Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 84
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Nature ; 618(7965): 590-597, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37258672

RESUMEN

Rapidly evolving influenza A viruses (IAVs) and influenza B viruses (IBVs) are major causes of recurrent lower respiratory tract infections. Current influenza vaccines elicit antibodies predominantly to the highly variable head region of haemagglutinin and their effectiveness is limited by viral drift1 and suboptimal immune responses2. Here we describe a neuraminidase-targeting monoclonal antibody, FNI9, that potently inhibits the enzymatic activity of all group 1 and group 2 IAVs, as well as Victoria/2/87-like, Yamagata/16/88-like and ancestral IBVs. FNI9 broadly neutralizes seasonal IAVs and IBVs, including the immune-evading H3N2 strains bearing an N-glycan at position 245, and shows synergistic activity when combined with anti-haemagglutinin stem-directed antibodies. Structural analysis reveals that D107 in the FNI9 heavy chain complementarity-determinant region 3 mimics the interaction of the sialic acid carboxyl group with the three highly conserved arginine residues (R118, R292 and R371) of the neuraminidase catalytic site. FNI9 demonstrates potent prophylactic activity against lethal IAV and IBV infections in mice. The unprecedented breadth and potency of the FNI9 monoclonal antibody supports its development for the prevention of influenza illness by seasonal and pandemic viruses.


Asunto(s)
Anticuerpos Antivirales , Especificidad de Anticuerpos , Virus de la Influenza A , Virus de la Influenza B , Vacunas contra la Influenza , Gripe Humana , Imitación Molecular , Neuraminidasa , Animales , Humanos , Ratones , Anticuerpos Monoclonales/química , Anticuerpos Monoclonales/inmunología , Anticuerpos Monoclonales/uso terapéutico , Anticuerpos Antivirales/química , Anticuerpos Antivirales/inmunología , Anticuerpos Antivirales/uso terapéutico , Especificidad de Anticuerpos/inmunología , Arginina/química , Dominio Catalítico , Hemaglutininas Virales/inmunología , Virus de la Influenza A/clasificación , Virus de la Influenza A/enzimología , Virus de la Influenza A/inmunología , Subtipo H3N2 del Virus de la Influenza A/enzimología , Subtipo H3N2 del Virus de la Influenza A/inmunología , Virus de la Influenza B/clasificación , Virus de la Influenza B/enzimología , Virus de la Influenza B/inmunología , Vacunas contra la Influenza/química , Vacunas contra la Influenza/inmunología , Vacunas contra la Influenza/uso terapéutico , Gripe Humana/inmunología , Gripe Humana/prevención & control , Neuraminidasa/antagonistas & inhibidores , Neuraminidasa/química , Neuraminidasa/inmunología , Infecciones por Orthomyxoviridae/inmunología , Infecciones por Orthomyxoviridae/prevención & control , Estaciones del Año , Ácidos Siálicos/química
2.
Proc Natl Acad Sci U S A ; 121(16): e2314990121, 2024 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-38593070

RESUMEN

Langya virus (LayV) is a recently discovered henipavirus (HNV), isolated from febrile patients in China. HNV entry into host cells is mediated by the attachment (G) and fusion (F) glycoproteins which are the main targets of neutralizing antibodies. We show here that the LayV F and G glycoproteins promote membrane fusion with human, mouse, and hamster target cells using a different, yet unknown, receptor than Nipah virus (NiV) and Hendra virus (HeV) and that NiV- and HeV-elicited monoclonal and polyclonal antibodies do not cross-react with LayV F and G. We determined cryoelectron microscopy structures of LayV F, in the prefusion and postfusion states, and of LayV G, revealing their conformational landscape and distinct antigenicity relative to NiV and HeV. We computationally designed stabilized LayV G constructs and demonstrate the generalizability of an HNV F prefusion-stabilization strategy. Our data will support the development of vaccines and therapeutics against LayV and closely related HNVs.


Asunto(s)
Virus Hendra , Infecciones por Henipavirus , Henipavirus , Virus Nipah , Humanos , Animales , Ratones , Microscopía por Crioelectrón , Glicoproteínas , Internalización del Virus
3.
Proc Natl Acad Sci U S A ; 119(22): e2122769119, 2022 05 31.
Artículo en Inglés | MEDLINE | ID: mdl-35617431

RESUMEN

Hendra virus (HeV) and Nipah virus (NiV) are deadly zoonotic Henipaviruses (HNVs) responsible for recurrent outbreaks in humans and domestic species of highly fatal (50 to 95%) disease. A HeV variant (HeV-g2) of unprecedented genetic divergence has been identified in two fatally diseased horses, and in two flying fox species in regions of Australia not previously considered at risk for HeV spillover. Given the HeV-g2 divergence from HeV while retaining equivalent pathogenicity and spillover potential, understanding receptor usage and antigenic properties is urgently required to guide One Health biosecurity. Here, we show that the HeV-g2 G glycoprotein shares a conserved receptor tropism with prototypic HeV and that a panel of monoclonal antibodies recognizing the G and F glycoproteins potently neutralizes HeV-g2­ and HeV G/F­mediated entry into cells. We determined a crystal structure of the Fab fragment of the hAH1.3 antibody bound to the HeV G head domain, revealing an antigenic site associated with potent cross-neutralization of both HeV-g2 and HeV. Structure-guided formulation of a tetravalent monoclonal antibody (mAb) mixture, targeting four distinct G head antigenic sites, results in potent neutralization of HeV and HeV-g2 and delineates a path forward for implementing multivalent mAb combinations for postexposure treatment of HNV infections.


Asunto(s)
Anticuerpos Monoclonales , Anticuerpos Neutralizantes , Anticuerpos Antivirales , Virus Hendra , Fragmentos Fab de Inmunoglobulinas , Proteínas del Envoltorio Viral , Anticuerpos Monoclonales/química , Anticuerpos Monoclonales/inmunología , Anticuerpos Neutralizantes/química , Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/química , Anticuerpos Antivirales/inmunología , Cristalografía por Rayos X , Epítopos/química , Epítopos/genética , Virus Hendra/genética , Virus Hendra/inmunología , Humanos , Fragmentos Fab de Inmunoglobulinas/química , Pruebas de Neutralización , Profilaxis Posexposición , Dominios Proteicos , Proteínas del Envoltorio Viral/genética , Proteínas del Envoltorio Viral/inmunología
4.
N Engl J Med ; 385(7): 595-608, 2021 08 12.
Artículo en Inglés | MEDLINE | ID: mdl-34379922

RESUMEN

BACKGROUND: Safe and effective long-acting injectable agents for preexposure prophylaxis (PrEP) for human immunodeficiency virus (HIV) infection are needed to increase the options for preventing HIV infection. METHODS: We conducted a randomized, double-blind, double-dummy, noninferiority trial to compare long-acting injectable cabotegravir (CAB-LA, an integrase strand-transfer inhibitor [INSTI]) at a dose of 600 mg, given intramuscularly every 8 weeks, with daily oral tenofovir disoproxil fumarate-emtricitabine (TDF-FTC) for the prevention of HIV infection in at-risk cisgender men who have sex with men (MSM) and in at-risk transgender women who have sex with men. Participants were randomly assigned (1:1) to receive one of the two regimens and were followed for 153 weeks. HIV testing and safety evaluations were performed. The primary end point was incident HIV infection. RESULTS: The intention-to-treat population included 4566 participants who underwent randomization; 570 (12.5%) identified as transgender women, and the median age was 26 years (interquartile range, 22 to 32). The trial was stopped early for efficacy on review of the results of the first preplanned interim end-point analysis. Among 1698 participants from the United States, 845 (49.8%) identified as Black. Incident HIV infection occurred in 52 participants: 13 in the cabotegravir group (incidence, 0.41 per 100 person-years) and 39 in the TDF-FTC group (incidence, 1.22 per 100 person-years) (hazard ratio, 0.34; 95% confidence interval, 0.18 to 0.62). The effect was consistent across prespecified subgroups. Injection-site reactions were reported in 81.4% of the participants in the cabotegravir group and in 31.3% of those in the TDF-FTC group. In the participants in whom HIV infection was diagnosed after exposure to CAB-LA, INSTI resistance and delays in the detection of HIV infection were noted. No safety concerns were identified. CONCLUSIONS: CAB-LA was superior to daily oral TDF-FTC in preventing HIV infection among MSM and transgender women. Strategies are needed to prevent INSTI resistance in cases of CAB-LA PrEP failure. (Funded by the National Institute of Allergy and Infectious Diseases and others; HPTN 083 ClinicalTrials.gov number, NCT02720094.).


Asunto(s)
Infecciones por VIH/prevención & control , Inhibidores de Integrasa VIH/administración & dosificación , Profilaxis Pre-Exposición , Piridonas/administración & dosificación , Tenofovir/uso terapéutico , Administración Oral , Adulto , Anciano , Fármacos Anti-VIH/uso terapéutico , Preparaciones de Acción Retardada/administración & dosificación , Método Doble Ciego , Esquema de Medicación , Resistencia a Medicamentos/genética , Femenino , Inhibidores de Integrasa VIH/efectos adversos , Homosexualidad Masculina , Humanos , Inyecciones Intramusculares/efectos adversos , Análisis de Intención de Tratar , Masculino , Cumplimiento de la Medicación , Persona de Mediana Edad , Piridonas/efectos adversos , Personas Transgénero , Adulto Joven
5.
AIDS Behav ; 2024 Sep 13.
Artículo en Inglés | MEDLINE | ID: mdl-39266888

RESUMEN

Little is known about HIV testing, pre-exposure prophylaxis (PrEP) awareness and uptake among adolescent and young men who have sex with men (AYMSM) in Vietnam. We conducted an online survey among AYMSM in Vietnam to determine the prevalence of HIV testing, PrEP awareness, uptake and their correlates. From December 2022-March 2023, 120 HIV-negative AYMSM from 15 to 19 years old in Hanoi and Ho Chi Minh city, Vietnam were recruited through peer referral to complete an online survey, which included questions on demographics, sexual behaviors, HIV risk perception and knowledge, HIV and sexually transmitted infections (STI) testing, PrEP awareness and uptake. Separate multivariable models were used to determine the correlates of HIV testing, PrEP awareness and uptake. Only 58% of participants had ever been tested for HIV. The majority of participants had heard of PrEP before (82%), but only 36% had ever used PrEP. HIV knowledge (aPR (adjusted prevalence ratio) = 1.59; 95%CI:1.06-2.39), a history of STI testing (aPR = 1.32; 95%CI:1.06-1.64), having had anal sex with another man (aPR = 4.49; 95%CI:1.40-14.38) and lower HIV risk perception (aPR = 0.62; 95%CI:0.47-0.83) were associated with HIV testing. HIV knowledge (aPR = 1.38; 95%CI:1.06-1.78) and a history of STI testing (aPR = 1.16; 95%CI:1.03-1.32) were also associated with PrEP awareness. Higher HIV risk perception was negatively associated with PrEP use (aPR = 0.59; 95%CI:0.35-0.99). Our findings underscored the urgent need for further research to explore the causes of the gaps in HIV testing and PrEP use as well as to design innovative interventions tailored to the needs of AYMSM to support HIV testing and PrEP use.

6.
Org Biomol Chem ; 22(6): 1234-1244, 2024 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-38240351

RESUMEN

Herein we report a method for affording 2-benzyl benzoxazoles from substituted styrenes and 2-nitrophenols. The success of this method relies on the use of simple reagents, namely elemental sulfur and DABCO. A combination of identical reagents was utilized for the annulation of styrenes with N,N-dialkyl-3-nitroanilines to afford 2-benzyl benzothiazoles. Overall, benzoxazoles and benzothiazoles bearing useful functionalities such as halogens, amines, and heterocyclic groups were isolated in moderate to good yields. Our methods are a rare example of divergent transformations of substituted nitroarenes towards 2-benzyl benzoxazoles and benzothiazoles.

8.
AIDS Res Ther ; 19(1): 63, 2022 12 14.
Artículo en Inglés | MEDLINE | ID: mdl-36517849

RESUMEN

BACKGROUND: Stigma around human immunodeficiency virus (HIV), injection drug use (IDU), and mental health disorders can be co-occurring and have different impacts on the well-being of people living with HIV (PWH) who use drugs and have mental health disorders. This stigma can come from society, health professionals, and internalized stigma. A person who has more than one health condition can experience overlapping health-related stigma and levels of stigma which can prevent them from receiving necessary support and healthcare, serving to intensify their experience with stigma. This study investigates HIV, drug use, and mental health stigmas in three dimensions (social, internalized, and professional) around PWH on methadone maintenance treatment (MMT) who have common mental disorders (CMDs) including depression, anxiety, and stress-related disorders in Hanoi, Vietnam.Please check and confirm whether corresponding author's email id is correctly identified.The cooresponding author's email is correct METHODS: We conducted semi-structured, in-depth interviews (IDIs) (n = 21) and two focus group discussions (FGDs) (n = 10) with PWH receiving MMT who have CMD symptoms, their family members, clinic health care providers, and clinic directors. We applied thematic analysis using NVIVO software version 12.0, with themes based on IDI and FGD guides and emergent themes from interview transcripts. RESULTS: The study found evidence of different stigmas towards HIV, IDU, and CMDs from the community, family, health care providers, and participants themselves. Community and family members were physically and emotionally distant from patients due to societal stigma around illicit drug use and fears of acquiring HIV. Participants often conflated stigmas around drug use and HIV, referring to these stigmas interchangeably. The internalized stigma around having HIV and injecting drugs made PWH on MMT hesitant to seek support for CMDs. These stigmas compounded to negatively impact participants' health. CONCLUSIONS: Strategies to reduce stigma affecting PWH on MMT should concurrently address stigmas around HIV, drug addiction, and mental health. Future studies could explore approaches to address internalized stigma to improve self-esteem, mental health, and capacities to cope with stigma for PWH on MMT. TRIAL REGISTRATION: NCT04790201, available at clinicaltrials.gov.


Asunto(s)
Infecciones por VIH , Trastornos Mentales , Metadona , Estigma Social , Humanos , Infecciones por VIH/psicología , Trastornos Mentales/psicología , Metadona/uso terapéutico , Trastornos Relacionados con Sustancias/tratamiento farmacológico , Trastornos Relacionados con Sustancias/psicología , Vietnam/epidemiología , Investigación Cualitativa
9.
J Infect Dis ; 221(Suppl 4): S471-S479, 2020 05 11.
Artículo en Inglés | MEDLINE | ID: mdl-31686101

RESUMEN

BACKGROUND: Nipah virus (NiV) and Hendra virus (HeV) are zoonotic paramyxoviruses that cause severe disease in both animals and humans. There are no approved vaccines or treatments for use in humans; however, therapeutic treatment of both NiV and HeV infection in ferrets and non-human primates with a cross-reactive, neutralizing human monoclonal antibody (mAb), m102.4, targeting the G glycoprotein has been demonstrated. In a previous study, we isolated, characterized, and humanized a cross-reactive, neutralizing anti-F mAb (h5B3.1). The mAb h5B3.1 blocks the required F conformational change needed to facilitate membrane fusion and virus infection, and the epitope recognized by h5B3.1 has been structurally defined; however, the efficacy of h5B3.1 in vivo is unknown. METHODS: The post-infection antiviral activity of h5B3.1 was evaluated in vivo by administration in ferrets after NiV and HeV virus challenge. RESULTS: All subjects that received h5B3.1 from 1 to several days after infection with a high-dose, oral-nasal virus challenge were protected from disease, whereas all controls died. CONCLUSIONS: This is the first successful post-exposure antibody therapy for NiV and HeV using a humanized cross-reactive mAb targeting the F glycoprotein, and the findings suggest that a combination therapy targeting both F and G should be evaluated as a therapy for NiV/HeV infection.


Asunto(s)
Anticuerpos Monoclonales/uso terapéutico , Virus Hendra , Infecciones por Henipavirus/terapia , Virus Nipah , Proteínas Virales de Fusión/inmunología , Animales , Reacciones Cruzadas , Hurones , Infecciones por Henipavirus/prevención & control , Infecciones por Henipavirus/virología , Humanos
10.
Angew Chem Int Ed Engl ; 60(39): 21211-21215, 2021 09 20.
Artículo en Inglés | MEDLINE | ID: mdl-34328683

RESUMEN

The coronavirus disease 2019 (COVID-19) pandemic has devastated families and disrupted healthcare, economies and societies across the globe. Molecular recognition agents that are specific for distinct viral proteins are critical components for rapid diagnostics and targeted therapeutics. In this work, we demonstrate the selection of novel DNA aptamers that bind to the SARS-CoV-2 spike glycoprotein with high specificity and affinity (<80 nM). Through binding assays and high resolution cryo-EM, we demonstrate that SNAP1 (SARS-CoV-2 spike protein N-terminal domain-binding aptamer 1) binds to the S N-terminal domain. We applied SNAP1 in lateral flow assays (LFAs) and ELISAs to detect UV-inactivated SARS-CoV-2 at concentrations as low as 5×105  copies mL-1 . SNAP1 is therefore a promising molecular tool for SARS-CoV-2 diagnostics.


Asunto(s)
Aptámeros de Nucleótidos/química , COVID-19/diagnóstico , SARS-CoV-2/aislamiento & purificación , Glicoproteína de la Espiga del Coronavirus/análisis , COVID-19/inmunología , Ensayo de Inmunoadsorción Enzimática , Humanos , Modelos Moleculares , SARS-CoV-2/inmunología , Glicoproteína de la Espiga del Coronavirus/inmunología
11.
Nat Methods ; 14(9): 891-896, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28737741

RESUMEN

We developed a chemically inducible Cas9 (ciCas9) and a droplet digital PCR assay for double-strand breaks (DSB-ddPCR) to investigate the kinetics of Cas9-mediated generation and repair of DSBs in cells. ciCas9 is a rapidly activated, single-component Cas9 variant engineered by replacing the protein's REC2 domain with the BCL-xL protein and fusing an interacting BH3 peptide to the C terminus. ciCas9 can be tunably activated by a compound that disrupts the BCL-xL-BH3 interaction within minutes. DSB-ddPCR demonstrates time-resolved, highly quantitative, and targeted measurement of DSBs. Combining these tools facilitated an unprecedented exploration of the kinetics of Cas9-mediated DNA cleavage and repair. We find that sgRNAs targeting different sites generally induce cleavage within minutes and repair within 1 or 2 h. However, we observe distinct kinetic profiles, even for proximal sites, and this suggests that target sequence and chromatin state modulate cleavage and repair kinetics.


Asunto(s)
Caspasa 9/genética , Roturas del ADN de Doble Cadena , Sondas de ADN/genética , Edición Génica/métodos , Técnicas de Sonda Molecular , Reacción en Cadena de la Polimerasa/métodos , Cinética
12.
Plant Foods Hum Nutr ; 75(4): 656-658, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-33009632

RESUMEN

Bitter gourd fruits contain high amounts of charantin, stigmasterol glucoside and ß-sitosterol glucoside, which have been shown to provide health benefits for humans. However, the bitterness of the fruit means they are rarely consumed. This study aimed to assess the effects of Lactobacillus plantarum fermentation, which has previously been reported to effectively reduce bitterness, on the contents of these compounds. The current results suggest that Lactobacillus plantarum fermentation should be considered as a potential approach to enhance the levels of these compounds in bitter gourd juice.


Asunto(s)
Lactobacillus plantarum , Momordica charantia , Fermentación , Glucósidos , Humanos , Sitoesteroles , Estigmasterol/análogos & derivados
13.
Parasitol Res ; 118(9): 2575-2581, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31375955

RESUMEN

Intraspecific variation of Parasaccocoelium mugili collected from mullet fish of the south of Russian Far East and Vietnam has previously been estimated on the basis of two molecular markers: ribosomal internal transcribed spacer 1 (ITS1) rDNA and mitochondrial cytochrome oxidase I (COI) gene sequences. In the present study, molecular identification of this species from the Kievka River, Primorye and from Vietnam was performed by analysis of 28S rDNA sequences. Analysis of ITS1 rDNA sequences variation revealed two highly differentiated main groups, representing trematode specimens from the two regions. Genetic variation within each region was relatively low. Mitochondrial COI gene sequence data analysis revealed fixed nucleotide and amino acid substitutions, and supported the existence of two genetically different groups associated with geographical origin. Analysis of the COI gene fragments showed extremely high variation within Russian and Vietnamese P. mugili samples. Our results for P. mugili most probably represent a case of initial step of allopotric speciation for this trematode, caused by living strategy of its definitive host at evolutionary scale. Mitochondrial DNA sequence data show that existence of gene flow between local populations of P. mugili in the Primorye Region caused by definitive hosts can be proposed.


Asunto(s)
ADN Espaciador Ribosómico/genética , Complejo IV de Transporte de Electrones/genética , Enfermedades de los Peces/parasitología , Proteínas del Helminto/genética , Trematodos/genética , Infecciones por Trematodos/veterinaria , Animales , ADN de Helmintos/genética , Variación Genética , Filogenia , Federación de Rusia , Análisis de Secuencia de ADN , Smegmamorpha/parasitología , Trematodos/clasificación , Trematodos/aislamiento & purificación , Infecciones por Trematodos/parasitología , Vietnam
14.
Plant Foods Hum Nutr ; 74(1): 54-60, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30368643

RESUMEN

Cocoa beans and cocoa products contain considerable amounts of bioactive compounds. Harvesting cocoa fruit too early or too late may have effects on the phenolic and alkaloid concentrations of the cocoa powder. Fermentation, a primary processing used to transform cocoa beans to cocoa powder, may also influence the contents of bioactive compounds. In this study, proanthocyanidins, the major compounds in cocoa polyphenols, caffeine and theobromine of cocoa beans, were evaluated at different maturities at harvest, and with different fermentation durations, with and without the addition of a commercial enzyme, Pectinex® Ultra SP-L. The amounts of proanthocyanidins, caffeine and theobromine, and the antioxidant capacities of the unfermented cocoa beans increased as the fruits matured. The values ranged from 16.12-27.28 g catechin equivalents (CE)/100 g dry weight (DW); 99.66-173.61 mg/100 g DW; 556.39-948.84 mg/100 g DW; 23.23-26.32 mol Trolox equivalents (TE)/100 g DW, respectively. Prolonged fermentation with or without the addition of pectinase, from three to seven days, significantly reduced the amounts of these compounds present. Fermentation using the enzyme significantly reduced the proanthocyanidin content and antioxidant capacity of the cocoa powder, with the overall means decreasing from 8.93-4.93 g CE/100 g DW and from 15.81-12.95 g mol TE/100 g DW, respectively. Two-way ANOVA analyses showed that the proanthocyanidins, caffeine, theobromine contents and the antioxidant capacity of cocoa beans were strongly dependet to their stages of maturity, fermentation methods and fermentation duration.


Asunto(s)
Alcaloides/análisis , Cacao/química , Cafeína/análisis , Fenoles/análisis , Fitoquímicos/química , Teobromina/análisis , Antioxidantes/análisis , Cacao/crecimiento & desarrollo , Catequina/análisis , Chocolate/análisis , Fermentación , Frutas/química , Frutas/crecimiento & desarrollo , Humanos , Polifenoles/análisis , Proantocianidinas/análisis
15.
Chemistry ; 24(48): 12592-12599, 2018 Aug 27.
Artículo en Inglés | MEDLINE | ID: mdl-29802668

RESUMEN

The direct partial oxidation of methane to methanol is a challenging scientific and economical objective to expand the application of this abundant fuel gas as a major resource for one-step production of value-added chemicals. Despite substantial efforts to commercialize this synthetic route, to date no heterogeneous catalyst can selectively oxidize methane to methanol by O2 with an economically acceptable conversion. Cu-exchanged zeolites have been recently highlighted as one of the most promising bioinspired catalysts toward the direct production of methanol from methane under mild conditions. In this work, Cu-based catalysts were prepared using mesoporous silica SBA-15 as an alternative support and their activity for this conversion was investigated. The results demonstrate that highly dispersed CuO species on SBA-15 are able to react with methane and subsequently produce methanol with high selectivity (>84 %) through water-assisted extraction. Furthermore, it was confirmed that the main intermediate formed after interaction of the catalyst with methane is a methoxyl species, which can be further converted to methanol or dimethyl ether on extraction with water or methanol, respectively.

18.
Plant Foods Hum Nutr ; 72(3): 236-242, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28584897

RESUMEN

Effects of processing methods including pressing, enzyme-assisted extraction, lactic acid fermentation by Lactobacillus acidophilus, and alcohol fermentation by Saccharomyces cerevisiae on total and soluble oxalate contents of carambola juices were studied. In comparison with pressing, the use of enzyme increased juice yields (15.89-17.29%), but resulted in higher total oxalate (1.60-1.73 times) and soluble oxalate contents (1.16-1.49 times). In addition, extension of enzyme incubation periods led to an increase in soluble oxalate contents in the products (p < 0.05). On the other hand, alcohol fermentation with Saccharomyces cerevisiae from 1 to 5 weeks reduced 37-58% of total oxalate and 39-59% of soluble oxalate contents. Prolonged fermentation also demonstrated better reduction of oxalate contents. Meanwhile, lactic acid fermentation using Lactobacillus acidophilus had no effects on total and soluble oxalate contents in carambola juices. These results suggested that carambola juice products should only be consumed moderately, and that alcohol fermentation could be a potential method to reduce oxalate contents in foods in order to prevent the risks of forming kidney stones.


Asunto(s)
Averrhoa/química , Fermentación , Jugos de Frutas y Vegetales , Lactobacillus acidophilus/fisiología , Oxalatos/química , Saccharomyces cerevisiae/fisiología , Alcoholes , Averrhoa/microbiología , Frutas/química , Oxalatos/metabolismo , Pectinas/metabolismo
19.
Cureus ; 16(1): e53010, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38410290

RESUMEN

Very late stent thrombosis (VLST) refers to stent thrombosis occurring beyond one year after coronary intervention. "Very" very or extremely late stent thrombosis (VVLST), occurring after five years of drug-eluting stent (DES) implantation, is extremely rare. We report a case of a 60-year-old male patient with ST-elevation myocardial infarction (STEMI) due to in-stent thrombosis 12.3 years after first-generation DES implantation; we also engage in a brief discussion of its pathogenesis and prevention.

20.
RSC Adv ; 14(23): 16389-16399, 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38774621

RESUMEN

In this work, we introduce a novel defective analogue of the representative 6-connected zirconium-based metal-organic framework (MOF-808), by employing 5-sulfoisophthalic acid monosodium salt (H2BTC-SO3Na) as a defect inducer via a mixed-linker approach. The structural integrity and different physicochemical properties were investigated by various characterization techniques, including powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and nitrogen physisorption at 77 K. Additionally, proton nuclear magnetic resonance (1H-NMR), energy-dispersive X-ray (EDX), and inductively coupled plasma optical emission spectroscopy (ICP-OES) were employed to confirm the presence of 6.9 mol% of the 5-sulfoisophthalate ligand within the highly crystalline MOF-808 structure. The defective material exhibited significant enhancements in the removal efficiency of various organic dyes, including approximately 64% and 77% for quinoline yellow and sunset yellow, and 56% and 13% for rhodamine B and malachite green, compared to its pristine counterpart. Importantly, the defective MOF-808 showed a remarkable selectivity toward anionic species in binary-component dyes comprising both anionic and cationic dyes.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA