Deep learning reconstruction for zero echo time lung magnetic resonance imaging: impact on image quality and lesion detection.

AIMS: This study aimed to examine the impact of deep-learning reconstruction (DLR) on zero echo time (ZTE) lung MRI. MATERIALS AND METHODS: Fifty-nine patients who underwent both chest CT and ZTE lung magnetic resonance imaging (MRI) were enrolled. Noise reduction in ZTE lung MRI was compared using various DLR intensities (DLR-M, DLR-H) and conventional image filtering techniques (NF1 âˆ¼ NF4). The normalized noise power spectrum (NPS) was analysed through phantom experiments. Image sharpness was evaluated using a blur metric. We compared subjective image quality and the detection of sub-centimetre nodules and emphysema between the original and noise-reduced images. Statistical analyses included the Wilcoxon signed-rank and McNemar's tests, with inter-reader agreement assessed via Kappa coefficients. RESULTS: NPS peaks were lower in NF1 through NF4, DLR-M, and DLR-H compared to the original images. While the average spatial frequency of the NPS shifted towards lower frequencies with increasing NF levels, it remained unchanged with DLR. Blur metric values of NF1∼NF4 were significantly higher than those of the original images (p<0.008). However, there were no significant differences in blur metric values between DLR-M, DLR-H, and the original images. Image quality was rated highest for DLR-H, with a statistically significant improvement over the original (p<0.05). DLR-H showed higher diagnostic confidence for detecting sub-centimetre nodules than the original images. DLR-H showed higher diagnostic performance than the original for detecting emphysema. CONCLUSIONS: DLR can improve ZTE lung MRI quality while preserving image texture and sharpness, thereby enhancing the potential of ZTE for evaluating pulmonary parenchymal disease.

Characterization of concrete reference material for analysis of artificial radionuclides in nuclear power plant decommissioning waste.

The decommissioning of nuclear power plants has led to a surge in the production of radioactive waste, necessitating the development of accurate and reliable measurement methods for safe waste disposal. This study presents the development of a new concrete reference material (RM) containing beta, and gamma nuclides for quality assurance and quality control (QA/QC) in concrete measurements. The newly developed RM manufacturing method was used to ensure sample homogeneity; rigorous processes were followed according to ISO guidelines. The RM, designed to mimic real waste matrices, targeted six radionuclides: 60Co, 134Cs, 137Cs, 152Eu, 154Eu, and 90Sr. Homogeneity and stability tests, conducted according to ISO guidelines, confirmed the suitability of the concrete RM for QA/QC purposes. Reference values for the six radionuclides in RM ranged from 66.0 to 172.6 Bq kg-1. The expanded uncertainties of the reference values, at a 95 % confidence level (k = 2), ranged from approximately 7.1 %-17.2 %. The developed RM holds potential as proficiency test material and for validating and verifying analytical methods in radioactive waste analysis. Additionally, the manufacturing method introduced here opens doors for diverse applications, enabling the production of accurate and reliable reference materials for various waste matrices.

Cell-free supernatant of Lactococcus lactis IDCC 2301 exerts anti-inflammatory effects in LPS-induced macrophages via NF-κB and MAPK signaling pathways.

This study investigated the anti-inflammatory effects of cell-free supernatant of Lactococcus lactis IDCC 2301 on lipopolysaccharide (LPS)-induced RAW 264.7 macrophages. Expression of inflammatory mediators and cytokines, and the production of nitric oxide (NO) and prostaglandin E2 (PGE2) were qualitatively analysed. The expression of signal transductors in inflammatory cascades was quantified by western blot. Treatment with cell-free supernatant of L. lactis IDCC 2301 significantly decreased the mRNA expression levels of tumour necrosis factor (TNF-α) and interleukins including IL-1ß and IL-6. The levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX-2) were also remarkably reduced in LPS-induced macrophages after the treatment. Furthermore, L. lactis IDCC 2301 reduced the levels of both dephosphorylated and phosphorylated forms of nuclear factor-kappa B (NF-κB), IκB-α, extracellular signal-regulated kinases (ERK), c-Jun amino-terminal kinases (JNK), and p38 in LPS-induced RAW 264.7 cells. Therefore, L. lactis IDCC 2301 shows anti-inflammatory activity by suppressing the NF-κB and mitogen-activated protein kinase (MAPK) signaling pathways.

Mobility Selective Ion Soft-Landing and Characterization Enabled Using Structures for Lossless Ion Manipulation.

While conventional ion-soft landing uses the mass-to-charge (m/z) ratio to achieve molecular selection for deposition, here we demonstrate the use of Structures for Lossless Ion Manipulation (SLIM) for mobility-based ion selection and deposition. The dynamic rerouting capabilities of SLIM were leveraged to enable the rerouting of a selected range of mobilities to a different SLIM path (rather than MS) that terminated at a deposition surface. A selected mobility range from a phosphazene ion mixture was rerouted and deposited with a current pulse (∼150 pA) resembling its mobility peak. In addition, from a mixture of tetra-alkyl ammonium (TAA) ions containing chain lengths of C5-C8, selected chains (C6, C7) were collected on a surface, reconstituted into solution-phase, and subsequently analyzed with a SLIM-qToF to obtain an IMS/MS spectrum, confirming the identity of the selected species. Further, this method was used to characterize triply charged tungsten-polyoxometalate anions, PW12O403- (WPOM). The arrival time distribution of the IMS/MS showed multiple peaks associated with the triply charged anion (PW12O403-), of which a selected ATD was deposited and imaged using TEM. Additionally, the identity of the deposited WPOM was ascertained using energy-dispersive (EDS) spectroscopy. Further, we present theory and computations that reveal ion landing energies, the ability to modulate the energies, and deposition spot sizes.

Development of reference material for quality control of uranium analysis in marine sediments.

Environmental radioactivity monitoring is strengthening due to public concerns over radioactive contamination since the Fukushima nuclear power plant accident. Therefore, various research laboratories, institutes, and universities have been conducting environmental radioactivity surveys around nuclear power plants (NPPs). However, the reliability of the results continues to trigger controversy in society. This study was conducted to develop reference material (RM) for the quality control of 238U and 234U analyses in marine sediments. The RM was prepared according to ISO Guides 31, 34, and 35. A homogeneity test of the marine sediment RM was implemented by analyzing two batch samples from ten bottles using multiple acid digestion and alkali fusion, respectively. We found that the 238U and 234U reference values of the RM were 43.0 ± 1.7 Bq kg-1(k=1) and 41.5 ± 1.9 Bq kg-1(k=1), respectively. This marine sediment RM will be useful for the quality control of analytical methods for similar samples and proficiency tests.

Development of metal radioactive liquid reference material for proficiency test.

This study developed liquid reference materials containing various metals, to be used for quality assurance of radiation measurements of the most common metallic wastes generated during the operation or decommissioning of nuclear power plants. The liquid reference materials were prepared by assuming the dissolution of stainless-steel using acid and melting of the major metals present in the stainless steel, namely Fe, Ni, Cr, and Mn, along with the standard sources (134Cs, 137Cs, 60Co, 90Sr). The theoretical massic activity of the standard sources added to the samples and the measured reference values of the gamma and beta emitters in the samples were compared, and they showed good agreement within a one-sigma confidence interval (k = 1). Using the developed reference materials, a proficiency test was conducted on three domestic labs, and the results were evaluated using Z-score. While the evaluation results showed good agreement between the reference values and the reported values for 137Cs and 60Co, all participating labs reported lower values than the reference value for 134Cs. For 90Sr, two out of the three labs reported significantly higher values than the reference value. Based on the results of this study, the developed metal radioactive liquid reference material is expected to be registered as certified reference material (CRM) in the future. They will be used as the CRM for measuring and ensuring the quality of radioactive metal waste.

Multivariable model of postoperative delirium in cardiac surgery patients: proteomic and demographic contributions.

Background: Delirium following cardiac surgery is common, morbid, and costly, but may be prevented with risk stratification and targeted intervention. Preoperative protein signatures may identify patients at increased risk for worse postoperative outcomes, including delirium. In this study, we aimed to identify plasma protein biomarkers and develop a predictive model for postoperative delirium in older patients undergoing cardiac surgery, while also uncovering possible pathophysiological mechanisms. Methods: SOMAscan analysis of 1,305 proteins in the plasma from 57 older adults undergoing cardiac surgery requiring cardiopulmonary bypass was conducted to define delirium-specific protein signatures at baseline (PREOP) and postoperative day 2 (POD2). Selected proteins were validated in 115 patients using the ELLA multiplex immunoassay platform. Proteins were combined with clinical and demographic variables to build multivariable models that estimate the risk of postoperative delirium and bring light to the underlying pathophysiology. Results: A total of 115 and 85 proteins from SOMAscan analyses were found altered in delirious patients at PREOP and POD2, respectively (p<0.05). Using four criteria including associations with surgery, delirium, and biological plausibility, 12 biomarker candidates (Tukey's fold change (|tFC|)>1.4, Benjamini-Hochberg (BH)-p<0.01) were selected for ELLA multiplex validation. Eight proteins were significantly altered at PREOP, and seven proteins at POD2 (p<0.05), in patients who developed postoperative delirium compared to non-delirious patients. Statistical analyses of model fit resulted in the selection of a combination of age, sex, and three proteins (angiopoietin-2 (ANGPT2); C-C motif chemokine 5 (CCL5); and metalloproteinase inhibitor 1 (TIMP1); AUC=0.829) as the best performing predictive model for delirium at PREOP. The delirium-associated proteins identified as biomarker candidates are involved with inflammation, glial dysfunction, vascularization, and hemostasis, highlighting the multifactorial pathophysiology of delirium. Conclusion: Our study proposes a model of postoperative delirium that includes a combination of older age, female sex, and altered levels of three proteins. Our results support the identification of patients at higher risk of developing postoperative delirium after cardiac surgery and provide insights on the underlying pathophysiology. ClinicalTrials.gov ( NCT02546765 ).

Nanogap traps for passive bacteria concentration and single-point confocal Raman spectroscopy.

A microfluidic device enabling the isolation and concentration of bacteria for analysis by confocal Raman spectroscopy is presented. The glass-on-silicon device employs a tapered chamber surrounded by a 500 nm gap that serves to concentrate cells at the chamber apex during sample perfusion. The sub-micrometer gap retains bacteria by size exclusion while allowing smaller contaminants to pass unimpeded. Concentrating bacteria within the fixed volume enables the use of single-point confocal Raman detection for the rapid acquisition of spectral signatures for bacteria identification. The technology is evaluated for the analysis of E. cloacae, K. pneumoniae, and C. diphtheriae, with automated peak extraction yielding distinct spectral fingerprints for each pathogen at a concentration of 103 CFU/ml that compare favorably with spectra obtained from significantly higher concentration reference samples evaluated by conventional confocal Raman analysis. The nanogap technology offers a simple, robust, and passive approach to concentrating bacteria from dilute samples into well-defined optical detection volumes, enabling rapid and sensitive confocal Raman detection for label-free identification of focused cells.

The Reclassification of Patients With Previously Diagnosed Eosinophilic Granulomatosis With Polyangiitis Based on the 2022 ACR/EULAR Criteria for Antineutrophil Cytoplasmic Antibody-Associated Vasculitis.

OBJECTIVE: The American College of Rheumatology (ACR) and the European Alliance of Associations for Rheumatology (EULAR) have proposed the 2022 classification criteria for eosinophilic granulomatosis with polyangiitis (EGPA). This study applied the 2022 ACR/EULAR criteria to Korean patients with previously diagnosed EGPA to investigate the concordance rate between the 2022 ACR/EULAR criteria and the old criteria for EGPA. METHODS: In total, 51 patients with EGPA who met the 1990 ACR criteria, the 2007 European Medicines Agency algorithm, and the 2012 Chapel Hill Consensus Conference definitions were reclassified based on the 2022 ACR/EULAR criteria. RESULTS: Of 51 patients, 44 (86.3%) were reclassified as having EGPA according to the 2022 ACR/EULAR criteria. Among the 7 patients who failed to meet the 2022 ACR/EULAR criteria, 3 patients were reclassified as having microscopic polyangiitis (MPA) and 1 was reclassified as having granulomatosis with polyangiitis (GPA) based on the 2022 ACR/EULAR criteria; as well, 3 patients were reclassified as having unclassifiable vasculitis. Moreover, 6 patients who met the 2022 ACR/EULAR criteria for EGPA simultaneously met the criteria for MPA based on the 2022 ACR/EULAR criteria for MPA, and 1 who met the criteria for EGPA simultaneously met the criteria for GPA based on the 2022 ACR/EULAR criteria for GPA. CONCLUSION: The concordance rate between the 2022 ACR/EULAR criteria for EGPA and the old criteria was 86.3%. The most important factor in the failure to reclassify patients as having EGPA was the exclusion of nonfixed pulmonary infiltrates in the 1990 ACR criteria for EGPA. We cautiously suggest reconsidering nonfixed pulmonary infiltrates in cases reclassified as unclassifiable vasculitis. Further, additional classification strategies are needed for patients who simultaneously satisfy both antineutrophil cytoplasmic antibody-associated vasculitis subtypes.

Development of concrete reference material for quality assurance/quality control of gamma radioactivity measurement for nuclear power plant decommissioning waste.

The Korea Research Institute of Standards and Science has developed a new concrete reference material (RM) for measuring gamma-emitting radionuclides, such as 134Cs, 137Cs, 65Zn, 241Am, and 60Co, to improve and maintain the quality assurance and quality control of the radioactivity measurement in radioactive waste generated during the decommissioning of nuclear power plants. In this study, cement, SiO2, and bentonite, which are the main components of concrete, were mixed in an appropriate ratio with radionuclides. For certification and homogeneity assessment, 10 bottles were randomly selected, two sub-samples were collected from each bottle, and radionuclides were measured via HPGe gamma spectrometry. The results of the homogeneity tests using a one-way analysis of variance on 241Am, 134Cs, 137Cs, 65Zn, and 60Co in the concrete RM fulfilled the requirements of ISO Guide 35. Coincidence summing and self-absorption correction were performed on measurement results by introducing the Monte Carlo efficiency transfer code and Monte Carlo N-Particle transport code. The reference values for five radionuclides (60Co, 65Zn, 241Am, 134Cs, and 137Cs) in the RM were in the range of 15-40 Bq/kg, and the expanded uncertainty was within 10% (k = 2). To the best of our knowledge, this was the first study to develop concrete RM for measuring gamma-emitting radionuclides.

Visit-To-Visit Blood Pressure Variability and Subthreshold Depressive Symptoms in Older Adults.

OBJECTIVES: Depression is related to increased risk for dementia, possibly through links with cerebrovascular disease. Blood pressure variability is an emerging risk factor for cerebrovascular disease and dementia, but relationships with affective symptoms remain understudied. DESIGN: Retrospective analysis of prospective cohort study. SETTING: Alzheimer's Disease Neuroimaging Initiative. PARTICIPANTS: 505 older adults without history of dementia or recent depression underwent three to four blood pressure measurements over 12 months and completed a self-report measure of depressive symptoms (Geriatric Depression Scale - 15 Item) at study baseline and 24-months follow-up. MEASUREMENTS: Blood pressure variability was calculated as variability independent of mean and maximum minus minimum. Regression models investigated relationships between blood pressure variability and severity of self-reported depressive symptoms at 24-months follow-up after controlling for several variables, including average blood pressure, antihypertensive use, antidepressant use, and baseline depressive symptom severity. RESULTS: Elevated diastolic blood pressure variability was related to greater total depressive symptom score at follow-up (ß = .16 [95% CI 0.02, .30]; p = 0.03), with specific contribution from increased severity of symptoms of dysphoria (odds ratio = 1.35 [95% CI 1.07, 1.75]; p = 0.02). Blood pressure variability was not significantly related to other symptom subscales, including those reflecting life satisfaction or withdrawal. CONCLUSIONS: Findings suggest that elevated diastolic blood pressure variability is related to subthreshold depressive symptomatology in older adults without history of dementia or recent depression, independent of average blood pressure. Blood pressure variability may be an understudied vascular risk factor linked with depression and cognitive impairment, with potential therapeutic implications.

New body mass index for predicting prognosis in patients with antineutrophil cytoplasmic antibody-associated vasculitis.

OBJECTIVES: Body mass index (BMI) is a known indicator of all-cause mortality. However, conventional BMI does not reflect the three-dimensional human body. To overcome this limitation, a new BMI has been proposed that provides a closer approximation of real human body shape. This study investigated the associations between the new BMI and poor outcomes in patients with antineutrophil cytoplasmic antibody-associated vasculitis (AAV). METHOD: We retrospectively reviewed the medical records of 242 patients with AAV in a single tertiary medical center. Based on the new BMI, the patients were categorized into four groups: underweight (<18.5 kg/m2.5 ), healthy weight (18.5 to <25.0 kg/m2.5 ), overweight (25.0 to <30.0 kg/m2.5 ), and obese (≥30.0 kg/m2.5 ). The association among the new BMI and death, relapse, end-stage renal disease (ESRD) development, cerebrovascular accident, and cardiovascular disease was analyzed. RESULTS: The underweight group, according to the new BMI, had higher hazard ratios (HRs) for all-cause mortality (HR: 3.180, 95% confidence interval [CI]: 1.134-8.922, p = 0.028), relapse (HR: 2.141, 95% CI: 1.019-4.368, p = 0.036), and ESRD development (HR: 2.729, 95% CI: 1.190-6.259, p = 0.018) than the healthy weight group. However, according to the conventional BMI, there were no differences in the risks for all poor outcomes between the underweight and healthy weight groups. Multivariate logistic regression analysis demonstrated that being underweight, according to the new BMI, was an independent risk factor for all-cause mortality (HR: 5.285; 95% CI: 1.468-19.018; p = 0.011). CONCLUSION: Being underweight, according to the new BMI, is associated with poor outcomes in patients with AAV.

Evidence for reduced plasmodesmata callose accumulation in Nicotiana benthamiana leaves with increased symplastic cell-to-cell communication caused by RNA processing defects of chloroplasts.

RNA processing defects in chloroplasts were previously associated with increased plasmodesmata (PD) permeability. However, the underlying mechanisms for such association are still unknown. To provide insight into this, we silenced the expression of chloroplast-located INCREASED SIZE EXCLUSION LIMIT 2 (ISE2) RNA helicase in Nicotiana benthamiana leaves and determined an increase in PD permeability which is caused by a reduction of PD callose deposition. Moreover, the silencing of two other nuclear genes encoding chloroplastic enzymes involved in RNA processing, RH3, and CLPR2, also increased PD permeability accompanied by reduced callose accumulation at PD. In addition, we quantified the plastidic hydrogen peroxide levels using the chloroplast-targeted fluorescent sensor, HyPer, in ISE2, RH3, and CLPR2 silenced N. benthamiana leaves. The levels of chloroplastic hydrogen peroxide were not correlated with the increased cell-to-cell movement of the marker protein GFP2X. We, therefore, propose that defects in chloroplast RNA metabolism mediate PD gating by suppressing PD callose deposition, and hydrogen peroxide levels in the organelles are not directly linked to this process.

Split and combine simulation extrapolation algorithm to correct geocoding coarsening of built environment exposures.

A major challenge in studies relating built environment features to health is measurement error in exposure due to geocoding errors. Faulty geocodes in built environment data introduce errors to exposure assessments that may induce bias in the corresponding health effect estimates. In this study, we examine the distribution of the measurement error in measures constructed from point-referenced exposures, quantify the extent of bias in exposure effect estimates due to geocode coarsening, and extend the simulation extrapolation (SIMEX) method to correct the bias. The motivating example focuses on the association between children's body mass index and exposure to the junk food environment, represented by the number of junk food outlets within a buffer area near their schools. We show, algebraically and through simulation studies, that coarsening of food outlet coordinates results in exposure measurement errors that have heterogeneous variance and nonzero mean, and that the resulting bias in the health effect can be away from the null. The proposed SC-SIMEX procedure accommodates the nonstandard measurement error distribution, without requiring external data, and provides the best bias correction compared to other SIMEX approaches.

Comparative analysis of Achilles tendon healing outcomes after open tenotomy versus percutaneous tenotomy: An experimental study in rats.

There is growing interest in conservative treatment of Achilles tendon rupture. However, the majority of experimental studies of Achilles tendon have been performed by open tenotomy. More appropriate model of conservative treatment of Achilles tendon rupture is required. We performed an experimental study to evaluate whether outcomes differ between open tenotomy and percutaneous tenotomy of the Achilles tendon in rats. The Achilles tendons of 48 rats were transected. The animals were divided into two groups according to surgical technique: open tenotomy or microscopy-assisted percutaneous tenotomy. After 1, 2, and 4 weeks, functional, biomechanical, and histological analyses were performed. Western blot was performed for quantitative molecular analysis at 1 week. The Achilles functional index was superior in the percutaneous tenotomy group, compared with the open tenotomy group, at 1 week. The cross-sectional area was significantly larger in the percutaneous tenotomy group than in the open tenotomy group at 4 weeks. Relative to the native tendons, load to failure and stiffness yielded comparable results at 2 weeks in the percutaneous tenotomy group and at 4 weeks in the open tenotomy group. The histological score was significantly better in the percutaneous tenotomy group than in the open tenotomy group at 1 week. At 1 week, interleukin-1ß expression in the open tenotomy group was higher than in the percutaneous tenotomy group. In summary, Achilles tendon healing was substantially affected by the tenotomy method. We presume that our percutaneous tenotomy method might constitute a useful experimental animal model for conservative treatment of Achilles tendon rupture.

High spatial-density, cladding-pumped 6-mode 7-core fiber amplifier for C-band operation.

We present a C-band 6-mode 7-core fiber amplifier in an all-fiberized cladding-pumped configuration for space division multiplexed transmission supporting a record 42 spatial channels. With optimized fiber components (e.g. passively cooled pump laser diode, pump coupler, pump stripper), high power multimode pump light is coupled to the active fiber without any noticeable thermal degradation and an average gain of 18 dB and noise figure of 5.4 dB are obtained with an average differential modal gain of 3.4 dB.