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1.
World Neurosurg ; 2024 Jul 23.
Artículo en Inglés | MEDLINE | ID: mdl-39053854

RESUMEN

OBJECTIVE: To assess the national and regional trend in the prevalence of lumbar spondylolysis and isthmic spondylolisthesis for adolescent males in South Korea from 2015 to 2022. METHODS: A total of 2,666,277 Korean adolescent males were routinely examined at regional Military Manpower Administration (MMA) offices. The data gathered from MMA were retrospectively collected to measure the prevalence and 95% confidence interval (CI) of lumbar spondylolysis and isthmic spondylolisthesis according to the year and region in South Korea. The Spearman correlation analysis was performed to assess the correlation between lumbar spondylolysis, isthmic spondylolisthesis, and several factors including height, weight, current smoking rate, and occasional and high-risk alcohol consumption. RESULTS: The prevalence of spondylolysis per 10,000 individuals showed a gradual increasing trend from 2015 to 2022 On the contrary, the prevalence of isthmic spondylolisthesis per 10,000 individuals decreased over a consecutive 8-year period. There were no statistical differences in the prevalence of spondylolysis and isthmic spondylolisthesis between Greater Seoul and the countryside. The prevalence of isthmic spondylolisthesis was significantly correlated with occasional (r = 0.81, P = 0.015) and high-risk alcohol consumption (r = 0.86, P = 0.007). CONCLUSIONS: The prevalence of lumbar spondylolysis among adolescent men has increased, whereas isthmic spondylolisthesis has shown a decline over a consecutive 8-year period. The trends in prevalence for both lumbar spondylosis and isthmic spondylolisthesis were similar across the regions in South Korea. Notably, there was a significant correlation between the prevalence of isthmic spondylolisthesis and the rate of alcohol consumption in adolescent men.

2.
Methods Mol Biol ; 2837: 59-66, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39044075

RESUMEN

Of all the chemical modifications of RNAs, the N6-methyladenosine (m6A) modification is the most prevalent and well-characterized RNA modification that is functionally implicated in a wide range of biological processes. The m6A modification occurs in hepatitis B virus (HBV) RNAs and this modification regulates the HBV life cycle in several ways. Thus, understanding the mechanisms underlying m6A modification of HBV RNAs is crucial in understanding HBV infectious process and associated pathogenesis. Here, we describe the currently utilized method in the detection and characterization of m6A-methylated RNAs during viral infection.


Asunto(s)
Adenosina , Virus de la Hepatitis B , Inmunoprecipitación , ARN Viral , Adenosina/análogos & derivados , Adenosina/metabolismo , Virus de la Hepatitis B/genética , ARN Viral/genética , ARN Viral/metabolismo , Humanos , Metilación , Inmunoprecipitación/métodos , Hepatitis B/virología
3.
ACS Macro Lett ; : 943-950, 2024 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-39008631

RESUMEN

Although extreme ultraviolet lithography (EUVL) has emerged as a leading technology for achieving high quality sub-10 nm patterns, the insufficient pattern height of photoresist patterns remains a challenge. Directed self-assembly (DSA) of block copolymers (BCPs) is expected to be a complementary technology for EUVL due to its ability to form periodic nanostructures. However, for a combination with EUV patterns, it is essential to develop advanced BCP systems that are suited to inorganic-containing EUV photoresists and offer improved resolution limits, pattern quality, and etch resistance. Here, we report a reverse-gradient BCP system, poly[(styrene-gradient-pentafluorostyrene)-b-4-tert-butyldimetilsiloxystyrene] [P(S-g-PFS)-b-P4BDSS] BCP, which enables universally vertically oriented lamellae even in the absence of a neutral layer, while also containing a Si-containing block with high etch resistance. The gradient block, characterized by a gradual compositional transition from the block junction to the tail, plays a crucial role in creating an adequate surface energy contrast that energetically drives the formation of perpendicular lamellae without neutral layer. When used as a pattern height enhancement layer in EUVL, a high aspect ratio (3.29) of patterns was achieved, thereby offering a supplementary solution for next-generation EUVL.

4.
Nat Commun ; 15(1): 6225, 2024 Jul 23.
Artículo en Inglés | MEDLINE | ID: mdl-39043671

RESUMEN

The deep ocean, a vast thermal reservoir, absorbs excess heat under greenhouse warming, which ultimately regulates the Earth's surface climate. Even if CO2 emissions are successfully reduced, the stored heat will gradually be released, resulting in a particular pattern of ocean warming. Here, we show that deep ocean warming will lead to El Niño-like ocean warming and resultant increased precipitation in the tropical eastern Pacific with southward shift of the intertropical convergence zone. Consequently, the El Niño-Southern Oscillation shifts eastward, intensifying Eastern Pacific El Niño events. In particular, the deep ocean warming could increase convective extreme El Niño events by 40 to 80% relative to the current climate. Our findings suggest that anthropogenic greenhouse warming will have a prolonged impact on El Niño variability through delayed deep ocean warming, even if CO2 stabilization is achieved.

6.
Molecules ; 29(11)2024 May 26.
Artículo en Inglés | MEDLINE | ID: mdl-38893384

RESUMEN

Analysis of the heavy fractions in crude oil has been important in petroleum industries. It is well known that heavy fractions such as vacuum gas oils (VGOs) include heteroatoms, of which sulfur and nitrogen are often characterized in many cases. We conducted research regarding the molecular species analysis of VGOs. Further refine processes using VGOs are becoming important when considering carbon recycling. In this work, we attempted to classify compounds within VGOs provided by Kuwait Institute for Scientific Research. Two VGOs were priorly distillated from Kuwait Export crude and Lower Fars crude. Quantitative analysis was performed mainly using matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOFMS). MALDI-TOF-MS has been developed for analyzing high-molecular-weight compounds such as polymer and biopolymers. As matrix selection is one of the most important aspects in MALDI-TOFMS, the careful selection of a matrix was firstly evaluated, followed by analysis using a Kendrick plot with nominal mass series (z*). The objective was to evaluate if this work could provide an effective classification of VGOs compounds. The Kendrick plot is a well-known method for processing mass data. The difference in the Kendrick mass defect (KMD) between CnH2n-14S and CnH2n-20O is only 0.0005 mass units, which makes it difficult in general to distinguish these compounds. However, since the z* value showed effective differences during the classification of these compounds, qualitative analysis could be possible. The analysis using nominal mass series showed the potential to be used as an effective method in analyzing heavy fractions.

7.
Artículo en Inglés | MEDLINE | ID: mdl-38788059

RESUMEN

BACKGROUND: Chronic stroke can impair cardiopulmonary function, mobility, and daily activities. This study assessed the impact of robot-assisted gait training (RAGT) on such impairments. OBJECTIVE: To investigate the effects of robot-assisted gait training on cardiopulmonary function, walking ability, lower extremity function and strength, activities of daily living (ADLs), and blood test results among individuals with chronic stroke. METHODS: A multicenter, prospective, single-blinded, randomized controlled trial with 22 chronic stroke participants compared RAGT against a control exercise regimen. RAGT involved three days weekly sessions of high-intensity interval training for 8 weeks (24 sessions) with a Morning Walk® device. The control group also performed home exercises. (24 sessions) Measures included VO2max, Functional Ambulatory Category, 2-minute walk test, 10-meter walk test, Motricity Index-Lower, Korean version of the Fugl-Meyer Assessment Scale, Modified Barthel Index, Berg Balance Scale, muscle strength, InBody body composition, and blood tests (cholesterol, lipid, glucose). RESULTS: RAGT significantly improved VO2max, gait, balance, and lower limb strength compared with controls, with significant improvements in 2-minute walk test, 10-meter walk test, Motricity Index-Lower, and Fugl-Meyer Assessment outcomes. No changes were seen in muscle mass or blood markers. CONCLUSION: RAGT enhances cardiopulmonary function and ambulatory capacity in chronic stroke patients, underscoring its potential in stroke rehabilitation.

8.
Sci Data ; 11(1): 516, 2024 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-38773111

RESUMEN

As IoT technology advances, using machine learning to detect user activities emerges as a promising strategy for delivering a variety of smart services. It is essential to have access to high-quality data that also respects privacy concerns and data streams from ambient sensors in the surrounding environment meet this requirement. However, despite growing interest in research, there is a noticeable lack of datasets from ambient sensors designed for public spaces, as opposed to those for private settings. To bridge this gap, we design the DOO-RE dataset within an actual meeting room environment, equipped with three types of ambient sensors: those triggered by actuators, users, and the environment itself. This dataset is compiled from the activities of over twenty students throughout a period of four months. DOO-RE provides reliable and purpose-oriented activity data in a public setting, with activity labels verified by multiple annotators through a process of cross-validation to guarantee data integrity. DOO-RE categorizes nine different types of activities and facilitates the study of both single and group activities. We are optimistic that DOO-RE will play a significant role in advancing human activity recognition technologies, enhancing smart automation systems, and enabling the rapid setup of smart spaces through ambient sensors.

9.
Food Sci Anim Resour ; 44(3): 586-606, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38765284

RESUMEN

The study was performed to determine the effect of faba bean protein isolate (FBPI) alone or in combination with microbial transglutaminase (MTG) on the rheological properties of pork myofibrillar protein gel (MPG), and physiochemical and textural properties of reduced-salt, low-fat pork model sausages (LFMSs). The cooking yields of MPGs with MTG or FBPI alone decreased and increased, respectively. However, the combination of FBPI and MTG was similar to the control (CTL) without FBPI or MTG. Gel strength values of MPG added with both FBPI and MTG were higher than treatments with FBPI or MTG alone. The hydrophobicity values of CTL were lower than those of MPG with FBPI alone, whereas the addition of MTG decreased the hydrophobicity of MPGs. The incorporation of FBPI alone or in combination with MTG decreased sulfhydryl groups (p<0.05). Shear stress values of MPGs with MTG tended to be higher than those of non-MTG treatments at all shear rates, and the addition of FBPI into MPGs increased shear stress values. Reduced-salt (1.0%) LFMSs with FBPI alone or combined with MTG had both lower cooking loss and expressible moisture values than those of CTL and similar values to the reference sample (REF, 1.5% salt). Textural properties of reduced-salt LFMSs with FBPI or MTG were similar to those of REF. These results demonstrated that the combination of FBPI and MTG could improve the water binding capacity and textural properties of pork MPGs and LFMSs and might be suitable for application in the development of healthier meat products.

10.
Dement Neurocogn Disord ; 23(2): 75-88, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38720824

RESUMEN

The Korean Dementia Association (KDA) has been organizing biennial international academic conferences since 2019, with the International Conference of the KDA (IC-KDA) 2023 held in Busan under the theme 'Beyond Boundaries: Advancing Global Dementia Solutions.' The conference comprised 6 scientific sessions, 3 plenary lectures, and 4 luncheon symposiums, drawing 804 participants from 35 countries. Notably, a Korea-Taiwan Joint Symposium addressed insights into Alzheimer's disease (AD). Plenary lectures by renowned scholars explored topics such as microbiome-related AD pathogenesis, social cognition in neurodegenerative diseases, and genetic frontotemporal dementia (FTD). On the first day, specific presentations covered subjects like the gut-brain axis and neuroinflammation in dementia, blood-based biomarkers in AD, and updates in AD therapeutics. The second day's presentations addressed recent issues in clinical neuropsychology, FTD cohort studies, and the pathogenesis of non-AD dementia. The Academic Committee of the KDA compiles lecture summaries to provide comprehensive understanding of the advanced dementia knowledge presented at IC-KDA 2023.

11.
Lab Anim Res ; 40(1): 14, 2024 Apr 08.
Artículo en Inglés | MEDLINE | ID: mdl-38589968

RESUMEN

BACKGROUND: Gastrodia elata Blume (GEB), a traditional medicinal herb, has been reported to have pharmacological effect including protection against liver, neuron and kidney toxicity. However, explanation of its underlying mechanisms remains a great challenge. This study investigated the protective effects of GEB extract on vancomycin (VAN)-induced nephrotoxicity in rats and underlying mechanisms with emphasis on the anti-oxidative stress, anti-inflammation and anti-apoptosis. The male Sprague-Dawley rats were randomly divided three groups: control (CON) group, VAN group and GEB group with duration of 14 days. RESULTS: The kidney weight and the serum levels of blood urea nitrogen and creatinine in the GEB group were lower than the VAN group. Histological analysis using hematoxylin & eosin and periodic acid Schiff staining revealed pathological changes of the VAN group. Immunohistochemical analysis revealed that the expression levels of N-acetyl-D-glucosaminidase, myeloperoxidase and tumor necrosis factor-alpha in the GEB group were decreased when compared with the VAN group. The number of terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling-positive cells, phosphohistone and malondialdehyde levels were lower in the GEB group than VAN group. The levels of total glutathione in the GEB group were higher than the VAN group. CONCLUSIONS: The findings of this study suggested that GEB extract prevents VAN-induced renal tissue damage through anti-oxidation, anti-inflammation and anti-apoptosis.

12.
J Clin Med ; 13(7)2024 Mar 27.
Artículo en Inglés | MEDLINE | ID: mdl-38610709

RESUMEN

(1) Background: This study investigated changes in the gut microbial composition of individuals with mild cognitive impairment (MCI) due to Alzheimer's disease (AD) and their relationship with positron emission tomography (PET) amyloid accumulation. (2) Methods: In total, 17 cognitively normal individuals without amyloid-beta (Aß) accumulation (Aß-NC) and 24 with Aß-positive mild cognitive impairment (Aß+MCI) who underwent 18F-florbetaben PET and fecal bacterial 16S ribosomal RNA gene sequencing were enrolled. The taxonomic compositions of the Aß-NC and Aß+MCI groups were compared. The abundance of taxa was correlated with the standardized uptake value ratio (SUVR), using generalized linear models. (3) Results: There were significant differences in microbiome richness (ACE, p = 0.034 and Chao1, p = 0.024), alpha diversity (Shannon, p = 0.039), and beta diversity (Bray-Curtis, p = 0.018 and Generalized UniFrac, p = 0.034) between the Aß-NC and Aß+MCI groups. The global SUVR was positively correlated with the genus Intestinibacter (q = 0.006) and negatively correlated with the genera Roseburia (q = 0.008) and Agathobaculum (q = 0.029). (4) Conclusions: In this study, we identified significant changes in the gut microbiota composition that occur in individuals with MCI due to AD. In particular, the correlation analysis results between PET amyloid burden and gut microbial abundance showed that amyloid deposition is associated with a reduction in specific taxa involved in butyrate production.

14.
Toxicol Res ; 40(2): 203-213, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38525138

RESUMEN

To initiate skin sensitization, haptens react with endogenous proteins. During this process, skin sensitizers react with small endogenous molecules containing thiol or amino groups. In this study, a simple spectrophotometric method to identify skin sensitizers in chemico was developed using the reactivity of glutathione (GSH) with test chemicals in a 96-well plate. To quantitate the remaining GSH following the reaction with a skin sensitizer, 5,5'-dithiobis-(2-nitrobenzoic acid) (DTNB) was employed. The optimized experimental conditions included the pH- and time-dependent stability of GSH, stability of derivatized products of GSH with optimal concentration and incubation time of DTNB, incubation time of GSH with the test chemicals, and molar ratios of GSH to the test chemicals. With the optimized conditions with both acetonitrile and DMSO as vehicles and incubation of GSH with test chemicals in 1:10 and 1:15 ratios for 24 h at 4 °C, 23 skin sensitizers and 23 non-sensitizers, based on the local lymph node assay, were tested to determine the predictive capacity of individual conditions. The best result showed a predictive capacity of 95.2% sensitivity, 91.3% specificity, and 93.2% accuracy, with 93.2% consistency in three trials, when 5.8% depletion was used as a cut-off value in 1:10 of GSH:test chemicals in DMSO. It would be an economic and useful screening tool for determining the skin sensitization potential of small molecules, because the present method employs simple endogenous GSH as an electron donor for sensitizers with a spectrophotometric detection system in 96-well plates, and because the method requires neither experimental animals nor cell cultures. Supplementary Information: The online version contains supplementary material available at 10.1007/s43188-023-00218-9.

15.
J Sci Food Agric ; 104(10): 6322-6329, 2024 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-38520300

RESUMEN

BACKGROUND: This study aimed to assess the effect of faba bean (Vicia faba L.) protein isolate (FBPI) on the rheological properties of pork myofibrillar protein gels (MPGs) and the quality characteristics of pork low-fat model sausages (LFMSs). RESULTS: Pork MPGs with 5 or 10 g kg-1 FBPI had higher cooking yield, gel strength, and viscosity than controls. The addition of FBPI to MPGs increased the protein surface hydrophobicity and decreased sulfhydryl groups. Adding FBPI to MPGs changed the protein profile and microstructure. The cooking loss and expressible moisture of LFMSs with 5, 10, or 15 g kg-1 FBPI were lower than those of controls and showed similar results to those with 15 g kg-1 soy protein isolate (SPI). Hardness values of LFMSs with FBPI and SPI were no different, and were higher than those of controls. CONCLUSION: The addition of FBPI potentially improves rheological properties of MPGs and the functional properties of LFMSs, including water-holding capacity and textural properties. © 2024 Society of Chemical Industry.


Asunto(s)
Culinaria , Geles , Productos de la Carne , Proteínas de Plantas , Reología , Vicia faba , Animales , Productos de la Carne/análisis , Vicia faba/química , Porcinos , Geles/química , Proteínas de Plantas/química , Viscosidad , Proteínas Musculares/química , Miofibrillas/química
16.
J Neurosurg Spine ; 40(6): 700-707, 2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38457786

RESUMEN

OBJECTIVE: The aim of this study was to investigate the correlation between radiological indices of shoulder balance (SB) and cosmetic indices of shoulder deformity in patients with Lenke type 2 adolescent idiopathic scoliosis (AIS) and to determine the extent to which patient-reported outcomes (PROs) correlate with these measurements. Current management decisions and outcomes for SB in AIS are primarily based on radiological measurements. It is crucial to understand how these radiological parameters and cosmetic indices relate to patient satisfaction. METHODS: The authors analyzed the preoperative radiological and photographic indices of SB, along with PROs, in patients with Lenke type 2 AIS. Lateral SB parameters included the radiological shoulder height (RSH) and clavicle angle, while medial SB parameters included the first rib angle and T1 tilt angle. Photographic indices included the shoulder height angle (SHA), axilla height angle (AHA), and the left/right trapezius angle (LRTA) ratio. The authors assessed the self-image, mental health, and total score domains of the Korean version of the 22-item Scoliosis Research Society questionnaire. RESULTS: In their analysis of Lenke type 2 patients, the authors found that correlation coefficients between radiological measurements and photographic indices ranged from -0.25 to 0.47, among which only lateral SB including clavicle angle and RSH showed a significant correlation with anterior and posterior photographic indices. No statistically significant correlations were found between radiological measurements and PROs. Anterior photographic indices including SHA and AHA significantly correlated with all three PROs (p < 0.05). CONCLUSIONS: Radiological shoulder parameters did not accurately reflect the perceived SB. Anterior photographic indices were reliable for evaluating clinical SB in patients with Lenke type 2 AIS and correlated with PROs. Spine surgeons may benefit from paying more attention to anterior photographic indices when making surgical decisions regarding clinical SB.


Asunto(s)
Medición de Resultados Informados por el Paciente , Satisfacción del Paciente , Escoliosis , Hombro , Humanos , Escoliosis/diagnóstico por imagen , Escoliosis/cirugía , Adolescente , Femenino , Masculino , Hombro/diagnóstico por imagen , Hombro/fisiopatología , Equilibrio Postural/fisiología , Radiografía , Encuestas y Cuestionarios
17.
Dement Neurocogn Disord ; 23(1): 54-66, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38362056

RESUMEN

Background and Purpose: Dementia subtypes, including Alzheimer's dementia (AD), dementia with Lewy bodies (DLB), and frontotemporal dementia (FTD), pose diagnostic challenges. This review examines the effectiveness of 18F-Fluorodeoxyglucose Positron Emission Tomography (18F-FDG PET) in differentiating these subtypes for precise treatment and management. Methods: A systematic review following Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines was conducted using databases like PubMed and Embase to identify studies on the diagnostic utility of 18F-FDG PET in dementia. The search included studies up to November 16, 2022, focusing on peer-reviewed journals and applying the gold-standard clinical diagnosis for dementia subtypes. Results: From 12,815 articles, 14 were selected for final analysis. For AD versus FTD, the sensitivity was 0.96 (95% confidence interval [CI], 0.88-0.98) and specificity was 0.84 (95% CI, 0.70-0.92). In the case of AD versus DLB, 18F-FDG PET showed a sensitivity of 0.93 (95% CI 0.88-0.98) and specificity of 0.92 (95% CI, 0.70-0.92). Lastly, when differentiating AD from non-AD dementias, the sensitivity was 0.86 (95% CI, 0.80-0.91) and the specificity was 0.88 (95% CI, 0.80-0.91). The studies mostly used case-control designs with visual and quantitative assessments. Conclusions: 18F-FDG PET exhibits high sensitivity and specificity in differentiating dementia subtypes, particularly AD, FTD, and DLB. This method, while not a standalone diagnostic tool, significantly enhances diagnostic accuracy in uncertain cases, complementing clinical assessments and structural imaging.

18.
Int J Geriatr Psychiatry ; 39(2): e6071, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38372966

RESUMEN

BACKGROUND: Geriatric depression and anxiety have been identified as mood disorders commonly associated with the onset of dementia. Currently, the diagnosis of geriatric depression and anxiety relies on self-reported assessments for primary screening purposes, which is uncomfortable for older adults and can be prone to misreporting. When a more precise diagnosis is needed, additional methods such as in-depth interviews or functional magnetic resonance imaging are used. However, these methods can not only be time-consuming and costly but also require systematic and cost-effective approaches. OBJECTIVE: The main objective of this study was to investigate the feasibility of training an end-to-end deep learning (DL) model by directly inputting time-series activity tracking and sleep data obtained from consumer-grade wrist-worn activity trackers to identify comorbid depression and anxiety. METHODS: To enhance accuracy, the input of the DL model consisted of step counts and sleep stages as time series data, along with minimal depression and anxiety assessment scores as non-time-series data. The basic structure of the DL model was designed to process mixed-input data and perform multi-label-based classification for depression and anxiety. Various DL models, including the convolutional neural network (CNN) and long short-term memory (LSTM), were applied to process the time-series data, and model selection was conducted by comparing the performances of the hyperparameters. RESULTS: This study achieved significant results in the multi-label classification of depression and anxiety, with a Hamming loss score of 0.0946 in the Residual Network (ResNet), by applying a mixed-input DL model based on activity tracking data. The comparison of hyper-parameter performance and the development of various DL models, such as CNN, LSTM, and ResNet contributed to the optimization of time series data processing and achievement of meaningful results. CONCLUSIONS: This study can be considered as the first to develop a mixed-input DL model based on activity tracking data for the multi-label identification of late-life depression and anxiety. The findings of the study demonstrate the feasibility and potential of using consumer-grade wrist-worn activity trackers in conjunction with DL models to improve the identification of comorbid mental health conditions in older adults. The study also established a multi-label classification framework for identifying the complex symptoms of depression and anxiety.


Asunto(s)
Aprendizaje Profundo , Humanos , Anciano , Depresión/diagnóstico , Depresión/epidemiología , Ansiedad/diagnóstico , Ansiedad/epidemiología , Trastornos de Ansiedad , Sueño
19.
ACS Macro Lett ; 13(1): 75-81, 2024 Jan 16.
Artículo en Inglés | MEDLINE | ID: mdl-38170942

RESUMEN

Cross-linking via the end-to-end click chemistry of multiarm star polymers creates polymer networks with minimal inhomogeneities. Although it has been suggested that the mechanical and swelling properties of such networks depend on the absence of defects, the structural details of homogeneous networks created by this method have not yet been studied at the molecular level. Here, we report the synthesis of discrete tetrahedral star macromolecules (dTSMs) composed of polylactide (PLA) arms with discrete molecular weight and sequence. Polymer networks prepared by 4 × 4 cross-linking by Cu-free strain-promoted cyclooctyne-azide click chemistry (SPAAC) reaction exhibited a high degree of swelling (>40 fold by weight) in solvents without sacrificing mechanical robustness (elastic modulus >4 kPa). The structural details of the networks were investigated by network disassembly spectrometry (NDS) using MALDI-TOF mass spectrometry. By implementing a cleavable repeating unit in the discrete PLA arms of dTSM in a sequence-specific manner, the networks could be disassembled into fragments having discrete molecular weights precisely representing their connectivity in the network. This NDS analysis confirmed that end-to-end click reactions of dTSM networks resulted in the formation of a homogeneous network above the critical concentration (∼10 w/v%) of building blocks in the solution.

20.
Plant J ; 118(2): 469-487, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38180307

RESUMEN

Fruit color is one of the most important traits in peppers due to its esthetic value and nutritional benefits and is determined by carotenoid composition, resulting from diverse mutations of carotenoid biosynthetic genes. The EMS204 line, derived from an EMS mutant population, presents bright-red color, compared with the wild type Yuwolcho cultivar. HPLC analysis indicates that EMS204 fruit contains more zeaxanthin and less capsanthin and capsorubin than Yuwolcho. MutMap was used to reveal the color variation of EMS204 using an F3 population derived from a cross of EMS204 and Yuwolcho, and the locus was mapped to a 2.5-Mbp region on chromosome 2. Among the genes in the region, a missense mutation was found in ZEP (zeaxanthin epoxidase) that results in an amino acid sequence alteration (V291 → I). A color complementation experiment with Escherichia coli and ZEP in vitro assay using thylakoid membranes revealed decreased enzymatic activity of EMS204 ZEP. Analysis of endogenous plant hormones revealed a significant reduction in abscisic acid content in EMS204. Germination assays and salinity stress experiments corroborated the lower ABA levels in the seeds. Virus-induced gene silencing showed that ZEP silencing also results in bright-red fruit containing less capsanthin but more zeaxanthin than control. A germplasm survey of red color accessions revealed no similar carotenoid profiles to EMS204. However, a breeding line containing a ZEP mutation showed a very similar carotenoid profile to EMS204. Our results provide a novel breeding strategy to develop red pepper cultivars containing high zeaxanthin contents using ZEP mutations.


Asunto(s)
Capsicum , Oxidorreductasas , Capsicum/genética , Capsicum/metabolismo , Zeaxantinas/metabolismo , Frutas/metabolismo , Mutación con Pérdida de Función , Fitomejoramiento , Carotenoides/metabolismo , Xantófilas
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