Using the Kriging Correlation for unsupervised feature selection problems.

This paper proposes a KC Score to measure feature importance in clustering analysis of high-dimensional data. The KC Score evaluates the contribution of features based on the correlation between the original features and the reconstructed features in the low dimensional latent space. A KC Score-based feature selection strategy is further developed for clustering analysis. We investigate the performance of the proposed strategy by conducting a study of four single-cell RNA sequencing (scRNA-seq) datasets. The results show that our strategy effectively selects important features for clustering. In particular, in three datasets, our proposed strategy selected less than 5% of the features and achieved the same or better clustering performance than when using all of the features.

Classification of Plank Techniques Using Wearable Sensors.

The plank is a common core-stability exercise. Developing a wearable inertial sensor system for distinguishing between acceptable and aberrant plank techniques and detecting specific deviations from acceptable plank techniques can enhance performance and prevent injury. The purpose of this study was to develop an inertial measurement unit (IMU)-based plank technique quantification system. Nineteen healthy volunteers (age: 20.5 ± 0.8 years, BMI: 22.9 ± 1.4 kg/m2) performed the standard plank technique and six deviations with five IMUs positioned on the occiput, cervical spine, thoracic spine, sacrum, and right radius to record movements. The random forest method was employed to perform the classification. The proposed binary tree classification model achieved an accuracy of more than 86%. The average sensitivities were higher than 90%, and the specificities were higher than 91%, except for one deviation (83%). These results suggest that the five IMU-based systems can classify the plank technique as acceptable or aberrant with good accuracy, high sensitivity, and acceptable specificity, which has significant implications in monitoring plank biomechanics and enabling coaching practice.

A network autoregressive model with GARCH effects and its applications.

In this study, a network autoregressive model with GARCH effects, denoted by NAR-GARCH, is proposed to depict the return dynamics of stock market indices. A GARCH filter is employed to marginally remove the GARCH effects of each index, and the NAR model with the Granger causality test and Pearson's correlation test with sharp price movements is used to capture the joint effects caused by other indices with the most updated market information. The NAR-GARCH model is designed to depict the joint effects of nonsynchronous multiple time series in an easy-to-implement and effective way. The returns of 20 global stock indices from 2006 to 2020 are employed for our empirical investigation. The numerical results reveal that the NAR-GARCH model has satisfactory performance in both fitting and prediction for the 20 stock indices, especially when a market index has strong upward or downward movements.

Suture granuloma mimicking local recurrence of colon cancer after open right hemicolectomy: a case report.

BACKGROUND: Foreign body granuloma is a rare surgery-related complication that can masquerade as cancer recurrence during postoperative surveillance. It may therefore deceive clinicians and lead to unnecessary interventions. The case presented herein demonstrates how a foreign body granuloma can be misleading in preoperative radiological studies and why this condition should not be ignored in differential diagnoses during surveillance of patients with previous history of abdominal surgery of any kind. CASE PRESENTATION: We report a case of suture granuloma mistaken for recurrent colon cancer, including the clinical history, imaging data, and histopathological photographs. A 60-year-old man was followed up at our institution after open right hemicolectomy 2 years earlier for ascending colon carcinoma. Contrast-enhanced computed tomography and magnetic resonance imaging revealed an infiltrative heterogeneous soft tissue lesion at the right mesenteric root, adjacent to the ileocolic anastomosis. Local recurrence was therefore suspected. We performed exploratory laparotomy, excised the tumor, and sent it for histopathological examination, which confirmed suture granuloma. CONCLUSIONS: Foreign body granuloma is a rare surgery-related complication that should be considered during surveillance following colectomy. Its radiological features may mimic recurrent lesions, thus misleading clinicians and causing unnecessary interventions or further complications.

A rare case of primary cutaneous diffuse large B-cell lymphoma, leg type, presenting as cellulitis: a case report.

Primary cutaneous diffuse large B-cell lymphoma, leg type, accounts for only 4% of all cutaneous lymphomas and bears a worse prognosis than other cutaneous B-cell lymphomas. Diagnosis at an early stage may be difficult due to its nonspecific manifestations. We report an 88-year-old female who was brought to our emergency department due to two rapidly growing painful skin lesions with local redness and swelling on her right lower leg. We performed incisional biopsy of the two right lower leg skin lesions and sent the specimens for histopathological examination. The pathological examination was compatible with diffuse large B-cell lymphoma. Primary cutaneous diffuse large B-cell lymphoma, leg type, is a rare condition that can present as skin cellulitis, thereby misleading clinicians and resulting in delayed treatment. This diagnosis should be considered when assessing skin lesions.

Leiomyomatosis peritonealis disseminata mimicking peritoneal carcinomatosis 13 years after laparoscopic uterine myomectomy: A case report.

INTRODUCTION: Leiomyomatosis peritonealis disseminata (LPD) is a rare clinical condition that can be challenging to diagnose because its clinical features mimic other conditions. We present a case of LPD mimicking peritoneal carcinomatosis 13 years after laparoscopic uterine myomectomy using a power morcellator. The aim of this paper is to report a rare case which surgeons can learn from and to provide more clinical information for further studies to investigate LPD. PRESENTATION OF CASE: A 49-year-old woman was referred to us because sonography revealed abnormal abdominal and pelvic nodules. Thirteen years previously, she had undergone laparoscopic uterine myomectomy using a power morcellator. An exploratory laparotomy revealed nodules on the peritoneum, greater omentum, intestinal mesentery, and terminal ileum. We surgically removed all visible nodules and performed bilateral salpingo-oophorectomy. LPD was confirmed based on the morphology and immunohistochemistry results. DISCUSSION: Diagnosing LPD preoperatively may be difficult because its clinical manifestations resemble peritoneal carcinomatosis or metastatic lesions. Abdominal pain due to diffuse tumor growth is a common manifestation. LPD degenerating into malignancy is rare, but possible. The probable etiological factors, clinical manifestations, and treatment options which may aid when dealing with LPD have been described in this report. CONCLUSION: LPD should be considered in women, particularly those with a history of gynecologic surgery presenting with disseminated intraabdominal or pelvic tumors.

Incidence and management of metabolic acidosis with sodium bicarbonate in the ICU: An international observational study.

BACKGROUND: Metabolic acidosis is a major complication of critical illness. However, its current epidemiology and its treatment with sodium bicarbonate given to correct metabolic acidosis in the ICU are poorly understood. METHOD: This was an international retrospective observational study in 18 ICUs in Australia, Japan, and Taiwan. Adult patients were consecutively screened, and those with early metabolic acidosis (pH < 7.3 and a Base Excess < -4 mEq/L, within 24-h of ICU admission) were included. Screening continued until 10 patients who received and 10 patients who did not receive sodium bicarbonate in the first 24 h (early bicarbonate therapy) were included at each site. The primary outcome was ICU mortality, and the association between sodium bicarbonate and the clinical outcomes were assessed using regression analysis with generalized linear mixed model. RESULTS: We screened 9437 patients. Of these, 1292 had early metabolic acidosis (14.0%). Early sodium bicarbonate was given to 18.0% (233/1292) of these patients. Dosing, physiological, and clinical outcome data were assessed in 360 patients. The median dose of sodium bicarbonate in the first 24 h was 110 mmol, which was not correlated with bodyweight or the severity of metabolic acidosis. Patients who received early sodium bicarbonate had higher APACHE III scores, lower pH, lower base excess, lower PaCO2, and a higher lactate and received higher doses of vasopressors. After adjusting for confounders, the early administration of sodium bicarbonate was associated with an adjusted odds ratio (aOR) of 0.85 (95% CI, 0.44 to 1.62) for ICU mortality. In patients with vasopressor dependency, early sodium bicarbonate was associated with higher mean arterial pressure at 6 h and an aOR of 0.52 (95% CI, 0.22 to 1.19) for ICU mortality. CONCLUSIONS: Early metabolic acidosis is common in critically ill patients. Early sodium bicarbonate is administered by clinicians to more severely ill patients but without correction for weight or acidosis severity. Bicarbonate therapy in acidotic vasopressor-dependent patients may be beneficial and warrants further investigation.

A Shape Approximation for Medical Imaging Data.

This study proposes a shape approximation approach to portray the regions of interest (ROI) from medical imaging data. An effective algorithm to achieve an optimal approximation is proposed based on the framework of Particle Swarm Optimization. The convergence of the proposed algorithm is derived under mild assumptions on the selected family of shape equations. The issue of detecting Parkinson's disease (PD) based on the Tc-99m TRODAT-1 brain SPECT/CT images of 634 subjects, with 305 female and an average age of 68.3 years old from Kaohsiung Chang Gung Memorial Hospital, Taiwan, is employed to demonstrate the proposed procedure by fitting optimal ellipse and cashew-shaped equations in the 2D and 3D spaces, respectively. According to the visual interpretation of 3 experienced board-certified nuclear medicine physicians, 256 subjects are determined to be abnormal, 77 subjects are potentially abnormal, 174 are normal, and 127 are nearly normal. The coefficients of the ellipse and cashew-shaped equations, together with some well-known features of PD existing in the literature, are employed to learn PD classifiers under various machine learning approaches. A repeated hold-out with 100 rounds of 5-fold cross-validation and stratified sampling scheme is adopted to investigate the classification performances of different machine learning methods and different sets of features. The empirical results reveal that our method obtains 0.88 ±0.04 classification accuracy, 0.87 ±0.06 sensitivity, and 0.88 ±0.08 specificity for test data when including the coefficients of the ellipse and cashew-shaped equations. Our findings indicate that more constructive and useful features can be extracted from proper mathematical representations of the 2D and 3D shapes for a specific ROI in medical imaging data, which shows their potential for improving the accuracy of automated PD identification.

Patterns of Oxygen Pulse Curve in Response to Incremental Exercise in Patients with Chronic Obstructive Pulmonary Disease - An Observational Study.

In COPD, pulmonary hyperinflation causes decreased stroke volume thereby decreased oxygen pulse (O2P). While O2P flattening is related to myocardial ischemia in cardiac patients, O2P patterns have seldom been explored in COPD. The aims of the study were to investigate O2P-curve patterns and associated factors in COPD. Seventy-five patients with stable COPD were enrolled. The demographics, cardiac size, physiological measurements and stress EKG were compared among O2P-curve pattern groups. An algorithm to identify O2P-curve patterns was developed in 28 patients. In the remaining 45 patients after excluding two with poor effort, this algorithm revealed 20 (44%) flattening, 16 (36%) increasing, and nine (20%) decreasing patterns. The flattening-type group had lower body mass, cardiac size, and diffusing capacity, and larger lung volumes (p = 0.05-<0.0001) compared to the increasing-type group. During exercise, the flattening-type group had a lower operable O2P and more hyperventilation and dyspnea (p = 0.02-<0.01). None had ST-T changes. Most differences were related to body mass and mildly to inspiratory fraction. The decreasing-type group performed higher effort than the increasing-type group (p < 0.05). In conclusion, O2P flattening was common and was associated with reduced body mass and pulmonary hyperinflation rather than with myocardial ischemia. The decreasing-type may be caused by motivation to exercise.

Instantaneous responses to high-frequency chest wall oscillation in patients with acute pneumonic respiratory failure receiving mechanical ventilation: A randomized controlled study.

BACKGROUND: Endotracheal intubation and prolonged immobilization of patients receiving mechanical ventilation may reduce expectoration function. High-frequency chest wall oscillation (HFCWO) may ameliorate airway secretion movement; however, the instantaneous changes in patients' cardiopulmonary responses are unknown. Moreover, HFCWO may influence ventilator settings by the vigorous oscillation. The aim of this study was to investigate these issues. METHODS: Seventy-three patients (52 men) aged 71.5 ±â€Š13.4 years who were intubated with mechanical ventilation for pneumonic respiratory failure were recruited and randomly classified into 2 groups (HFCWO group, n = 36; and control group who received conventional chest physical therapy (CCPT, n = 37). HFCWO was applied with a fixed protocol, whereas CCPT was conducted using standard protocols. Both groups received sputum suction after the procedure. Changes in ventilator settings and the subjects' responses were measured at preset intervals and compared within groups and between groups. RESULTS: Oscillation did not affect the ventilator settings (all P > 0.05). The mean airway pressure, breathing frequency, and rapid shallow breathing index increased, and the tidal volume and SpO2 decreased (all P < 0.05). After sputum suction, the peak airway pressure (Ppeak) and minute ventilation decreased (all P < 0.05). The HFCWO group had a lower tidal volume and SpO2 at the end of oscillation, and lower Ppeak and tidal volume after sputum suction than the CCPT group. CONCLUSIONS: HFCWO affects breathing pattern and SpO2 but not ventilator settings, whereas CCPT maintains a steadier condition. After sputum suction, HFCWO slightly improved Ppeak compared to CCPT, suggesting that the study extends the indications of HFCWO for these patients in intensive care unit. (ClinicalTrials.gov number NCT02758106, retrospectively registered.).

Revisiting Unplanned Endotracheal Extubation and Disease Severity in Intensive Care Units.

Most reports regarding unplanned extubation (UE) are case-control studies with matching age and disease severity. To avoid diminishing differences in matched factors, this study with only matching duration of mechanical ventilation aimed to re-examine the risk factors and the factors governing outcomes of UE in intensive care units (ICUs). This case-control study was conducted on 1,775 subjects intubated for mechanical ventilation. Thirty-seven (2.1%) subjects with UE were identified, and 156 non-UE subjects were randomly selected as the control group. Demographic data, acute Physiological and Chronic Health Evaluation II (APACHE II) scores, and outcomes of UE were compared between the two groups. Logistic regression analysis was used to identify the risk factors of UE. Milder disease, younger age, and higher Glasgow Coma Scale (GCS) scores with more frequently being physically restrained (all p<0.05) were related to UE. Logistic regression revealed that APACHE II score (odds ratio (OR) 0.91, p<0.01), respiratory infection (OR 0.24, p<0.01), physical restraint (OR 5.36, p<0.001), and certain specific diseases (OR 3.79-5.62, p<0.05) were related to UE. The UE patients had a lower ICU mortality rate (p<0.01) and a trend of lower in-hospital mortality rate (p = 0.08). Cox regression analysis revealed that in-hospital mortality was associated with APACHE II score, age, shock, and oxygen used, all of which were co-linear, but not UE. The results showed that milder disease with higher GCS scores thereby requiring a higher use of physical restraints were related to UE. Disease severity but not UE was associated with in-hospital mortality.

High Vertical Resolution Full-Field Reflection-Type Three-Dimensional Angle-Deviation Microscope with Nonlinear Error Compensation.

This study examines the use of reflectivity-height transformation in full-field angle-deviation microscopes (ADM). In such microscopes, two light intensity distribution images of a prism's total internal reflection and critical angle are obtained separately with two charge-coupled devices (CCDs), and are converted into a reflectivity profile point-to-point and then into angle of deviation matrix after the beam is reflected by the test sample; finally, the surface height of the sample is found through the triangular geometrical relationship. This method obtains the image through the effective imaging area of CCD. Once the two-dimensional (2D) image is obtained, the third dimension, height, is added to create a full-field 3D surface profile. Its conversion process is nonlinear; therefore, compensation must be made to reduce measurement errors. The optical magnification of high vertical resolution full-field 3D reflection-type ADM could reach >250 times, thus providing submicron measurements with nanometer vertical resolution and allowing for the simultaneous measurement of 2D and 3D images. Small defects on both transparent and nontransparent surfaces can be rapidly detected.

Cardiovascular and respiratory dysfunction in chronic obstructive pulmonary disease complicated by impaired peripheral oxygenation.

BACKGROUND: Impaired peripheral oxygenation (IPO)-related variables readily achieved with cardiopulmonary exercise testing (CPET) represent cardiovascular dysfunction. These variables include peak oxygen uptake ( [Formula: see text] predicted, anaerobic threshold [Formula: see text] predicted, [Formula: see text] rate slope <8.6 mL/watt, oxygen pulse <80% predicted, and ventilatory equivalents for O2 and CO2 at nadir of >31 and >34, respectively. Some of these six variables may be normal while the others are abnormal in patients with chronic obstructive pulmonary disease (COPD). This may result in confusion when using the interpretation algorithm for diagnostic purposes. We therefore hypothesized that patients found to have abnormal values for all six variables would have worse cardiovascular function than patients with abnormal values for none or some of these variables. METHODS: In this cross-sectional comparative study, 58 COPD patients attending a university teaching hospital underwent symptom-limited CPET with multiple lactate measurements. Patients with abnormal values in all six IPO-related variables were assigned to an IPO group while those who did not meet the requirements for the IPO group were assigned to a non-IPO group. Cardiovascular function was measured by two-dimensional echocardiography and [Formula: see text], and respiratory dynamics were compared between the two groups. RESULTS: Fourteen IPO and 43 non-IPO patients were entered into the study. Both groups were similar with regard to left ventricular ejection fraction and right ventricular morphology (P>0.05 for both). At peak exercise, both groups reached a similar heart rate level and [Formula: see text]. The IPO patients had an unfavorable dead space to tidal volume ratio, mean inspiratory tidal flow, and shallow breathing (P<0.05-P<0.001). CONCLUSION: Our IPO and non-IPO patients with COPD had similar cardiovascular performance at rest and at peak exercise, indicating that IPO variables are non-specific for cardiovascular function in these patients. COPD patients with full IPO variables have more deranged ventilatory function.