissue, 67 (93%) of which were also identified using ctDNA, including 100% of predicted germline variants. ctDNA harbored some BRCA1/2 alterations not identified by tissue testing, and ctDNA was enriched in therapy resistance alterations, as well as possible clonal hematopoiesis mutations (e.g., in ATM and CHEK2). Potential androgen receptor resistance alterations were detected in 940 of 2,213 patients (42%), including amplifications, polyclonal and compound mutations, rearrangements, and novel deletions in exon 8. Conclusions: Genomic analysis of ctDNA from patients with mCRPC recapitulates the genomic landscape detected in tissue biopsies, with a high level of agreement in detection of BRCA1/2 mutations, but more acquired resistance alterations detected in ctDNA. CGP of ctDNA is a compelling clinical complement to tissue CGP, with reflex to tissue CGP if negative for actionable variants. See related commentary by Hawkey and Armstrong, p. 2961

PD-L1 immunohistochemistry (IHC) currently has the most Food and Drug Administration (FDA) approvals as a companion diagnostic (CDx) for immunotherapies in specific tumor types; however, multiple other immunotherapy biomarkers exist. We performed this study to examine and report the prevalence of PD-L1 expression in a wide variety of tumor types and examine its relationship to microsatellite instability (MSI), tumor mutational burden (TMB), and CD274 (PD-L1) gene amplification. We performed a retrospective analysis of all cases in which both PD-L1 IHC (using the DAKO 22C3 IHC assay with either tumor proportion score (TPS) or combined positive score (CPS); or the VENTANA SP142 assay with infiltrating immune cell score (IC)) and comprehensive genomic profiling (CGP) were tested at Foundation Medicine between January 2016 and November 2019. Of note, PD-L1 positivity is defined per the CDx indication and tumor proportion score (TPS ≥ 1) for indications without a CDx claim; and TMB positivity is defined as ≥10 mutations/Mb. A total of 48,782 cases were tested for PD-L1 IHC and CGP. Immune cell expression of PD-L1 was more frequently identified than tumor cell expression of PD-L1. We saw a high correlation between PD-L1 expression and CD274 gene amplification (p

We examined a large dataset of female metastatic breast cancers (MBCs) profiled with comprehensive genomic profiling (CGP) to identify the prevalence and distribution of immunotherapy responsiveness‐associated biomarkers. DNA was extracted from 3831 consecutive MBCs: 1237 (ERpos/HER2 neg), 1953 ERneg/HER2 amp, and 641 triple‐negative breast cancer (TNBC). CGP was performed using the FoundationOne® or FoundationOne®CDx NGS assay. Tumor mutational burden (TMB) and microsatellite instability (MSI) were determined in a subset of cases. PD‐L1 expression in immunocytes in a subset of cases was determined by immunohistochemistry using the companion diagnostic VENTANA PD‐L1 SP142 Assay. The median age of the cohort was 54 years (range 20–89). Genomic alterations (GAs)/tumor were similar (range: 5.9–7.3). Markers of potential immune checkpoint inhibitor (ICPI) benefit included: CD274 (PD‐L1) amplification (1%–3%), BRAF GA (1%–4%), TMB of ≥10 mutations/Mb (8%–12%), MSI‐high (0.1%–0.4%), PBRM1 GA (1%), and positive PD‐L1 staining of immunocytes ranging from 13% in ERpos/HER2 neg and 33% in ERneg/HER2 amp to 47% in the TNBC group. Potential markers of ICPI resistance included inactivating STK11 GA (1%–2%) and MDM2 amplification (3%–6%). MTOR pathway targets were common with lowest frequency in TNBC. ERBB2 short variant mutations were most frequent ERpos/HER2 neg and absent in TNBC. BRCA1/2 GA were least frequent in ERneg/HER2 amp. The demonstrations of clinical benefit of immunotherapy in MBC support the need for development and utilization of biomarkers to guide the use of ICPIs for these patients. In addition to guiding therapy selection, CGP shows potential to identify GA linked to response and resistance to ICPI in MBC., Both our results and published literature suggest that in addition to guiding targeted therapy selection, comprehensive genomic profiling shows potential to identify genomic alterations linked to response and resistance to immune checkpoint inhibitor (ICPI) therapy in metastatic breast cancer (MBC). The demonstration of clinical benefit of immune checkpoint blockade in MBC supports the need for the development of biomarkers used to guide the use of ICPI drugs for these patients.