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1.
Cell Rep Med ; : 101570, 2024 May 10.
Article in English | MEDLINE | ID: mdl-38749422

ABSTRACT

While an association between Parkinson's disease (PD) and viral infections has been recognized, the impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on PD progression remains unclear. Here, we demonstrate that SARS-CoV-2 infection heightens the risk of PD using human embryonic stem cell (hESC)-derived dopaminergic (DA) neurons and a human angiotensin-converting enzyme 2 (hACE2) transgenic (Tg) mouse model. Our findings reveal that SARS-CoV-2 infection exacerbates PD susceptibility and cellular toxicity in DA neurons pre-treated with human preformed fibrils (hPFFs). Additionally, nasally delivered SARS-CoV-2 infects DA neurons in hACE2 Tg mice, aggravating the damage initiated by hPFFs. Mice infected with SARS-CoV-2 display persisting neuroinflammation even after the virus is no longer detectable in the brain. A comprehensive analysis suggests that the inflammatory response mediated by astrocytes and microglia could contribute to increased PD susceptibility associated with SARS-CoV-2. These findings advance our understanding of the potential long-term effects of SARS-CoV-2 infection on the progression of PD.

2.
Biol Psychol ; 187: 108768, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38432426

ABSTRACT

Relationship with parents is a special bond that shapes self-other representations and have an impact on adult-child's marriage, especially in the early stages of marriage. This study sought to investigate the neural mechanisms underlying self-parents processing as well as their relationship with marriage. Seventy-eight premarital Korean participants were scanned in functional MRI while evaluating traits of the self and parents. Then, 21 of them returned after being married to engage in the identical task three years later. The precuneus and temporoparietal junction were identified to activate stronger for parents than self at both marital statuses. The dorsal anterior cingulate cortex, posterior cingulate cortex, parietal operculum, and caudate activated more for self than parents before marriage, but their activities changed during marriage. The activation increase of the parietal operculum between marital statuses in the parents condition was negatively correlated with the level of marital dissatisfaction, and this association only appeared among participants with a child. Self-parents processing may recruit brain regions involved in autobiographical memory and self-other distinction, and marriage has an impact on the way individuals process rewards and multimodal sensory information during this processing. Marriage may lead to changes in brain function that affect the processing of emotions toward parents and a more parents-oriented perspective shift in collectivistic societies.


Subject(s)
Marriage , Parents , Adult , Humans , Marriage/psychology , Parents/psychology , Emotions , Brain/diagnostic imaging
4.
J Microbiol Biotechnol ; 34(4): 949-957, 2024 Apr 28.
Article in English | MEDLINE | ID: mdl-38480002

ABSTRACT

There has been a growing interest in skin beauty and antimelanogenic products. Melanogenesis is the process of melanin synthesis whereby melanocytes are activated by UV light or hormone stimulation to produce melanin. Melanogenesis is mediated by several enzymes, such as tyrosinase (TYR), microphthalmia-associated transcription factor (MITF), tyrosinase-related protein-1 (TRP-1), and TRP-2. In this study, we investigated the effect of Tuber himalayense extract on melanin synthesis in α-melanocyte-stimulating hormone (α-MSH)-treated B16F10 melanoma cells. We confirmed that T. himalayense extract was not toxic to α-MSH-treated B16F10 melanoma cells and exhibited a significant inhibitory effect on melanin synthesis at concentrations of 25, 50, and 100 µg/ml. Additionally, the T. himalayense extract inhibited melanin, TRP-1, TRP-2, tyrosinase, and MITF, which are enzymes involved in melanin synthesis, in a concentration-dependent manner. Furthermore, T. himalayense extract inhibited the mitogen-activated protein kinase (MAPK) pathways, such as extracellular signal-regulated kinase-1/2 (ERK), c-Jun N-terminal kinase (JNK), and p38. Therefore, we hypothesized that various components of T. himalayense extract affect multiple factors involved in melanogenesis in B16F10 cells. Our results indicate that T. himalayense extract could potentially be used as a new material for preparing whitening cosmetics.


Subject(s)
Melanins , Microphthalmia-Associated Transcription Factor , Monophenol Monooxygenase , Plant Extracts , Melanins/biosynthesis , Melanins/metabolism , Animals , Mice , Plant Extracts/pharmacology , Plant Extracts/chemistry , Monophenol Monooxygenase/antagonists & inhibitors , Monophenol Monooxygenase/metabolism , Cell Line, Tumor , Republic of Korea , Microphthalmia-Associated Transcription Factor/metabolism , Microphthalmia-Associated Transcription Factor/genetics , Intramolecular Oxidoreductases/metabolism , alpha-MSH/pharmacology , alpha-MSH/metabolism , Melanoma, Experimental/metabolism , Oxidoreductases/metabolism , Plant Tubers/chemistry , Membrane Glycoproteins/metabolism , Melanocytes/drug effects , Melanocytes/metabolism , Cell Survival/drug effects
5.
Neurol Sci ; 2024 Mar 23.
Article in English | MEDLINE | ID: mdl-38520638

ABSTRACT

OBJECTIVE: Type 2 diabetes mellitus (T2DM) is a risk factor for cognitive impairment, and reduced heart rate variability (HRV) has been correlated with cognitive impairment in elderly individuals. This study investigated risk factors and validated a predictive model for mild cognitive impairment (MCI) in patients with T2DM using an autonomic function test. METHODS: Patients with T2DM, 50-85 years of age, who attended the diabetes clinic at Gyeongsang National University Hospital between March 2018 and December 2019, were included. A total of 201 patients had been screened; we enrolled 124 patients according to the inclusion and exclusion criteria in this study. Cognitive function was assessed using the Montreal Cognitive Assessment-Korean version (MOCA-K); MCI was defined as a total MOCA-K score ≤ 23. Risk factors for MCI in patients with T2DM, including demographic- and diabetes-related factors, and autonomic function test results, were analyzed. Based on multivariate logistic regression, a nomogram was developed as a prediction model for MCI. RESULTS: Thirty-nine of 124 patients were diagnosed with MCI. Age, education, and decreased cardiovagal function were associated with a high risk for MCI, with cardiovagal function exerting the greatest influence. However, diabetes-related factors, such as glycemic control, duration of diabetes, or medications, were not associated with the risk for MCI. The nomogram demonstrated excellent discrimination (area under the curve, 0.832) and was well calibrated. CONCLUSION: Approximately one-third of patients had MCI; as such, carefully evaluating cognitive function in elderly T2DM patients with reduced HRV is important to prevent progression to dementia.

6.
J Oral Sci ; 66(2): 96-101, 2024 Apr 16.
Article in English | MEDLINE | ID: mdl-38325857

ABSTRACT

PURPOSE: This study evaluated the dentin bonding strength and biomineralization effect of a recently developed premixed calcium aluminate-based endodontic sealer (Dia-Root Bio Sealer) in comparison with existing calcium silicate-based sealers. METHODS: The root canals of 80 mandibular premolars were filled with Dia-Root Bio Sealer, Endoseal MTA, EndoSequence BC Sealer, and AH Plus Bioceramic Sealer. Medial and apical specimens were then obtained by sectioning. The push-out bond strength was measured using the medial specimens, and the failure mode was recorded. Intratubular biomineralization in the apical specimens was analyzed using scanning electron microscopy and energy-dispersive X-ray spectroscopy (EDS). The data were analyzed using one-way analysis of variance followed by the Tukey test (P < 0.05). RESULTS: The push-out bond strength of Dia-Root Bio Sealer was significantly higher than that of the other tested materials, and a cohesive failure pattern was observed in all groups. Dia-Root Bio Sealer also exhibited a significantly higher degree of biomineralization than the other groups, and EDS analysis indicated that the biomineralized precipitates were amorphous calcium phosphate. CONCLUSION: The results of this study indicate that Dia-Root Bio Sealer has the potential to be used as an adequate root canal sealer due to its favorable bonding performance.


Subject(s)
Aluminum Compounds , Calcium Compounds , Dental Bonding , Root Canal Filling Materials , Root Canal Filling Materials/chemistry , Epoxy Resins/chemistry , Epoxy Resins/pharmacology , Biomineralization , Dental Bonding/methods , Materials Testing , Dentin , Silicates/chemistry
7.
Heliyon ; 10(3): e25269, 2024 Feb 15.
Article in English | MEDLINE | ID: mdl-38333803

ABSTRACT

We present research on the role of multiple quantum well periods in extended short-wavelength infrared InGaAs/InAsPSb type-I LEDs. The fabricated LEDs consisted of 6, 15, and 30 quantum well periods, and we evaluated the structural properties and device performance through a combination of theoretical simulations and experimental characterization. The strain and energy band offset was precisely controlled by carefully adjusting the composition of the InAsPSb quaternary material, achieving high valence and conduction band offsets of 350 meV and 94 meV, respectively. Our LEDs demonstrated a high degree of relaxation of 94-96 %. Additionally, we discovered that the temperature-dependent dark current characterization attributed to generation-recombination and trap-assign tunneling, with trap-assign tunneling being more dominant at lower current injections. Electroluminescence analysis revealed that the predominant emission mechanism of the LEDs originated from localized exciton and free exciton radiative recombination, which the 30 quantum wells LED exhibited the highest contribution of the localized exciton/free exciton radiative recombination. We observed that increasing the quantum well periods from 6 to 15 led to an increase in the 300 K electroluminescence intensity of the LED. However, extending the quantum well period to 30 resulted in a decline in emission intensity due to the degradation of the epitaxial film quality.

8.
Comput Methods Programs Biomed ; 245: 108002, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38215659

ABSTRACT

BACKGROUND AND OBJECTIVES: Although magnetic resonance imaging (MRI) is commonly used for breast tumor detection, significant challenges remain in determining and presenting the three-dimensional (3D) morphology of tumors to guide breast-conserving surgery. To address this challenge, we have developed the augmented reality-breast surgery guide (AR-BSG) and compared its performance with that of a traditional 3D-printed breast surgical guide (3DP-BSG). METHODS: Based on the MRI results of a breast cancer patient, a breast phantom made of skin, body, and tumor was fabricated through 3D printing and silicone-casting. AR-BSG and 3DP-BSG were executed using surgical plans based on the breast phantom's computed tomography scan images. Three operators independently inserted a catheter into the phantom using each guide. Their targeting accuracy was then evaluated using Bland-Altman analysis with limits of agreement (LoA). Differences between the users of each guide were evaluated using the intraclass correlation coefficient (ICC). RESULTS: The entry and end point errors associated with AR-BSG were -0.34±0.68 mm (LoA: -1.71-1.01 mm) and 0.81±1.88 mm (LoA: -4.60-3.00 mm), respectively, whereas 3DP-BSG was associated with entry and end point errors of -0.28±0.70 mm (LoA: -1.69-1.11 mm) and -0.62±1.24 mm (LoA: -3.00-1.80 mm), respectively. The AR-BSG's entry and end point ICC values were 0.99 and 0.97, respectively, whereas 3DP-BSG was associated with entry and end point ICC values of 0.99 and 0.99, respectively. CONCLUSIONS: AR-BSG can consistently and accurately localize tumor margins for surgeons without inferior guiding accuracy AR-BSG can consistently and accurately localize tumor margins for surgeons without inferior guiding accuracy compared to 3DP-BSG. Additionally, when compared with 3DP-BSG, AR-BSG can offer better spatial perception and visualization, lower costs, and a shorter setup time.


Subject(s)
Augmented Reality , Breast Neoplasms , Surgery, Computer-Assisted , Humans , Female , Mastectomy, Segmental , Tomography, X-Ray Computed/methods , Breast Neoplasms/diagnostic imaging , Breast Neoplasms/surgery , Phantoms, Imaging , Imaging, Three-Dimensional/methods , Surgery, Computer-Assisted/methods , Printing, Three-Dimensional
9.
PLoS One ; 19(1): e0296282, 2024.
Article in English | MEDLINE | ID: mdl-38165980

ABSTRACT

OBJECTIVE: Patients with Parkinson's disease (PD) have an increased risk of sarcopenia which is expected to negatively affect gait, leading to poor clinical outcomes including falls. In this study, we investigated the gait patterns of patients with PD with and without sarcopenia (sarcopenia and non-sarcopenia groups, respectively) using an app-derived program and explored if gait parameters could be utilized to predict sarcopenia based on machine learning. METHODS: Clinical and sarcopenia profiles were collected from patients with PD at Hoehn and Yahr (HY) stage ≤ 2. Sarcopenia was defined based on the updated criteria of the Asian Working Group for Sarcopenia. The gait patterns of the patients with and without sarcopenia were recorded and analyzed using a smartphone application. The random forest model was applied to predict sarcopenia in patients with PD. RESULTS: Data from 38 patients with PD were obtained, among which 9 (23.7%) were with sarcopenia. Clinical parameters were comparable between the sarcopenia and non-sarcopenia groups. Among various clinical and gait parameters, the average range of motion of the hip joint showed the highest association with sarcopenia. Based on the random forest algorithm, the combined difference in knee and ankle angles from standing still before walking to the maximum angle during walking (Kneeankle_diff), the difference between the angle when standing still before walking and the maximum angle during walking for the ankle (Ankle_dif), and the min angle of the hip joint (Hip_min) were the top three features that best predict sarcopenia. The accuracy of this model was 0.949. CONCLUSIONS: Using smartphone app and machine learning technique, our study revealed gait parameters that are associated with sarcopenia and that help predict sarcopenia in PD. Our study showed potential application of advanced technology in clinical research.


Subject(s)
Parkinson Disease , Sarcopenia , Humans , Parkinson Disease/complications , Sarcopenia/complications , Sarcopenia/diagnosis , Gait , Walking , Machine Learning
11.
Heliyon ; 9(11): e21751, 2023 Nov.
Article in English | MEDLINE | ID: mdl-38053859

ABSTRACT

Public transportation facilities, especially road crossings, which raise the pathogenic potential of urban environments, are the most conducive places for the transfer of germs between people and the environment. It is necessary to study the variety of the microbiome and describe its unique characteristics to comprehend these relationships. In this investigation, we used 16 S rRNA gene sample sequencing to examine the biological constituents and inhalable, thoracic, and alveolar particles in aerosol samples collected from busy areas in the Gangnam-gu district of the Seoul metropolitan area using a mobile vehicle. We also conducted a comparison analysis of these findings with the previously published data and tested for antibiotic resistance to determine the distribution of bacteria related to the human microbiome and the environment. Actinobacteria, Cyanobacteria, Bacteriodetes, Proteobacteria, and Firmicutes were the top five phyla in the bacterial 16 S rRNA libraries, accounting for >90 % of all readings across all examined locations. The most prevalent classes among the 12 found bacterial classes were Bacilli (45.812 %), Gammaproteobacteria (25.238 %), Tissierellia (13.078 %), Clostridia (5.697 %), and Alphaproteobacteria (5.142 %). The data acquired offer useful information on the variety of bacterial communities and their resistance to antibiotic drugs on the streets of Gangnam-gu, one of the most significant social centers in the Seoul metropolitan area. This work emphasizes the relevance of biological particles and particulate matter in the air, and it suggests more research is needed to perform biological characterization of the ambient particulate matter.

12.
Yonsei Med J ; 64(12): 712-720, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37992743

ABSTRACT

PURPOSE: Delirium in the intensive care unit (ICU) poses a significant safety and socioeconomic burden to patients and caregivers. However, invasive interventions for managing delirium have severe drawbacks. To reduce unnecessary interventions during ICU hospitalization, we aimed to investigate the features of delirium among ICU patients according to the occurrence of hypoactive symptoms, which are not expected to require invasive intervention. MATERIALS AND METHODS: Psychiatrists assessed all patients with delirium in the ICU during hospitalization. Patients were grouped into two groups: a "non-hypoactive" group that experienced the non-hypoactive motor subtype once or more or a "hypoactive only" group that only experienced the hypoactive motor subtype. Clinical variables routinely gathered for clinical management were collected from electronic medical records. Group comparisons and logistic regression analyses were conducted. RESULTS: The non-hypoactive group had longer and more severe delirium episodes than the hypoactive only group. Although the non-hypoactive group was prescribed more antipsychotics and required restraints longer, the hypoactive only group also received both interventions. In multivariable logistic regression analysis, BUN [odds ratio (OR): 0.993, pH OR: 0.202], sodium (OR: 1.022), RASS score (OR: 1.308) and whether restraints were applied [OR: 1.579 (95% confidence interval 1.194-2.089), p<0.001] were significant predictors of hypoactive only group classification. CONCLUSION: Managing and predicting delirium patients based on whether patients experienced non-hypoactive delirium may be clinically important. Variables obtained during the initial 48 hours can be used to determine which patients are likely to require invasive interventions.


Subject(s)
Antipsychotic Agents , Delirium , Humans , Retrospective Studies , Longitudinal Studies , Delirium/diagnosis , Delirium/drug therapy , Delirium/epidemiology , Antipsychotic Agents/therapeutic use , Intensive Care Units
13.
Toxics ; 11(11)2023 Nov 16.
Article in English | MEDLINE | ID: mdl-37999584

ABSTRACT

Driven by industrialization and urbanization, urban air pollution can increase respiratory, heart, and cerebrovascular diseases, and thus mortality rates; as such, it is necessary to improve air quality through the consideration of individual pollutants and emission sources. In Republic of Korea, national and local governments have installed urban and roadside air quality monitoring systems. However, stations are lacking outside metropolitan regions, and roadside stations are sparsely distributed, limiting comparisons of pollutant concentrations with vehicle traffic and floating population levels. Local governments have begun using mobile laboratories (MLs) to supplement the fixed measurement network and investigate road pollution source characteristics based on their spatiotemporal distribution; however, the collected data cannot be used effectively if they are not visualized. Here, we propose a method to collect and visualize global information system (GIS)-based air quality data overlayed with environmental variables to support air quality management measures. Spatiotemporal analyses of ML-derived data from Bucheon, Korea, confirmed that particulate and gaseous pollutant concentrations were high during typical commuting hours, at intersections, and at a specially managed road. During commuting hours, the maximum PM10 concentration reached 200.7 µg/m3 in the Nae-dong, Gyeongin-ro, and Ojeong-dong ready-mix concrete complex areas, and the maximum PM2.5 concentration was 161.7 µg/m3. The maximum NOx, NO2, and NO levels of 1.34 ppm, 0.18 ppm, and 1.18 ppm, respectively, were also detected during commuting hours. These findings support the need for targeted management of air pollution in this region, and highlight the benefit of comprehensively comparing road levels, driving speed, and traffic levels when identifying hotspots of air pollution. Such analyses will contribute to the development of air quality management measures customized to regional characteristics.

14.
Korean J Women Health Nurs ; 29(3): 229-238, 2023 09.
Article in English | MEDLINE | ID: mdl-37813666

ABSTRACT

PURPOSE: This study analyzed the effects of virtual reality simulation-based problem-based learning on nursing students' critical thinking ability, problem-solving ability, and self-efficacy in the nursing care of women undergoing induction of labor. METHODS: A nonequivalent control group pretest and posttest design was employed. The study participants included 52 nursing students (24 in the experimental group and 28 in the control group). The experimental group took a problem-based learning (PBL) class in the first week, and then engaged in self-directed learning using virtual reality simulation. In the second week, lectures about emergency nursing care for induction of labor and drug administration were given. The control group participated in PBL in the first week and lectures in the second week. The study was conducted from April 17 to May 19, 2023. Data were analyzed using the chi-square test, Fisher exact test, analysis of variance, and the independent t-test. RESULTS: Before-and-after differences between the two groups were statistically significant in problem solving ability (t=-5.47, p<.001) and self-efficacy (t=-5.87, p<.001). Critical thinking ability did not show a statistically significant difference between the two groups. The score for satisfaction with the virtual reality simulation program was 3.64±5.88 out of 5 in the experimental group. CONCLUSION: PBL education using a virtual reality simulation was found to be an effective way of teaching. Although convenience sampling was used, PBL education using virtual reality can be used as an educational strategy to enhance nursing students' problem-solving ability and self-efficacy.


Subject(s)
Students, Nursing , Virtual Reality , Female , Humans , Problem Solving , Problem-Based Learning , Thinking
15.
Mycobiology ; 51(4): 256-263, 2023.
Article in English | MEDLINE | ID: mdl-37711981

ABSTRACT

Species in the genus Trametes (Basidiomycota, Polyporales) have been used in natural medicine for a long time. Many studies reported that mycelia or fruiting bodies of Trametes spp. exhibited effects of antioxidant, anti-inflammatory, anticancer, and antimicrobial activities. However, comparative analysis in this genus is scarce due to limitation of morphological identification and the sample number. In this study, the 19 strains of seven Trametes species were chosen to generate a five-gene-based phylogeny with the 31 global references. In addition, 39 culture extracts were prepared for 13 strains to test for anticancer and antibacterial activities. Strong anticancer activities were found in several extracts from T. hirsuta and T. suaveolens. Anticancer activities of T. suaveolens, T. cf. junipericola and T. trogii were first described here. The antibacterial ability of T. versicolor and T. hirsuta extracts has been confirmed. The antibacterial activities of T. suaveolens have been reported at the first time in this study. These results suggest an efficient application of the genus Trametes as the drug resources especially for anticancer agents.

16.
Ann Clin Microbiol Antimicrob ; 22(1): 76, 2023 Aug 24.
Article in English | MEDLINE | ID: mdl-37620875

ABSTRACT

BACKGROUND: The emergence of carbapenem-resistant Enterobacterales (CRE) infections is rapidly increasing and represents a serious public threat. In 2020, a total of 16,883 carbapenemase-producing Enterobacterales strains were collected; among these isolates, 21 strains were repeatedly isolated in a local tertiary care hospital. METHODS: Antimicrobial susceptibility testing was performed using the broth microdilution method. All 21 strains of CRKP were analyzed by PFGE after XbaI digestion. The 21 CRKP strains were sequenced on the Illumina Miseq and Oxford Nanopore GridION platforms. RESULTS: These 21 CRKP isolates showed an identical antimicrobial resistance profile, including resistance to ampicillin, carbapenems, cephems, chloramphenicol, fluoroquinolone, macrolides and trimethoprim/sulfamethoxazole. Based on whole-genome analysis, these 21 CRKP isolates shared a common genetic structure (ISAba125-IS630-blaNDM-1-bleMBL) and harbored additional resistance determinants (blaOXA-1, blaCTX-M-15, blaSHV-11, blaSHV-67, aac(6')-Ib-cr, qnrS1, OqxA, OqxB, catB3, mph(A), sul1, and dfrA12) and mutations in the quinolone resistance-determining regions of gyrA (S83I) and parC (S80I). These isolates belonged to the ST147 and KL64 capsular types, which were carried on IncFIB replicon plasmids. The 21 CRKP strains collected from one hospital were divided into five PFGE patterns, and they were closely related with a minimum similarity value of 95.2%. These isolates were found to be highly related based on the presence of between 2 and 27 SNPs. CONCLUSIONS: These findings indicate that NDM-1-producing K. pneumoniae ST147 may have been introduced via a common source, implying nosocomial transmission; furthermore, continuous monitoring is necessary to prevent endemic transmission.


Subject(s)
Carbapenem-Resistant Enterobacteriaceae , Klebsiella pneumoniae , Humans , Klebsiella pneumoniae/genetics , Tertiary Care Centers , Republic of Korea/epidemiology , Anti-Bacterial Agents/pharmacology , Carbapenem-Resistant Enterobacteriaceae/genetics , Carbapenems/pharmacology
17.
Magn Reson Med Sci ; 2023 May 13.
Article in English | MEDLINE | ID: mdl-37183027

ABSTRACT

PURPOSE: Although diffusion-weighted imaging (DWI) with ultra-high b-values is reported to be advantageous in the detection of some tumors, its applicability is not yet known in biliary malignancy. Therefore, this study aimed to evaluate the impact of measured b = 1400 s/mm2 (M1400) and calculated b = 1400 s/mm2 (C1400) DWI on image quality and quality of lesion discernibility using a modern 3T MR system compared to conventional b = 800 s/mm2 DWI (M800). METHODS: We evaluated 56 patients who had pathologically proven biliary malignancy. All the patients underwent preoperative or baseline 3T MRI using DWI (b = 50, 400, 800, and 1400 s/mm2). The calculated DWI was obtained using a conventional DWI set (b = 50, 400, and 800). The tumor-to-bile contrast ratio (CR) and tumor SNR were compared between the different DWI images. Likert scores were given on a 5-point scale to assess the overall image quality, overall artifacts, ghost artifacts, misregistration artifacts, margin sharpness, and lesion discernibility. Repeated-measures analysis of variance with post hoc analyses was used for statistical evaluations. RESULTS: The CR of the tumor-to-bile was significantly higher in both M1400 and C1400 than in M800 (Pa < 0.01). SNRs were significantly higher in M800, followed by C1400 and M1400 (Pa < 0.01). Lesion discernibility was significantly improved for M1400, followed by C1400 and M800 for both readers (Pa < 0.01). CONCLUSION: Using a 3T MRI, both measured and calculated DWI with an ultra-high b-value offer superior lesion discernibility for biliary malignancy compared to the conventional DWI.

18.
Nanoscale Adv ; 5(3): 633-639, 2023 Jan 31.
Article in English | MEDLINE | ID: mdl-36756508

ABSTRACT

The optical, plasmonic, and imaging performance of an infra-red polarized system exceeds that of a conventional infra-red detector due to its high resolution and precision. The wire-grid polarizer has large potential for use in an infra-red polarized imaging device owing to its large polarization efficiency. In this study, we theoretically and experimentally investigate a method to improve the polarization efficiency of a wire-grid polarizer. Here, we demonstrated a high-performance wire grid polarizer with a maximum extinction ratio (ER) of 355 using a bilayer structure and dielectric material in the mid-wavelength infra-red (MWIR) region (3000 nm-5000 nm), which is a 4 times higher ER value than that of the monolayer structure. More interestingly, we were able to improve the performance of the bilayer wire-grid polarizer by devising a method to improve the surface roughness using Ar ion milling. The ER for the after-milled sample was 1255, which was markedly larger than that of the before-milled sample. The results of transmittance measurement confirmed that the improvement in the ER was due to the Fabry-Perot (F-P) phenomenon caused by constructive or destructive interference in the bilayer wire-grid structure and the enhancement of the surface smoothness. These results will help design a polarizer structure that will maximize the polarization efficiency and realize a high-performance infrared polarized imaging system.

19.
J Cancer ; 14(1): 50-60, 2023.
Article in English | MEDLINE | ID: mdl-36605488

ABSTRACT

One of the biggest obstacles in cancer treatment is the development of chemoresistance. To overcome this, attempts have been made to screen novel anticancer substances derived from natural products. The purpose of this study is to find new anticancer candidates in the mycelium culture extract of mushrooms belonging to Polyporus. Here, we used a high-throughput screening to find agents capable of inhibiting cancer cell proliferation. The culture extract of Polyporus Parvovarius mycelium in DY medium (pp-DY) was effective. pp-DY inhibited cancer cell proliferation by inducing apoptosis and S-phase arrest. The anticancer property of pp-DY was not only effective against one type of cancer, but also against another type of cancer. Compound fractionation was performed, and the active ingredient exhibiting anticancer effects in pp-DY was identified as 3,4-dihydroxybenzaldehyde (Protocatechualdehyde, PCA). PCA, like pp-DY, inhibited the proliferation of cancer cells by inducing apoptosis and S-phase arrest. Furthermore, unlike conventional anticancer drugs, PCA did not increase the proportion of the side population that plays the most important role in the development of chemoresistance. Taken together, our data revealed the novel mycelium culture extract that exhibited anticancer property, and identified active ingredients that did not activate a proportion of the side population. These novel findings may have clinical applications in the treatment of cancer, particularly chemo-resistant cancer.

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