multivariate modeling
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A prediction model based on the processing of FTIR spectra and partial least squares regression (PLS) was developed for the determination of thehydroperoxide number of diesel fuels. The sets of calibration and validation standards were composed of fresh and aged diesel fuels. The hydroperoxide number determined via the standard titration method ranged from 0 to 65 mg·kg-1. While the calibration standards were utilized for the model construction, the validation standards were used for its optimization and validation. Several preprocessing methods, together with various numbers of latent variables, were utilized to improve model prediction ability. The model with the lowest Root Mean Square Error of Prediction was developed using mean centering, variance scaling, second derivative, and smoothing methods. Both examined smoothing techniques, i.e., Savitzky-Golay and Gap-Segment derivative, provided similar results. The use of the commonly available and affordable FTIR method, allowing rapid analysis, proved to be cost effective alternative to highly erroneous and laborious titration methods utilizing toxic reagents. In general, the developed model showed good predictive ability and is a perfect solution for fast screening of oxidative aging level of conventional hydrocarbon-based fuels.
- Klíčová slova
- FTIR spectroscopy, Hydroperoxide, Hydroperoxide number, Multivariate calibration, Partial least squares regression,
- Publikační typ
- časopisecké články MeSH
Compositional data are characterized by the fact that their elemental information is contained in simple pairwise logratios of the parts that constitute the composition. While pairwise logratios are typically easy to interpret, the number of possible pairs to consider quickly becomes too large even for medium-sized compositions, which may hinder interpretability in further multivariate analysis. Sparse methods can therefore be useful for identifying a few important pairwise logratios (and parts contained in them) from the total candidate set. To this end, we propose a procedure based on the construction of all possible pairwise logratios and employ sparse principal component analysis to identify important pairwise logratios. The performance of the procedure is demonstrated with both simulated and real-world data. In our empirical analysis, we propose three visual tools showing (i) the balance between sparsity and explained variability, (ii) the stability of the pairwise logratios, and (iii) the importance of the original compositional parts to aid practitioners in their model interpretation.
- Klíčová slova
- Compositional data, Geochemical data, Pairwise logratios, Sparse PCA,
- Publikační typ
- časopisecké články MeSH
BACKGROUND: Red wine is a common target of fraudulent acts considering its high market value and popularity. Although there has been much effort to assess the geographical and varietal origin of wine, this is not the case for wine vintage. Vintage is a crucial parameter for the market price, especially in the case of reputable wines. Considering the season-to-season variations affecting wine quality and the ever-occurring unstable climatological conditions due to climate change, developing analytical strategies to accurately assess wine vintage is topical and of high interest. RESULTS: In this study, we successfully employed ultraviolet-visible spectroscopy, fluorescence spectroscopy and mid-infrared spectroscopy to identify the vintage of a protected designation of origin red wine produced during four different vintages (n = 36). Class-based clustering and great discriminatory performance was achieved for the majority of the developed multivariate models and the impact of the applied spectral pre-processing was significant. Importantly, the tested scatter correction methods resulted in the best cross-validation parameters (goodness of fit, R2Y > 0.9 and goodness of prediction, Q2Y > 0.8) with calculated recognition and prediction abilities in the range 77-100% and 65-96%, respectively, when using partial least squares discriminant analysis. In addition, in the case of fluorescence spectroscopy, a batch effect was revealed, which was compensated by the spectral pre-processing methods. Spectral feature selection was performed in all cases to use only the analytically important spectral signals and omit model overfitting. CONCLUSIONS: The developed method is simple, cost-efficient and non-destructive, indicating its high potential for industrial applications as a rapid screening tool. © 2025 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
- Klíčová slova
- absorption spectroscopy, attenuated total reflectance Fourier transform infrared spectroscopy, chemometrics, spectral pre‐processing, wine authenticity,
- MeSH
- diskriminační analýza MeSH
- fluorescenční spektrometrie metody MeSH
- roční období MeSH
- spektrální analýza * metody MeSH
- víno * analýza MeSH
- Vitis * chemie růst a vývoj MeSH
- Publikační typ
- časopisecké články MeSH
- hodnotící studie MeSH
OBJECTIVE: To evaluate the impact of discordant histological diagnoses between transurethral resection of bladder tumour (TURBT) and radical cystectomy (RC) on cancer-specific mortality (CSM) in patients with bladder cancer (BCa). PATIENTS AND METHODS: We relied on a multi-institutional database collecting data of patients with BCa who underwent TURBT and subsequent RC from nine centres between 2000 and 2023. We tested concordance rates between TURBT and RC in detecting urothelial carcinoma of the urinary bladder (UCUB) as well as non-UCUB hystological subtypes, using RC as the reference standard. Concordance was defined as the agreement between a specific histological subtype identified both at TURBT and RC and evaluated according to Cohen's kappa coefficient. Subsequently, survival analyses consisted of Kaplan-Meier plots and multivariable Cox regression (MCR) models addressing CSM according to concordance between TURBT and RC (namely, concordant vs discordant). RESULTS: Overall, 3160 patients were identified. Of these, 2762 (87%) harboured UCUB and 398 (13%) non-UCUB at TURBT vs 2481 (79%) UCUB and 679 (21%) non-UCUB at RC. There were 683 (21.6%) patients with a discordant diagnosis between TURBT and RC. The overall concordance in detecting non-UCUB subtypes was defined as fair concordance (Cohen's kappa coefficient: 0.32). In MCR models, a discordant diagnosis exhibited higher CSM relative to those with a concordant diagnosis (hazard ratio [HR] 1.3, 95% confidence interval [CI] 1.1-1.6; P = 0.002). In a sensitivity analysis including patients with UCUB not exposed to neoadjuvant chemotherapy, this survival disadvantage was even higher (HR 1.5, 95% CI 1.1-1.7; P = 0.04). CONCLUSIONS: A discordant histopathological diagnosis between TURBT and RC is associated with higher CSM rates, particularly in cases initially misdiagnosed as UCUB. However, we also observed a moderate concordance between TURBT and RC in identifying non-UCUB subtypes.
- Klíčová slova
- accuracy, bladder cancer, bladder cancer histology, conconrdance, histological evaluation, histological subtypes, histological variants, radical cystectomy, survival, transurethral resection, turbt,
- MeSH
- cystektomie * metody MeSH
- karcinom z přechodných buněk * patologie chirurgie mortalita MeSH
- lidé středního věku MeSH
- lidé MeSH
- nádory močového měchýře * chirurgie patologie mortalita MeSH
- retrospektivní studie MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- transuretrální resekce močového měchýře MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- multicentrická studie MeSH
BACKGROUNDS: Autologous cell therapy (ACT) could be a treatment option for patients with chronic limb-threatening ischemia (CLTI) when standard vascular intervention is impossible. This study aimed to analyze risk factors affecting therapeutic success and identify patients with diabetes most responsive to ACT. METHODS: In this prospective study, 129 treatments were provided to 118 limbs in 107 no-option CLTI patients with diabetes. Bone marrow was obtained, and stem cells were processed and injected into the calf muscles of the affected limb. After 16 years, we analyzed the influence of baseline factors related to patients (diabetes parameters, comorbidities, medications), limb ischemia (TcPO2 value, Graziani and GLASS classifications), ulcer (descriptions according to Wagner, WIfI, SINBAD and Texas classifications), and infection (the value of CRP, the presence of the osteomyelitis, resistant bacteria and clinical signs of infections). Outcomes were limb salvage (LS) and amputation-free survival (AFS), which were assessed using Cox regression models. RESULTS: Major amputation was performed in 41 out of 118 limbs (31.8%). The use of immunosuppressive therapy (HR 2.48, CI 1.30-4.73), higher stages of GLASS FP (femoropopliteal) score (HR 1.58, CI 1.31-1.90) in the univariate model, and signs of clinical infection (HR 2.21, CI 1.01-4.839) in the multivariable model significantly impacted LS. Shorter AFS was associated with a higher GLASS FP score (HR 1.28, CI 1.13-1.46), dialysis (HR 2.05, CI 1.33 - 3.16 ), hypoalbuminemia (HR 0.93, CI 0.89-0.98), signs of clinical infection (HR 1.99, CI 1.26-3.15) in the univariable model, and immunosuppression (HR 2.31, CI 1.09-4.95) in the multivariable model. CONCLUSION: Decisions to manage patients with no-option CLTI should be based on involvement of the peripheral circulation, the presence of infection and co-morbidities. Those with minimal impairment of the FP segment, with the best possible nutritional status and without signs of infection would benefit the most. Furthermore, we should be careful with dialysis patients and those on immunosuppressive therapy.
- Klíčová slova
- Amputation, Amputation-free survival, Ischemia, Peripheral artery disease, Stem cell therapy,
- MeSH
- amputace MeSH
- autologní transplantace MeSH
- buněčná a tkáňová terapie * metody MeSH
- chronická kritická ischemie končetin * terapie MeSH
- ischemie * terapie MeSH
- lidé středního věku MeSH
- lidé MeSH
- prospektivní studie MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- záchrana končetiny * metody MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
BACKGROUND AND AIMS: Pulmonary embolism (PE) is a life-threatening condition with significant short- and long-term mortality risk. Although existing risk stratification models focus on short-term outcomes, the role of nutritional status in predicting long-term mortality remains underexplored. This retrospective study investigated the prognostic value of the Controlling Nutritional Status (CONUT) score, a composite index derived from serum albumin, total cholesterol, and lymphocyte counts. METHODS: A total of 274 patients with confirmed PE were treated at a tertiary care center between January 2021 and March 2023. The primary endpoint was long-term all-cause mortality, as assessed using hospital records and follow-up interviews. RESULTS: Multivariate analysis identified the CONUT score as an independent predictor of mortality (odds ratio [OR], 1.298; 95% confidence interval [CI], 1.066-1.580; P=0.009). A cut-off score of 2.5 demonstrated high prognostic accuracy (AUC, 0.844; sensitivity, 89%; specificity, 72%). Patients with higher CONUT scores exhibited increased inflammatory marker levels, lower serum albumin levels, and worse outcomes. CONCLUSION: These findings highlight CONUT score as a simple and cost-effective tool for assessing nutritional and inflammatory status, enabling improved long-term risk stratification in patients with PE. Future studies should validate these results in diverse populations and evaluate the impact of targeted nutritional and anti-inflammatory interventions on patient outcomes.
- Klíčová slova
- CONUT score, controlling nutritional status score, long-term mortality, pulmonary embolism,
- Publikační typ
- časopisecké články MeSH
BACKGROUND: This study aims to evaluate the clinical characteristics of COPD patients with AATD according to their age at diagnosis. METHODS: Data was obtained from the European Alpha-1 Research Collaboration (EARCO) registry, an international prospective cohort study. AATD patients with COPD registered between February 2020 and October 2024 were analysed. Clinical charateristics were compared between groups, stratified by age of AATD diagnosis as follows; <45, 45-65 and ≥65 years. A multivariable logistic regression model explored factors associated with age at diagnosis. RESULTS: A total of 1,565 AATD-COPD patients were included, with 18.2% receiving an AATD diagnosis at age ≥ 65. In univariate comparisons according to diagnosis age revealed that the prevalence of patients with Pi*ZZ mutation was lower in the ≥ 65 age group (47.1%) compared to the 45-65 (65.5%) and < 45 (78.5%) age groups. In contrast, the prevalence of Pi*SZ and Pi*SS were higher in the ≥ 65 group compared to the younger age groups. The proportion of never-smokers was highest in the ≥ 65 group (39.5%), whereas only 15.3% of patients under 45 were never-smokers. Multivariate analysis showed that; compared to never-smokers, former smoking (OR: 0.08; 95% CI: 0.03-0.23) and current smoking (OR: 0.43; 95% CI: 0.27-0.70) were negatively associated with a diagnosis at age ≥ 65 in all sample. Compared to the Pi*ZZ genotype, among all sample, Pi*SS was associated with more than a 3-fold increased likelihood of diagnosis at age ≥ 65 and when considering only index cases Pi*SZ was associated with diagnosis age of ≥ 65 (OR: 2.01, 95%CI: 1.01-4.04). Among patients with the Pi*ZZ, current smoking was negatively associated (OR:0.24,95%CI: 0.13-0.47) with a diagnosis at age ≥ 65, whereas higher FEV1% and serum AAT levels were positively associated with later diagnosis. CONCLUSION: Patients diagnosed at an older age had lower tobacco exposure and less severe disease. This suggests that subclinical symptoms may contribute to delays in diagnosis, as COPD features can be subtle or under-recognised until later in life. Our findings highlight the importance of considering AATD in all COPD patients, regardless of age, to avoid missed or delayed diagnoses.
- Klíčová slova
- AATD, COPD, Diagnosis age, Elderly,
- MeSH
- chronická obstrukční plicní nemoc * epidemiologie patofyziologie etiologie diagnóza MeSH
- deficit alfa1-antitrypsinu * komplikace genetika epidemiologie MeSH
- kouření epidemiologie MeSH
- lidé středního věku MeSH
- lidé MeSH
- logistické modely MeSH
- prevalence MeSH
- prospektivní studie MeSH
- registrace MeSH
- senioři MeSH
- věkové faktory MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Evropa epidemiologie MeSH
PURPOSE: We combined classical association analyses with one-sample and two-sample Mendelian randomization (MR), to comprehensively assess the causal relation among central corneal thickness (CCT), corneal hysteresis, Fuchs endothelial corneal dystrophy (FECD), and open-angle glaucoma (OAG). METHODS: We analyzed data from a large population-based cohort study (the Rotterdam Study), an FECD case-control study, and genome wide association study summary statistics. We defined OAG as reproducible visual field loss, independent of IOP. Multivariable regression was performed. One-sample MR was performed using the same regression models, with the corresponding genetic risk score (GRS) as independent variable. Two-sample MR was performed using inverse variance weighted, MR Egger, weighted median, simple mode, and weighted mode methods. RESULTS: In total, 303 participants with OAG and 10,598 controls from the Rotterdam Study were included, with 753 FECD cases from the FECD cohort. The odds ratio (OR) 95% confidence interval (CI) of OAG was 0.67 (95% CI = 0.56-0.81) per standard deviation (SD) increase in CCT (P < 0.001). However, one-sample MR showed no significant association between a CCT-GRS and OAG (P = 0.688). Two-sample MR found an OR (95% CI) of 1.23 (95% CI = 1.06-1.42) for each SD increase in the CCT instrumental variable. We observed no association between an FECD-GRS and OAG (P = 0.946). CONCLUSIONS: We found no evidence for a causal link between CCT and OAG. Nevertheless, CCT measurements are still valuable for population-based risk stratification. We found no clear relationship between FECD and OAG.
- MeSH
- celogenomová asociační studie MeSH
- Fuchsova endoteliální dystrofie * genetika MeSH
- glaukom s otevřeným úhlem * genetika patofyziologie diagnóza epidemiologie MeSH
- jednonukleotidový polymorfismus MeSH
- lidé středního věku MeSH
- lidé MeSH
- mendelovská randomizace * metody MeSH
- nitrooční tlak fyziologie MeSH
- rizikové faktory MeSH
- rohovka * patologie patofyziologie MeSH
- senioři MeSH
- studie případů a kontrol MeSH
- zraková pole fyziologie MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
BACKGROUND: There is a paucity of data on treatment outcomes following stereotactic radiosurgery (SRS) for brain metastases from sarcoma primaries. METHODS: The International Radiosurgery Research Foundation member-sites were queried for patients with brain metastases from sarcoma primaries treated with SRS. Overall survival (OS) and local control (LC) were calculated via Kaplan-Meier analysis. Univariate analyses examined prognostic factors associated with LC and OS via log-rank t-tests and multivariate analyses (MVA) via Cox proportional hazards model. RESULTS: A total of 146 patients with 309 brain metastases were identified. Two-hundred and thirty lesions were treated with single-fraction SRS with a median dose of 20 Gy (15-24 Gy). Ninety-five patients had extracranial metastases, including 75 oligometastatic patients. One- and 2-year OS and LC rates were 47.7% and 37.3%, and 78.3% and 62.2%, respectively. On univariate analyses, superior 1-year OS was noted among leiomyosarcomas (69.7% vs. 42.6%; p = .02) with poorer outcomes among pleomorphic histologies (10.5% vs. 50.7%; p = .002). Pleomorphic histologies were associated with poorer OS on MVA (hazard ratio [HR], 3.13; p = .006). On MVA, LC was inferior among patients of age ≥45 years (HR, 3.78; p < .001) and superior among leiomyosarcomas (HR, 0.31; p = .03). OS was prognosticated based on adverse factors (ie, nonleiomyosarcoma histology and progressive extracranial metastases). Two-year OS for patients with and without adverse features were 78.6% and 31.5%, respectively. CONCLUSIONS: LC outcomes were driven by histology and age with superior LC among leiomyosarcomas and patients of age <45 years. OS was driven by nonleiomyosarcoma histology and the presence of progressive extracranial disease.
- Klíčová slova
- brain metastases, local control, overall survival, sarcoma primary, stereotactic radiosurgery,
- MeSH
- dospělí MeSH
- Kaplanův-Meierův odhad MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladý dospělý MeSH
- nádory mozku * sekundární radioterapie mortalita chirurgie MeSH
- prognóza MeSH
- radiochirurgie * metody MeSH
- retrospektivní studie MeSH
- sarkom * patologie mortalita radioterapie sekundární MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- výsledek terapie MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- multicentrická studie MeSH
BACKGROUND: Personalized therapeutic approaches for localized prostate cancer have evolved significantly, with tissue-based biomarker tests supplementing traditional risk stratification tools. However, national testing patterns and geographic variability remain limited a decade after coverage implementation. We aimed to assess current nationwide utilization and urban-rural differences in tissue-based biomarker testing. METHODS: Using full Medicare claims data, we retrospectively identified patients with newly diagnosed prostate cancer and tissue-based biomarker testing claims from 2019 to 2023. Patients' county of residence was categorized as metro, urban, or rural. Regional testing rates were further assessed across hospital referral regions. A multivariable logistic regression model was performed to assess the effect of residence on test receipt. RESULTS: Our final cohort included 749 202 patients, of whom 79.5% lived in metro, 11.4% in urban and 8.00% in rural counties. Overall, 86 908 (11.6%) patients underwent tissue-based biomarker tests. Hospital referral region-level testing rates ranged from 2.4% to 42.7%. Rural patients were 18% less likely to undergo testing compared to metro patients (odds ratio [OR] 0.82, 95% CI = 0.73 to 0.91). Independently, the odds of undergoing testing were lower among Black (OR 0.82, 95% CI = 0.77 to 0.88) and Hispanic patients (OR 0.80, 95% CI = 0.73 to 0.88) compared to White patients. CONCLUSION: This study reveals high geographic variability in tissue-based biomarker testing for prostate cancer. Further, Black and Hispanic patients were less likely to receive testing. Our findings highlight regional practice variation in the use of advanced, not routinely recommended tests and underscore the need to minimize disparities in diagnostic access.
- MeSH
- běloch MeSH
- černoši nebo Afroameričané statistika a číselné údaje MeSH
- disparity zdravotní péče * statistika a číselné údaje etnologie MeSH
- lidé MeSH
- Medicare * statistika a číselné údaje MeSH
- městské obyvatelstvo statistika a číselné údaje MeSH
- nádorové biomarkery * analýza MeSH
- nádory prostaty * diagnóza patologie MeSH
- retrospektivní studie MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- venkovské obyvatelstvo statistika a číselné údaje MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Spojené státy americké MeSH
- Názvy látek
- nádorové biomarkery * MeSH