Prognostic value of serum oncomarkers for patients hospitalized with acute exacerbation of interstitial lung disease.

BACKGROUND: Different types of inflammatory processes and fibrosis have been implicated in the pathogenesis of interstitial lung disease (ILD), a heterogeneous, diffuse, parenchymal lung disease. Acute exacerbation (AE) of ILD is characterized by significant respiratory deterioration and is associated with high mortality rates. Several serum oncomarkers have been used to determine the prognosis of ILD; however, the prognostic value of serum oncomarker levels in patients with AE-ILD remains unclear. OBJECTIVE: To evaluate the prognostic value of serum oncomarker levels in patients with AE-ILD and its main subtypes. DESIGN: Retrospective study. METHODS: The serum levels of 8 oncomarkers in 281 patients hospitalized with AE-ILD at our institution between 2017 and 2022 were retrospectively reviewed. The baseline characteristics and serum oncomarker levels were compared between the survival and non-survival groups of AE-ILD and its main subtypes. Multivariate logistic regression analysis was performed to identify independent prognosis-related markers, and the best prognostic predictor was analyzed using receiver operating characteristic curve (ROC) analysis. RESULT: Idiopathic pulmonary fibrosis (IPF; n = 65), idiopathic nonspecific interstitial pneumonia (iNSIP; n = 26), and connective tissue disease-associated interstitial lung disease (CTD-ILD; n = 161) were the three main subtypes of ILD. The in-hospital mortality rate among patients with AE-ILD was 21%. The serum oncomarker levels of most patients with AE-ILD and its main subtypes in the non-survival group were higher than those in the survival group. Multivariate analysis revealed that ferritin and cytokeratin 19 fragments (CYFRA21-1) were independent prognostic risk factors for patients hospitalized with AE-ILD or AE-CTD-ILD. CYFRA21-1 was identified as an independent prognostic risk factor for patients hospitalized with AE-IPF or AE-iNSIP. CONCLUSION: CYFRA21-1 may be a viable biomarker for predicting the prognosis of patients with AE-ILD, regardless of the underlying subtype of ILD. Ferritin has a prognostic value in patients with AE-ILD or AE-CTD-ILD.

Clinical manifestations and prognostic factors analysis of patients hospitalised with acute exacerbation of idiopathic pulmonary fibrosis and other interstitial lung diseases.

BACKGROUND: Acute exacerbation (AE) is a life-threatening condition taking place not only in idiopathic pulmonary fibrosis (IPF) but also in interstitial lung diseases (ILD) other than IPF (non-IPF ILD). This study aims to compare the clinical manifestations between patients hospitalised with AE-IPF and AE-non-IPF ILD, and further analyse the risk factors related to in-hospital mortality. METHODS: Clinical data of 406 patients hospitalised with AE-IPF (93 cases) and AE-non-IPF ILD (313 cases) were retrospectively collected. Clinical features were compared between the two groups. Risk factors related to in-hospital mortality in patients with overall AE-ILD, AE-IPF and AE-non-IPF ILD were identified by multiple logistic regression analyses, respectively, and assessed by receiver operating characteristic curve. RESULTS: In addition to having more smokers and males, the AE-IPF group also had more respiratory failure on admission, comorbidities of pulmonary hypertension (PAH) or coronary artery disease/heart failure, a longer history of pre-existing ILD. Comorbidity of coronary heart disease/heart failure, respiratory failure at admission, neutrophil (N)%, serum hydroxybutyrate dehydrogenase (HBDH), lactate dehydrogenase (LDH) and low cholesterol levels were independent risk factors for patients with AE-ILD, while respiratory failure on admission, N%, serum HBDH, urea nitrogen, LDH and low albumin levels were risk factors for the AE-non-IPF ILD group, and fever, N% and PAH were the AE-IPF group's. Among them, HBDH 0.758 (sensitivity 85.5%, specificity 56%, cut-off 237.5 U/L) for patients with AE-ILD; N% 0.838 (sensitivity 62.5%, specificity 91.18%, cut-off 83.55%) for the AE-IPF group and HBDH 0.779 (sensitivity 86.4%, specificity 55.1%, cut-off 243.5 U/L) for the AE-non-IPF ILD group were the risk factors with the highest area under the curve. CONCLUSIONS: Clinical characteristics differ between patients with AE-IPF and AE-non-IPF ILD. HBDH outperformed LDH in predicting the prognosis for patients with AE-ILD and AE-non-IPF ILD. N% was an independent predictor of death in-hospital in all three groups, especially in the AE-IPF group.

Reconciling patterns of long-term topographic growth with coseismic uplift by synchronous duplex thrusting.

How long-term changes in surface topography relate to coseismic uplift is key to understanding the creation of high elevations along active mountain fronts, and remains hotly debated. Here we investigate this link by modeling the development of growth strata and the folding of river terraces above the Pishan duplex system in the southern Tarim Basin. We show that synchronous duplex thrusting of two neighboring faults with varying slip rates, associated with in-sequence propagation of the Pishan thrust system, is required to explain the presence of opposite-dipping panels of growth strata on the duplex front, and basinward migration of terrace fold crests. Importantly, this process of synchronous thrusting within the duplex reconciles the discrepancy between the deformation of terrace folds at the 10-1-100 million-year timescale and the maximum coseismic uplift of the 2015 Mw 6.4 Pishan earthquake on the frontal thrust. These results suggest that topography mismatch at different time scales can reflect the long-term kinematic evolution of fault systems. Thus, our study highlights the importance of characterizing complex subsurface fault kinematics for studying topographic growth, and motivates rethinking of the mountain building process in worldwide active fold-and-thrust belts, from short-term to long-term timescales.

Lupus pathogenesis and autoimmunity are exacerbated by high fat diet-induced obesity in MRL/lpr mice.

OBJECTIVE: SLE is an autoimmune disease characterised by persistent inflammation and autoantibody production. Genetic predisposition and environmental factors such as a high-fat diet (HFD) may contribute to lupus development. However, the immune cell profile and gender difference in response to HFD in lupus have not been reported. Here we investigated the impact of HFD on lupus pathogenesis and autoimmunity using lupus-prone mice. METHODS: Thirty male and 30 female MRL/lymphoproliferation (lpr) mice were fed with regular diet (RD) or HFD. Body weights were recorded weekly. SLE progression was monitored by skin lesion, urine protein, titres of antidouble-strand DNA (dsDNA) and ANA. At week 14, kidney and skin tissue sections were stained with H&E and periodic acid-Schiff to detect histological kidney index and skin score. Splenocytes were identified by immunofluorescence staining and flow cytometry. RESULTS: HFD significantly increased body weight and lipid levels compared with RD (p<0.01). Skin lesions were observed in 55.6% of the HFD group compared with 11.1% of the RD group, with greater histopathological skin scores in the female HFD group (p<0.01). Although both male and female mice had higher serum IgG in the HFD group than in the RD group, only the male HFD group showed an increased trend in anti-dsDNA Ab and ANA titres. Kidney pathological changes in the HFD group were more severe in male mice than in female mice (p<0.05), detected by proteinuria, kidney index and glomerular cell proliferation. Significant increases of germinal centre B cells and T follicular helper cells were observed in the spleens of HFD mice (p<0.05). CONCLUSION: HFD induced an accelerated and exacerbated lupus development and autoimmunity in MRL/lpr mice. Our results parallel many known clinical lupus phenotypes and sexual dimorphism in which male patients are likelier to have a severe disease (nephritis) than female lupus patients who may have a broader range of lupus symptoms.

Stellate ganglion block as an intervention in refractory eosinophilic granulomatosis with polyangiitis: a case report.

BACKGROUND: Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare vasculitis. Although glucocorticoid therapy with or without immunosuppressants leads to remission in the majority of cases, most EGPA patients remain dependent on glucocorticoid therapy and experience frequent relapses. Here, we report a case of refractory EGPA which responded to stellate ganglion blocks (SGBs). CASE PRESENTATION: A 32-year-old woman with aggravated wheezing, purpura, numbness of multiple fingers, and epigastric and abdominal pain was referred to our clinic. Laboratory and radiographic studies led to the diagnosis of EGPA. After an initial favorable response to glucocorticoid and immunosuppressant therapy, she experienced a relapse during a glucocorticoid taper. We found that SGB brought symptomatic relief and impeded disease progression. The mechanism of action of SGB on EGPA is undetermined, but may be related to vasodilation, immune modulation, and central nervous system regulation. CONCLUSIONS: This report not only proposes a novel treatment modality for EGPA, but also provides a clinical reference point for further in-depth studies of SGB in multiple immune-linked disorders.

Associations between sarcoidosis, autoimmune diseases, and autoantibodies: a single-center retrospective study in China.

To describe the clinical manifestations, immunological features, and risk factors in patients with sarcoidosis complicated with autoimmune diseases (ADs) as well as determine the frequency of autoantibodies and possible correlation between autoantibodies and laboratory data. Patients with pathologically confirmed sarcoidosis at Beijing Chaoyang Hospital (China) between January 2017 and October 2020 were included. Age- and sex-matched patients who visited the rheumatology outpatient clinic without systemic or ADs were included as controls. Demographic, clinical, serological, and radiological data of sarcoidosis patients were recorded and analyzed. To exclude ADs, autoantibodies, such as antinuclear antibody, extractable nuclear antigen antibodies, and anti-cyclic citrullinated peptide antibody were assessed in controls. A total of 154 sarcoidosis patients (111 females; 72.1%) with a mean ± standard deviation age of 50.7 ± 10.3 years were included. Nineteen patients (12.3%) had ADs; Hashimoto's thyroiditis (n = 6) and Sjogren's syndrome (n = 4) were common. Age, globulin, immunoglobulin G, erythrocyte sedimentation rate (ESR), and C-reactive protein were significantly different between sarcoidosis patients with and without ADs. The ESR level might be a risk factor for sarcoidosis complicated with ADs (RR = 1.053; P = 0.018). Autoantibodies were detected in 29 patients (18.8%), and the frequency was significantly higher than that in controls (18.8% vs. 3%; P = 0.001). Sarcoidosis patients were more likely to have autoantibodies despite the absence of ADs (10.4% vs. 3%; P = 0.031). Age may be a risk factor for sarcoidosis patients presenting with autoantibodies (RR = 1.077; P = 0.042). An association was identified between ADs and sarcoidosis. The inflammatory indexes, such as ESR, IgG, and CRP, were significantly different between sarcoidosis patients with and without ADs. ESR might be a risk factor for the coexistence of ADs and sarcoidosis. Sarcoidosis patients were prone to being autoantibody-positive despite the absence of ADs, and age might be a risk factor for sarcoidosis presenting with autoantibodies.

Screening of Quality Markers During the Processing of Reynoutria multiflora Based on the UHPLC-Q-Exactive Plus Orbitrap MS/MS Metabolomic Method.

The root of Reynoutria multiflora (Thunb.) Moldenke (syn: Polygonum multiflorum Thunb.) is a distinguished herb that has been popularly used in traditional Chinese medicine. The raw Reynoutria multiflora (RRM) should be processed by steaming before use, and the processing time is not specified in the processing specification. Our previous studies showed that the efficacy and toxicity of processed Reynoutria multiflora (PRM) at different processing times were inconsistent. A comprehensive identification method was established in this study to find a quality marker of raw Reynoutria multiflora (RRM) and processed Reynoutria multiflora (PRM) with different processing times. Metabolomics based on ultra-high-performance liquid chromatography tandem quadrupole/electrostatic field orbitrap high-resolution mass spectrometry (UHPLC-Q-Exactive plus orbitrap MS/MS) was used in this study. Using the CD.2 software processed database, multivariate statistical analysis methods coupled with cluster analysis and heatmap were implemented to distinguish between RRMs and PRMs with different processing times. The results showed that RRM and PRMs processed for 4, 8, 12, and 18 h cluster into group 1, and PRM processed for 24 and 32 h into group 2, indicating that it can effectively distinguish between the two groups and twenty potential markers, made the highest contributions to the observed chemical differences between two groups. Among them, tetrahydroxystilbene-O-hexoside-O-galloyl and sucrose can be used to identify PRM processed for 24 h. Therefore, the properties of RRM changed after 24 h of processing, and the quality markers were screened to distinguish RRM and PPM. It can also be used as an important control technology for the processing of RM, which has wide application prospects.

Clinical features of anti-synthetase syndrome associated interstitial lung disease: a retrospective cohort in China.

BACKGROUND: Anti-synthetase syndrome (ASSD) is a chronic autoimmune condition characterized by antibodies directed against an aminoacycl transfer RNA synthetase (ARS) along with a group of clinical features including the classical clinical triad: inflammatory myopathy, arthritis, and interstitial lung disease (ILD). ASSD is highly heterogenous due to different organ involvement, and ILD is the main cause of mortality and function loss, which presents as different patterns when diagnosed. We designed this retrospective cohort to describe the clinical features and disease behaviour of ASSD associated ILD. METHODS: Data of 108 cases of ASSD associated ILD were retrospectively collected in Beijing Chaoyang Hospital from December 2017 to March 2019. Data were obtained from the Electronic Medical Record system. Patients were divided into 5 groups according to distinct aminoacyl tRNA synthetase (ARS) antibodies. RESULTS: Overall, 108 consecutive patients were recruited. 33 were JO-1 positive, 30 were PL-7 positive, 23 were EJ positive, 13 were PL-12 positive and 9 were OJ positive. The JO-1 (+) group had a significant higher rate of mechanic's hand (57.6%) than other 4 groups. Polymyositis/dermatomyositis (PM/DM) was diagnosed in 25 (23.1%) patients and no difference was observed among the 5 groups. The PL-7 (+) group had a higher frequency of UIP pattern (13.3%) than the other 4 groups but the difference was not significant, and the EJ (+) group had the most frequent OP pattern (78.2%), which was significantly higher than the PL-7 (+) (P < 0.001) and PL-12 (+) groups (P = 0.025). The median follow-up time was 10.7 months, during which no patients died. All received prednisone treatment, with or without immunosuppressants. At the 6-month follow-up, 96.3% of all patients (104/108) had a positive response to therapy, the JO-1 (+) and EJ (+) groups had a significantly higher improvement of forced vital capacity than the other 3 groups (P < 0.05), and the PL-7 group had the lowest FVC improvement (P < 0.05). The JO-1 (+) group and EJ (+) group had significantly higher anti-Ro-52 positive occurrence than the other 3 groups (P < 0.05). CONCLUSION: Anti PL-7 antibody had the same frequency as anti-JO-1 in ASSD-ILD, in which the ILD pattern was different with distinct anti-ARS antibodies. Most ASSD-ILD had a positive response to steroid therapies, with or without immunosuppressants. The PL-7 (+) group had the highest occurrence of UIP pattern, and a significantly lower response to therapy.

Luminance calculation method accounting for mesopic vision and fog penetration ability.

A new luminance calculation method that accounts for mesopic vision and fog penetration ability is presented. This method aims to select a suitable light source for street lighting and is obtained using the mesopic luminance calculation and transmittance calculation methods at each individual wavelength. Additionally, the new method was evaluated using six LED light sources between 3500 and 6000 K. Overall, the calculation results indicate that suitable LEDs' CCT decreases with an increase of luminance for low transmittance rates. However, for high transmittance rates, high CCT LED lamps are the most suitable for street lighting. The recommended CCT of LED light sources for street lighting under different visibility and luminance conditions is presented.

Triple junction kinematics accounts for the 2016 Mw 7.8 Kaikoura earthquake rupture complexity.

The 2016, moment magnitude (Mw) 7.8, Kaikoura earthquake generated the most complex surface ruptures ever observed. Although likely linked with kinematic changes in central New Zealand, the driving mechanisms of such complexity remain unclear. Here, we propose an interpretation accounting for the most puzzling aspects of the 2016 rupture. We examine the partitioning of plate motion and coseismic slip during the 2016 event in and around Kaikoura and the large-scale fault kinematics, volcanism, seismicity, and slab geometry in the broader Tonga-Kermadec region. We find that the plate motion partitioning near Kaikoura is comparable to the coseismic partitioning between strike-slip motion on the Kekerengu fault and subperpendicular thrusting along the offshore West-Hikurangi megathrust. Together with measured slip rates and paleoseismological results along the Hope, Kekerengu, and Wairarapa faults, this observation suggests that the West-Hikurangi thrust and Kekerengu faults bound the southernmost tip of the Tonga-Kermadec sliver plate. The narrow region, around Kaikoura, where the 3 fastest-slipping faults of New Zealand meet, thus hosts a fault-fault-trench (FFT) triple junction, which accounts for the particularly convoluted 2016 coseismic deformation. That triple junction appears to have migrated southward since the birth of the sliver plate (around 5 to 7 million years ago). This likely drove southward stepping of strike-slip shear within the Marlborough fault system and propagation of volcanism in the North Island. Hence, on a multimillennial time scale, the apparently distributed faulting across southern New Zealand may reflect classic plate-tectonic triple-junction migration rather than diffuse deformation of the continental lithosphere.

Thymic epithelial tumor complicated by immunological abnormalities: results from a single-center retrospective study in China.

BACKGROUND: To describe the clinical manifestations, immunological features, treatments, and outcomes of patients with thymic epithelial tumor (TET) complicated by immunological abnormalities, and to improve knowledge on immunological abnormalities in this rare disease. METHODS: Patients with pathologically confirmed TET at Beijing Chaoyang Hospital between January 2013 and May 2018 were included in this study, and clinical data were analyzed retrospectively. Immunological abnormalities were classified into two groups as follows: Good syndrome (GS) and autoimmune disease (AD). RESULTS: Fifty-nine TET patients were enrolled; twenty-two patients (37.3%) had immune dysfunction. There were no gender, age, or histological type differences between groups with or without immunological abnormalities. Six patients had GS, of whom four patients were diagnosed after thymectomy. Recurrent respiratory infections, particularly opportunistic infections, were the most common manifestation. Three GS patients developed a second cancer (50%; P=0.011). Anti-infective therapy and immunoglobulin supplements effectively treated GS. Seventeen patients developed ADs, including myasthenia gravis (MG) (n=13), Hashimoto's thyroiditis (n=4), Sjogren's syndrome (n=1), rheumatoid arthritis (n=1), pemphigus (n=1), and Evans syndrome (n=1). One patient developed both MG and GS and 4 patients presented with two ADs. Three AD cases occurred after thymectomy. Pemphigus and 80% (8/10) of MG cases were resolved following thymectomy. CONCLUSIONS: There is a strong association between immunological abnormalities and TET, which may present at any time point during the disease, even after thymectomy. In addition to infection, GS patients are more likely to develop a second cancer. Thymectomy may produce favorable outcomes for MG in this study, while surgery does not improve immunodeficiency in GS patients.

Statistical monitoring for non-Gaussian processes based on MICA-KDR method.

The focus of the current work attempts to propose a purely data-based model for generating residuals for non-Gaussian process monitoring purposes, the idea of residual generation is borrowed from the field of model-based fault detection and applied in statistical monitoring, the generated residual instead of the measured variables is thus modeled and monitored. The proposed approach first employs the modified independent component analysis (MICA) algorithm to extract independent components (ICs) from a given dataset. Secondly, through assuming but only one variable is missing at one time, the known data regression (KDR) method dealing with missing data problem is then used for estimating the corresponding ICs. The inconsistency between the actual and estimated ICs is called residual and may present much lower level of non-Gaussianity, in contrast to the actual ICs. Thirdly, a principal component analysis based statistical monitoring model can be utilized for online fault detection based on the generated residual. Finally, the superiority and efficiency of the MICA-KDR approach over its counterparts are validated by implementing comparisons on two industrial processes, the proposed MICA-KDR method is demonstrated to be a comparative alternative in monitoring non-Gaussian processes.

A missing variable approach for decentralized statistical process monitoring.

The main focus of the current work is on the investigation and application of a missing variable approach in principal component analysis (PCA) model for decentralized process monitoring purpose. Given that the widely studied PCA algorithm can recover the correlations between measured variables, a missing variable approach is employed for computing score estimation error and residual estimation error from the developed PCA model. Through assuming but only one variable is missing in sequence, the residual between the actual and estimated components is generated and then monitored instead of the original data. The presented method implements a missing variable based offline modeling and online monitoring in a decentralized manner. Generally, the generated residual is expected to follow or at least become much closer to a Gaussian distribution, the resulted model has no restriction on Gaussian distributed dataset and can achieve salient monitoring performance in contrast to its counterparts. Finally, its superiority and effectiveness have been demonstrated by conducting comparisons on two industrial examples.

Breast panniculitis with liquefactive fat necrosis: A case report.

Panniculitis is a group of heterogeneous disorders characterized by inflammation of the subcutaneous adipose tissue. Panniculitis of breast tissue as the initial manifestation has rarely been reported and is often misdiagnosed. Breast panniculitis may cause substantial morbidity and early diagnosis and treatment are important for the prognosis of the disease. The present study has reported a case of panniculitis with inflammation of the mammary glands as the initial presentation and provided a detailed description of ultrasonography, X-ray, computed tomography, magnetic resonance imaging and other imaging features of breast panniculitis. The treatment and follow-up were also described. Following treatment with systemic corticosteroids combined with methotrexate and thalidomide for 2 months, the breast appeared to be normal without scar formation. The present case report provides a good reference for the future diagnosis and treatment of breast panniculitis.

Risk factors and treatment of pneumothorax secondary to granulomatosis with polyangiitis: a clinical analysis of 25 cases.

OBJECTIVES: To investigate the risk factors and treatment strategies for pneumothorax secondary to granulomatosis with polyangiitis (GPA). METHOD: Retrospective analysis of cases with pneumothorax secondary to GPA from our own practice and published on literature. RESULTS: A total of 25 patients, 18 males and 7 females, mean age 44 ± 15.7 years, were analyzed. Diagnosis included pneumothorax (11 cases), hydropneumothorax (n = 5), empyema (n = 8) and hemopneumothorax (n = 1). 88% (22/25) patients showed single/multiple pulmonary/ subpleural nodules with/without cavitation on chest imaging. Erythrocyte sedimentation rate and C-reactive protein were both elevated. Corticosteroids and immunosuppressive agents were used in 16 cases. Five cases received steroid pulse therapy, of which 4 patients survived. Pleural drainage was effective in some patients. Seven patients underwent surgical operations. In the 10 fatal cases, infection and respiratory failure were the most common cause. Lung biopsy/ autopsy showed lung/pleural necrotizing granulomatous vasculitis, breaking into the chest cavity, pleural fibrosis, bronchial pleural fistula, etc. The mean age in the death group was greater than the survival group (53 ± 12.9 years vs 40.1 ± 14.7 years, p = 0.05), the ineffective pleural drainage was also higher in the death group (5/5 vs 0/7, p = 0.01). CONCLUSIONS: Pneumothorax was seen in the active GPA, due to a variety of reasons, and gave rise to high fatality rate. Aggressive treatment of GPA can improve the prognosis. Older and lack of response for pleural drainage indicates poor prognosis.

A rare case of meningoencephalitis by Listeria monocytogenes in systemic lupus erythematosus: case report and review.

Patients with systemic lupus erythematosus (SLE) have a high risk of infection. Central nervous system infection and neuropsychiatric SLE are both major causes of death. It is vital to distinguish between these two conditions to improve prognosis due to the treatment paradigms required for each condition. Here, we report one case of meningoencephalitis by Listeria monocytogenes (LM) in a patient with SLE who presented with fever and developed headache and altered in consciousness in the hospital. The cerebrospinal fluid culture was positive for LM, and magnetic resonance imaging (MRI) findings were suggestive of ependymitis and periventricular white matter lesions. Amoxicillin/sulbactam, trimethoprim-sulfamethoxazole, and rifampicin were administered for 8 weeks. The patient had a relative good recovery without serious neurological sequelae after a follow-up of nearly 2 years. MRI abnormalities also had obvious resolution.

Successful treatment of granulomatosis with polyangiitis with hydropneumothorax using corticosteroids and immunosuppressant.

Pneumothorax and pleural effusion is a rare and serious complication of granulomatosis with polyangiitis (GPA). The present study reported a case with a history of sinusitis for 20 years, dry cough for three years and exacerbated purulent nasal discharge and recurrent skin ulcers for two years. The patient experienced sudden difficulty in breathing two months prior to presentation. Lung computed tomography (CT) showed multiple bilateral lung nodules and cavitary nodules as well as right hydropneumothorax. Paranasal sinus CT showed soft tissue infiltration. The cytoplasmic pattern of anti-neutrophil cytoplasmic antibody (c-ANCA) was positive and anti-proteinase 3 (PR3) antibodies, erythrocyte sedimentation rate and C-reactive protein were elevated. After pleural drainage and methylprednisolone pulse treatment, followed by cyclophosphamide and cyclosporine, the patient's symptoms were ameliorated, lungs were re-expanded, and c-ANCA, PR3 and inflammatory markers returned to normal levels.

Double-layer ensemble monitoring of non-gaussian processes using modified independent component analysis.

The modified independent component analysis (MICA) was proposed mainly to obtain a consistent solution that cannot be ensured in the original ICA algorithm and has been widely investigated in multivariate statistical process monitoring (MSPM). Within the MICA-based non-Gaussian process monitoring circle, there are two main problems, i.e., the selection of a proper non-quadratic function for measuring non-Gaussianity and the determination of dominant ICs for constructing latent subspace, have not been well attempted so far. Given that the MICA method as well as other MSPM approaches are usually implemented in an unsupervised manner, the two problems are always solved by some empirical criteria without respect to enhancing fault detectability. The current work aims to address the challenging issues involved in the MICA-based approach and propose a double-layer ensemble monitoring method based on MICA (abbreviated as DEMICA) for non-Gaussian processes. Instead of proposing an approach for selecting a proper non-quadratic function and determining the dominant ICs, the DEMICA method combines all possible base MICA models developed with different non-quadratic functions and different sets of dominant ICs into an ensemble, and a double-layer Bayesian inference is formulated as a decision fusion method to form a unique monitoring index for online fault detection. The effectiveness of the proposed approach is then validated on two systems, and the achieved results clearly demonstrate its superior proficiency.

Statistical process monitoring based on orthogonal multi-manifold projections and a novel variable contribution analysis.

Multivariate statistical methods have been widely applied to develop data-based process monitoring models. Recently, a multi-manifold projections (MMP) algorithm was proposed for modeling and monitoring chemical industrial processes, the MMP is an effective tool for preserving the global and local geometric structure of the original data space in the reduced feature subspace, but it does not provide orthogonal basis functions for data reconstruction. Recognition of this issue, an improved version of MMP algorithm named orthogonal MMP (OMMP) is formulated. Based on the OMMP model, a further processing step and a different monitoring index are proposed to model and monitor the variation in the residual subspace. Additionally, a novel variable contribution analysis is presented for fault diagnosis by integrating the nearest in-control neighbor calculation and reconstruction-based contribution analysis. The validity and superiority of the proposed fault detection and diagnosis strategy are then validated through case studies on the Tennessee Eastman benchmark process.