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1.
Eur J Haematol ; 112(5): 819-831, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38243840

RESUMEN

OBJECTIVES: To describe late transplant-associated thrombotic microangiopathy (TA-TMA) as chronic endothelial complication in bone marrow (BM) after allogeneic hematopoietic stem cell transplantation (HSCT). METHODS: BM specimens along with conventional diagnostic parameters were assessed in 14 single-institutional patients with late TA-TMA (more than 100 days after HCST), including 11 late with history of early TA-TMA, 10 with early TA-TMA (within 100 days), and 12 non TA-TMA patients. Three non-HSCT patients served as control. The time points of BM biopsy were +1086, +798, +396, and +363 days after HSCT, respectively. RESULTS: Late TA-TMA patients showed an increase of CD34+ and von Willebrand Factor (VWF)+ microvascular endothelial cells with atypical VWF+ conglomerates forming thickened VWF+ plaque sinus in the BM compared to patients without late TA-TMA and non-HSCT. Severe chronic (p = .002), steroid-refractory GVHD (p = .007) and reactivation of HHV6 (p = .002), EBV (p = .003), and adenovirus (p = .005) were pronounced in late TA-TMA. Overall and relapse-free survival were shorter in late TA-TMA than in patients without late TA-TMA (5-year OS and RFS: 78.6% vs. 90.2%, 71.4% vs. 86.4%, respectively). CONCLUSION: Chronic allo-immune microangiopathy in BM associated with chronic, steroid-refractory GVHD and/or viral infections are key findings of late, high-risk TA-TMA, which deserves clinical attention.


Asunto(s)
Enfermedad Injerto contra Huésped , Trasplante de Células Madre Hematopoyéticas , Microangiopatías Trombóticas , Virosis , Humanos , Médula Ósea/patología , Células Endoteliales/patología , Factor de von Willebrand , Microangiopatías Trombóticas/diagnóstico , Microangiopatías Trombóticas/etiología , Microangiopatías Trombóticas/terapia , Enfermedad Injerto contra Huésped/diagnóstico , Enfermedad Injerto contra Huésped/etiología , Trasplante de Células Madre Hematopoyéticas/efectos adversos , Virosis/complicaciones , Biopsia , Esteroides
2.
J Formos Med Assoc ; 123(4): 523-529, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38092654

RESUMEN

PURPOSE: To evaluate the effectiveness of the progestin-primed ovarian stimulation (PPOS) protocol versus the gonadotropin-releasing hormone antagonist (GnRH-ant) protocol in ovarian stimulation. METHODS: In this retrospective cohort study, we included 804 patients who were treated between January 1st, 2022, and July 1st, 2023. Outcomes of ovarian stimulation were compared between the PPOS (n = 206) and GnRH-ant (n = 598). The primary outcome was the number of good cleavage embryos. RESULTS: Baseline characteristics were comparable in both groups. In both unadjusted and adjusted analysis, the mean number of good cleavage embryos in PPOS (6.33) was non-inferior to GnRH-ant (6.44; unadjusted ratio of two means 1.02, 95%CI 0.92, 1.13). The trigger-day estradiol level in patients with PPOS was higher than in patients with GnRH-ant (4,420 vs 3,830 pg/ml, respectively) despite similar total follicle stimulating hormone dose and fewer days of ovarian stimulation. The number of oocytes, MII oocytes, cleavage and blastocyst embryos were comparable between the two protocols. After the first transfer of embryos, the clinical pregnancy rate and implantation rate were higher in the PPOS group, while the pregnancy rate and ongoing pregnancy were not significantly different. None of the PPOS patients had an unexpected LH surge, and serum LH levels decreased slightly during ovarian stimulation. CONCLUSIONS: The PPOS protocol with dydrogesterone provided similar embryo outcomes to the GnRH-ant protocol, with notable distinctions in clinical pregnancy and implantation rate. The serum LH concentration during ovarian stimulation using PPOS was well-controlled.


Asunto(s)
Fertilización In Vitro , Progestinas , Embarazo , Femenino , Humanos , Progestinas/farmacología , Fertilización In Vitro/métodos , Estudios Retrospectivos , Puntaje de Propensión , Inducción de la Ovulación/métodos , Antagonistas de Hormonas , Hormona Liberadora de Gonadotropina
3.
Phys Chem Chem Phys ; 25(23): 15941-15952, 2023 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-37261379

RESUMEN

Combining semiconductor and noble metal nanostructures into a hybrid system has shown many complementary advantages in the optical properties, making them more attractive in practical applications. Herein, we prepared a semiconductor/noble metal hybrid system composed of Ag nanoparticles decorated on ZnO nanoplates acting as a surface-enhanced Raman scattering (SERS) substrate for probing methyl red. The tuning of the optical characteristics of the hybrid system was demonstrated through the changes in the absorption, fluorescence, and Raman spectra. The formation of the local electromagnetic field at the heterostructure interface plays a pivotal role in its SERS activity. Thanks to density functional theory calculations, methyl red's vibrational modes and symmetry properties were assigned to be consistent with the contribution of the neutral trans conformer and protonated state. Then, using Herzberg-Teller-surface selection rules, these assignments strongly support the realization that the SERS mechanism based on the ZnO/Ag substrate has a significant electromagnetic contribution versus the Ag substrate in which charge transfer plays a pivotal role. To the best of our knowledge, this is the first investigation that has clarified the mechanism and advantage of semiconductor/metal (ZnO/Ag nanostructures) even over noble metals (Ag nanoparticles) in SERS applications. Moreover, the SERS behavior based on the ZnO/Ag substrate was also examined and the results indicated high sensitivity and good repeatability.

4.
Cell Microbiol ; 23(5): e13306, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33355403

RESUMEN

Salmonella Paratyphi A (SPtA) remains one of the leading causes of enteric (typhoid) fever. Yet, despite the recent increased rate of isolation from patients in Asia, our understanding of its pathogenesis is incomplete. Here we investigated inflammasome activation in human macrophages infected with SPtA. We found that SPtA induces GSDMD-mediated pyroptosis via activation of caspase-1, caspase-4 and caspase-8. Although we observed no cell death in the absence of a functional Salmonella pathogenicity island-1 (SPI-1) injectisome, HilA-mediated overexpression of the SPI-1 regulon enhances pyroptosis. SPtA expresses FepE, an LPS O-antigen length regulator, which induces the production of very long O-antigen chains. Using a ΔfepE mutant we established that the very long O-antigen chains interfere with bacterial interactions with epithelial cells and impair inflammasome-mediated macrophage cell death. Salmonella Typhimurium (STm) serovar has a lower FepE expression than SPtA, and triggers higher pyroptosis, conversely, increasing FepE expression in STm reduced pyroptosis. These results suggest that differential expression of FepE results in serovar-specific inflammasome modulation, which mirrors the pro- and anti-inflammatory strategies employed by STm and SPtA, respectively. Our studies point towards distinct mechanisms of virulence of SPtA, whereby it attenuates inflammasome-mediated detection through the elaboration of very long LPS O-polysaccharides.


Asunto(s)
Inflamasomas/metabolismo , Macrófagos/microbiología , Macrófagos/fisiología , Antígenos O/fisiología , Fiebre Paratifoidea/microbiología , Piroptosis , Salmonella paratyphi A/patogenicidad , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Caspasas/metabolismo , Células HeLa , Humanos , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Macrófagos/inmunología , Antígenos O/química , Proteínas de Unión a Fosfato/metabolismo , Salmonella paratyphi A/inmunología , Células THP-1 , Sistemas de Secreción Tipo III/metabolismo , Virulencia , Factores de Virulencia/metabolismo
5.
Mol Biol Rep ; 49(5): 3413-3421, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-35088378

RESUMEN

BACKGROUND: DNA methylation on cytosine in the CpG dinucleotides is one of the most common epigenetic perturbations taking place during cancer initiation, progression, occurrence and resistance therapy. DNA methylation seems to be sufficiently stable epigenetic modification to be utilized as a cancer biomarker in in vitro diagnostic (IVD) settings. Nowadays, the SHOX2 methylation (mSHOX2) is one of the most valuable DNA methylation biomarkers of lung cancer that is the leading cause of cancer death. It is being continuously validated across ethnicities, lifestyles and lifespan. This study focused on characteristics of mSHOX2 in Vietnamese patients with lung cancer since a lack of investigation and evidence of its utility in this country. METHODS: The probe and primer sets were designed according to the MethyLight method for quantitative assessment of the mSHOX2 in 214 formalin-fixed paraffin-embedded (FFPE) lung tissues and 57 plasma samples. RESULTS: mSHOX2 in FFPE tissues allowed discriminating benign and malignant lung diseases with 60% (95% CI 50.7-68.8%) sensitivity and 90.4% (95% CI 82.6-95.5%) specificity. Importantly, based on mSHOX2 in plasma, lung cancer could be detected with 83.3% (95% CI 65.3-94.4%) sensitivity and 92.6% (95% CI 75.7-99.1%) specificity, respectively. There were insignificant associations between mSHOX2 with age, cancer stage, EGFR mutation and serum CEA, CYFRA21-1 concentrations except for that gender. CONCLUSION: Our study indicated that mSHOX2 was satisfactory for distinguishing malignant from benign lung tissue and noninvasively detecting lung cancer.


Asunto(s)
Metilación de ADN , Proteínas de Homeodominio , Neoplasias Pulmonares , Antígenos de Neoplasias , Pueblo Asiatico , Biomarcadores de Tumor/genética , Proteínas de Homeodominio/genética , Humanos , Queratina-19 , Neoplasias Pulmonares/patología
6.
Curr Microbiol ; 79(7): 209, 2022 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-35639194

RESUMEN

Ammonia and nitrite treatments are the critical steps that must be done to ensure the healthy growth of aquatic animals. The nitrification process is often used for nitrogen removal purposes due to its efficiency and environmentally friendly properties. However, the varied growth rate between ammonia and nitrite-oxidizing bacteria can cause nitrite accumulation, leading to the massive mortality of aquatic animals at high concentrations. Therefore, this study aimed to integrate the fast-growing heterotrophic nitrite-reducing bacteria with nitrifying bacteria to achieve a quicker nitrite removal activity. The two denitrifying Bacillus sp. ST20 and Bacillus sp. ST26 were screened from shrimp ponds in Bac Lieu province, Vietnam. Obtained results showed that under anoxic conditions, the nitrite removal efficiency of these two strains reached 68.5-82% at nitrite initial concentration of 20 mgN-NO2/L after 72 h. Higher efficiency of over 95% was gained under oxic conditions. Hence, it enabled the use of denitrifying and nitrifying bacteria-co-immobilized carriers for ammonia oxidation and nitrite reduction simultaneously in a single-aerated bioreactor. A total of over 96% nitrogen content was removed during the bioreactor operation, despite the increase of inputting nitrogen concentration from 40 to 200 mgN/L. Moreover, the suitable conditions for bacterial growth and nitrite conversion activity of the ST20 and ST26 were detected as 15‰ salinity and 35 °C. The isolates also utilized various C-sources for growth, hence widening their applicability. The present study suggested that the isolated aerobic denitrifying bacteria are potentially used for the complete removal of nitrogen compounds from aquaculture wastewater.


Asunto(s)
Bacillus , Nitrógeno , Amoníaco , Acuicultura , Bacterias/genética , Desnitrificación , Nitritos , Agua
7.
Cult Health Sex ; 24(3): 358-373, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-33512308

RESUMEN

Social norms surrounding sex and relationships remain gendered among young people in Vietnam, with men maintaining a privileged role in heterosexual relationships. This analysis explored how university students in Vietnam perceived prevailing gender norms, and how these norms influenced men's understanding of sexual consent in dating relationships. This analysis drew primarily on in-depth interviews with heterosexual men and secondarily from interviews with women attending two universities in Hanoi in 2018. Thematic analysis of the interviews revealed a broader narrative about how prevailing gender norms shape men's dating behaviour and beliefs about consent. Participants expected young men to be independent and decisive. Men were seen as free to initiate dating and sexual encounters. Some participants expected young women to be accommodating in dating relationships, although acceptable relationships for women were restricted, and premarital sex was a reputational risk. Most participants described cues for consent and non-consent for sex; however, dismissal of women's refusals, and normalised sexual coercion were common. Among university men in Hanoi, gender norms privileging men and growing expectations of premarital sex may be normalising sexual coercion in dating relationships. University educational programmes are needed to promote equitable gender norms, affirmative sexual consent and expanded definitions of sexual coercion.


Asunto(s)
Hombres , Conducta Sexual , Adolescente , Femenino , Humanos , Masculino , Estudiantes , Universidades , Vietnam
8.
Subst Abus ; 43(1): 1317-1321, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-35896001

RESUMEN

Background: Racial, sex, and age disparities in buprenorphine treatment have previously been demonstrated. We evaluated trends in buprenorphine treatment disparities before and after the onset of the COVID pandemic in Massachusetts. Methods: This cross-sectional study used data from an integrated health system comparing 12-months before and after the March 2020 Massachusetts COVID state of emergency declaration, excluding March as a washout period. Among patients with a clinical encounter during the study periods with a diagnosis of opioid use disorder or opioid poisoning, we extracted outpatient buprenorphine prescription rates by age, sex, race and ethnicity, and language. Generating univariable and multivariable Poisson regression models, we calculated the probability of receiving buprenorphine. Results: Among 4,530 patients seen in the period before the COVID emergency declaration, 57.9% received buprenorphine. Among 3,653 patients seen in the second time period, 55.1% received buprenorphine. Younger patients (<24) had a lower likelihood of receiving buprenorphine in both time periods (adjusted prevalence ratio (aPR), 0.56; 95% CI, 0.42-0.75 before vs. aPR, 0.76; 95% CI, 0.60-0.96 after). Male patients had a greater likelihood of receiving buprenorphine compared to female patients in both time periods (aPR: 1.05; 95% CI, 1.00-1.11 vs. aPR: 1.09; 95% CI, 1.02-1.16). Racial disparities emerged in the time period following the COVID pandemic, with non-Hispanic Black patients having a lower likelihood of receiving buprenorphine compared to non-Hispanic white patients in the second time period (aPR, 0.85; 95% CI, 0.72-0.99). Conclusions: Following the onset of the COVID pandemic in Massachusetts, ongoing racial, age, and gender disparities were evident in buprenorphine treatment with younger, Black, and female patients less likely to be treated with buprenorphine across an integrated health system.


Asunto(s)
Buprenorfina , COVID-19 , Buprenorfina/uso terapéutico , Estudios Transversales , Femenino , Humanos , Masculino , Massachusetts/epidemiología , Pandemias
9.
J Reprod Infant Psychol ; : 1-12, 2022 Jul 19.
Artículo en Inglés | MEDLINE | ID: mdl-35852090

RESUMEN

OBJECTIVES: The present study aims to investigate whether each coping style used by Vietnamese people living with infertility diagnosis is associated with specific types of infertility-related stress (IRS). METHODS: In this cross-sectional design study, 997 patients with primary infertility diagnosis from three hospitals and two clinics in three regions of Vietnam completed questionnaire that consisted of Fertility Problem Inventory, the Copenhagen Multi-Centre Psychosocial Infertility and other questions. Four different linear regression analyses were performed on four coping styles. The five types of IRS and covariates were included in these models. FINDINGS: The results show that participants who experience all five types of IRS reported the dominant use of active-avoidance coping, while having four types of IRS, except for social concern, was associated with higher use of meaning-based coping. Utilising active-confronting coping was reported to be the outcome of experiencing increasing need for parenthood and decreasing rejection of child-free lifestyle. Choice of passive-avoidance coping was more common among those with increasing social concern and need for parenthood. Age and educational level impacted infertile people's choice of avoidance coping strategies. CONCLUSIONS: The results provide evidence to understand the direct impact of each type of IRS on infertile people's choice of coping styles to better support them during their individual and family therapy.

10.
J Ethn Subst Abuse ; : 1-16, 2022 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-35635379

RESUMEN

Integration of substance use disorder (SUD) treatment and HIV care can increase antiretroviral therapy coverage among people with opioid use disorder (OUD). However, implementation of integrated treatment models remains limited. Stigma towards people with OUD poses a barrier to initiation of, and adherence to, HIV treatment. We sought to understand the extent of stigma towards SUD and HIV among people with OUD in Vietnam, and the effect of stigma on integrated OUD and HIV treatment services utilization. Between 2013 and 2015, we conducted in-depth interviews with 43 patients and 43 providers at 7 methadone clinics and 8 HIV clinics across 4 provinces in Vietnam. We used thematic analysis with a mixed deductive and inductive approach at the semantic level to analyze key topics. Two main themes were identified: (1) Confidentiality concerns about HIV status make patients reluctant to receive integrated care at HIV clinics, given the requirements for daily buprenorphine dosing at HIV clinics. (2) Provider stigma existed mostly toward people with OUD and seemed to center on the belief that substance use causes a deterioration in one's morals, and was most frequently manifested in the form of providers' apprehensive approach towards patients. Concerns regarding stigmatization may cause patients to feel reluctant to receive treatment for both OUD and HIV at a single integrated clinic. Interventions to reduce stigma at the clinic and policy levels may thus serve to improve initiation of and adherence to integrated care.

11.
Sugar Tech ; 24(5): 1330-1341, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35281432

RESUMEN

Sugarcane is one of the most important industrial crops in Vietnam and covers a total of 127,000 hectares of plantation area. In the season 2020-2021, Vietnam has produced 0.763 million tons of sugar (accounting for 0.34% total world sugar production). A current sugarcane production of 7.498 million tons is being used mainly for sugar production for direct consumption, ethanol production, bio-electricity and fertilization. To ensure crop sustainability, various policies and plans have been implemented. Crop breeding and zoning improvement programme significantly influence sugarcane production and sugar yield. Over 25 years since the programme "one million ton of sugar" was promoted, Vietnam currently possesses 25 sugar mills with a total capacity of 110,000 tons of sugarcane per day. Major problems of sugarcane industry as well as research and development have been discussed in this review. Recent research and development work focused on the added values of co-products to ensure sustainability of the sugarcane industry. Molasses will be used for ethanol production, and bagasse is used as the biomass for the alternative energy. Sugarcane and sugar would be the main feedstocks for those bio-economy growths in Vietnam. To keep the sustainable development of the sugar industry, and to meet the demand of the food and non-food requirements, it is necessary to upgrade the sugar value chain through the adoption and the development of co-products of the sugar industry.

12.
Clin Infect Dis ; 72(5): e120-e127, 2021 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-33515460

RESUMEN

BACKGROUND: The emergence and spread of antimicrobial resistance (AMR) pose a major threat to the effective treatment and control of typhoid fever. The ongoing outbreak of extensively drug-resistant Salmonella Typhi (S. Typhi) in Pakistan has left azithromycin as the only remaining broadly efficacious oral antimicrobial for typhoid in South Asia. Ominously, azithromycin-resistant S. Typhi organisms have been subsequently reported in Bangladesh, Pakistan, and Nepal. METHODS: Here, we aimed to understand the molecular basis of AMR in 66 S. Typhi organisms isolated in a cross-sectional study performed in a suburb of Chandigarh in Northern India using whole-genome sequencing and phylogenetic analysis. RESULTS: We identified 7 S. Typhi organisms with the R717Q mutation in the acrB gene that was recently found to confer resistance to azithromycin in Bangladesh. Six out of the seven azithromycin-resistant S. Typhi isolates also exhibited triple mutations in gyrA (S83F and D87N) and parC (S80I) genes and were resistant to ciprofloxacin. These contemporary ciprofloxacin/azithromycin-resistant isolates were phylogenetically distinct from each other and from those reported from Bangladesh, Pakistan, and Nepal. CONCLUSIONS: The independent emergence of azithromycin-resistant typhoid in Northern India reflects an emerging broader problem across South Asia and illustrates the urgent need for the introduction of typhoid conjugate vaccines in the region.


Asunto(s)
Salmonella typhi , Fiebre Tifoidea , Antibacterianos/farmacología , Azitromicina/farmacología , Bangladesh/epidemiología , Estudios Transversales , Farmacorresistencia Bacteriana , Genotipo , Humanos , India/epidemiología , Pruebas de Sensibilidad Microbiana , Nepal , Pakistán , Filogenia , Salmonella typhi/genética , Fiebre Tifoidea/epidemiología
13.
Neurobiol Dis ; 159: 105504, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34509607

RESUMEN

BACKGROUND: The neuropathology of sporadic Creutzfeldt-Jakob disease (sCJD) is usually investigated using formalin-fixed and formic acid-treated brain tissue. However, formalin and formic acid treatment can interfere with immunostaining of abnormal prion protein. Therefore, there is a need for biochemical methods other than immunostaining to investigate abnormal prion protein in postmortem tissue. We developed RT-QuIC to quantitate the seeding activity (SD50) of sCJD brain tissue treated with formalin and formic acid. METHODS: We used endpoint RT-QuIC assays to analyze SD50 in formalin-fixed brain tissue from 19 sCJD patients (14 MM1 cases, 3 MM2-thalamic form [MM2T] cases and 2 MM2-cortical form [MM2C] cases) diagnosed according to Parchi's classification. We assessed SD50 in brains after incubation in formalin solution for over 1 month, and after treating formalin-fixed brain tissue with formic acid. We also examined how the SD50 values from formalin-fixed brain samples compared with neuropathological and immunohistochemical findings. RESULTS: The SD50 values of formalin-fixed brain samples from 14 MM1 cases, 2 MM2C cases, and 2 MM2T cases were 107.77±0.57/g tissue, 107.44±0.24/g tissue and 106.00±0.77/g tissue, respectively. The average SD50 value in MM1 unfixed brains decreased by 102.04 after formalin fixation for 1 month. In MM1 cases, after combined formalin and formic acid treatment, the SD50 value was reduced by approximately 105.16 compared with that of unfixed tissue. The SD50 values of formalin-fixed tissue showed a consistent pattern with the neuropathological findings in most brain regions examined. CONCLUSION: RT-QuIC enables the study of formalin-fixed brain tissue from sCJD patients that has not previously been amenable to analysis.


Asunto(s)
Encéfalo/metabolismo , Síndrome de Creutzfeldt-Jakob/metabolismo , Proteínas Priónicas/metabolismo , Anciano , Anciano de 80 o más Años , Encéfalo/patología , Síndrome de Creutzfeldt-Jakob/patología , Femenino , Fijadores , Formaldehído , Formiatos , Humanos , Masculino , Persona de Mediana Edad , Manejo de Especímenes
14.
J Environ Manage ; 280: 111858, 2021 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-33360552

RESUMEN

Flash flood is one of the most dangerous hydrologic and natural phenomena and is considered as the top ranking of such events among various natural disasters due to their fast onset characteristics and the proportion of individual fatalities. Mapping the probability of flash flood events remains challenges because of its complexity and rapid onset of precipitation. Thus, this study aims to propose a state-of-the-art data mining approach based on a hybrid equilibrium optimized SysFor, namely, the HE-SysFor model, for spatial prediction of flash floods. A tropical storm region located in the Northwest areas of Vietnam is selected as a case study. For this purpose, 1866 flash-flooded locations and ten indicators were used. The results show that the proposed HE-SysFor model yielded the highest predictive performance (total accuracy = 93.8%, Kappa index = 0.875, F1-score = 0.939, and AUC = 0.975) and produced the better performance than those of the C4.5 decision tree (C4.5), the radial basis function-based support vector machine (SVM-RBF), the logistic regression (LReg), and deep learning neural network (DeepLNN) models in both the training and the testing phases. Among the ten indicators, elevation, slope, and land cover are the most important. It is concluded that the proposed model provides an alternative tool and may help for effectively monitoring flash floods in tropical areas and robust policies for decision making in mitigating the flash flood impacts.


Asunto(s)
Tormentas Ciclónicas , Inundaciones , Minería de Datos , Ríos , Vietnam
15.
J Chem Inf Model ; 60(3): 1329-1351, 2020 03 23.
Artículo en Inglés | MEDLINE | ID: mdl-31999921

RESUMEN

This computational and experimental work aims to elucidate physicochemical and photophysical natures of free radical scavenging and ultraviolet radiation (UVR) filtering activities of five terpenoids available in the extract of marine fungus. The antioxidant activities of ochraceopone F (C1), aspertetranone D (C2), cycloechinulin (C3), wasabidienone E (C4), and mactanamide (C5) are evaluated by using density functional theory (DFT) at the M05-2X/6-311++G(d,p) level of theory in the gas phase, water, and pentyl ethanoate (PEA). Double antioxidant mechanisms allowing the second (H+/e-) donation such as double hydrogen atom transfer (dHAT), double single electron transfer-proton transfer (dSET-PT), and double sequential proton loss-electron transfer (dSPL-ET) are considered. Reaction enthalpies (ΔrH0), standard Gibbs free energies (ΔrG0) and potential energy surfaces of reactions toward HOO• radical are then established to evaluate the hydrogen transfer (HT) and radical adduct formation (RAF) mechanisms. The computational results are supported by DPPH• and ABTS•+ antioxidant essays. Results show that all compounds C1-C5 are able to scavenge two free radicals via dHAT, dSET-PT, and dSPL-ET mechanisms. Among the compounds, C3 and C4 represent the most potential antioxidants, especially via HAT and RAF mechanisms in all the reaction media. Their rate constants for both HAT and RAF reactions are remarkably higher than that of Trolox and ascorbic acid. The kinetic calculations on activation Gibbs free energies (ΔG⧧) and rate constants (kTST) based on conventional transition state theory (TST) reveal that HAT and RAF processes are in competition in solvents. Photophysical processes occurring during UVR exposure are investigated using the time dependent density functional theory (TD-DFT) combined with UV-vis experiments. The obtained results highlight the promising activities of C1-C5 in UVR absorption in the ranges of UVA and UVB. Among them, C3 and C4 also show better UV absorption properties with the easiest excitations (band gaps equal to 4.06 and 3.65 eV). This study suggests the natural candidates possibly used in organic sunscreen.


Asunto(s)
Antioxidantes , Rayos Ultravioleta , Teoría Funcional de la Densidad , Hongos , Termodinámica
16.
Epidemiol Infect ; 148: e144, 2020 05 26.
Artículo en Inglés | MEDLINE | ID: mdl-32450932

RESUMEN

Non-typhoidal Salmonella (NTS) serovars, sequences types and antimicrobial susceptibility profiles have specific associations with animal and human infections in Vietnam. Antimicrobial resistance may have an effect on the manifestation of human NTS infections, with isolates from asymptomatic individuals being more susceptible to antimicrobials than those associated with animals and human diarrhoea.


Asunto(s)
Antibacterianos/farmacología , Farmacorresistencia Bacteriana , Infecciones por Salmonella/epidemiología , Infecciones por Salmonella/microbiología , Salmonella/efectos de los fármacos , Animales , Niño , Heces , Humanos , Vietnam
17.
J Phys Chem A ; 124(14): 2736-2740, 2020 Apr 09.
Artículo en Inglés | MEDLINE | ID: mdl-32183517

RESUMEN

We report the first time-resolved resonant Raman (TR3) spectra of photoinduced charge transfer from [Ru(bpy)3]2+ to methyl viologen, with observations of vibrational structure. The presence of singly charged methyl viologen in solution is noted by the appearance of several spectroscopic lines, which are visible in the spectra following subtraction of reagent molecules. Assignments are confirmed using both density functional theory (DFT) calculations and literature values and are shown to be consistent with transient absorption spectroscopy data. This presents proof-of-concept for the application of TR3 in mechanistic studies of photocatalytic systems.

18.
Molecules ; 25(20)2020 Oct 14.
Artículo en Inglés | MEDLINE | ID: mdl-33066513

RESUMEN

We introduce two novel solution-processable electron acceptors based on an isomeric core of the much explored diketopyrrolopyrrole (DPP) moiety, namely pyrrolo[3,2-b]pyrrole-1,4-dione (IsoDPP). The newly designed and synthesized compounds, 6,6'-[(1,4-bis{4-decylphenyl}-2,5-dioxo-1,2,4,5-tetrahydropyrrolo[3,2-b]pyrrole-3,6-diyl)bis(thiophene-5,2-diyl)]bis[2-(2-butyloctyl)-1H-benzo[de]isoquinoline-1,3(2H)-dione] (NAI-IsoDPP-NAI) and 5,5'-[(1,4-bis{4-decylphenyl}-2,5-dioxo-1,2,4,5-tetrahydropyrrolo[3,2-b]pyrrole-3,6-diyl)bis(thiophene-5,2-diyl)]bis[2-(2-butyloctyl)isoindoline-1,3-dione] (PI-IsoDPP-PI) have been synthesized via Suzuki couplings using IsoDPP as a central building block and napthalimide or phthalimide as end-capping groups. The materials both exhibit good solubility in a wide range of organic solvents including chloroform (CF), dichloromethane (DCM), and tetrahydrofuran (THF), and have a high thermal stability. The new materials absorb in the wavelength range of 300-600 nm and both compounds have similar electron affinities, with the electron affinities that are compatible with their use as acceptors in donor-acceptor bulk heterojunction (BHJ) organic solar cells. BHJ devices comprising the NAI-IsoDPP-NAI acceptor with poly(3-n-hexylthiophene) (P3HT) as the donor were found to have a better performance than the PI-IsoDPP-PI containing cells, with the best device having a VOC of 0.92 V, a JSC of 1.7 mAcm-2, a FF of 63%, and a PCE of 0.97%.


Asunto(s)
Imidas/química , Cetonas/química , Ftalimidas/química , Pirroles/química , Energía Solar , Rastreo Diferencial de Calorimetría , Suministros de Energía Eléctrica , Electroquímica/instrumentación , Electroquímica/métodos , Electrones , Fulerenos/química , Solubilidad , Solventes , Espectrofotometría Ultravioleta , Termogravimetría
19.
Environ Monit Assess ; 192(7): 411, 2020 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-32494862

RESUMEN

In this article, the authors apply the relative air pollution index (RAPI) proposed by Pham Ngoc Ho for aggregate assessment of daily air pollution level (RAPId) using data from 3 daily standards (1, 8, and 24 h) of each country's standard, including Vietnam Technical Regulation QCVN 05:2013/MONRE. By using the automated data of ambient air at 3 monitoring stations in Cam Pha coal mining area, Quang Ninh province in 2018, results of the frequency of pollution by month (f%) have shown that overall, the air quality in dry season (October-March) is worse than that in rainy season (April-September). Results of pollution frequency by month in a year f% also indicate that air pollution in 2018 at 3 stations is mostly at level I (no pollution) with f% ranged from 10 to 58.3%, but pollution level II-IV (light pollution-very heavy pollution) also happened as f% fluctuated from 20 to 42% in some months. Comparing with air quality assessment in 2011-2015 at this area by periodic monitoring equipment of Quang Ninh Center for Environmental Monitoring, results in 2018 have shown that individual index of RAPI is consistent with the current status of air quality with high accuracy. To compare with RAPId, we used VN_AQId index of the Vietnam Environment Administration (VEA). Comparison results show that both indices do not encounter eclipsing effect. However, ambiguous effect occurred in the case of VN_AQId index (warning not suitable for reality in some cases). In addition, advantages and limitations of these two methods have been analyzed and explained in detail.


Asunto(s)
Contaminantes Atmosféricos , Minas de Carbón , Monitoreo del Ambiente , Contaminantes Atmosféricos/análisis , Monitoreo del Ambiente/métodos , Vietnam
20.
J Infect Dis ; 219(2): 295-304, 2019 01 07.
Artículo en Inglés | MEDLINE | ID: mdl-30321351

RESUMEN

Background: Nontyphoidal Salmonella (NTS) organisms are a major cause of gastroenteritis and bacteremia, but little is known about maternally acquired immunity and natural exposure in infant populations residing in areas where NTS disease is highly endemic. Methods: We recruited 503 pregnant mothers and their infants (following delivery) from urban areas in Vietnam and followed infants until they were 1 year old. Exposure to the dominant NTS serovars, Salmonella enterica serovars Typhimurium and Enteritidis, were assessed using lipopolysaccharide (LPS) O antigen-specific antibodies. Antibody dynamics, the role of maternally acquired antibodies, and NTS seroincidence rates were modeled using multivariate linear risk factor models and generalized additive mixed-effect models. Results: Transplacental transfer of NTS LPS-specific maternal antibodies to infants was highly efficient. Waning of transplacentally acquired NTS LPS-specific antibodies at 4 months of age left infants susceptible to Salmonella organisms, after which they began to seroconvert. High seroincidences of S. Typhimurium and S. Enteritidis LPS were observed, and infants born with higher anti-LPS titers had greater plasma bactericidal activity and longer protection from seroconversion. Conclusions: Although Vietnamese infants have extensive exposure to NTS, maternally acquired antibodies appear to play a protective role against NTS infections during early infancy. These findings suggest that prenatal immunization may be an appropriate strategy to protect vulnerable infants from NTS disease.


Asunto(s)
Anticuerpos Antibacterianos/inmunología , Inmunidad Materno-Adquirida/inmunología , Inmunidad , Infecciones por Salmonella/inmunología , Adulto , Anticuerpos Antibacterianos/sangre , Estudios de Cohortes , Femenino , Humanos , Lactante , Recién Nacido , Lipopolisacáridos/inmunología , Masculino , Análisis Multivariante , Antígenos O , Factores de Riesgo , Salmonella enteritidis , Salmonella typhimurium , Estudios Seroepidemiológicos , Serogrupo , Vietnam
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