Feasibility and usefulness of cognitive monitoring using a new home-based cognitive test in mild cognitive impairment: a prospective single arm study.

BACKGROUND: The risk of dementia is increased in subjects with mild cognitive impairment (MCI). Despite the plethora of in-person cognitive tests, those that can be administered over the phone are lacking. We hypothesized that a home-based cognitive test (HCT) using phone calls would be feasible and useful in non-demented elderly. We aimed to assess feasibility and validity of a new HCT as an optional cognitive monitoring tool without visiting hospitals. METHODS: Our study was conducted in a prospective design during 24 weeks. We developed a new HCT consisting of 20 questions (score range 0-30). Participants with MCI (n = 38) were consecutively enrolled and underwent regular HCTs during 24 weeks. Associations between HCT scores and in-person cognitive scores and Alzheimer's disease (AD) biomarkers were evaluated. In addition, HCT scores in MCI participants were cross-sectionally compared with age-matched cognitively normal (n = 30) and mild AD dementia (n = 17) participants for discriminative ability of the HCT. RESULTS: HCT had good intra-class reliability (test-retest Cronbach's alpha 0.839). HCT scores were correlated with the Mini-Mental State Examination (MMSE), verbal memory delayed recall, and Stroop test scores but not associated with AD biomarkers. HCT scores significantly differed among cognitively normal, MCI, and mild dementia participants, indicating its discriminative ability. Finally, 32 MCI participants completed follow-up evaluations, and 8 progressed to dementia. Baseline HCT scores in dementia progressors were lower than those in non-progressors (p = 0.001). CONCLUSION: The feasibility and usefulness of the HCT were demonstrated in elderly subjects with MCI. HCT could be an alternative option to monitor cognitive decline in early stages without dementia.

Development of a basin-scale total nitrogen prediction model by integrating clustering and regression methods.

Nutrient runoff into rivers caused by human activity has led to global eutrophication issues. The Nakdong River in South Korea is currently facing significant challenges related to eutrophication and harmful algal blooms, underscoring the critical importance of managing total nitrogen (T-N) levels. However, traditional methods of indoor analysis, which depend on sampling, are labor-intensive and face limitations in collecting high-frequency data. Despite advancements in sensor allowing for the measurement of various parameters, sensors still cannot directly measure T-N, necessitating surrogate regression methods. Therefore, we conducted T-N predictions using a water quality dataset collected from 2018 to 2022 at 157 observatories within the Nakdong River basin. To account for the water quality characteristics of each location, we employed a clustering technique to divide the basin and compared a Gaussian mixture model with K-means clustering. Moreover, optimal regressor for each cluster was selected by comparing multiple linear regression (MLR), random forest, and XGBoost. The results showed that forming four clusters via K-means clustering was the most suitable approach and MLR was reasonably accurate for all clusters. Subsequently, recursive feature elimination cross-validation was used to identify suitable parameters for T-N prediction, thus leading to the construction of high-accuracy T-N prediction models. Clustering was useful not only for improving the regressors but also for spatially analyzing the water quality characteristics of the Nakdong River. The MLR model can reveal causal relationships and thus is useful for decision-making. The results of this study revealed that the combination of a simple linear regression model and clustering method can be applied to a wide watershed. The clustering-based regression model showed potential for accurately predicting T-N at the basin level and is expected to contribute to nationwide water quality management through future applications in various fields.

Improving Durability of Dye-Based Polarizing Films Using Novel Reactive Dyes as Dichroic Materials.

Iodine is commonly used as a dichroic material in polarizing films, while dichroic dyes are employed when high heat resistance is necessary. Direct dyes, which can be applied to poly(vinyl alcohol) (PVA) in an acidic environment, are the most popular; however, their hydrogen bonding interaction with the PVA chain can weaken in high-humidity conditions, leading to a potential change in color value or polarization property. Reactive dyes offer a promising alternative for use in high-humidity environments. In this study, five novel reactive dyes were synthesized and used to prepare dye-based polarizing films. The dichroic ratios, order parameters, and transition moments of the reactive dyes were calculated and compared to those of corresponding direct dyes. Molecular orbital calculations indicated minimal effects on the optical anisotropy of the polarizing films due to the transition moments of the reactive dyes remaining close to their molecular axes. As a result, the dichroic ratios of the polarizing films were mainly dependent on the orientation of the dyes towards their stretching direction, and showed a similar behavior compared to direct dyes. Under high-temperature and high-humidity conditions, the polarizing film using reactive dyes showed superior durability compared to the direct dye-based film.

Comparison of Optimal Machine Learning Algorithms for Early Detection of Unknown Hazardous Chemicals in Rivers Using Sensor Monitoring Data.

Water environment pollution due to chemical spills occurs constantly worldwide. When a chemical accident occurs, a quick initial response is most important. In previous studies, samples collected from chemical accident sites were subjected to laboratory-based precise analysis or predictive research through modeling. These results can be used to formulate appropriate responses in the event of chemical accidents; however, there are limitations to this process. For the initial response, it is important to quickly acquire information on chemicals leaked from the site. In this study, pH and electrical conductivity (EC), which are easy to measure in the field, were applied. In addition, 13 chemical substances were selected, and pH and EC data for each were established according to concentration change. The obtained data were applied to machine learning algorithms, including decision trees, random forests, gradient boosting, and XGBoost (XGB), to determine the chemical substances present. Through performance evaluation, the boosting method was found to be sufficient, and XGB was the most suitable algorithm for chemical substance detection.

Untreated hypertension and prognosis paradox in acute ischemic stroke.

INTRODUCTION: This study is to explore the long-term functional outcome of antihypertensive medication-naïve, untreated hypertension (HTN) patients with acute ischemic stroke compared to those with no prior HTN and those with treated HTN. PATIENTS AND METHODS: We analyzed a prospectively collected stroke registry of all patients with acute ischemic stroke consecutively admitted to Incheon St. Mary's Hospital. Patients who received reperfusion therapy were excluded. Long-term functional outcomes were assessed at a 3-month follow-up visit using the modified Rankin Scale. RESULTS: A total of 1044 patients was enrolled. Compared to patients with no or treated HTN, those with untreated HTN had higher odds for more favorable outcomes (adjusted odds ratio (OR): 1.7 [95% CI: 1.0-2.7, p = 0.050*] and 1.7 [95% CI: 1.0-2.8, p = 0.047*], respectively) when the stroke was large vessel atherosclerosis (LAA)/cardioembolic (CE) with large vessel occlusion/stenosis. However, no such association was observed when there was no large vessel occlusion or stenosis, in total patients, or if the index stroke was related to SVO. In untreated HTN patients with LAA/CE and large vessel occlusion/stenosis compared to patients in the lowest mean arterial pressure quartile (< 96.7 mmHg), patients in the second and third highest quartiles had higher odds of favorable outcomes. CONCLUSIONS: Patients with untreated HTN had significantly more favorable outcomes at 3 months after ischemic stroke compared to those with no or treated HTN when the stroke was LAA/CE with large vessel occlusion/stenosis. Untreated HTN patients also showed an association between higher MAP and favorable outcomes.

Multiple chronic lacunes predicting early neurological deterioration and long-term functional outcomes according to TOAST classification in acute ischemic stroke.

INTRODUCTION: Studies regarding multiple chronic lacunes (MCLs) and clinical outcome according to stroke etiology are scarce. We sought to evaluate the association between MCL and short-term/long-term clinical outcomes according to stroke etiology. PATIENTS AND METHODS: We analyzed a prospectively collected stroke registry of acute ischemic stroke patients over 4 years. The enrolled patients were classified as having large artery atherosclerosis (LAA), small vessel occlusion (SVO), cardioembolic (CE) stroke, and other etiology. The early neurological deterioration (END) and favorable outcome at 3 months were assessed. RESULTS: A total of 1070 patients were enrolled. Patients with MCL had significantly more END compared to those without MCL both in total population (adjusted odds ratio (OR), 1.7; 95% confidence interval [CI], 1.1-2.5; p = 0.013*) and in the LAA group (adjusted OR, 2.3; 95% CI, 1.3-4.2, p < 0.006). Patients with MCL had a significantly lower OR for favorable outcome at 3 months compared to those without MCL both in total population (adjusted OR, 0.7; 95% CI, 0.5-1.0, p = 0.035) and in the LAA group (adjusted OR, 0.6; 95% CI, 0.3-1.0, p = 0.043). However, MCL was not associated with END or long-term functional outcome in patients with SVO, CE, or other etiology. CONCLUSIONS: The presence of MCL was an independent predictive factor for END as well as long-term poor functional outcome in acute ischemic stroke patients. These associations were only observed in patients with LAA, not in those with SVO, CE, or other etiology.

Effect of intraoperative intravenous ferric derisomaltose supplementation on reduction of postoperative anemia and transfusion in chronic kidney disease patients after total knee replacement.

Total knee replacement (TKR) is associated with a large amount of bleeding; therefore, the prevalence of postoperative anemia is high. In particular, patients with chronic kidney disease (CKD) are more vulnerable to postoperative anemia than are healthy individuals. Accordingly, the effect of intraoperative intravenous ferric derisomaltose (FDI) supplementation on postoperative anemia and blood transfusion volume reduction in patients with CKD was studied. Patients who underwent unilateral TKR between January 2019 and December 2020 were retrospectively reviewed. In analyzing the data, the patients fell into the CKD group (n = 85) and the non-CKD group (n = 106). Each group was divided into a group using FDI and a non-FDI group, and classified into 4 groups. The postoperative hemoglobin level for each postoperative day (POD) was determined as the primary outcome. In addition, the patient transfusion rate, volume of transfusion, and length of hospital stay were set as secondary study outcomes during the period from surgery to discharge. There was no statistically significant difference in hemoglobin levels on PODs 0, 1, 2, 7, and 14 in the CKD group. In the CKD group, the transfusion volume of the FDI group was 0.58 ± 0.91 units per person, which was statistically significantly lower than 1.28 ± 1.28 units of the non-FDI group (P = .01). In the CKD group, the transfusion rate of the FDI group was 30.2%, which was statistically significantly lower than that of the non-FDI group, which was 56.3% (P = .02). This study showed that intravenous FDI supplementation after TKR in CKD patients did not reduce postoperative anemia but was an effective and safe treatment to reduce transfusion volume and transfusion rate. There was no statistically significant difference in hemoglobin levels on POD 0, 1, 2, 7, and 14 in the non-CKD group. In the non-CKD group, the transfusion volume of the FDI group was 0.46 ± 0.88 units per person, which was lower than the 0.56 ± 0.91 units of the non-FDI group, but it was not statistically significant (P = .59). In the non-CKD group, the transfusion rate of the FDI group was 23.0%, which was lower than that of the non-FDI group, which was 31.3%, but it was not statistically significant (P = .37).

Experimental Study on the Detection of Hazardous Chemicals Using Alternative Sensors in the Water Environment.

Chemical accidents in rivers may be triggered by natural or anthropogenic causes and refer to the flow of large quantities of hazardous chemicals into rivers. In South Korea, domestic water is sourced from large rivers, such as the Nakdong River. However, owing to rapid industrialization, industrial facilities have become heavily concentrated in the middle and upper reaches of the Nakdong River. Therefore, severe problems could arise if harmful chemicals are leaked from industrial facilities into the river, and this contaminated river water is supplied to cities. Quantitative evaluation based on instrumental analysis during chemical accidents and prediction research based on modeling is actively being conducted however, research on the initial response is insufficient. Therefore, in this study, the variations in pH and EC were analyzed according to their chemical concentrations for seven chemicals. These seven chemicals are designated accident-preparedness substances that frequently cause chemical spills in South Korea. Additionally, we evaluated the possibility of identifying unknown substances by comparing the variations in pH and EC and statistics while diluting unknown substances. Thus, the potential of pH and EC as alternative indicators for detecting and identifying chemicals was evaluated in this study. NaF, NH4HF2, NaCN, and NH4OH were classified by comparing their spatial distributions in a pH-EC relation curve. However, H2SO4, HCl, and SOCl2 showed similar spatial distributions in the pH-EC curves and were difficult to identify. The results of this study provide information for chemical detection and identification using alternative sensors that permit easy and rapid field measurements in the event of a chemical spill and could be used as preliminary data for rapidly responding to accidents.

A clinical study of 288 patients with anterior cerebral artery infarction.

OBJECTIVE: Acute ischemic stroke in the territory of anterior cerebral artery (ACA) is uncommon. Therefore, large population studies evaluating ACA infarction are scarce. We sought to evaluate epidemiological and etiological characteristics of ACA infarction compared to other territorial infarctions. METHODS: We analyzed a prospectively collected stroke registry of all acute ischemic stroke patients for 19 years at two tertiary hospitals. We included patients with acute ischemic stroke caused by large vessel stenosis or occlusion including ACA, middle cerebral artery (MCA), posterior cerebral artery (PCA), and vertebrobasilar artery (VBA). RESULTS: A total of 4171 patients were enrolled. Patients with ACA infarction (N = 288) were significantly older with more females than those with MCA, PCA, or VBA infarction. There were more patients with history of prior ischemic stroke in the ACA infarction group than in other groups. The etiology of the ACA infarction was similar to those of the MCA, PCA and also the total population (66.7-71.8% of LAA and 17.9-20.9% of CE). When patients had prior ischemic stroke history, ACA infarction was more likely to be caused by LAA than MCA or PCA infarction (OR = 6.2, 95% CI 2.0-19.2, p = 0.002 and OR = 4.0, 95% CI 1.1-14.6, p = 0.038, respectively). CONCLUSIONS: Patients with ACA infarction had significantly more prior ischemic stroke than those with MCA, PCA, or VBA infarction. The etiology of ACA infarction in patients with prior ischemic stroke showed significantly more LAA than that of MCA or PCA infarction.

Regional Cerebral Blood Flow Abnormalities in Neurosyphilis: A Pilot SPECT Study.

Objective: Clinical and radiological findings on neurosyphilis are fairly non-specific and there is a paucity of functional neuroimaging studies on neurosyphilis other than case reports and case series. The purpose of this study was to investigate brain perfusion abnormalities in patients with neurosyphilis. Methods: Four HIV-negative neurosyphilis patients and 4 healthy controls underwent clinical evaluation, brain technetium-99m ethyl cysteinate dimer (99mTc-ECD) single-photon emission computed tomography (SPECT) imaging, and neuropsychological assessments which included the Mini-Mental State Examination (MMSE), Clinical Dementia Rating (CDR), Clinical Dementia Rating-Sum of Boxes (CDR-SOB), and Global Deterioration Scale (GDS). Voxel-wise differences in regional cerebral blood flow were compared between the two groups. Results: Neuropsychological test results indicated cognitive impairment in all patients. SPECT analysis revealed multifocal hypoperfusion predominantly in the frontal, insular, and posterior cingulate regions in neurosyphilis patients compared with healthy controls (family-wise error corrected p < 0.05). Conclusions: Together with previous findings, our results suggest that the hypoperfusion in the frontal, insular, and posterior cingulate regions may reflect cognitive impairments observed in neurosyphilis patients. Further studies with larger samples are needed to confirm our findings.

The Association between Herpes Zoster and Increased Cancer Risk: A Nationwide Population-Based Matched Control Study.

BACKGROUND: Herpes zoster (HZ) is strongly associated with decreased immune function, a factor of cancer development. Previous studies suggested inconsistent results regarding the association between HZ and increased cancer risk. We aimed to analyze the association between HZ and specific cancer risk. METHODS: Of 134,454 patients diagnosed with HZ between 2002 and 2015, 81,993 HZ patients were matched 1:1 with non-HZ individuals by age, sex, and Charlson comorbidity index. Both groups were examined at 1, 3, and 5 years for cancer diagnosis. A Cox proportional hazard regression model was used to estimate cancer risk in both groups. The postherpetic neuralgia (PHN) and non-HZ groups were compared for specific cancer risk. RESULTS: The HZ group showed a slightly decreased overall cancer risk compared with the non-HZ group (hazard ratio [HR] 0.94, 95% confidence interval [CI] 0.90-0.97, p = 0.002). The HRs for specific cancer risk were 0.41 (95% CI, 0.33-0.50, p < 0.001); 0.86 (95% CI, 0.81-0.91, p < 0.001); 0.87 (95% CI, 0.78-0.97, p = 0.014); 0.80 (95% CI 0.73-0.87, p < 0.001); 1.20 (95% CI, 1.07-1.34, p = 0.001); and 1.66 (95% CI, 1.35-2.03, p < 0.001) for cancers of the lips, mouth, and pharynx; digestive system; respiratory system; unknown secondary and unspecified sites; thyroid and endocrine glands; and lymphoid and hematopoietic systems, respectively. The HZ with PHN group showed higher HR for specific cancer risk, such as lymphoid and hematopoietic systems (95% CI, 1.27-2.39, p < 0.001). CONCLUSION: HZ was associated with increased or decreased incidence of specific cancers. PHN further increased the risk of developing certain cancers in HZ patients.

Imaging Characteristics of Brain SPECT, PET, and MRI in Neurosyphilis.

The incidence of neurosyphilis has declined since effective penicillin therapy against Treponema pallidum was introduced. However, the diagnosis of neurosyphilis early in the disease course is very important in order to select appropriate antibiotic therapy. We report brain MRI, SPECT with Tc-99m ECD, and PET with F-18 FDG findings before antibiotic therapy in a neurosyphilis patient with neurological symptoms. The cerebral cortices showed hypoperfusion with a patchy distribution on SPECT and foci with high signal intensity on MRI, suggesting ischemia. Brain PET showed areas with hypometabolism in the temporoparietal lobes bilaterally.

Atypical presentation of complex regional pain syndrome: neuropathic itching - A case report.

BACKGROUND: In some patients with neuropathic pain (NP), such as complex regional pain syndrome (CRPS), itching rather than pain is the main symptom making diagnosis and treatment difficult. CASE: We report a case of a 23-year-old male with a history of hypoxic brain damage who presented with pruritus of the left foot and ankle. His left foot was fractured, and he underwent surgery 6 months previously. After the operation and cast application, he developed uncontrolled pruritus, swelling, sweating, and flushing of the left foot skin with limping. On examination, he showed well-known features of CRPS without pain. He was diagnosed with an atypical CRPS with neuropathic itching (NI). With treatment modalities used for NP and CRPS, his pruritus subsided gradually, and the his ankle mobility improved. CONCLUSIONS: Unexplained itching can be the main symptom in some CRPS patients. Treatment according to NP can improve symptoms of NI in CRPS patients.

Programmable self-assembly of M13 bacteriophage for micro-color pattern with a tunable colorization.

Over the last decade, the M13 bacteriophage has been used widely in various applications, such as sensors, bio-templating, and solar cells. The M13 colorimetric sensor was developed to detect toxic gases to protect the environment, human health, and national security. Recent developments in phage-based colorimetric sensor technologies have focused on improving the sensing characteristics, such as the sensitivity and selectivity on a large scale. On the other hand, few studies have examined precisely controllable micro-patterning techniques in phage-based self-assembly. This paper developed a color patterning technique through self-assembly of the M13 bacteriophages. The phage was self-assembled into a nanostructure through precise temperature control at the meniscus interface. Furthermore, barcode color patterns could be fabricated using self-assembled M13 bacteriophage on micrometer scale areas by manipulating the grooves on the SiO2 surface. The color patterns exhibited color tunability based on the phage nano-bundles reactivity. Overall, the proposed color patterning technique is expected to be useful for preparing new color sensors and security patterns.

Superficial Siderosis of the Central Nervous System due to Spinal Ependymoma.

A 75-year-old woman presented with a 3-year history of progressive hearing loss, gait ataxia, and cognitive impairment. Brain magnetic resonance imaging (MRI) with a time gradient echo sequence showed deposition of hemosiderin along the surface of the cerebral cortex, brainstem, and cerebellum, as well as severe atrophy in the diffuse cerebral cortex and cerebellum. We established the diagnosis of superficial siderosis of the central nervous system on the grounds of former pathognomonic MRI findings. The thoraco-lumbar spine MRI demonstrated a myxopapillary ependymoma in the T11-L2 spinal canal that was considered to be the cause of a chronic subarachnoid hemorrhage, affecting the leptomeninges and subpial layers of the central nervous system.

Gradients in cytoarchitectural landscapes of the isocortex: Diprotodont marsupials in comparison to eutherian mammals.

Although it has been claimed that marsupials possess a lower density of isocortical neurons compared with other mammals, little is known about cross-cortical variation in neuron distributions in this diverse taxonomic group. We quantified upper-layer (layers II-IV) and lower-layer (layers V-VI) neuron numbers per unit of cortical surface area in three diprotodont marsupial species (two macropodiformes, the red kangaroo and the parma wallaby, and a vombatiform, the koala) and compared these results to eutherian mammals (e.g., xenarthrans, rodents, primates). In contrast to the notion that the marsupial isocortex contains a low density of neurons, we found that neuron numbers per unit of cortical surface area in several marsupial species overlap with those found in eutherian mammals. Furthermore, neuron numbers vary systematically across the isocortex of the marsupial mammals examined. Neuron numbers under a unit of cortical surface area are low toward the frontal cortex and high toward the caudo-medial (occipital) pole. Upper-layer neurons (i.e., layers II-IV) account for most of the variation in neuron numbers across the isocortex. The variation in neuron numbers across the rostral to the caudal pole resembles primates. These findings suggest that diprotodont marsupials and eutherian mammals share a similar cortical architecture despite their distant evolutionary divergence.

Brain perfusion alterations in depressed patients with Parkinson's disease.

OBJECTIVE: Although Parkinson's disease (PD) is frequently accompanied by depression, brain perfusion deficits in PD with depression remain unclear. This study aimed to assess alterations in regional cerebral blood flow (rCBF) in depressed PD patients using 99mTc hexamethyl-propylene-amine-oxime single-photon emission computed tomography (SPECT). METHODS: Among 78 patients with PD, 35 patients were classified into the depressed PD group, while the rest (43 patients) was assigned to the nondepressed PD group based on the scores of the Geriatric Depressive Scale (GDS). All participants underwent brain SPECT imaging. The voxel-wise whole-brain analysis and region-of-interest (ROI) analysis of the limbic areas were conducted to compare rCBF between the depressed and nondepressed PD groups. RESULTS: The depressed PD patients demonstrated higher GDS scores than nondepressed patients, whereas between-group differences in the PD severity and cognitive function were not significant. Perfusion in the left cuneus was increased, while that in the right superior temporal gyrus and right medial orbitofrontal cortex was reduced in the depressed PD patients as compared with nondepressed PD patients. In addition, the ROI analysis demonstrated rCBF decreases in the amygdala, anterior cingulate cortex, hippocampus, and parahippocampal gyrus in the depressed PD group. A positive correlation was found between the GDS scores and rCBF in the left cuneus cluster in the depressed PD patients. CONCLUSION: This study identified the regional pattern of brain perfusion that distinguished depressed from nondepressed PD patients. Hyperperfusion in the occipital areas and hypoperfusion in the fronto-temporo-limbic regions may be potential imaging biomarkers for depression in PD.