23 research outputs found

    Quantum critical dynamics in a 5000-qubit programmable spin glass

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    Experiments on disordered alloys suggest that spin glasses can be brought into low-energy states faster by annealing quantum fluctuations than by conventional thermal annealing. Due to the importance of spin glasses as a paradigmatic computational testbed, reproducing this phenomenon in a programmable system has remained a central challenge in quantum optimization. Here we achieve this goal by realizing quantum critical spin-glass dynamics on thousands of qubits with a superconducting quantum annealer. We first demonstrate quantitative agreement between quantum annealing and time-evolution of the Schr\"odinger equation in small spin glasses. We then measure dynamics in 3D spin glasses on thousands of qubits, where simulation of many-body quantum dynamics is intractable. We extract critical exponents that clearly distinguish quantum annealing from the slower stochastic dynamics of analogous Monte Carlo algorithms, providing both theoretical and experimental support for a scaling advantage in reducing energy as a function of annealing time

    Nonfluent/Agrammatic PPA with In-Vivo Cortical Amyloidosis and Pick’s Disease Pathology

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    The role of biomarkers in predicting pathological findings in the frontotemporal dementia (FTD) clinical spectrum disorders is still being explored. We present comprehensive, prospective longitudinal data for a 66 year old, right-handed female who met current criteria for the nonfluent/agrammatic variant of primary progressive aphasia (nfvPPA). She first presented with a 3-year history of progressive speech and language impairment mainly characterized by severe apraxia of speech. Neuropsychological and general motor functions remained relatively spared throughout the clinical course. Voxel-based morphometry (VBM) showed selective cortical atrophy of the left posterior inferior frontal gyrus (IFG) and underlying insula that worsened over time, extending along the left premotor strip. Five years after her first evaluation, she developed mild memory impairment and underwent PET-FDG and PiB scans that showed left frontal hypometabolism and cortical amyloidosis. Three years later (11 years from first symptom), post-mortem histopathological evaluation revealed Pick's disease, with severe degeneration of left IFG, mid-insula, and precentral gyrus. Alzheimer’s disease (AD) (CERAD frequent/Braak Stage V) was also detected. This patient demonstrates that biomarkers indicating brain amyloidosis should not be considered conclusive evidence that AD pathology accounts for a typical FTD clinical/anatomical syndrome

    Quantum error mitigation in quantum annealing

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    Quantum Error Mitigation (QEM) presents a promising near-term approach to reduce error when estimating expectation values in quantum computing. Here, we introduce QEM techniques tailored for quantum annealing, using Zero-Noise Extrapolation (ZNE). We implement ZNE through zero-temperature extrapolation as well as energy-time rescaling. We conduct experimental investigations into the quantum critical dynamics of a transverse-field Ising spin chain, demonstrating the successful mitigation of thermal noise through both of these techniques. Moreover, we show that energy-time rescaling effectively mitigates control errors in the coherent regime where the effect of thermal noise is minimal. Our ZNE results agree with exact calculations of the coherent evolution over a range of annealing times that exceeds the coherent annealing range by almost an order of magnitude.Comment: 10 pages, 5 figure

    Nonfluent/agrammatic PPA with in-vivo cortical amyloidosis and Pick's disease pathology.

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    The role of biomarkers in predicting pathological findings in the frontotemporal dementia (FTD) clinical spectrum disorders is still being explored. We present comprehensive, prospective longitudinal data for a 66 year old, right-handed female who met current criteria for the nonfluent/agrammatic variant of primary progressive aphasia (nfvPPA). She first presented with a 3-year history of progressive speech and language impairment mainly characterized by severe apraxia of speech. Neuropsychological and general motor functions remained relatively spared throughout the clinical course. Voxel-based morphometry (VBM) showed selective cortical atrophy of the left posterior inferior frontal gyrus (IFG) and underlying insula that worsened over time, extending along the left premotor strip. Five years after her first evaluation, she developed mild memory impairment and underwent PET-FDG and PiB scans that showed left frontal hypometabolism and cortical amyloidosis. Three years later (11 years from first symptom), post-mortem histopathological evaluation revealed Pick's disease, with severe degeneration of left IFG, mid-insula, and precentral gyrus. Alzheimer's disease (AD) (CERAD frequent/Braak Stage V) was also detected. This patient demonstrates that biomarkers indicating brain amyloidosis should not be considered conclusive evidence that AD pathology accounts for a typical FTD clinical/anatomical syndrome

    Influence of Treatment Package Time on outcomes in High-Risk Oral Cavity Carcinoma in patients receiving Adjuvant Radiation and Concurrent Systemic Therapy: A Multi-Institutional Oral Cavity Collaborative study

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    OBJECTIVES: To explore the influence of treatment package time(TPT) in high-risk oral cavity squamous cell carcinoma(OCSCC) receiving adjuvant radiotherapy with concurrent chemotherapy(CRT). MATERIALS AND METHODS: We queried our multi-institutional OCSCC collaborative database for cases diagnosed between 2005 and 2015 who underwent surgery followed by adjuvant CRT. All patients had high-risk features: extranodal extension(ENE) and/or positive surgical margin(PM). TPT was days between surgery to last radiotherapy fraction. Kaplan-Meier curves, log-rank p-values and multivariate analysis(MVA) were used to investigate the impact of TPT on overall(OS), disease-free(DFS), locoregional failure-free(LRFS) and distant metastases-free(DMFS) survival. RESULTS: We identified 187 cases: median age 58 (range, 24-87 years), males 66%, and ever smokers 69%. ENE and PM were detected in 85% and 32%, and oral tongue and floor of the mouth constituted 49% and 18%, respectively. Median radiotherapy and cisplatin doses received were 66 Gy and 200 mg/m2. Overall, median TPT was 98 (range, 63-162 days). OS was worse for TPT \u3e 90-days (n = 134) than TPT ≤ 90 (n = 53) at two-(65% vs. 71%) and five-years (45% vs. 62%); p = 0.05, with similar results for DFS. No influence on LRFS or DMFS was noted. More lymph nodes(LN) dissected(P = 0.039), T3-4 disease(P = 0.017), and unplanned reoperations(P = 0.037) occurred with TPT \u3e 90-days. On MVA, TPT in 10-day increments was independently detrimental for OS (Hazard Ratio: 1.14; 95 %Confidence Interval [1-1.28]; P = 0.043), perineural invasion, age and positive LN (p \u3c 0.05 for all). CONCLUSION: In one of the largest multi-institutional cohorts, TPT \u3e 90-days predicted worse OS for high-risk OCSCC receiving adjuvant CRT. All efforts are needed to optimize perioperative care and baseline conditions for favorable outcomes

    Outcomes of Post-Operative Treatment with Concurrent Chemoradiotherapy (CRT) in High-Risk Resected Oral Cavity Squamous Cell Carcinoma (OCSCC): A Multi-Institutional Collaboration

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    Adjuvant chemoradiation (CRT), with high-dose cisplatin remains standard treatment for oral cavity squamous cell carcinoma (OCSCC) with high-risk pathologic features. We evaluated outcomes associated with different cisplatin dosing and schedules, concurrent with radiation (RT), and the effect of cumulative dosing of cisplatin. An IRB-approved collaborative database of patients (pts) with primary OCSCC (Stage I–IVB AJCC 7th edition) treated with primary surgical resection between January 2005 and January 2015, with or without adjuvant therapy, was established from six academic institutions. Patients were categorized by cisplatin dose and schedule, and resultant groups compared for demographic data, pathologic features, and outcomes by statistical analysis to determine disease free survival (DFS) and freedom from metastatic disease (DM). From a total sample size of 1282 pts, 196 pts were identified with high-risk features who were treated with adjuvant CRT. Administration schedule of cisplatin was not significantly associated with DFS. On multivariate (MVA), DFS was significantly better in patients without perineural invasion (PNI) and in those receiving ≥200 mg/m2 cisplatin dose (p < 0.001 and 0.007). Median DFS, by cisplatin dose, was 10.5 (<200 mg/m2) vs. 20.8 months (≥200 mg/m2). Our analysis demonstrated cumulative cisplatin dose ≥200 mg/m2 was associated with improved DFS in high-risk resected OCSCC pts

    Complications, Mortality, and Functional Decline in Patients 80 Years or Older Undergoing Major Head and Neck Ablation and Reconstruction

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    Importance Data regarding outcomes after major head and neck ablation and reconstruction in the growing geriatric population (specifically ≥80 years of age) are limited. Such information would be extremely valuable in preoperative discussions with elderly patients about their surgical risks and expected functional outcomes. Objectives To identify patient and surgical factors associated with 30-day postoperative complications, 90-day mortality, and 90-day functional decline; to explore whether an association exists between the type of reconstructive procedure and outcome; and to create a preoperative risk stratification system for these outcomes. Design, Setting, and Participants This retrospective, multi-institutional cohort study included patients 80 years or older undergoing pedicle or free-flap reconstruction after an ablative head and neck surgery from January 1, 2015, to December 31, 2017, at 17 academic centers. Data were analyzed from February 1 through April 20, 2019. Main Outcomes and Measures Thirty-day serious complication rate, 90-day mortality, and 90-day decline in functional status. Preoperative comorbidity and frailty were assessed using the American Society of Anesthesiologists classification, Adult Comorbidity Evaluation–27 score, and Modified Frailty Index. Multivariable clustered logistic regressions were performed. Conjunctive consolidation was used to create a risk stratification system. Results Among 376 patients included in the analysis (253 [67.3%] men), 281 (74.7%) underwent free-flap reconstruction. The median age was 83 years (range, 80-98 years). A total of 193 patients (51.3%) had 30-day serious complications, 30 (8.0%) died within 90 days, and 36 of those not dependent at baseline declined to dependent status (11.0%). Type of flap (free vs pedicle, bone vs no bone) was not associated with these outcomes. Variables associated with worse outcomes were age of at least 85 years (odds ratio [OR] for 90-day mortality, 1.19 [95% CI 1.14-1.26]), moderate or severe comorbidities (OR for 30-day complications, 1.80 [95% CI, 1.34-2.41]; OR for 90-day mortality, 3.33 [95% CI, 1.29-8.60]), body mass index (BMI) of less than 25 (OR for 30-day complications, 0.95 [95% CI, 0.91-0.99]), high frailty (OR for 30-day complications, 1.72 [95% CI, 1.10-2.67]), duration of surgery (OR for 90-day functional decline, 2.94 [95% CI, 1.81-4.79]), flap failure (OR for 90-day mortality, 3.56 [95% CI, 1.47-8.62]), additional operations (OR for 30-day complications, 5.40 [95% CI, 3.09-9.43]; OR for 90-day functional decline, 2.94 [95% CI, 1.81-4.79]), and surgery of the maxilla, oral cavity, or oropharynx (OR for 90-day functional decline, 2.51 [95% CI, 1.30-4.85]). Age, BMI, comorbidity, and frailty were consolidated into a novel 3-tier risk classification system. Conclusions and Relevance Important demographic, clinical, and surgical characteristics were found to be associated with postoperative complications, mortality, and functional decline in patients 80 years or older undergoing major head and neck surgery. Free flap and bony reconstruction were not independently associated with worse outcomes. A novel risk stratification system is presented
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