Convex Hull-Based Multi-objective Genetic Programming for Maximizing ROC Performance

ROC is usually used to analyze the performance of classifiers in data mining. ROC convex hull (ROCCH) is the least convex major-ant (LCM) of the empirical ROC curve, and covers potential optima for the given set of classifiers. Generally, ROC performance maximization could be considered to maximize the ROCCH, which also means to maximize the true positive rate (tpr) and minimize the false positive rate (fpr) for each classifier in the ROC space. However, tpr and fpr are conflicting with each other in the ROCCH optimization process. Though ROCCH maximization problem seems like a multi-objective optimization problem (MOP), the special characters make it different from traditional MOP. In this work, we will discuss the difference between them and propose convex hull-based multi-objective genetic programming (CH-MOGP) to solve ROCCH maximization problems. Convex hull-based sort is an indicator based selection scheme that aims to maximize the area under convex hull, which serves as a unary indicator for the performance of a set of points. A selection procedure is described that can be efficiently implemented and follows similar design principles than classical hyper-volume based optimization algorithms. It is hypothesized that by using a tailored indicator-based selection scheme CH-MOGP gets more efficient for ROC convex hull approximation than algorithms which compute all Pareto optimal points. To test our hypothesis we compare the new CH-MOGP to MOGP with classical selection schemes, including NSGA-II, MOEA/D) and SMS-EMOA. Meanwhile, CH-MOGP is also compared with traditional machine learning algorithms such as C4.5, Naive Bayes and Prie. Experimental results based on 22 well-known UCI data sets show that CH-MOGP outperforms significantly traditional EMOAs

Label-free quantitative imaging of cholesterol in intact tissues by hyperspectral stimulated Raman scattering microscopy

A finger on the pulse: Current molecular analysis of cells and tissues routinely relies on separation, enrichment, and subsequent measurements by various assays. Now, a platform of hyperspectral stimulated Raman scattering microscopy has been developed for the fast, quantitative, and label-free imaging of biomolecules in intact tissues using spectroscopic fingerprints as the contrast mechanism

miR-638 is a new biomarker for outcome prediction of non-small cell lung cancer patients receiving chemotherapy.

MicroRNAs (miRNAs), a class of small non-coding RNAs, mediate gene expression by either cleaving target mRNAs or inhibiting their translation. They have key roles in the tumorigenesis of several cancers, including non-small cell lung cancer (NSCLC). The aim of this study was to investigate the clinical significance of miR-638 in the evaluation of NSCLC patient prognosis in response to chemotherapy. First, we detected miR-638 expression levels in vitro in the culture supernatants of the NSCLC cell line SPC-A1 treated with cisplatin, as well as the apoptosis rates of SPC-A1. Second, serum miR-638 expression levels were detected in vivo by using nude mice xenograft models bearing SPC-A1 with and without cisplatin treatment. In the clinic, the serum miR-638 levels of 200 cases of NSCLC patients before and after chemotherapy were determined by quantitative real-time PCR, and the associations of clinicopathological features with miR-638 expression patterns after chemotherapy were analyzed. Our data helped in demonstrating that cisplatin induced apoptosis of the SPC-A1 cells in a dose- and time-dependent manner accompanied by increased miR-638 expression levels in the culture supernatants. In vivo data further revealed that cisplatin induced miR-638 upregulation in the serum derived from mice xenograft models, and in NSCLC patient sera, miR-638 expression patterns after chemotherapy significantly correlated with lymph node metastasis. Moreover, survival analyses revealed that patients who had increased miR-638 levels after chemotherapy showed significantly longer survival time than those who had decreased miR-638 levels. Our findings suggest that serum miR-638 levels are associated with the survival of NSCLC patients and may be considered a potential independent predictor for NSCLC prognosis

Photoacoustic tomography of intact human prostates and vascular texture analysis identify prostate cancer biopsy targets

Prostate cancer is poorly visualized on ultrasonography (US) so that current biopsy requires either a templated technique or guidance after fusion of US with magnetic resonance imaging. Here we determined the ability for photoacoustic tomography (PAT) and US followed by texture-based image processing to identify prostate biopsy targets. K-means clustering feature learning and testing was performed on separate datasets comprised of 1064 and 1197 nm PAT and US images of intact, ex vivo human prostates. 1197 nm PAT was found to not contribute to the feature learning, and thus, only 1064 nm PAT and US images were used for final feature testing. Biopsy targets, determined by the tumor-assigned pixels' center of mass, located 100% of the primary lesions and 67% of the secondary lesions. In conclusion, 1064 nm PAT and US texture-based feature analysis provided successful prostate biopsy targets

A fiber optoacoustic guide with augmented reality for precision breast-conserving surgery

Lumpectomy, also called breast-conserving surgery, has become the standard surgical treatment for early-stage breast cancer. However, accurately locating the tumor during a lumpectomy, especially when the lesion is small and nonpalpable, is a challenge. Such difficulty can lead to either incomplete tumor removal or prolonged surgical time, which result in high re-operation rates (~25%) and increased surgical costs. Here, we report a fiber optoacoustic guide (FOG) with augmented reality (AR) for sub-millimeter tumor localization and intuitive surgical guidance with minimal interference. The FOG is preoperatively implanted in the tumor. Under external pulsed light excitation, the FOG omnidirectionally broadcasts acoustic waves through the optoacoustic effect by a specially designed nano-composite layer at its tip. By capturing the acoustic wave, three ultrasound sensors on the breast skin triangulate the FOG tip's position with 0.25-mm accuracy. An AR system with a tablet measures the coordinates of the ultrasound sensors and transforms the FOG tip's position into visual feedback with <1-mm accuracy, thus aiding surgeons in directly visualizing the tumor location and performing fast and accurate tumor removal. We further show the use of a head-mounted display to visualize the same information in the surgeons' first-person view and achieve hands-free guidance. Towards clinical application, a surgeon successfully deployed the FOG to excise a "pseudo tumor" in a female human cadaver. With the high-accuracy tumor localization by FOG and the intuitive surgical guidance by AR, the surgeon performed accurate and fast tumor removal, which will significantly reduce re-operation rates and shorten the surgery time

High‐speed Intraoperative Assessment of Breast Tumor Margins by Multimodal Ultrasound and Photoacoustic Tomography

Conventional methods for breast tumor margins assessment need a long turnaround time, which may lead to re‐operation for patients undergoing lumpectomy surgeries. Photoacoustic tomography (PAT) has been shown to visualize adipose tissue in small animals and human breast. Here, we demonstrate a customized multimodal ultrasound and PAT system for intraoperative breast tumor margins assessment using fresh lumpectomy specimens from 66 patients. The system provides the margin status of the entire excised tissue within 10 minutes. By subjective reading of three researchers, the results show 85.7% [95% confidence interval (CI), 42.0% ‐ 99.2%] sensitivity and 84.6% (95% CI, 53.7% ‐ 97.3%) specificity, 71.4% (95% CI, 30.3% ‐ 94.9%) sensitivity and 92.3% (95% CI, 62.1% ‐ 99.6%) specificity, and 100% (95% CI, 56.1% ‐ 100%) sensitivity and 53.9% (95% CI, 26.1% ‐ 79.6%) specificity respectively when cross‐correlated with post‐operational histology. Furthermore, a machine learning‐based algorithm is deployed for margin assessment in the challenging ductal carcinoma in situ tissues, and achieved 85.5% (95% CI, 75.2% ‐ 92.2%) sensitivity and 90% (95% CI, 79.9% ‐ 95.5%) specificity. Such results present the potential of using mutlimodal ultrasound and PAT as a high‐speed and accurate method for intraoperative breast tumor margins evaluation

The consensus guideline of perioperative antiviral therapy for AIDS patients in China based on clinical practice

The prevalence of human immunodeficiency virus (HIV) and acquired immune deficiency syndrome (AIDS) has emerged as a major public health concern in China. When patients with HIV infection undergo surgical treatment, there are two main challenges. Firstly, medical staff face a high risk of HIV infection due to occupational exposure. Secondly, the patient’s immune function is impaired, increasing the risk of opportunistic infections and postoperative complications. The surgical treatment of such patients is unique, and the risk of occupational exposure during the operation primarily depends upon the viral load of HIV/AIDS patients. Therefore, perioperative antiretroviral therapy is of paramount importance in order to standardize the perioperative antiretroviral therapy (ART) for HIV/AIDS patients. The Surgery Group of the Chinese Association of STD and AIDS Prevention and Control, in collaboration with the Treatment Association, and Surgery Group of the Chinese Medical Association of Tropical Diseases and Parasitology, has developed an expert consensus on perioperative antiretroviral therapy for HIV/AIDS patients. This consensus encompasses various aspects, including surgical risk assessment, selection of perioperative antiretroviral therapy regimens, prevention of opportunistic infections, and the crucial focus on rapid preoperative viral load reduction and immune function reconstruction for HIV/AIDS patients

Modelo de educación de la inteligencia colectiva

The research carried out is part of the field of study of Collective Intelligence (CI) with the use of Information and Communication Technologies (ICT) in Higher Education. The heart of this research was focused on the study, design and construction of electronic tools according to the paradigms of CI, to be applied in Higher Education. As an instrument for the implementation of these tools, an educational model with a collective work approach was designed. The research strategy used was Design-Based Research (DBR), because it investigates a phenomenon in its real context, iterative and incremental, and it is especially recommended for the field of education. DBR in each experimental cycle updates literature, model and tools. Empirical studies were conducted in four universities and fields of study in Latin America and Europe. The refinements demanded by the research strategy provided the scientific and empirical evidence to design ICT tools that meet the requirements of CI. In addition, the results indicate that the educational model and the tools have generated a positive perception in teachers and students about the effects on the teaching-learning process. Based on this fact, the experimental cycles present significant contributions to the research carried out around the CI with ICT tools in Higher Education.La investigación realizada se enmarca en el campo de estudio de la Inteligencia Colectiva (IC) con el uso de las Tecnologías de la Información y la Comunicaciones (TIC) en la Educación Superior. El corazón de ésta investigación estuvo enfocada en el estudio, diseño y construcción de herramientas electrónicas acorde a los paradigmas de IC, para ser aplicadas en la Educación Superior. Como vía de instrumentación de dichas herramientas, se diseñó un modelo educativo con enfoque de trabajo colectivo. La estrategia de investigación que se utilizó fue la Investigación Basada en el Diseño (DBR), porque investiga un fenómeno en su contexto real, es iterativa e incremental, y está especialmente recomendada para el ámbito de la educación.DBR en cada ciclo experimental actualiza literatura, modelo y herramientas. Los estudios empíricos se realizaron en cuatro universidades y campos de estudio en Hispanoamérica y Europa. Los múltiples refinamientos exigidos por la estrategia de investigación, proporcionaron la evidencia científica y empírica para diseñar herramientas TIC que cumplan con los requisitos de IC. Además, los resultados indican que el modelo educativo y las herramientas han generado una percepción positiva en docentes y estudiantes sobre los efectos en el proceso de enseñanza-aprendizaje. Basados en este hecho, los ciclos experimentales presentan aportes significativos a las investigaciones que se realizan en torno a la IC con herramientas TIC en la Educación Superior

Broad-line region in NGC 4151 monitored by two decades of reverberation mapping campaigns. I. Evolution of structure and kinematics

We report the results of long-term reverberation mapping (RM) campaigns of the nearby active galactic nuclei (AGN) NGC 4151, spanning from 1994 to 2022, based on archived observations of the FAST Spectrograph Publicly Archived Programs and our new observations with the 2.3m telescope at the Wyoming Infrared Observatory. We reduce and calibrate all the spectra in a consistent way, and derive light curves of the broad H$\beta$ line and 5100\,{\AA} continuum. Continuum light curves are also constructed using public archival photometric data to increase sampling cadences. We subtract the host galaxy contamination using {\it HST} imaging to correct fluxes of the calibrated light curves. Utilizing the long-term archival photometric data, we complete the absolute flux-calibration of the AGN continuum. We find that the H$\beta$ time delays are correlated with the 5100\,{\AA} luminosities as $\tau_{\rm H\beta}\propto L_{5100}^{0.46\pm0.16}$. This is remarkably consistent with Bentz et al. (2013)'s global size-luminosity relationship of AGNs. Moreover, the data sets for five of the seasons allow us to obtain the velocity-resolved delays of the H$\beta$ line, showing diverse structures (outflows, inflows and disks). Combining our results with previous independent measurements, we find the measured dynamics of the H$\beta$ broad-line region (BLR) are possibly related to the long-term trend of the luminosity. There is also a possible additional $\sim$1.86 years time lag between the variation in BLR radius and luminosity. These results suggest that dynamical changes in the BLR may be driven by the effects of radiation pressure.Comment: Accepted for publication in MNRAS; comments welcome