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1.
Acta sci., Health sci ; 44: e53802, Jan. 14, 2022.
Artigo em Inglês | LILACS | ID: biblio-1363583

RESUMO

Chronic kidney disease (CKD) has become a global public health challenge. The objective of this study was to analyze the relationship between self-perception of oral health and clinical condition among patients with CKD. This isa quanti-qualitative survey conducted in a CKD specialized service. The sample consisted of 60 patients who underwent oral examinations to have their severity of caries (DMFT) and need for dental prosthesis checked. Age, sex, time on dialysis, marital status, skin color, education and pre-existing diseases were also analyzed. Among the kidney patients who agreed to undergo the clinical examinations and showed communication skills, some were selected, and three focus groups were created, with the participation of a moderator and six to 10 kidney patients in each group. Their speeches were processed in the IRAMUTEQ software and analyzed through the similarity analysis and word cloud techniques. As for profile, the patients were aged 60.23 ± 10.87 years old; were male (73.33%); were on dialysis for 41.90 ± 56.57 months; were married (61.67%); were white (76.67%); had incomplete primary education (41.66%); had arterial hypertension (76.67%); had a DMFT index of 22.55 ± 8.39; 43.33% needed an upper complete denture; and 30.00% needed a lower complete denture. The similarity analysis revealed many doubts and uncertainties about current health services, which can be proven by the words 'no' and 'treatment'. The quanti-qualitative analysis showed a high rate of dental loss and the need for complete dentures and suggests inequities in oral health care for chronic kidney disease patients, especially in tertiary care. There was a positive representation regarding oral health, but the lexicographical analyses of the textual corpusconfirmed the self-perception of lack of dental care.


Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Idoso , Saúde Bucal , Insuficiência Renal Crônica/diagnóstico , Atenção Terciária à Saúde/organização & administração , Saúde Pública/métodos , Perda de Dente/diagnóstico , Assistência Odontológica/métodos , Grupos Focais/métodos , Prótese Dentária/métodos , Cárie Dentária/prevenção & controle , Pesquisa Qualitativa , Diagnóstico Bucal/métodos , Diálise/métodos , Serviços de Saúde/provisão & distribuição
2.
Nat Rev Nephrol ; 16(10): 573-585, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32733095

RESUMO

The development of dialysis by early pioneers such as Willem Kolff and Belding Scribner set in motion several dramatic changes in the epidemiology, economics and ethical frameworks for the treatment of kidney failure. However, despite a rapid expansion in the provision of dialysis - particularly haemodialysis and most notably in high-income countries (HICs) - the rate of true patient-centred innovation has slowed. Current trends are particularly concerning from a global perspective: current costs are not sustainable, even for HICs, and globally, most people who develop kidney failure forego treatment, resulting in millions of deaths every year. Thus, there is an urgent need to develop new approaches and dialysis modalities that are cost-effective, accessible and offer improved patient outcomes. Nephrology researchers are increasingly engaging with patients to determine their priorities for meaningful outcomes that should be used to measure progress. The overarching message from this engagement is that while patients value longevity, reducing symptom burden and achieving maximal functional and social rehabilitation are prioritized more highly. In response, patients, payors, regulators and health-care systems are increasingly demanding improved value, which can only come about through true patient-centred innovation that supports high-quality, high-value care. Substantial efforts are now underway to support requisite transformative changes. These efforts need to be catalysed, promoted and fostered through international collaboration and harmonization.


Assuntos
Diálise , Diálise/instrumentação , Diálise/métodos , Diálise/estatística & dados numéricos , Diálise/tendências , Previsões , Saúde Global/economia , Saúde Global/estatística & dados numéricos , Custos de Cuidados de Saúde/estatística & dados numéricos , Humanos , Invenções/tendências , Rins Artificiais/ética , Rins Artificiais/estatística & dados numéricos , Diálise Peritoneal/instrumentação , Diálise Peritoneal/métodos , Diálise Peritoneal/estatística & dados numéricos , Diálise Peritoneal/tendências , Diálise Renal/instrumentação , Diálise Renal/métodos , Diálise Renal/estatística & dados numéricos , Diálise Renal/tendências , Insuficiência Renal/epidemiologia , Insuficiência Renal/terapia
3.
Forum Health Econ Policy ; 23(1)2020 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-32134730

RESUMO

Background The optimal timing of treatment with vitamin D therapy for patients with chronic kidney disease (CKD), vitamin D insufficiency, and secondary hyperparathyroidism (SHPT) is a pressing question in nephrology with economic and patient outcome implications. Objective The objective of this study was to estimate the cost-effectiveness of earlier vitamin D treatment in CKD patients not on dialysis with vitamin D insufficiency and SHPT. Design A cost-effectiveness analysis based on a Markov model of CKD progression was developed from the Medicare perspective. The model follows a hypothetical cohort of 1000 Stage 3 or 4 CKD patients over a 5-year time horizon. The intervention was vitamin D therapy initiated in CKD stages 3 or 4 through CKD stage 5/end-stage renal disease (ESRD) versus initiation in CKD stage 5/ESRD only. The outcomes of interest were cardiovascular (CV) events averted, fractures averted, time in CKD stage 5/ESRD, mortality, quality-adjusted life years (QALYs), and costs associated with clinical events and CKD stage. Results Vitamin D treatment in CKD stages 3 and 4 was a dominant strategy when compared to waiting to treat until CKD stage 5/ESRD. Total cost savings associated with treatment during CKD stages 3 and 4, compared to waiting until CKD stage 5/ESRD, was estimated to be $19.9 million. The model estimated that early treatment results in 159 averted CV events, 5 averted fractures, 269 fewer patient-years in CKD stage 5, 41 fewer deaths, and 191 additional QALYs. Conclusions Initiating vitamin D therapy in CKD stages 3 or 4 appears to be cost-effective, largely driven by the annual costs of care by CKD stage, CV event costs, and risks of hypercalcemia. Further research demonstrating causal relationships between vitamin D therapy and patient outcomes is needed to inform decision making regarding vitamin D therapy timing.


Assuntos
Diálise/métodos , Benefícios do Seguro/economia , Vitamina D/uso terapêutico , Análise Custo-Benefício/métodos , Diálise/tendências , Humanos , Benefícios do Seguro/métodos , Insuficiência Renal Crônica/prevenção & controle , Vitamina D/economia , Vitaminas/economia , Vitaminas/uso terapêutico
4.
J Steroid Biochem Mol Biol ; 190: 207-211, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30970279

RESUMO

Testosterone (T) is strongly bound to sex hormone binding globulin and measurement of free T may be more appropriate than measuring total serum T, according to the free hormone theory. This view remains controversial and it has its detractors who claim that little extra benefit is gained than simply measuring total T, but it is endorsed by recent clinical practice guidelines for investigation of androgen disorders in both men and women. Free T measurement is very challenging. The gold standard equilibrium dialysis methods are too complex for use in routine clinical laboratories, assays are not harmonized and consequently there are no common reference intervals to aid result interpretation. The algorithms derived for calculating free T are inaccurate because they were founded on faulty models of testosterone binding to SHBG, however they can still give clinically useful results. To negate the effects of differences in binding protein constants, some equations for free T have been derived from accurate measurement of testosterone in large population studies, however a criticism is that the equations may not hold true in different patient populations. The free androgen index is not recommended for use in men because of inaccuracy at extremes of SHBG concentration, and in women it can also give inaccurate results when SHBG concentrations are low. If the free hormone hypothesis is to be believed, then calculated free testosterone may offer the best way forward but better equations are needed to improve accuracy and these should be derived from detailed knowledge of testosterone binding to SHBG. There is still much work to be done to improve harmonization of T and SHBG assays between laboratories because these can have a profound effect on the equations used to calculate free testosterone.


Assuntos
Testosterona/análise , Algoritmos , Diálise/métodos , Feminino , Humanos , Masculino , Ligação Proteica , Saliva/química , Saliva/metabolismo , Globulina de Ligação a Hormônio Sexual/metabolismo , Testosterona/sangue , Testosterona/metabolismo
5.
Eur Heart J ; 40(11): 887-898, 2019 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-30085056

RESUMO

AIMS: End-stage renal disease (ESRD) is a strong cardiovascular risk factor. We aimed to determine the extent to which cause of kidney disease independently contributes to this risk. METHODS AND RESULTS: Using a national US ESRD registry, we selected patients with eight different causes of ESRD who initiated dialysis 1997-2014. We used proportional sub-distribution hazard models, with non-cardiovascular death or kidney transplantation as competing risks, to estimate hazard ratios (HRs) for a first composite cardiovascular event (myocardial infarction, ischaemic stroke, or cardiovascular or cerebrovascular death), by cause of ESRD. The population was restricted to those using Medicare insurance at Day 91 after dialysis initiation (when most patients become Medicare eligible). Outcomes were ascertained from Medicare claims or Death Notifications. Among the 658 168 patients identified, composite event rates ranged from 3.5/100 person-years in IgA nephropathy to 14.6/100 person-years in diabetic nephropathy (DN). After adjusting for demographics, socioeconomic factors, comorbidities, dialysis modality, and laboratory values, cardiovascular event HRs differed significantly by cause of ESRD. Comparing to IgA nephropathy, the adjusted HR was highest for DN [aHR = 2.97, 95% confidence interval (CI) 2.77-3.20], next highest for lupus nephritis (aHR = 1.86, 95% CI 1.71-2.03), and thereafter ranged from 1.29 (95% CI 1.19-1.39) in autosomal dominant polycystic kidney disease to 1.67 (95% CI 1.52-1.83) in membranous nephropathy. CONCLUSION: High cardiovascular event rates in dialysis patients vary considerably by cause of ESRD. Determining underlying reasons for these differences might provide new insights in to cardiovascular disease mechanisms as well as inform future drug development and clinical trial design.


Assuntos
Nefropatias Diabéticas/complicações , Diálise/efeitos adversos , Glomerulonefrite por IGA/complicações , Nefropatias/complicações , Falência Renal Crônica/etiologia , Adulto , Morte Encefálica/fisiopatologia , Isquemia Encefálica/fisiopatologia , Estudos de Coortes , Comorbidade , Morte , Nefropatias Diabéticas/epidemiologia , Diálise/métodos , Diálise/tendências , Feminino , Glomerulonefrite por IGA/epidemiologia , Humanos , Nefropatias/epidemiologia , Falência Renal Crônica/terapia , Masculino , Medicare/normas , Pessoa de Meia-Idade , Infarto do Miocárdio/epidemiologia , Estudos Retrospectivos , Fatores de Risco , Acidente Vascular Cerebral/epidemiologia , Estados Unidos/epidemiologia
6.
Rev Bras Enferm ; 71(4): 1915-1920, 2018.
Artigo em Inglês, Português | MEDLINE | ID: mdl-30156677

RESUMO

OBJECTIVE: to identify damages resulting from incidents with the Hickman® catheter. METHOD: descriptive, retrospective, qualitative approach. The source of data were the notifications of incidents that occurred between January 2012 and May 2015, as well as the information available on the medical records of patients involved in incidents with the Hickman® catheter. RESULTS: the incidents related to the Hickman® catheter with the greatest impact on patient care were obstruction, fracture and traction. All incidents caused damage to patients, in a greater or lesser degree, in the dimensions of physical damage and subjective damage. FINAL CONSIDERATIONS: damage or potential risk of damage was present in all incidents analyzed. The need to revise cleaning and obstruction protocols for the maintenance of the permeability of Hickman® catheters was demonstrated.


Assuntos
Infecções Relacionadas a Cateter/economia , Diálise/instrumentação , Transplante de Medula Óssea/efeitos adversos , Transplante de Medula Óssea/métodos , Análise Custo-Benefício , Diálise/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pesquisa Qualitativa , Estudos Retrospectivos , Fatores de Risco
7.
Rev. bras. enferm ; 71(4): 1915-1920, Jul.-Aug. 2018. tab, graf
Artigo em Inglês | LILACS, BDENF | ID: biblio-958670

RESUMO

ABSTRACT Objective: to identify damages resulting from incidents with the Hickman® catheter. Method: descriptive, retrospective, qualitative approach. The source of data were the notifications of incidents that occurred between January 2012 and May 2015, as well as the information available on the medical records of patients involved in incidents with the Hickman® catheter. Results: the incidents related to the Hickman® catheter with the greatest impact on patient care were obstruction, fracture and traction. All incidents caused damage to patients, in a greater or lesser degree, in the dimensions of physical damage and subjective damage. Final considerations: damage or potential risk of damage was present in all incidents analyzed. The need to revise cleaning and obstruction protocols for the maintenance of the permeability of Hickman® catheters was demonstrated.


RESUMEN Objetivo: identificar el acaecimiento de daños en incidentes relacionados con el catéter de Hickman®. Método: investigación descriptiva, retrospectiva, de abordaje cualitativo. Como fuente de datos, se utilizaron fichas de notificación de incidentes ocurridos entre enero de 2012 y mayo de 2015, además de informaciones relatadas en los prontuarios de los pacientes involucrados en los incidentes relacionados con el catéter de Hickman®. Resultados: los incidentes de impacto más importantes en la atención al paciente, relacionados con el catéter de Hickman®, fueron la obstrucción, la fractura y la tracción. Todos los incidentes generaron, en mayor o menor grado, daños a los pacientes en las dimensiones física y subjetiva. Consideraciones finales: se encontraba presente en todos los incidentes analizados, el daño en sí mismo o el riesgo potencial para el daño. Quedó en evidencia la necesidad de revisar los protocolos de lavado y bloqueo del catéter de Hickman® para el mantenimiento de su permeabilidad.


RESUMO Objetivo: identificar a ocorrência de danos nos incidentes relacionados ao cateter de Hickman®. Método: pesquisa descritiva, retrospectiva, de abordagem qualitativa. Como fonte dos dados, foram utilizadas as fichas de notificação de incidentes ocorridos entre janeiro de 2012 e maio de 2015, além de informações dos prontuários dos pacientes envolvidos com incidentes relacionados ao cateter de Hickman®. Resultados: os incidentes, relacionados ao cateter de Hickman®, de maior impacto para a assistência ao paciente foram a obstrução, fratura e tração. Todos os incidentes geraram dano aos pacientes, de maior ou menor grau, nas dimensões de dano físico e danos subjetivos. Considerações finais: dano ou risco potencial para dano esteve presente em todos os incidentes analisados. Evidenciou-se a necessidade de revisar os protocolos de lavagem e bloqueio para a manutenção da permeabilidade do cateter de Hickman®.


Assuntos
Humanos , Masculino , Feminino , Diálise/instrumentação , Infecções Relacionadas a Cateter/economia , Estudos Retrospectivos , Fatores de Risco , Transplante de Medula Óssea/efeitos adversos , Transplante de Medula Óssea/métodos , Análise Custo-Benefício , Pesquisa Qualitativa , Diálise/métodos , Pessoa de Meia-Idade
8.
Crit Care ; 22(1): 25, 2018 01 30.
Artigo em Inglês | MEDLINE | ID: mdl-29382394

RESUMO

BACKGROUND: The aim of the study was to describe the population pharmacokinetics (PK) of meropenem in critically ill patients receiving sustained low-efficiency dialysis (SLED). METHODS: Prospective population PK study on 19 septic patients treated with meropenem and receiving SLED for acute kidney injury. Serial blood samples for determination of meropenem concentrations were taken before, during and after SLED in up to three sessions per patient. Nonparametric population PK analysis with Monte Carlo simulations were used. Pharmacodynamic (PD) targets of 40% and 100% time above the minimal inhibitory concentration (f T > MIC) were used for probability of target attainment (PTA) and fractional target attainment (FTA) against Pseudomonas aeruginosa. RESULTS: A two-compartment linear population PK model was most appropriate with residual diuresis supported as significant covariate affecting meropenem clearance. In patients without residual diuresis the PTA for both targets (40% and 100% f T > MIC) and susceptible P. aeruginosa (MIC ≤ 2 mg/L) was > 95% for a dose of 0.5 g 8-hourly. In patients with a residual diuresis of 300 mL/d 1 g 12-hourly and 2 g 8-hourly would be required to achieve a PTA of > 95% and 93% for targets of 40% f T > MIC and 100% f T > MIC, respectively. A dose of 2 g 8-hourly would be able to achieve a FTA of 97% for 100% f T > MIC in patients with residual diuresis. CONCLUSIONS: We found a relevant PK variability for meropenem in patients on SLED, which was significantly influenced by the degree of residual diuresis. As a result dosing recommendations for meropenem in patients on SLED to achieve adequate PD targets greatly vary. Therapeutic drug monitoring may help to further optimise individual dosing. TRIAL REGISTRATION: Clincialtrials.gov, NCT02287493 .


Assuntos
Diálise/métodos , Sepse/tratamento farmacológico , Tienamicinas/farmacocinética , Injúria Renal Aguda/tratamento farmacológico , Injúria Renal Aguda/prevenção & controle , Adulto , Idoso , Estado Terminal/reabilitação , Feminino , Alemanha , Humanos , Masculino , Meropeném , Testes de Sensibilidade Microbiana/métodos , Pessoa de Meia-Idade , Método de Monte Carlo , Escores de Disfunção Orgânica , Estudos Prospectivos , Tienamicinas/uso terapêutico
9.
J Ren Care ; 44(2): 82-95, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29357407

RESUMO

BACKGROUND: Living with end stage kidney disease and having dialysis is burdensome, and there is a need for support from informal caregivers (i.e. family members and friends). Renal health professionals readily acknowledge and value the support provided by caregivers although the activities and experiences of caring for a loved-one who is receiving dialysis is less well understood. OBJECTIVES: To review studies about the perspectives and experiences of family members and friends who provide support for adults receiving either haemodialysis or peritoneal dialysis. METHODS: A mixed-methods systematic review was conducted. Eight databases (Medline, CINAHL, EMBASE, PsycINFO, Proquest, Web of Science, Cochrane Library and JBI library) were comprehensively searched using relevant key words for studies regardless of design published in English from January 2006 to July 2017. RESULTS: Twenty studies were included in this review. Informal caregivers undertake many everyday activities as well as a range of dialysis-specific activities, report an elevated level of burden, feel overwhelmed, experience social isolation, and also need to consider their own health. A unique finding was that caregivers also experienced personal growth that may defuse the impact of caregiving burden and to help them develop a sense of resilience to sustain the support through the tough times and for many years. CONCLUSION: This review substantiates that caregiver burden is due to the unrelenting nature of complex dialysis-specific activities although resilience often develops. Additional research is necessary to understand social support in this context and how health teams can assist caregivers further.


Assuntos
Cuidadores/psicologia , Diálise/normas , Acontecimentos que Mudam a Vida , Assistência ao Paciente/métodos , Adaptação Psicológica , Efeitos Psicossociais da Doença , Diálise/métodos , Humanos , Apoio Social , Estresse Psicológico/etiologia , Estresse Psicológico/psicologia
12.
Water Sci Technol ; 66(10): 2185-93, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22949250

RESUMO

Water shortage has become an emerging environmental issue. Reclamation of the effluent from municipal wastewater treatment plant (WWTP) is feasible for meeting the growth of water requirement from industries. In this study, the results of a pilot-plant setting in Futian wastewater treatment plant (Taichung, Taiwan) were presented. Two processes, sand filter - ultrafiltration - reverse osmosis (SF-UF-RO) and sand filter - electrodialysis reversal (SF-EDR), were operated in parallel to evaluate their stability and filtrate quality. It has been noticed that EDR could accept inflow with worse quality and thus required less pretreatment compared with RO. During the operation, EDR required more frequent chemical cleaning (every 3 weeks) than RO did (every 3 months). For the filtrate quality, the desalination efficiency of SF-EDR ranged from 75 to 80% in continuous operation mode, while the conductivity ranged from 100 to 120 µS/cm, with turbidity at 0.8 NTU and total organic carbon at 1.3 mg/L. SF-EDR was less efficient in desalinating the multivalent ions than SF-UF-RO was. However for the monovalent ions, the performances of the two processes were similar to each other. Noticeably, total trihalomethanes in SF-EDR filtrate was lower than that of SF-UF-RO, probably because the polarization effects formed on the concentrated side of the EDR membrane were not significant. At the end of this study, cost analysis was also conducted to compare the capital requirement of building a full-scale wastewater reclamation plant using the two processes. The results showed that using SF-EDR may cost less than using SF-UF-RO, if the users were to accept the filtrate quality of SF-EDR.


Assuntos
Diálise/métodos , Técnicas Eletroquímicas/métodos , Eliminação de Resíduos Líquidos/métodos , Água/química , Cidades , Filtração/instrumentação , Filtração/métodos , Osmose , Projetos Piloto , Salinidade , Cloreto de Sódio , Eliminação de Resíduos Líquidos/economia , Purificação da Água/economia , Purificação da Água/instrumentação , Purificação da Água/métodos
13.
Nature ; 488(7411): 313-9, 2012 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-22895336

RESUMO

Water has always been crucial to combustion and hydroelectric processes, but it could become the source of power in membrane-based systems that capture energy from natural and waste waters. Two processes are emerging as sustainable methods for capturing energy from sea water: pressure-retarded osmosis and reverse electrodialysis. These processes can also capture energy from waste heat by generating artificial salinity gradients using synthetic solutions, such as thermolytic salts. A further source of energy comes from organic matter in waste waters, which can be harnessed using microbial fuel-cell technology, allowing both wastewater treatment and power production.


Assuntos
Diálise/métodos , Energia Renovável , Água , Biocombustíveis , Biomassa , Eletricidade , Temperatura Alta , Energia Renovável/economia , Salinidade
14.
Water Sci Technol ; 63(9): 1855-63, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21902023

RESUMO

Species, dose, and mean ion resident time (MIRT(c)) in the concentrate of electro-dialysis reversal (EDR) desalination are analysed. In the classical EDR, dimensions, flow, and velocity of dilute and concentrate are equal; Langelier saturation index (LSI) and CaSO4 saturation are used to control the scaling and fouling processes in concentrate, as such LSI < + 2.16 for preventing CaCO3 from fouling and CaSO4 saturation level < 200 for averting CaSO4 from precipitation. If LSI is more than allowable limit, acid is added in concentrate to keep CaCO3 continuously dissolving; if CaSO4 saturation level in concentrate is more than the allowable limit, sodium hexametaphosphate (SHMP) is added in concentrate to maintain CaSO4 dissolving. EDR, however, was successfully modernised to operate with the higher water recovery rate (R) without any anti-scalant and without acid; this new EDR operated with LSI at 2.29 and CaSO4 saturation level 358.9% at lower dose and lower MIRT(c). Dose and MIRT(c) are proposed to address the controlling process. Monographs for the acids and SHMP requirements, and for the desalting cost including desalting power, membrane surface area, and chemicals usage, are developed. By lowering R and polar reversal interval, EDR can be operated at MIRT(c) < 130 min; at MIRT(c0 < 130 min, desalting cost/ energy can be minimised by eliminating chemicals requirement.


Assuntos
Diálise/métodos , Técnicas Eletroquímicas/métodos , Cloreto de Sódio/química , Purificação da Água/métodos , Água/química , Modelos Teóricos , Fatores de Tempo , Abastecimento de Água
15.
J Food Sci ; 74(7): E363-71, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19895465

RESUMO

Fish sauce has a unique, pleasant flavor, but contains high levels of sodium chloride, which is nowadays not desirable for health-conscious consumers. Although many researchers have attempted to solve this problem by substituting sodium with potassium in fish sauce, potassium-based products are still unsuitable for patients with kidney disease. Thus, electrodialysis (ED) desalination of fish sauce was carried out. The rate of salt removal, evolution of total soluble solids, and electrical conductivity of the electrodialysis-treated fish sauce were investigated. Moreover, the system performance in terms of yield, energy consumption, and current efficiency were examined. Density, viscosity, ion concentrations (that is, Na(+), K(+)), total nitrogen, amino nitrogen, and color were investigated at various values of input voltage (6, 7, and 8 V) and remaining salt concentration (22%, 18%, 14%, 10%, 6%, and 2%[w/w]). The results indicated that an increase in the input voltage led to an increase in the rates of salt removal, electrical conductivity, and total soluble solids. The energy consumption increased whereas current efficiency and yield decreased significantly with an increase in input voltage and the salt removal level. Physicochemical properties of the treated fish sauce, in terms of the total soluble solids, density, viscosity, ion concentrations (that is, Na(+), K(+)), total nitrogen, and color were significantly affected by the input voltage and the salt-removal level.


Assuntos
Condimentos , Diálise/métodos , Produtos Pesqueiros , Cloreto de Sódio na Dieta , Animais , Fenômenos Químicos , Condimentos/análise , Produtos Pesqueiros/análise , Peixes , Manipulação de Alimentos/economia , Manipulação de Alimentos/métodos , Pigmentação , Controle de Qualidade , Cloreto de Sódio na Dieta/análise
17.
Anal Biochem ; 387(1): 122-7, 2009 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-19454255

RESUMO

Quantification of RNA is essential for various molecular biology studies. In this work, three quantification methods were evaluated: ultraviolet (UV) absorbance, microcapillary electrophoresis (MCE), and fluorescence-based quantification. Viral, bacterial, and eukaryotic RNA were measured in the 500 to 0.05-ng microl(-1) range via an ND-1000 spectrophotometer (UV), Agilent RNA 6000 kits (MCE), and Quant-iT RiboGreen assay (fluorescence). The precision and accuracy of each method were assessed and compared with a concentration derived independently using inductively coupled plasma-optical emission spectroscopy (ICP-OES). Cost, operator time and skill, and required sample volumes were also considered in the evaluation. Results indicate an ideal concentration range for each quantification technique to optimize accuracy and precision. The ND-1000 spectrophotometer exhibits high precision and accurately quantifies a 1-microl sample in the 500 to 5-ng microl(-1) range. The Quant-iT RiboGreen assay demonstrates high precision in the 1 to 0.05-ng microl(-1) range but is limited to lower RNA concentrations and is more costly than the ND-1000 spectrophotometer. The Agilent kits exhibit less precision than the ND-1000 spectrophotometer and Quant-iT RiboGreen assays in the 500 to 0.05-ng microl(-1) range. However, the Agilent kits require 1 microl of sample and can determine the integrity of the RNA, a useful feature for verifying whether the isolation process was successful.


Assuntos
RNA Bacteriano/análise , RNA Viral/análise , RNA/análise , Técnicas de Química Analítica/economia , Diálise/métodos , Eletroforese em Microchip , Reprodutibilidade dos Testes , Espectrometria de Fluorescência , Espectrofotometria Ultravioleta
18.
J Agric Food Chem ; 56(21): 10019-26, 2008 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-18937492

RESUMO

Chitosan, a linear polysaccharide composed of beta-1,4 linked d-glucosamine residues, can be depolymerized into oligomers by enzymatic reaction with chitosanase. Recently, bipolar membrane electrodialysis (BMED) has been used for chitosan solubilization and for terminating the enzymatic reaction by action of electrogenerated acid and base, respectively. The aim of the present study was to test a complete "3-in-1" process using a three-compartment BMED configuration to perform simultaneously the solubilization of chitosan, the inactivation of chitosanase, and the demineralization of the oligomers. In addition, the BMED process was compared to a conventional process using chemical acid and base. The BMED method was found to be as effective as the conventional method for solubilizing the chitosan and for inactivating the chitosanase. Furthermore, the use of BMED allowed a demineralization rate of 53% of the chito-oligomer solution in the diluate compartment. A global process of chitosan hydrolysis into its oligomers using a BMED system was proposed. This technology has great potential for industrial application in chitosan oligomer preparation, because it is convenient and ecological and it produces chito-oligomers with a lower mineral content compared with the conventional method.


Assuntos
Quitosana/química , Diálise/métodos , Eletroquímica/métodos , Proteínas de Bactérias/antagonistas & inibidores , Proteínas de Bactérias/metabolismo , Quitosana/metabolismo , Diálise/economia , Eletroquímica/economia , Glicosídeo Hidrolases/antagonistas & inibidores , Glicosídeo Hidrolases/metabolismo , Hidrólise , Membranas , Membranas Artificiais , Streptomyces/enzimologia
19.
Environ Sci Technol ; 42(15): 5785-90, 2008 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-18754509

RESUMO

The global potential to obtain clean energy from mixing river water with seawater is considerable. Reverse electrodialysis is a membrane-based technique for direct production of sustainable electricity from controlled mixing of river water and seawater. It has been investigated generally with a focus on obtained power, without taking care of the energy recovery. Optimizing the technology to power output only, would generally give a low energetic efficiency. In the present work, therefore, we emphasized the aspect of energy recovery. No fundamental obstacle exists to achieve an energy recovery of > 80%. This number was obtained with taking into account no more than the energetic losses for ionic transport. Regarding the feasibility, it was assumed to be a necessary but not sufficient condition that these internal losses are limited. The internal losses could be minimized by reducing the intermembrane distance, especially from the compartments filled with the low-conducting river water. It was found that a reduction from 0.5 to 0.2 mm indeed could be beneficial, although not to the expected extent. From an evaluation of the internal losses, it was supposed that besides the compartment thickness, also the geometry of the spacer affects the internal resistance.


Assuntos
Conservação dos Recursos Naturais/métodos , Diálise/métodos , Eletricidade , Água Doce/química , Sais/química , Água do Mar/química , Purificação da Água/métodos , Conservação dos Recursos Naturais/economia , Diálise/instrumentação , Purificação da Água/economia , Purificação da Água/instrumentação
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