22 results on '"Jeffrey Yang"'
Search Results
2. Completeness of Resection and Long-Term Survival of Patients Undergoing Resection for Pathologic T3 NSCLC: An International Association for the Study of Lung Cancer Analysis.
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Ugalde Figueroa, Paula A., Marques, Edouard, Cilento, Vanessa J., Giroux, Dorothy J., Nishimura, Katherine K., Detterbeck, Frank C., Van Schil, Paul, Bertoglio, Pietro, Jeffrey Yang, Chi-Fu, and Fang, Wentao
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- 2024
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3. Role of sex in lung cancer risk prediction based on single low-dose chest computed tomography.
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Simon, Judit, Mikhael, Peter, Tahir, Ismail, Graur, Alexander, Ringer, Stefan, Fata, Amanda, Jeffrey, Yang Chi-Fu, Shepard, Jo-Anne, Jacobson, Francine, Barzilay, Regina, Sequist, Lecia V., Pace, Lydia E., and Fintelmann, Florian J.
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DISEASE risk factors ,LUNG cancer ,EARLY detection of cancer ,ARTIFICIAL intelligence ,COUGH - Abstract
A validated open-source deep-learning algorithm called Sybil can accurately predict long-term lung cancer risk from a single low-dose chest computed tomography (LDCT). However, Sybil was trained on a majority-male cohort. Use of artificial intelligence algorithms trained on imbalanced cohorts may lead to inequitable outcomes in real-world settings. We aimed to study whether Sybil predicts lung cancer risk equally regardless of sex. We analyzed 10,573 LDCTs from 6127 consecutive lung cancer screening participants across a health system between 2015 and 2021. Sybil achieved AUCs of 0.89 (95% CI: 0.85–0.93) for females and 0.89 (95% CI: 0.85–0.94) for males at 1 year, p = 0.92. At 6 years, the AUC was 0.87 (95% CI: 0.83–0.93) for females and 0.79 (95% CI: 0.72–0.86) for males, p = 0.01. In conclusion, Sybil can accurately predict future lung cancer risk in females and males in a real-world setting and performs better in females than in males for predicting 6-year lung cancer risk. [ABSTRACT FROM AUTHOR]
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- 2023
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4. An Investigation of Cancer-Directed Surgery for Different Histologic Subtypes of Malignant Pleural Mesothelioma.
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Mansur, Arian, Potter, Alexandra L., Zurovec, Alexander J., Nathamuni, Krithika V., Meyerhoff, R. Ryan, Berry, Mark F., Kang, Augustine, and Jeffrey Yang, Chi-Fu
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MESOTHELIOMA ,OVERALL survival ,SURVIVAL rate ,SURGERY ,DATABASES - Abstract
The role of cancer-directed surgery in the treatment of stage I-IIIA malignant pleural mesothelioma (MPM) by histologic subtypes remains controversial. The objective of this study was to evaluate the survival of the different histologic subtypes for stage I-IIIA MPM stratified by cancer-directed surgery and nonoperative management. How is the histologic subtype, clinical stage, and use of cancer-directed surgery for MPM associated with overall survival? Overall survival of patients with stage I-IIIA epithelioid, sarcomatoid, and biphasic MPM in the National Cancer Database from 2004 through 2017 who underwent cancer-directed surgery (ie, surgery with or without chemotherapy or radiation) or chemotherapy with or without radiation (nonoperative management) was evaluated using Kaplan-Meier analysis, multivariable Cox proportional hazards analysis, and propensity score-matched analysis. Of 2,285 patients with stage I-IIIA MPM who met inclusion criteria, histologic subtype was epithelioid in 71% of patients, sarcomatoid in 12% of patients, and biphasic in 17% of patients. Median survival was 20 months in the epithelioid group, 8 months in the sarcomatoid group, and 13 months in the biphasic group (P <.01). Among patients who underwent surgery, median survival was 25 months in the epithelioid group, 8 months in the sarcomatoid group, and 15 months in the biphasic group (P <.01). In multivariable Cox proportional hazards analyses, surgery was associated with improved survival in the epithelioid group (P <.01) but not in the sarcomatoid (P =.63) or biphasic (P =.21) groups. These findings were consistent in propensity score-matched analyses for each MPM histologic type. In this national analysis, cancer-directed surgery was found to be associated with improved survival for stage I-IIIA epithelioid MPM, but not for biphasic or sarcomatoid MPM. [ABSTRACT FROM AUTHOR]
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- 2023
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5. Meta-Analysis of Neoadjuvant Immunotherapy for Patients with Resectable Non-Small Cell Lung Cancer.
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Cao, Christopher, Le, Anthony, Bott, Matthew, Chi-Fu Jeffrey Yang, Gossot, Dominique, Melfi, Franca, Tian, David H., and Guo, Allen
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NON-small-cell lung carcinoma ,IMMUNOTHERAPY ,PROGNOSIS ,ADVERSE health care events ,TIBIAL plateau fractures ,NEOADJUVANT chemotherapy - Abstract
Purpose: Immunotherapy has created a paradigm shift in the treatment of metastatic non-small cell lung cancer (NSCLC), overcoming the therapeutic plateau previously achieved by systemic chemotherapy. There is growing interest in the utility of immunotherapy for patients with resectable NSCLC in the neoadjuvant setting. The present systematic review and meta-analysis aim to provide an overview of the existing evidence, with a focus on pathological and radiological response, perioperative clinical outcomes, and long-term survival. Methods: A systematic review was conducted using electronic databases from their dates of inception to August 2021. Pooled data on pathological response, radiological response, and perioperative outcomes were meta-analyzed where possible. Results: Eighteen publications from sixteen studies were identified, involving 548 enrolled patients who underwent neoadjuvant immunotherapy, of whom 507 underwent surgery. Pathologically, 52% achieved a major pathological response, 24% a complete pathological response, and 20% reported a complete pathological response of both the primary lesion as well as the sampled lymph nodes. Radiologically, 84% of patients had stable disease or partial response. Mortality within 30 days was 0.6%, and morbidities were reported according to grade and frequency. Conclusion: The present meta-analysis demonstrated that neoadjuvant immunotherapy was feasible and safe based on perioperative clinical data and completion rates of surgery within their intended timeframe. The pathological response after neoadjuvant immunotherapy was superior to historical data for patients who were treated with neoadjuvant chemotherapy alone, whilst surgical and treatment-related adverse events were comparable. The limitations of the study included the heterogenous treatment regimens, lack of long-term follow-up, variations in the reporting of potential prognostic factors, and potential publication bias. [ABSTRACT FROM AUTHOR]
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- 2021
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6. Reconsidering the American Joint Committee on Cancer Eighth Edition TNM Staging Manual Classifications for T2b and T3 NSCLC.
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Kumar, Arvind, Kumar, Sanjeevani, Gilja, Shivee, Potter, Alexandra L., Raman, Vignesh, Muniappan, Ashok, Liou, Douglas Z., Jeffrey Yang, Chi-Fu, Potter, Alexandra, and Liou, Douglas
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- 2021
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7. Estimating the Impact of Extended Delay to Surgery for Stage I Non-small-cell Lung Cancer on Survival.
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Mayne, Nicholas R., Elser, Holly C., Darling, Alice J., Raman, Vignesh, Liou, Douglas Z., Colson, Yolonda L., D’Amico, Thomas A., and Chi-Fu Jeffrey Yang
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- 2021
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8. The Effect of Tumor Size and Histologic Findings on Outcomes After Segmentectomy vs Lobectomy for Clinically Node-Negative Non-Small Cell Lung Cancer.
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Raman, Vignesh, Jawitz, Oliver K., Voigt, Soraya L., Rhodin, Kristen E., D'Amico, Thomas A., Harpole, David H., Jeffrey Yang, Chi-Fu, and Tong, Betty C.
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NON-small-cell lung carcinoma ,LOBECTOMY (Lung surgery) ,SQUAMOUS cell carcinoma ,SURVIVAL analysis (Biometry) ,LUNG cancer ,DATABASES ,ANTHROPOMETRY ,LUNG tumors ,RETROSPECTIVE studies ,TUMOR classification ,TREATMENT effectiveness ,PNEUMONECTOMY ,PROPORTIONAL hazards models - Abstract
Background: The interaction between tumor size and the comparative prognosis of lobar and sublobar resection has been defined poorly.Research Question: The purpose of this study was to characterize the relationship between tumor size and the receipt of segmentectomy or lobectomy in association with overall survival in patients with clinically node-negative non-small cell lung cancer (NSCLC).Study Design and Methods: The 2004-2015 National Cancer Database (NCDB) was queried for patients with cT1-3N0M0 NSCLC who underwent segmentectomy or lobectomy without neoadjuvant therapy or missing survival data. The primary outcome was overall survival, which was evaluated using multivariate Cox proportional hazards including an interaction term between tumor size and type of surgery.Results: A total of 143,040 patients were included: 135,446 (95%) underwent lobectomy and 7594 (5%) underwent segmentectomy. In multivariate Cox regression, a significant three-way interaction was found among tumor size, histologic results, and type of surgery (P < .001). When patients were stratified by histologic results, lobectomy was associated with significantly improved survival compared with segmentectomy beyond a tumor size of approximately 10 mm for adenocarcinoma and 15 mm for squamous cell carcinoma that was recapitulated in subgroup analyses. No interaction between tumor size and type of surgery was found for patients with neuroendocrine tumors.Interpretation: In this NCDB study of patients with node-negative NSCLC, we found different tumor size thresholds, based on histologic results, that identified populations of patients who least and most benefitted from lobectomy compared with segmentectomy. [ABSTRACT FROM AUTHOR]- Published
- 2021
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9. Impact of Surveillance After Lobectomy for Lung Cancer on Disease Detection and Survival.
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Mayne, Nicholas R., Mallipeddi, Mohan K., Darling, Alice J., Jeffrey Yang, Chi-Fu, Eltaraboulsi, Walid R., Shoffner, Adam R., Naqvi, Ibtehaj A., D'Amico, Thomas A., and Berry, Mark F.
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- 2020
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10. Improving arsenopyrite oxidation rate laws: implications for arsenic mobilization during aquifer storage and recovery (ASR).
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Neil, Chelsea W., Jason Todd, M., and Jeffrey Yang, Y.
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ARSENOPYRITE ,AQUIFER pollution ,GROUNDWATER pollution ,IRON sulfides ,WATER pollution - Abstract
Aquifer storage and recovery (ASR) and aquifer recharge (AR) provide technical solutions to address water supply deficits and growing future water demands. Unfortunately, the mobilization of naturally present arsenic due to ASR/AR operations has undermined its application on a larger scale. Predicting arsenic mobility in the subsurface during ASR/AR is further complicated by site-specific factors, including the arsenic mobilization mechanisms, groundwater flow conditions, and multi-phase geochemical interactions. In order to ensure safe and sustainable ASR/AR operation, a better understanding of these factors is needed. The current study thus aims to better characterize and model arsenic remobilization at ASR/AR sites by compiling and analyzing available kinetic data on arsenic mobilization from arsenopyrite under different aqueous conditions. More robust and widely applicable rate laws are developed for geochemical conditions relevant to ASR/AR. Sensitivity analysis of these new rate laws gives further insight into the controlling geochemical factors for arsenic mobilization. When improved rate laws are incorporated as the inputs for reactive transport modeling, arsenic mobilization in ASR/AR operations can be predicted with an improved accuracy. The outcomes will be used to guide groundwater monitoring and specify ASR/AR operational parameters, including water pretreatment requirements prior to injection. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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11. Actigraphy assessment of sleep quality among patients with acute myeloid leukaemia during induction chemotherapy.
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Chi-Fu Jeffrey Yang, Aibel, Kelli, Meyerhoff, Ryan, Wang, Frances, Harpole, David, Abernethy, Amy P., and LeBlanc, Thomas W.
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- 2018
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12. Long-term survival following open versus thoracoscopic lobectomy after preoperative chemotherapy for non-small cell lung cancer.
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Chi-Fu Jeffrey Yang, Meyerhoff, Robert Ryan, Mayne, Nicholas Ryan, Singhapricha, Terry, Toomey, Christopher B., Speicher, Paul J., Hartwig, Matthew G., Tong, Betty C., Onaitis, Mark W., Harpole Jr, David H., D'Amico, Thomas A., and Berry, Mark F.
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CANCER treatment ,NON-small-cell lung carcinoma ,CHEST endoscopic surgery ,LOBECTOMY (Lung surgery) ,PREOPERATIVE care ,CANCER chemotherapy ,LUNG cancer treatment - Abstract
OBJECTIVES: Video-assisted thoracoscopic (VATS) lobectomy is increasingly accepted for the management of early-stage non-small cell lung cancer (NSCLC), but its role for locally advanced cancers has not been as well characterized. We compared outcomes of patients who received induction therapy followed by lobectomy, via VATS or thoracotomy. METHODS: Perioperative complications and long-term survival of all patients with NSCLC who received induction chemotherapy (ICT) (with or without induction radiation therapy) followed by lobectomy from 1996-2012 were assessed using Kaplan-Meier and Cox proportional hazard analysis. Propensity score-matched comparisons were used to assess the potential impact of selection bias. RESULTS: From 1996 to 2012, 272 patients met inclusion criteria and underwent lobectomy after ICT: 69 (25%) by VATS and 203 (75%) by thoracotomy. An 'intent-to-treat' analysis was performed. Compared with thoracotomy patients, VATS patients had a higher clinical stage, were older, had greater body mass index, and were more likely to have coronary disease and chronic obstructive pulmonary disease. Induction radiation was used more commonly in thoracotomy patients [VATS 28% (n = 19) vs open 72% (n = 146), P < 0.001]. Thirty-day mortality was similar between the VATS [3% (n = 2)] and open [4% (n = 8)] groups (P = 0.69). Seven (10%) of the VATS cases were converted to thoracotomy due to difficulty in dissection from fibrotic tissue and adhesions (n = 5) or bleeding (n = 2); none of these conversions led to perioperative deaths. In univariate analysis, VATS patients had improved 3-year survival compared with thoracotomy (61% vs 43%, P = 0.010). In multivariable analysis, the VATS approach showed a trend towards improved survival, but this did not reach statistical significance (hazard ratio, 0.56; 95% confidence interval, 0.32-1.01; P = 0.053). Moreover, a propensity score-matched analysis balancing patient characteristics demonstrated that the VATS approach had similar survival to an open approach (P = 0.56). CONCLUSIONS: VATS lobectomy in patients treated with induction therapy for locally advanced NSCLC is feasible and effective and does not appear to compromise oncologic outcomes. [ABSTRACT FROM AUTHOR]
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- 2016
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13. Impact of patient selection and treatment strategies on outcomes after lobectomy for biopsy-proven stage IIIA pN2 non-small cell lung cancer.
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Chi-Fu Jeffrey Yang, Adil, Syed M., Anderson, Kevin L., Meyerhoff, Robert Ryan, Turley, Ryan S., Hartwig, Matthew G., Harpole Jr, David H., Tong, Betty C., Onaitis, Mark W., D'Amico, Thomas A., and Berry, Mark F.
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NON-small-cell lung carcinoma ,CANCER treatment ,PATIENT selection ,HEALTH outcome assessment ,LUNG cancer treatment ,LOBECTOMY (Lung surgery) ,BIOPSY - Abstract
OBJECTIVES: We evaluated the impact of patient selection and treatment strategies on long-term outcomes of patients who had lobectomy after induction therapy for stage IIIA pN2 non-small cell lung cancer (NSCLC). METHODS: The impact of various patient selection, induction therapy and operative strategies on survival of patients with biopsy-proven stage IIIA pN2 NSCLC who received induction chemotherapy ± radiation followed by lobectomy from 1995 to 2012 was assessed using Cox proportional hazards analysis. RESULTS: From 1995 to 2012, 111 patients had lobectomy for stage IIIA pN2 NSCLC after chemotherapy ± radiation with an overall 5-year survival of 39%. The use of induction chemoradiation decreased over time; from 1996 to 2007, 46/65 (71%) patients underwent induction chemoradiation, whereas from 2007 to 2012, 36/46 (78%) patients underwent induction chemotherapy. The use of video-assisted thoracoscopic surgery (VATS) increased over the time period of the study, from 0/26 (0%) in 1996-2001, to 4/39 (10%) in 2002-07 to 33/46 (72%) in 2008-12. Compared with patients given induction chemotherapy alone, patients given additional induction radiation were more likely to have complete pathologic response (30 vs 11%, P = 0.01) but had worse 5-year survival in univariable analysis (31 vs 48%, log-rank P = 0.021). Patients who underwent pathologic mediastinal restaging following induction therapy but prior to resection had an improved overall survival compared with patients who did not undergo pathologic mediastinal restaging {5-year survival: 45.2 [95% confidence interval (CI): 33.9-55.9] vs 13.9% (95% CI: 2.5-34.7); log-rank, P = 0.004}. In multivariable analysis, the particular induction therapy strategy and the surgical approach used, as well as the extent of mediastinal disease were not important predictors of survival. However, pathologic mediastinal restaging was associated with improved survival (HR 0.39; 95% CI: 0.21-0.72; P = 0.003). CONCLUSIONS: For patients with stage IIIA pN2 NSCLC, the VATS approach or the addition of radiation to induction therapy can be selectively employed without compromising survival. The strategy of assessing response to induction therapy with pathologic mediastinal restaging allows one to select appropriate patients for complete resection and is associated with a 5-year overall survival of 39% in this population. [ABSTRACT FROM AUTHOR]
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- 2016
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14. As if a Ring.
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Jeffrey Yang
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PAINTING ,MUSIC - Published
- 2017
15. Encouraging Guideline-Concordant Treatment for T3 NSCLC.
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Kumar, Arvind, Kumar, Sanjeevani, Gilja, Shivee, Potter, Alexandra, and Jeffrey Yang, Chi-Fu
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- 2021
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16. Chlorine decay and DBP formation under different flow regions in PVC and ductile iron pipes: Preliminary results on the role of flow velocity and radial mass transfer.
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Y. Jeffrey Yang, Impellitteri, Christopher A., Clark, Robert M., Haught, Roy C., Schupp, Donald A., Panguluri, Srinivas, and Krishnan, E. Radha
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- 2008
17. Mixing at double-Tee junctions with unequal pipe sizes in water distribution systems.
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Tingchao Yu, Hongying Qiu, Jeffrey Yang, Yu Shao, and Liang Tao
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PIPE size ,WATER distribution ,PIPE flow ,TURBULENT flow ,REYNOLDS number - Abstract
Pipe flow mixing with various solute concentrations and flow rates at pipe junctions is investigated. The degree of mixing affects contaminant spread in a water distribution system, and many studies have focused on mixing at the cross junctions; however, only a few have focused on double-Tee junctions of unequal pipe diameters. To investigate the solute mixing at such junctions, a series of experiments was conducted in a turbulent regime (Re = 12,500-50,000) with different Reynolds number ratios and connecting pipe lengths. Dimensionless outlet concentrations were found to depend on mixing mechanism at the impinging interface of junctions, where junctions with a larger pipe diameter ratio were associated with more complete mixing. Further, the inlet Reynolds number ratio affected mixing more strongly than the outlet Reynolds number ratio. Finally, the dimensionless connecting pipe length in a double-Tee played an important and complicated role in the flow mixing. The results were used to develop two-dimensional isopleth maps for the calculation of normalized north outlet concentrations. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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18. Comparative Sensor Fusion Between Hyperspectral and Multispectral Satellite Sensors for Monitoring Microcystin Distribution in Lake Erie.
- Author
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Chang, Ni-Bin, Vannah, Benjamin, and Jeffrey Yang, Y.
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Urban growth and agricultural production have caused an influx of nutrients into Lake Erie, leading to eutrophication in the water body. These conditions result in the formation of algal blooms, some of which are toxic due to the presence of Microcystis (a cyanobacteria), which produces the hepatotoxin microcystin. The hepatotoxin microcystin threatens human health and the ecosystem, and it is a concern for water treatment plants using the lake water as a tap water source. This study demonstrates the prototype of a near real-time early warning system using integrated data fusion and mining (IDFM) techniques with the aid of both hyperspectral (MERIS) and multispectral (MODIS and Landsat) satellite sensors to determine spatiotemporal microcystin concentrations in Lake Erie. In the proposed IDFM, the MODIS images with high temporal resolution are fused with the MERIS and Landsat images with higher spatial resolution to create synthetic images on a daily basis. The spatiotemporal distributions of microcystin within western Lake Erie were then reconstructed using the band data from the fused products with machine learning or data mining techniques such as genetic programming (GP) models. The performance of the data mining models derived using fused hyperspectral and fused multispectral sensor data are quantified using four statistical indices. These data mining models were further compared with traditional two-band models in terms of microcystin prediction accuracy. This study confirmed that GP models outperformed traditional two-band models, and additional spectral reflectance data offered by hyperspectral sensors produces a noticeable increase in the prediction accuracy especially in the range of low microcystin concentrations. [ABSTRACT FROM PUBLISHER]
- Published
- 2014
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19. Wave intensity analysis of para-aortic counterpulsation.
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Pong-Jeu Lu, Chi-Fu Jeffrey Yang, Meng-Yu Wu, Chun-Hao Hung, Ming-Yao Chan, and Tzu-Cheng Hsu
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Wave intensity analysis (WIA) was used to delineate and maximize the efficacy of a newly developed para-aortic blood pump (PABP). The intra-aortic balloon pump (IABP) was employed as the comparison benchmark. Acute porcine experiments using eight pigs, randomly divided into IABP (n = 4) and PABP (n = 4) groups, were conducted to compare the characteristics of intra- and para-aortic counterpulsation. We measured pressure and velocity with probes installed in the left anterior descending coronary artery and aorta, during and without PABP assistance. Wave intensity for aortic and left coronary waves were derived from pressure and flow measurements with synchronization correction applied. To achieve maximized support efficacy, deflation timings ranging from 25 ms ahead of to 35 ms after the R-wave were tested. Similar to those associated with IABP counterpulsation, the PABP-generated backward-traveling waves predominantly drove aortic and coronary blood flows. However, in contrast with IABP counterpulsation, the nonocclusive nature of the PABP allowed systolic unloading to be delayed into early systole, which resulted in near elimination of coronary blood steal without diminution of systolic left ventricular ejection wave intensities. WIA can elucidate subtleties among different counterpulsatile support means with high sensitivity. Total accelerating wave intensity (TAWI), which was defined as the sum of the time integration of accelerated parts of the positive and negative wave intensities, was used to quantify counterpulsation efficacy. In general, the larger the TAWI gain, the better the counterpulsatile support efficacy. However, when PABP deflation timings were delayed to after the R-wave, the TAWI was found to be inversely correlated with coronary perfusion. In this delayed deflation timing setting, greater wave cancellation occurred, which led to decreased TAWI but increased coronary perfusion attributed to blood regurgitation reduction. [ABSTRACT FROM AUTHOR]
- Published
- 2012
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20. Fathers have lower salivary testosterone levels than unmarried men and married non-fathers in Beijing, China.
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Peter B. Gray, Chi-Fu Jeffrey Yang, and Harrison G. Pope
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MAN-woman relationships ,TESTOSTERONE ,PARENTING - Abstract
A growing body of evidence, almost entirely from North America, has found that male testosterone levels are positively associated with mating effort (male–male competition and mate-seeking behaviour), while lower testosterone levels have been associated with affiliative pair bonding and paternal care. To expand the cross-cultural scope of this research, here we investigate variation in salivary testosterone levels among Chinese men in relation to marital and parenting variables. One hundred and twenty-six men drawn from a Beijing university setting between the ages of 21 and 38 completed a questionnaire and provided both morning and late afternoon saliva samples from which testosterone levels were measured. The 66 unmarried men had slightly higher levels of testosterone than the 30 married non-fathers, but this difference was not statistically significant. However, the 30 fathers exhibited significantly lower testosterone levels than both unmarried men and married non-fathers. Among married non-fathers, marital relationship quality was not significantly related to testosterone levels. Among married fathers, men with children aged less than 4 years of age did not have lower testosterone levels than men with older children. These data are the first outside of North America to show lower testosterone levels among fathers, and lend support to the theoretical view that male testosterone levels differ according to mating and parenting effort. [ABSTRACT FROM AUTHOR]
- Published
- 2006
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21. Effect of electrical bias on metastability in hydrogenated nanocrystalline silicon solar cells.
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Guozhen Yue, Baojie Yan, Jeffrey Yang, and Subhendu Guha
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SOLAR cells ,PHOTOVOLTAIC cells ,SILICON ,DIRECT energy conversion ,SOLAR energy ,NANOCRYSTALS - Abstract
The effect of electrical bias on metastability in hydrogenated nanocrystalline silicon (nc-Si:H) solar cells is studied. We find that forward bias current injection in the dark does not cause any degradation in nc-Si:H solar cells, while light soaking under reverse bias enhances the light-induced degradation in the cell performance. These phenomena are contrary to those found in hydrogenated amorphous silicon solar cells. We argue that the forward injected carriers mainly transport through the nanocrystallites where carrier recombination does not create metastable defects. The increased degradation under reverse bias is explained in terms of the heterogeneity of the material structure. [ABSTRACT FROM AUTHOR]
- Published
- 2005
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22. Highly sensitive thermal damage sensors for polymer composites: time temperature indicator based on thermochromic fluorescence turn-on response.
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Ryan Toivola, Tucker Howie, Jeffrey Yang, Po-Ni Lai, Zhengwei Shi, Sei-Hum Jang, Alex K-Y Jen, and Brian D Flinn
- Abstract
Carbon fiber epoxy composites have become prevalent in a variety of industries, especially in aerospace. The significant non-destructive evaluation (NDE) challenges of composites require new solutions, especially in detecting the onset of thermal damage. This work proposes the use of thermochromic fluorescent molecules dispersed in the composites as sensors for such detection. A molecule has been developed which transitions from a colorless, non-fluorescent state to a colorful, highly fluorescent state when exposed to temperature-time combinations that can cause damage in composites. This molecule dispersed in polymer composites of epoxy and PDMS matrices shows unique activation kinetics that can be used to quantitatively simulate the degradation kinetics of aerospace epoxies. The novel sensor materials based on the thermochromic activation of fluorescence can provide highly efficient and widely applicable NDE materials and techniques for carbon fiber epoxy composites. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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