Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 15 de 15
Filtrar
1.
Virus Evol ; 10(1): veae045, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38952820

RESUMEN

Animal rotaviruses A (RVAs) are considered the source of emerging, novel RVA strains that have the potential to cause global spread in humans. A case in point was the emergence of G8 bovine RVA consisting of the P[8] VP4 gene and the DS-1-like backbone genes that appeared to have jumped into humans recently. However, it was not well documented what evolutionary changes occurred on the animal RVA-derived genes during circulation in humans. Rotavirus surveillance in Vietnam found that DS-1-like G8P[8] strains emerged in 2014, circulated in two prevalent waves, and disappeared in 2021. This surveillance provided us with a unique opportunity to investigate the whole process of evolutionary changes, which occurred in an animal RVA that had jumped the host species barrier. Of the 843 G8P[8] samples collected from children with acute diarrhoea in Vietnam between 2014 and 2021, fifty-eight strains were selected based on their distinctive electropherotypes of the genomic RNA identified using polyacrylamide gel electrophoresis. Whole-genome sequence analysis of those fifty-eight strains showed that the strains dominant during the first wave of prevalence (2014-17) carried animal RVA-derived VP1, NSP2, and NSP4 genes. However, the strains from the second wave of prevalence (2018-21) lost these genes, which were replaced with cognate human RVA-derived genes, thus creating strain with G8P[8] on a fully DS-1-like human RVA gene backbone. The G8 VP7 and P[8] VP4 genes underwent some point mutations but the phylogenetic lineages to which they belonged remained unchanged. We, therefore, propose a hypothesis regarding the tendency for the animal RVA-derived genes to be expelled from the backbone genes of the progeny strains after crossing the host species barrier. This study underlines the importance of long-term surveillance of circulating wild-type strains in order to better understand the adaptation process and the fate of newly emerging, animal-derived RVA among the human population. Further studies are warranted to disclose the molecular mechanisms by which spillover animal RVAs become readily transmissible among humans, and the roles played by the expulsion of animal-derived genes and herd immunity formed in the local population.

2.
J Air Waste Manag Assoc ; 74(7): 478-489, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38916528

RESUMEN

This study partially replaced the clay with sewer sludge (SS) and rice husk (RH-SS) to make fired bricks. The brick samples were examed in terms of shrinkage, water absorption, and compressive strength. Besides, they were analyzed via XRD and metal extraction to determine the heavy metal residuals in the products. The results showed that it was possible to fabricate fired bricks using sewer sludge or rice husk-blended sludge with up to 30% by weight. These brick samples complied with the technical standard for clay brick production, in which the compressive strength was more than 7.5 MPa, water absorption was from 11-16%, and the linear shrinkage was all less than 5%. The rice husk addition helped mitigate the heavy metal residuals in the bricks and leaching liquid, in which all the values were lower than the US-EPA maximum concentration of contaminants for toxicity characteristics.Implications: Previous studies have proved the possibility of mixing sewage sludge from different origins (sewage sludge, river sediment, canal sediment, sewer sediment, etc.) with clay and some wastes to make bricks. In which, mostof the studies used sewage sludge from wastewater treatment plants, very fewdealt with lake/river or sewer sediment. This study shall be the first to study the possibility of employing sewer sediments with the addition of rice husk powder to achieve two targets, including (1) the reuse of biowaste and sludge for brick fabrication and (2) the reduction of heavy metals in final calcined bricks. Different ratios of the rice-husk blended sewer sludge (RH-SS) - clay mixture shall be tested to find the optimized compositions. The results showed that it was possible to fabricate fired bricks using sewer sludge or rice husk-blended sludge with up to 30% by weight, which meant reduce 30% of clay in the brick production. The final products were proved to meet the quality standard in terms of compressive strength (more than 10 MPa), water absorption(from 11-16%), and the linear shrinkage (less than 5%). Larger scale of this study can be an evident to recommend for policy change in the waste reuse in construction field.


Asunto(s)
Materiales de Construcción , Aguas del Alcantarillado , Aguas del Alcantarillado/análisis , Aguas del Alcantarillado/química , Materiales de Construcción/análisis , Metales Pesados/análisis , Reciclaje/métodos , Oryza
3.
Commun Chem ; 6(1): 282, 2023 Dec 20.
Artículo en Inglés | MEDLINE | ID: mdl-38123721

RESUMEN

The direct oxidation of methane to methanol has been spotlighted research for decades, but has never been commercialized. This study introduces cost-effective process for co-producing methanol and sulfuric acid through a direct oxidation of methane. In the initial phase, methane oxidation forms methyl bisulfate (CH3OSO3H), then transformed into methyl trifluoroacetate (CF3CO2CH3) via esterification, and hydrolyzed into methanol. This approach eliminates the need for energy-intensive separation of methyl bisulfate from sulfuric acid by replacing the former with methyl trifluoroacetate. Through the superstructure optimization, our sequential process reduces the levelized cost of methanol to nearly two-fold reduction from the current market price. Importantly, this process demonstrates adaptability to smaller gas fields, assuring its economical operation across a broad range of gas fields. The broader application of this process could substantially mitigate global warming by utilizing methane, leading to a significantly more sustainable and economically beneficial methanol industry.

4.
J Air Waste Manag Assoc ; 73(8): 625-637, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37378540

RESUMEN

Nowadays, when the zero-waste strategy is an inevitable component of the circular economy, the reuse of waste, including dredged sludges, has drawn the attention of many researchers. This study evaluated four kinds of bio-wastes (corn core powder, rice husk powder, sugarcane bagasse powder, and peanut shell powders) and two kinds of construction wastes (autoclaved aerated concrete-AAC and pavement stone) in enhancing the dewaterability of dredged sludge from the lake, in which the sludges would then be reused for brick production. The results showed that the moisture contents decreased from 62 ± 0.14% to 57 ± 1.89% after mixing and then to 35 ± 8.31% after compressing for the construction waste-blended sludge. Among the bio-wastes, the sugarcane bagasse additive performed the best at a mixing ratio of 1:3 by weight and rice husk powder worked best at a mixing ratio of 1:5 by weight. The organic matter was increased up to 80% when the bio-wastes were added, while it was decreased to 5% for the case of construction wastes. The optimum percentage of sludge in the mixture to meet all the oxide contents in the brick and energy saving shall be about 30%. The results have revealed a potentially green route for brick production with lake sediment and bio-waste/construction wastes.Implications: It is the first time the reuse of agro-wastes/construction waste was evaluated to mix with lake sediment to partly replace clay for brick production; Among the bio-wastes, the sugarcane bagasse additive performed the best at a mixing ratio of 1:3 by weight; Moisture contents decreased from 62 ± 0.14% to 57 ± 1.89% after mixing and then to 35 ± 8.31% after compressing for the blended sludge; The optimum percentage of mixed sludge, possibly replaced the clay in brick production, considering oxide contents and energy saving shall be up to 30%.


Asunto(s)
Saccharum , Aguas del Alcantarillado , Arcilla , Celulosa , Lagos , Polvos , Materiales de Construcción , Óxidos
5.
Glob Health Sci Pract ; 11(1)2023 02 28.
Artículo en Inglés | MEDLINE | ID: mdl-36853635

RESUMEN

INTRODUCTION: There is growing interest among low- and middle-income countries to introduce electronic immunization registries (EIRs) that capture individual-level vaccine data. We compare the design, development, and deployment of EIRs in Vietnam, Tanzania, and Zambia. Through desk review and the authors' firsthand implementation experiences, we describe experiences related to timeline, partnerships, financial costs, and technology and infrastructure. IMPLEMENTATION EXPERIENCE: The country cases highlight the multi-year timeline required to implement an EIR at scale and the benefit of multiple iterative cycles to pilot and redesign the system before achieving scale. Of the 3 countries, only Vietnam has achieved nationwide scale of the EIR, which took 7 years. In all 3 countries, national government leadership as part of an interdisciplinary team (with experience in leadership, technology, and immunization) was important to ensure country ownership and sustainability. Where international software developers were contracted, partnering with a local software company helped improve responsiveness and sustainability. Across all 3 countries, governments contributed significant in-kind time in addition to investments from donors. Cost savings were observed in Tanzania and Zambia, largely driven by health worker time savings from using the EIR. All 3 case countries underscore the need to understand the local technology and infrastructure context and design the EIR to fit the context. In Vietnam, an initial landscape assessment was conducted to assess technology and infrastructure, whereas in Tanzania and Zambia, user advisory groups provided insights. Existing infrastructure informed EIR design decisions, such as choosing a system with offline functionality in Tanzania and Zambia. All 3 countries have a local partner to provide ongoing technical support. CONCLUSION: Comparing implementation factors across these cases highlights practical experience and recommendations that complement existing EIR guidance documents. The findings and recommendations from this study can inform other countries considering or in the process of implementing an EIR.


Asunto(s)
Electrónica , Inmunización , Humanos , Tanzanía , Zambia , Vietnam , Sistema de Registros
6.
HardwareX ; 12: e00353, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-36082147

RESUMEN

In a continuous and closed system of culturing microalgae, constantly monitoring and controlling pH, dissolved oxygen (DO) and microalgal density in the cultivation environment are paramount, which ultimately influence on the growth rate and quality of the microalgae products. Apart from the pH and DO parameters, the density of microalgae can be used to contemplate what light condition in the culture chamber is or when nutrients should be supplemented, which both also decide productivity of the cultivation. Moreover, the microalgal density is considered as an indicator indicating when the microalgae can be harvested. Therefore, this work proposes a low-cost monitoring equipment that can be employed to observe pH, DO and microalgal density over time in a culture environment. The measurements obtained by the proposed monitoring device can be utilized for not only real-time observations but also controlling other sub-systems in a continuous culture model including stirring, ventilating, nutrient supplying and harvesting, which leads to more efficiency in the microalgal production. More importantly, it is proposed to utilize the off-the-shelf materials to fabricate the equipment with a total cost of about 513 EUR, which makes it practical as well as widespread. The proposed monitoring apparatus was validated in a real-world closed system of cultivating a microalgae strain of Chlorella vulgaris. The obtained results indicate that the measurement accuracies are 0.3%, 3.8% and 8.6% for pH, DO and microalgae density quantities, respectively.

7.
JMIR Form Res ; 5(10): e28096, 2021 Oct 25.
Artículo en Inglés | MEDLINE | ID: mdl-34694232

RESUMEN

BACKGROUND: Vietnam is one of the first low- to middle-income countries to develop and implement a national-scale electronic immunization registry. This system was finalized into the National Immunization Information System (NIIS) and scaled up to a national-level system in 2017. As a result, immunization coverage and the timeliness of vaccinations have drastically improved. The time spent on planning and reporting vaccinations has drastically reduced; as a result, vaccination planning and reporting has become more accurate and effective. However, to date, end users have been tasked with managing both the NIIS and paper-based systems in parallel until a formal assessment of the readiness to fully transition to the NIIS is conducted. OBJECTIVE: This study aims to evaluate the readiness to move to an entirely digital NIIS in 2 provinces of Vietnam-Ha Noi and Son La. METHODS: All health facilities were surveyed to assess their infrastructure, capacity, and need for human resources. NIIS end users were observed and interviewed to evaluate their NIIS knowledge and skill sets. Data from immunization cards and facility paper-based logbooks were compared with data from the NIIS, and vaccine stocks at selected facilities were tallied and compared with data from the NIIS. RESULTS: Of the 990 health facilities evaluated, most used the NIIS to enter and track immunizations (987/990, 99.7%) and vaccine stocks (889/990, 90.8%). Most had stable electricity (971/990, 98.1%), at least 1 computer (986/990, 99.6%), and ≥2 trained NIIS end users (825/990, 83.3%). End users reported that the NIIS supported them in managing and reporting immunization data and saving them time (725/767, 94.5%). Although many end users were able to perform basic skills, almost half struggled with performing more complex tasks. Immunization data were compiled from the NIIS and immunization cards (338/378, 89.4%) and paper-based logbooks (254/269, 94.4%). However, only 54.5% (206/378) of immunization IDs matched, 57% (13/23) of Bacillus Calmette-Guérin vaccination records were accurate, and 70% (21/30) of the facilities had consistent physical vaccine stock balances. The feedback received from NIIS end users suggests that more supportive supervision, frequent refresher training for strengthening their skill sets, and detailed standardized guides for improving data quality are needed. CONCLUSIONS: The readiness to transition to a digital system is promising; however, additional resources are required to address the timeliness, completeness, and accuracy of the data.

8.
New Phytol ; 232(4): 1591-1602, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34018616

RESUMEN

Mangroves are among the world's most carbon-dense ecosystems, but have suffered extensive deforestation, prompting reforestation projects. The effects of mangrove reforestation on belowground carbon dynamics are poorly understood. In particular, we do not know how fine root production develops following mangrove reforestation, despite fine root production being a major carbon sink and an important control of mangrove soil accretion. Using minirhizotrons, we investigated fine root production and its depth variation along a chronosequence of mature Vietnamese mangroves. Our results showed that fine root production decreases strongly with stand age in the uppermost 32 cm of our soil profiles. In younger mangrove stands, fine root production declines with depth, possibly due to a vertical gradient in soil nutrient availability; while root production in the oldest stand is low at all depths and exhibits no clear vertical pattern. A major fraction of fine root production occurs deeper than 30 cm, depths that are commonly omitted from calculations of mangrove carbon budgets. Younger mangroves may accrue shallow soil organic matter faster than older mangroves. Therefore, root productivity and forest stand age should be accounted for when forecasting mangrove carbon budgets and resistance to sea-level rise.


Asunto(s)
Ecosistema , Humedales , Carbono , Secuestro de Carbono , Bosques , Suelo
9.
BMJ Open ; 11(2): e044416, 2021 02 22.
Artículo en Inglés | MEDLINE | ID: mdl-33619200

RESUMEN

OBJECTIVES: This study aims to investigate the prevalence of impairment of activities of daily living (ADLs) in older patients with heart failure (HF), and to examine the impact of ADL impairment on readmission after discharge. DESIGN AND SETTINGS: A prospective cohort study was conducted in patients aged ≥65 years with HF admitted to a tertiary hospital in Vietnam from August 2016 to June 2017. Difficulties with six ADLs were assessed by a questionnaire. Participants were classified into two categories (with and without ADL impairment). The associations of ADL impairment with 3-month readmission were examined using logistic regression models. RESULTS: There were 180 participants (mean age 80.6±8.2, 50% female) and 26.1% were classified as having ADL impairment. The most common impaired activity was bathing (21.1%), followed by transferring (20.0%), toileting (12.2%), dressing (8.9%), eating (3.3%), and continence (2.8%). During 3-month follow-up, 32.8% of the participants were readmitted to hospitals (55.3% in participants with ADL impairment, 24.8% in those without ADL impairment, p<0.001). ADL impairment significantly increased the risk of 3-month readmission (adjusted OR 2.75, 95% CI 1.25 to 6.05, p=0.01). CONCLUSIONS: In summary, ADL impairment was common in older hospitalised patients with HF and was associated with increased readmission. These findings suggest further studies on ADL assessment and intervention during transition care for older patients with HF after discharge to prevent readmission.


Asunto(s)
Actividades Cotidianas , Insuficiencia Cardíaca , Anciano , Anciano de 80 o más Años , Estudios de Cohortes , Femenino , Evaluación Geriátrica , Insuficiencia Cardíaca/epidemiología , Humanos , Masculino , Readmisión del Paciente , Estudios Prospectivos , Vietnam
10.
PLoS Comput Biol ; 17(2): e1008638, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33635861

RESUMEN

In this work we develop a novel algorithm for reconstructing the genomes of ancestral individuals, given genotype or sequence data from contemporary individuals and an extended pedigree of family relationships. A pedigree with complete genomes for every individual enables the study of allele frequency dynamics and haplotype diversity across generations, including deviations from neutrality such as transmission distortion. When studying heritable diseases, ancestral haplotypes can be used to augment genome-wide association studies and track disease inheritance patterns. The building blocks of our reconstruction algorithm are segments of Identity-By-Descent (IBD) shared between two or more genotyped individuals. The method alternates between identifying a source for each IBD segment and assembling IBD segments placed within each ancestral individual. Unlike previous approaches, our method is able to accommodate complex pedigree structures with hundreds of individuals genotyped at millions of SNPs. We apply our method to an Old Order Amish pedigree from Lancaster, Pennsylvania, whose founders came to North America from Europe during the early 18th century. The pedigree includes 1338 individuals from the past 12 generations, 394 with genotype data. The motivation for reconstruction is to understand the genetic basis of diseases segregating in the family through tracking haplotype transmission over time. Using our algorithm thread, we are able to reconstruct an average of 224 ancestral individuals per chromosome. For these ancestral individuals, on average we reconstruct 79% of their haplotypes. We also identify a region on chromosome 16 that is difficult to reconstruct-we find that this region harbors a short Amish-specific copy number variation and the gene HYDIN. thread was developed for endogamous populations, but can be applied to any extensive pedigree with the recent generations genotyped. We anticipate that this type of practical ancestral reconstruction will become more common and necessary to understand rare and complex heritable diseases in extended families.


Asunto(s)
Variaciones en el Número de Copia de ADN , Estudio de Asociación del Genoma Completo/métodos , Haplotipos , Dinámica Poblacional , Algoritmos , Animales , Mapeo Cromosómico/métodos , Simulación por Computador , Frecuencia de los Genes , Ligamiento Genético , Genotipo , Humanos , Desequilibrio de Ligamiento , Modelos Genéticos , Linaje , Polimorfismo de Nucleótido Simple , Programas Informáticos , Secuenciación Completa del Genoma
11.
Environ Sci Pollut Res Int ; 28(10): 12131-12143, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32948943

RESUMEN

Nowadays, together with the economic development, public health activities have gained substantial attention with increasing number of hospitals during the past decades. A multi-method approach involving site visits, questionnaires, and interviews, in combination with secondary data revealed that the healthcare waste (HCW) generation, varied with different specialties (general or pediatric/obstetric hospitals) and different level of hospitals (central, provincial, district levels). The HCW generation from different kinds of surveyed hospitals varied from 0.8 to 1.0 kg/bed/day for domestic waste, 0.15 to 0.25 kg/bed/day for infectious and hazardous waste, and less than 0.1 kg/bed/day for recycled waste. Only 94.3% of central hospitals, 92% of provincial hospitals, and 82% of district hospitals complied with national regulation in hazardous medical waste treatment. For healthcare wastewater treatment, the actual operating rates were 91%, 73%, and 50% for central, provincial, and district hospitals, respectively. The cost for HCW management accounted for only 10-15% of the total budget allocated for the medical facilities. Most of the provincial hospitals spent about $0.2-$0.4/bed/year for HCW management. This is the root cause of ineffective HCW management.


Asunto(s)
Eliminación de Residuos Sanitarios , Residuos Sanitarios , Administración de Residuos , Niño , Atención a la Salud , Residuos Peligrosos , Humanos , Vietnam
12.
Environ Sci Pollut Res Int ; 28(10): 11928-11941, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32077016

RESUMEN

This study assessed the performance of rainwater-harvesting systems installed for selected public utilities in the northern provinces of Vietnam where rainwater was collected, stored in stainless steel tanks, and treated with a complex filtration unit and Ultraviolet (UV) disinfection system (full system). Results from an operation of over 5 years show that the untreated rainwater could not be used directly for drinking purposes as it was contaminated with bacteria (total coliforms TC = 200-300 CFU/100 ml, Pseudomonas aeruginosa PA = 40-160 CFU/100 ml), and turbidity = 2-4 NTU. Most of the heavy metals detected were found below the standard limits. Phenol and its derivatives were detected occasionally as higher than the standard value (1 µg/L). After treatment, all parameters met the drinking water standards. The capital costs of the rainwater systems were approximately US$200/m3 and US$180/m3 for a full system and simplified system (without complex filtration unit), respectively, while the operation and maintenance (O&M) costs were 3 cents/L and 0.8 cents/L on average for a full system and simplified one, correspondingly.


Asunto(s)
Agua Potable , Desinfección , Lluvia , Vietnam , Abastecimiento de Agua
13.
Vaccine ; 38(52): 8343-8350, 2020 12 14.
Artículo en Inglés | MEDLINE | ID: mdl-33221065

RESUMEN

BACKGROUND: Hepatitis B virus (HBV) infection is a significant public health issue in Vietnam. Our goal was to understand the determinants of attitudes towards and practices of hepatitis B vaccine birth dose (HepB-BD) in certain regions of Vietnam. METHOD: A rapid qualitative assessment was conducted in three geographically diverse provinces that reported low coverage (<50%) of HepB-BD. Using purposive sampling of participants, 29 focus group discussions and 20 in-depth interviews were held with caregivers (n = 96), healthcare providers (n = 75), and healthcare administrators (n = 16). Summary notes from these were translated, and inductive coding was used to derive themes. The SAGE Vaccine Hesitancy Determinants Matrix was used as a theoretical framework to organize barriers and facilitators associated with the themes into three levels of influence. RESULTS: At the individual and group level, caregivers who had higher levels of knowledge about HepB-BD sought the vaccine proactively, while others with lower knowledge faced barriers to the vaccine. Some caregivers reported a negative attitude toward health services because of a language barrier or had generalized concerns about HepB-BD due to media reporting of the past adverse events. Distress arising from potential adverse events was equally common among healthcare providers. At the contextual level, the physical environment made it difficult for caregivers to access healthcare facilities and for providers to conduct outreach. Home births posed a challenge for timely administration of HepB-BD, while health facility births facilitated it. Vaccination-specific barriers included misinterpretation of pre-vaccination screening criteria and asking for the consent of caregivers. Inadequate resources for service delivery negatively influenced HepB-BD attitudes and practices. CONCLUSION: Given the diversity of barriers associated with attitudes towards and practices of HepB-BD in the three provinces, tailored interventions will be necessary for both demand- and supply-side factors. Rural areas, often with more home births and geographic barriers, may require focused attention.


Asunto(s)
Vacunas contra Hepatitis B , Hepatitis B , Actitud , Femenino , Hepatitis B/prevención & control , Humanos , Embarazo , Vacunación , Vietnam/epidemiología
14.
J Med Internet Res ; 22(9): e19923, 2020 09 22.
Artículo en Inglés | MEDLINE | ID: mdl-32960184

RESUMEN

BACKGROUND: Digital health innovations can improve health system performance, yet previous experience has shown that many innovations do not advance beyond the pilot stage to achieve scale. Vietnam's National Immunization Information System (NIIS) began as a series of digital health pilots, first initiated in 2010, and was officially launched nationwide in 2017. The NIIS is one of the few examples of an electronic immunization registry (EIR) at national scale in low- and middle-income countries. OBJECTIVE: The aim of this study was to understand the determinants of scale-up of the national EIR in Vietnam. METHODS: This qualitative study explored the facilitators and barriers to national scale-up of the EIR in Vietnam. Qualitative data were collected from October to December 2019 through in-depth key informant interviews and desk review. The mHealth Assessment and Planning for Scale (MAPS) Toolkit guided the development of the study design, interview guides, and analytic framework. MAPS defines the key determinants of success, or the "axes of scale," to be groundwork, partnerships, financial health, technology and architecture, operations, and monitoring and evaluation. RESULTS: The partnership and operations axes were critical to the successful scale-up of the EIR in Vietnam, while the groundwork and monitoring and the evaluation axes were considered to be strong contributors in the success of all the other axes. The partnership model leveraged complementary strengths of the technical working group partners: the Ministry of Health General Department of Preventive Medicine, the National Expanded Program on Immunization, Viettel (the mobile network operator), and PATH. The operational approach to introducing the NIIS with lean, iterative, and integrated training and supervision was also a key facilitator to successful scale-up. The financial health, technology and architecture, and operations axes were identified as barriers to successful deployment and scale-up. Key barriers to scale-up included insufficient estimates of operational costs, unanticipated volume of data storage and transmission, lack of a national ID to support interoperability, and operational challenges among end users. Overall, the multiple phases of EIR deployment and scale-up from 2010 to 2017 allowed for continuous learning and improvement that strengthened all the axes and contributed to successful scale-up. CONCLUSIONS: The results highlight the importance of the measured, iterative approach that was taken to gradually expand a series of small pilots to nationwide scale. The findings from this study can be used to inform other countries considering, introducing, or in the process of scaling an EIR or other digital health innovations.


Asunto(s)
Electrónica/métodos , Programas de Inmunización/métodos , Humanos , Proyectos Piloto , Investigación Cualitativa , Sistema de Registros , Telemedicina/métodos , Vietnam
15.
Talanta ; 150: 525-30, 2016 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-26838439

RESUMEN

Lichens are symbiotic organisms known for producing unique secondary metabolites with attractive cosmetic and pharmacological properties. In this paper, we investigated three standard methods of preparation of Pseudevernia furfuracea (blender grinding, ball milling, pestle and mortar). The materials obtained were characterized by electronic microscopy, nitrogen adsorption and compared from the point of view of extraction. Their microscopic structure is related to extraction efficiency. In addition, it is shown using thalline reactions and mass spectrometry mapping (TOF-SIMS) that these metabolites are not evenly distributed throughout the organism. Particularly, atranorin (a secondary metabolite of interest) is mainly present in the cortex of P. furfuracea. Finally, using microwave assisted extraction (MAE) we obtained evidence that an appropriate preparation can increase the extraction efficiency of atranorin by a factor of five.


Asunto(s)
Mezclas Complejas/normas , Hidroxibenzoatos/análisis , Hidroxibenzoatos/aislamiento & purificación , Líquenes/química , Manejo de Especímenes/métodos , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...