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1.
Front Endocrinol (Lausanne) ; 14: 1220044, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37711887

RESUMEN

Introduction: Obesity and related metabolic issues are a growing global health concern. Recently, the discovery of new probiotics with anti-obesity properties has gained interest. Methods: In this study, four Faecalibacte-rium prausnitzii strains were isolated from healthy human feces and evaluated on a high-fat diet-induced mouse model for 12 weeks. Results: The F. prausnitzii strains reduced body weight gain, liver and fat weights, and calorie intake while improving lipid and glucose metabolism in the liver and adipose tissue, as evidenced by regulating lipid metabolism-associated gene expression, including ACC1, FAS, SREBP1c, leptin, and adiponectin. Moreover, the F. prausnitzii strains inhibited low-grade inflammation, restored gut integrity, and ameliorated hepatic function and insulin resistance. Interestingly, the F. prausnitzii strains modulated gut and neural hormone secretion and reduced appetite by affecting the gut-brain axis. Supplementation with F. prausnitzii strains noticeably changed the gut microbiota composition. Discussion: In summary, the novel isolated F. prausnitzii strains have therapeutic effects on obesity and associated metabolic disorders through modulation of the gut-brain axis. Additionally, the effectiveness of different strains might not be achieved through identical mechanisms. Therefore, the present findings provide a reliable clue for developing novel therapeutic probiotics against obesity and associated metabolic disorders.


Asunto(s)
Faecalibacterium prausnitzii , Enfermedades Metabólicas , Humanos , Animales , Ratones , Dieta Alta en Grasa/efectos adversos , Enfermedades Metabólicas/etiología , Obesidad/etiología , Preparaciones Farmacéuticas
2.
J Dairy Sci ; 106(12): 8262-8271, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37678767

RESUMEN

The anti-obesity effect of milk intake has been suggested via a variety of designed studies, but findings of obesity interventions for Korean adults are scarcely reported. The study aimed to investigate the anti-obesity effect of cow milk in Korean adults with an 8-wk randomized intervention. A total of 121 adults overweight aged 19 to 60 yr old were randomly assigned to 1 of the 2 groups: milk or control. During the intervention, both groups were encouraged 500 kcal of restriction a day, and the milk group consumed 200 mL of milk twice a day; the same energy intake as the control group, including milk intake, was recommended for 8 wk. We detected no significant differences in body weight (BW) and body mass index (BMI) between the milk and control groups during the 8-wk intervention, although the changes in BW and BMI of those within the milk group were significant. High-density lipoprotein cholesterol levels and serum calcium levels increased significantly in the milk group compared with the control group. Calcium, phosphorus, vitamin A, and riboflavin intakes increased significantly, when compared with the control. In conclusion, 8-wk milk consumption had no effect on weight loss and BMI change but improved some blood biomarkers and nutrient intake in Korean adults who were overweight. To evaluate the effect of milk on obesity reduction, well-designed, long-term, and large-scale studies are needed.


Asunto(s)
Enfermedades de los Bovinos , Sobrepeso , Femenino , Bovinos , Animales , Sobrepeso/veterinaria , Leche , Calcio , Obesidad/veterinaria , Peso Corporal , Índice de Masa Corporal , Ingestión de Energía , República de Corea
3.
Int J Mol Sci ; 24(13)2023 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-37446296

RESUMEN

We recently developed a multiplex diagnostic kit, QPLEX™ Alz plus assay kit, which captures amyloid-ß1-40, galectin-3 binding protein, angiotensin-converting enzyme, and periostin simultaneously using microliters of peripheral blood and utilizes an optimized algorithm for screening Alzheimer's disease (AD) by correlating with cerebral amyloid deposition. Owing to the demand for early AD detection, we investigate the potential of our kit for the early clinical diagnosis of AD. A total of 1395 participants were recruited, and their blood samples were analyzed with the QPLEX™ kit. The average of QPLEX™ algorithm values in each group increased gradually in the order of the clinical progression continuum of AD: cognitively normal (0.382 ± 0.150), subjective cognitive decline (0.452 ± 0.130), mild cognitive impairment (0.484 ± 0.129), and AD (0.513 ± 0.136). The algorithm values between each group showed statistically significant differences among groups divided by Mini-Mental State Examination and Clinical Dementia Rating. The QPLEX™ algorithm values could be used to distinguish the clinical continuum of AD or cognitive function. Because blood-based diagnosis is more accessible, convenient, and cost- and time-effective than cerebral spinal fluid or positron emission tomography imaging-based diagnosis, the QPLEX™ kit can potentially be used for health checkups and the early clinical diagnosis of AD.


Asunto(s)
Enfermedad de Alzheimer , Trastornos del Conocimiento , Disfunción Cognitiva , Humanos , Enfermedad de Alzheimer/metabolismo , Pruebas Neuropsicológicas , Disfunción Cognitiva/complicaciones , Cognición , Trastornos del Conocimiento/etiología , Tomografía de Emisión de Positrones , Péptidos beta-Amiloides/metabolismo , Biomarcadores , Progresión de la Enfermedad
4.
Front Microbiol ; 14: 1123547, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37007480

RESUMEN

Introduction: Nonalcoholic steatohepatitis (NASH) is an advanced nonalcoholic fatty liver disease characterized by chronic inflammation and fibrosis. A dysbiosis of the gut microbiota has been associated with the pathophysiology of NASH, and probiotics have proven helpful in its treatment and prevention. Although both traditional and next-generation probiotics have the potential to alleviate various diseases, studies that observe the therapeutic effect of next-generation probiotics on NASH are lacking. Therefore, we investigated whether a next-generation probiotic candidate, Faecalibacterium prausnitzii, contributed to the mitigation of NASH. Methods: In this study, we conducted 16S rRNA sequencing analyses in patients with NASH and healthy controls. To test F. prausnitzii could alleviate NASH symptoms, we isolated four F. prausnitzii strains (EB-FPDK3, EB-FPDK9, EB-FPDK11, and EB-FPYYK1) from fecal samples collected from four healthy individuals. Mice were maintained on a high-fructose high-fat diet for 16 weeks to induce a NASH model and received oral administration of the bacterial strains. Changes in characteristic NASH phenotypes were assessed via oral glucose tolerance tests, biochemical assays, and histological analyses. Results: 16S rRNA sequencing analyses confirmed that the relative abundance of F. prausnitzii reduced significantly in patients with NASH compared to healthy controls (p < 0.05). In the NASH mice, F. prausnitzii supplementation improved glucose homeostasis, prevented hepatic lipid accumulation, curbed liver damage and fibrosis, restored damaged gut barrier functions, and alleviated hepatic steatosis and liver inflammation. Furthermore, real-time PCR assays documented that the four F. prausnitzii strains regulated the expression of genes related to hepatic steatosis in these mice. Discussion: Our study, therefore, confirms that the administration of F. prausnitzii bacteria can alleviate NASH symptoms. We propose that F. prausnitzii has the potential to contribute to the next-generation probiotic treatment of NASH.

5.
Sci Rep ; 13(1): 4140, 2023 03 13.
Artículo en Inglés | MEDLINE | ID: mdl-36914667

RESUMEN

Spinach has been suggested as a potential rotation crop for increasing crop yield by enhancing beneficial fungal microbes in continuous monocropping. However, no research on the use of spinach as a green manure has been reported. Thus, we tested the effects of spinach and Korean mustard cultivars (green and red mustards) (10 g pot -1) as green manure on soil chemical properties, pepper productivity, and soil microbiome of long-year pepper-monocropped soil. Spinach improved the soil nutrition (e.g., pH, SOM, TN, NH4+, and K), weed suppression, and pepper growth. Spinach had by far the highest fruit yield, over 100% pepper fruit yield increment over the mustard green manures and control. Our study showed that the major influencing factors to cause a shift in both bacterial and fungal community assemblies were soil pH, TC TN, and K. Following green manure amendment Bacillota, especially Clostridium, Bacillus and Sedimentibacter, were enriched, whereas Chloroflexi and Acidobacteriota were reduced. In addition, spinach highly reduced the abundance of Leotiomycetes and Fusarium but enriched Papiliotrema. FAPROTAX and FUNGuild analysis revealed that predicted functional profiles of bacterial and fungal communities in spinach-amended soil were changed. Spinach-treated soil was differentially abundant in function related to hydrocarbon degradation and functional guilds of symbiotrophs and ectomycorrhizal. This study contributes significantly to our understanding of how the soil fertility and soil microbiome alteration via spinach green manure application as a pre-plant soil treatment might help alleviate continuous cropping obstacles.


Asunto(s)
Microbiota , Suelo , Suelo/química , Spinacia oleracea , Estiércol , Nutrientes , Bacterias , Microbiología del Suelo
6.
Front Plant Sci ; 14: 1072216, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36760641

RESUMEN

Ginseng is a profitable crop worldwide; however, the ginseng replanting problem (GRP) is a major threat to its production. Soil amendment is a non-chemical method that is gaining popularity for alleviating continuous cropping obstacles, such as GRP. However, the impact of soil amendment with either cow dung or canola on GRP reduction and the associated soil microbiota remains unclear. In the present study, we evaluated the effect of soil amendment with cow dung, canola seed powder, and without amendment (control), on the survival of ginseng seedling transplants, the soil bacterial and fungal communities, and their associated metabolic functions. The results showed that cow dung increased ginseng seedling survival rate by 100 percent and had a remarkable positive effect on ginseng plant growth compared to control, whereas canola did not. Cow dung improved soil nutritional status in terms of pH, electrical conductivity, NO 3 - , total carbon, total phosphorus, and available phosphorus. The amplicon sequencing results using Illumina MiSeq showed that canola had the strongest negative effect in reducing soil bacterial and fungal diversity. On the other hand, cow dung stimulated beneficial soil microbes, including Bacillus, Rhodanobacter, Streptomyces, and Chaetomium, while suppressing Acidobacteriota. Community-level physiological profiling analysis using Biolog Ecoplates containing 31 different carbon sources showed that cow dung soil had a different metabolic activity with higher utilization rates of carbohydrates and polymer carbon sources, mainly Tween 40 and beta-methyl-d-glucoside. These carbon sources were most highly associated with Bacillota. Furthermore, predicted ecological function analyses of bacterial and fungal communities showed that cow dung had a higher predicted function of fermentation and fewer functions related to plant pathogens and fungal parasites, signifying its potential to enhance soil suppressiveness. Co-occurrence network analysis based on random matrix theory (RMT) revealed that cow dung transformed the soil microbial network into a highly connected and complex network. This study is the first to report the alleviation of GRP using cow dung as a soil amendment, and the study contributes significantly to our understanding of how the soil microbiota and metabolic alterations via cow dung can aid in GRP alleviation.

7.
Plants (Basel) ; 11(21)2022 Oct 25.
Artículo en Inglés | MEDLINE | ID: mdl-36365287

RESUMEN

Peach gummosis disease has been identified as a serious challenge in Korean agriculture and has developed to become a major cause of agricultural productivity losses. However, treatments for gummosis have not been systemically established and studies of the microbiome closely related to this plant disease are lacking. Therefore, we analyzed the bacterial and fungal communities in the bark and rhizosphere soil of healthy peach trees and those with gummosis. Through high-throughput sequencing, we obtained unprecedented insights into the bacterial and fungal dynamics of each group, including their diversity and taxonomic classification, as well as network analyses. We found that the presence of gummosis drives a significantly higher alpha diversity in the bark bacterial community. Peach gummosis bark mycobiomes included greater numbers of opportunistic pathogens such as Ascochyta, Botryosphaeria, Saccharomyces, Nectriaceae_NA, Trametes, and Valsaceae_NA. However, the microbiome also included bacteria beneficial to plant growth and the production of polysaccharides-namely, 1174-901-12, Catenibacterium, Cutibacterium, Friedmanniella, Methylobacterium-Methylorubrum, Pseudomonas, Rhodobacter, and Sphingomonas. Furthermore, we confirmed that gummosis induced a more complex structure in the bark microbiome network. We conclude that the findings of this study provide a valuable aid in profiling the overall peach tree microbial ecosystem, which can be utilized to develop precise biomarkers for the early diagnosis of gummosis.

8.
J Med Food ; 25(6): 565-575, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35708632

RESUMEN

Muscular atrophy is a muscle disease in which muscle mass and strength decrease due to aging, injury, metabolic disorders, or chronic conditions. Proteins in muscle tissue are degraded by the ubiquitin-proteasome pathway, and atrophy accelerates this pathway. Akkermansia muciniphila and Faecalibacterium prausnitzii strains are effective agents against metabolic and inflammatory diseases in next-generation probiotic research. In this study, we evaluated the efficacy of A. muciniphila strain EB-AMDK19 and F. prausnitzii strain EB-FPDK11 in a mouse model of muscular atrophy, since atrophy inhibits energy metabolism and immune activation. After oral administration of each strain for 4 weeks, the hind legs of the mice were fixed with a plaster cast to immobilize them for a week. As a result, the administration of EB-AMDK19 and EB-FPDK11 strains improved grip strength but did not increase muscle mass. At the molecular level, A. muciniphila and F. prausnitzii treatments decreased the expression levels of ubiquitin-proteasome genes, atrogin-1, MuRF, and cathepsin L. They increased the expression level of the mitochondrial biogenesis regulatory gene, PGC-1α. The effect of the strains was confirmed by a decrease in myostatin. Furthermore, A. muciniphila and F. prausnitzii modulated the immune function by enhancing ZO-1 and inhibiting IL-6. In particular, EB-AMDK19 promoted the expression of IL-10, an anti-inflammatory cytokine. These results suggest that A. muciniphila and F. prausnitzii may have beneficial effects on muscular atrophy, verified by newly isolated EB-AMDK19 and EB-FPDK11 as potential next-generation probiotics.


Asunto(s)
Faecalibacterium prausnitzii , Complejo de la Endopetidasa Proteasomal , Akkermansia , Animales , Faecalibacterium prausnitzii/metabolismo , Ratones , Fuerza Muscular , Atrofia Muscular/etiología , Ubiquitinas/metabolismo , Verrucomicrobia/fisiología
9.
Sci Rep ; 12(1): 7324, 2022 05 05.
Artículo en Inglés | MEDLINE | ID: mdl-35513696

RESUMEN

Atopic dermatitis (AD) is a common inflammatory skin disease, and its pathogenesis is closely associated with microbial homeostasis in the gut, namely the gut-skin axis. Particularly, recent metagenomics studies revealed that the abundance of two major bacterial species in the gut, Faecalibacterium prausnitzii and Akkermansia muciniphila, may play a critical role in the pathogenesis of AD, but the effect of these species in AD has not yet been elucidated. To evaluate the potential beneficial effect of F. prausnitzii or A. muciniphila in AD, we conducted an animal model study where F. prausnitzii EB-FPDK11 or A. muciniphila EB-AMDK19, isolated from humans, was orally administered to 2,5-dinitrochlorobenzene (DNCB)-induced AD models using NC/Nga mice at a daily dose of 108 CFUs/mouse for six weeks. As a result, the administration of each strain of F. prausnitzii and A. muciniphila improved AD-related markers, such as dermatitis score, scratching behavior, and serum immunoglobulin E level. Also, the F. prausnitzii and A. muciniphila treatments decreased the level of thymic stromal lymphopoietin (TSLP), triggering the production of T helper (Th) 2 cytokines, and improved the imbalance between the Th1 and Th2 immune responses induced by DNCB. Meanwhile, the oral administration of the bacteria enhanced the production of filaggrin in the skin and ZO-1 in the gut barrier, leading to the recovery of functions. Taken together, our findings suggest that F. prausnitzii EB-FPDK11 and A. muciniphila EB-AMDK19 have a therapeutic potential in AD, which should be verified in humans.


Asunto(s)
Dermatitis Atópica , Dinitroclorobenceno , Administración Oral , Akkermansia , Animales , Citocinas/farmacología , Dermatitis Atópica/tratamiento farmacológico , Dermatitis Atópica/terapia , Dinitroclorobenceno/farmacología , Modelos Animales de Enfermedad , Faecalibacterium prausnitzii , Humanos , Ratones , Piel/patología , Verrucomicrobia
10.
Nutrients ; 13(11)2021 Nov 05.
Artículo en Inglés | MEDLINE | ID: mdl-34836212

RESUMEN

Iodine is an essential component of thyroid hormones, but excessive iodine intake can lead to thyroid dysfunction. Traditionally, Korean mothers consume brown seaweed soup (miyeokguk), a high source of iodine, after childbirth. There is controversy regarding the effects of excessive postpartum iodine intake on the health of mothers and infants. Thus far, there have been no nationwide large-scale surveys regarding the status of iodine intake among postpartum women in Korea. Therefore, we conducted a nationwide survey of postpartum dietary iodine intake among Korean women. In total, 1054 Korean women aged ≥19 years, at less than 8 weeks postpartum, participated in this survey. Dietary data were collected using self-reported 2-day dietary records, along with before-and-after meal photos. To evaluate the correlation between dietary iodine and urinary iodine excretion (UIE), spot urine, and 24 h urine samples were collected from 98 and 29 participants, respectively. The mean daily iodine intake among all participants was 2945.6 µg, and it gradually decreased over time after childbirth. Dietary iodine intake was significantly correlated with 24 h UIE (r = 0.396, p < 0.05) and spot urine UIE (r = 0.312, p < 0.05). Follow-up studies are required to examine the influence of excessive postpartum iodine intake on thyroid health in mothers and their infants.


Asunto(s)
Ingestión de Alimentos , Yodo/orina , Periodo Posparto/orina , Encuestas y Cuestionarios , Adulto , Femenino , Humanos , República de Corea
11.
Microorganisms ; 9(10)2021 Sep 27.
Artículo en Inglés | MEDLINE | ID: mdl-34683361

RESUMEN

Akkermansia muciniphila (A. muciniphila) is a promising probiotic candidate owing to its health-promoting properties. A previous study reported that the pasteurized form of A. muciniphila strains isolated from human stool samples had a beneficial impact on high-fat diet-induced obese mice. On the other hand, the differences in the probiotic effects between live and pasteurized A. muciniphila on the metabolism and immune system of the host are still inconclusive. This study examines the differences between the live and pasteurized forms of A. muciniphila strains on the lipid and glucose metabolism and on regulating the inflammatory immune responses using a HFD-fed obese mouse model. The animals were administered the live and pasteurized forms of two A. muciniphila strains five times per week for the entire study period of 12 weeks. Both forms of the bacterial strains improved the HFD-induced obesity and metabolic dysregulation in the mice by preventing body-weight gains after one week. In addition, they cause a decrease in the weights of the major adipose tissues, adipogenesis/lipogenesis and serum TC levels, improvement in glucose homeostasis and suppression of inflammatory insults. Furthermore, these treatments restored the damaged gut architecture and integrity and improved the hepatic structure and function in HFD-induced animals. On the other hand, for both bacterial strains, the pasteurized form was more potent in improving glucose tolerance than the live form. Moreover, specific A. muciniphila preparations with either live or pasteurized bacteria decreased the number and population (%) of splenic Treg cells (CD4+ Foxp3+) significantly in the HFD-fed animals, further supporting the anti-inflammatory properties of these bacteria.

12.
Microorganisms ; 8(9)2020 Sep 14.
Artículo en Inglés | MEDLINE | ID: mdl-32937828

RESUMEN

The identification of new probiotics with anti-obesity properties has attracted considerable interest. In the present study, the anti-obesity activities of Akkermansia muciniphila (A. muciniphila) strains isolated from human stool samples and their relationship with the gut microbiota were evaluated using a high fat-diet (HFD)-fed mice model. Three strains of A. muciniphila were chosen from 27 isolates selected based on their anti-lipogenic activity in 3T3-L1 cells. The anti-lipogenic, anti-adipogenic and anti-obesity properties of these three strains were evaluated further in HFD-induced obese mice. The animals were administered these strains six times per week for 12 weeks. The treatment improved the HFD-induced metabolic disorders in mice in terms of the prevention of body weight gain, caloric intake and reduction in the weights of the major adipose tissues and total fat. In addition, it improved glucose homeostasis and insulin sensitivity. These effects were also associated with the inhibition of low-grade intestinal inflammation and restoration of damaged gut integrity, prevention of liver steatosis and improvement of hepatic function. These results revealed a difference in the distribution pattern of the gut microbial communities between groups. Therefore, the gut microbial population modulation, at least in part, might contribute to the beneficial impact of the selected A. muciniphila strains against metabolic disorders.

13.
Nutrients ; 12(8)2020 Jul 23.
Artículo en Inglés | MEDLINE | ID: mdl-32717913

RESUMEN

Omega-3 fatty acid (n-3 FA) intake is known to have a preventive effect on depressive symptoms in a general population. This study assessed the effects of n-3 FA intake on depressive symptoms and brain function in middle-aged women. Depressive symptoms were screened using the Beck Depression Inventory-II (BDI-II) and Center for Epidemiologic Studies-Depression scale (CES-D) assessment questionnaires, and n-3 FA intakes were assessed using semiquantitative food frequency questionnaire. We found that n-3 FA intakes were negatively associated with depressive symptoms in middle-aged women. Psychiatrists diagnosed the presence of depressive disorders using the 5th edition of the Mental Disorder Diagnosis and Statistics Manual (DSM-5). Resting-state functional magnetic resonance imaging (rs-fMRI) was performed to investigate the association between n-3 FA intake and brain functional connectivity. Functional connectivity of the right middle frontal cortex (default mode network) and the right middle temporal pole (frontoparietal network) was positively associated with depressive symptom scores and negatively associated with n-3 FA intakes. In conclusion, high n-3 FA intake decreases the risk of depressive symptoms and modifies the brain functional connectivity in middle-aged women.


Asunto(s)
Encéfalo/efectos de los fármacos , Depresión/tratamiento farmacológico , Ácidos Grasos Omega-3/administración & dosificación , Anciano , Pueblo Asiatico , Encéfalo/metabolismo , Manual Diagnóstico y Estadístico de los Trastornos Mentales , Femenino , Humanos , Imagen por Resonancia Magnética , Persona de Mediana Edad , Evaluación Nutricional , República de Corea , Factores Socioeconómicos , Encuestas y Cuestionarios
14.
Clin Exp Vaccine Res ; 8(2): 94-102, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-31406690

RESUMEN

PURPOSE: Results from a post-marketing study to generate evidence on 1-year antibody persistence and safety following vaccination of infants from South Korea with the quadrivalent meningococcal conjugate vaccine MenACWY-CRM. MATERIALS AND METHODS: In this phase IV, open-label, multi-center study (NCT02446691), 128 infants received MenACWY-CRM at ages 2, 4, 6, and 12 months. One-year antibody persistence following the full vaccination course was evaluated (primary objective) for the four meningococcal serogroups (Men) by serum bactericidal activity assay using human or rabbit complement (hSBA/rSBA). Immune responses at 1-month post-vaccination and safety were also assessed. RESULTS: The percentage of children with hSBA titers ≥8 ranged between 94% (MenA) and 100% (MenY/W) 1-month post-vaccination, and from 39% (MenA) to 89% (MenY) 1-year post-vaccination. At least 99% and 92% of children had rSBA titers ≥8 and ≥128 against each meningococcal serogroup, 1-month post-vaccination. One-year post-vaccination, the percentage of children with rSBA titers ≥8 and ≥128 ranged from 54% (MenC) to 99% (MenA) and from 30% (MenC) to 98% (MenA). Geometric mean titers declined from 1-month to 1-year post-vaccination, when they varied between 6.8 (MenA) and 53.6 (MenW) by hSBA and between 17.2 (MenC) and 2,269.5 (MenA) by rSBA. At least one solicited and unsolicited adverse event was reported for 79% and 66% of children. Of 36 serious adverse events reported, none were vaccination-related. CONCLUSION: Antibody persistence (hSBA/rSBA titers ≥8) was determined in 39%-99% of children 1 year after a 4-dose MenACWY-CRM series during infancy, with an acceptable clinical safety profile.

15.
ACS Appl Mater Interfaces ; 11(27): 24715-24724, 2019 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-31192584

RESUMEN

Hot-electron chemistry at gold nanoparticle (AuNP) surfaces has received much attention recently because its understanding provides a basis for plasmonic photocatalysis and photovoltaics. Nonradiative decay of excited surface plasmons produces energetic hot charge carriers that transfer to adsorbate molecules and induce chemical reactions. Such plasmon-driven reactions, however, have been limited to a few systems, notably the dimerization of 4-aminobenzenethiol to 4,4'-dimercaptoazobenzene. In this work, we explore a new class of plasmon-driven reactions associated with a unimolecular bond cleavage process. We unveil the mechanism of the decarboxylation reaction of 4-mercaptobenzoic acid and extend the mechanism to account for the ß-cleavage reaction of 4-mercaptobenzyl alcohol. Combining the construction of well-controlled nanogap systems and sensitive Raman spectroscopy with methodical changes of experimental conditions (laser wavelengths, interface materials, pH, ambient gases, etc.), we track the hot charge carriers from the formation to the transfer to reactants, which provides insights into how plasmon excitation eventually leads to the C-C bond cleavage of the molecules in the nanogap.

17.
J Mov Disord ; 12(1): 57-59, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-30563312
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