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1.
Chemosphere ; 247: 125800, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31927182

RESUMO

Long-term operational stability of biotrickling filters (BTFs) degrading volatile organic compounds (VOCs) is dependent on both physicochemical as well as biological properties. Effects of increasingly stressful levels of air pollutants on the microbial structure of biofilms within BTFs are not well understood, especially for VOCs such as styrene. To investigate the relationship between biofilm biodiversity and operational stability, the temporal dynamics of a biofilm from a biotrickling filter subjected to stepwise increasing levels of air polluted with styrene was investigated using 16S rDNA pyrosequencing and PCR-denaturing gradient gel electrophoresis (PCR-DGGE). As styrene contaminant loads were increased, microbial community composition was distinctly altered and diversity was initially reduced in early stages but gradually stabilized and increased diversity in later stages, suggesting a recovery and acclimatization period within the microbial community during incremental exposure of the pollutant. Although temporary reductions in known styrene-degrading bacterial genera (Pseudomonas and Rhodococcus) occurred under increased styrene loads, stable BTF performance was maintained due to functional redundancy. New candidate genera for styrene degradation (Azoarcus, Dokdonella) were identified in conditions of high styrene loads, and may have supported the observed stable BTF performance throughout the experiment. Styrene inlet load was found to be important modulator of community composition and may have been partly responsible for the observed temporary reductions of Pseudomonas. Notable differences between dominant genera detected via pyrosequencing compared to species detected by PCR-DGGE suggests that simultaneous implementation of both techniques is valuable for fully characterizing dynamic microbial communities.


Assuntos
Bactérias/isolamento & purificação , Biodegradação Ambiental , Biodiversidade , Biofilmes/efeitos dos fármacos , Filtração/instrumentação , Estireno/farmacologia , Poluentes Atmosféricos/análise , Poluentes Atmosféricos/metabolismo , Poluentes Atmosféricos/farmacologia , Bactérias/metabolismo , Reatores Biológicos/microbiologia , Eletroforese em Gel de Gradiente Desnaturante/métodos , Eletroforese em Gel de Gradiente Desnaturante/normas , Filtração/métodos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Sequenciamento de Nucleotídeos em Larga Escala/normas , Microbiota/efeitos dos fármacos , Estireno/metabolismo , Compostos Orgânicos Voláteis/metabolismo
2.
Urology ; 135: 106-110, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31626857

RESUMO

OBJECTIVE: To examine long- and short-term outcomes using cell salvage with a commercially available leukocyte depletion filter following radical cystectomy in an oncologic population. MATERIALS AND METHODS: One hundred and fifty-seven patients, 87 of whom received a cell salvage transfusion, were retrospectively identified from chart review. Ninety-day outcomes as well as long-term mortality and cancer recurrence data were collected. Chi-square, Student's t, or Mann-Whitney U tests were used as appropriate. Multivariable regressions of survival were performed with a Cox proportional-hazards model. RESULTS: Those who received a cell salvage transfusion did not show any differences in rate of cancer recurrence (23%) vs those who did not receive a cell salvage transfusion (24%; P = .85). There were also no differences noted in mortality rates between the 2 populations (12% vs 17%; P = .36). Furthermore, no differences were noted in postoperative complication rates, length of hospital stay, 90-day culture positive infections or readmissions (P >.05). CONCLUSION: There are no significant differences in short-term or long-term patient outcomes between those who did and did not receive an intraoperative cell salvage transfusion. Cell salvage transfusions with a leukocyte depletion filter are safe and effective methods to reduce the need for allogeneic blood transfusions while controlling for the theoretical risk of metastatic spread.


Assuntos
Perda Sanguínea Cirúrgica/prevenção & controle , Transfusão de Sangue Autóloga/efeitos adversos , Cistectomia/efeitos adversos , Recidiva Local de Neoplasia/epidemiologia , Recuperação de Sangue Operatório/efeitos adversos , Neoplasias da Bexiga Urinária/cirurgia , Idoso , Idoso de 80 Anos ou mais , Transfusão de Sangue Autóloga/métodos , Feminino , Filtração/instrumentação , Seguimentos , Humanos , Tempo de Internação/estatística & dados numéricos , Procedimentos de Redução de Leucócitos/instrumentação , Leucócitos/patologia , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/etiologia , Inoculação de Neoplasia , Recuperação de Sangue Operatório/instrumentação , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Estudos Retrospectivos , Análise de Sobrevida , Resultado do Tratamento , Neoplasias da Bexiga Urinária/mortalidade , Neoplasias da Bexiga Urinária/patologia
3.
Chemosphere ; 245: 125618, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31855749

RESUMO

Semi-aerobic aged refuse biofilters (SAARB) are known to efficiently remove organic matter, nitrogenous substances, and anions from landfill leachate. However, long-term recirculation of mature landfill leachate inevitably leads to accumulation of pollutants and decreases treatment capacity. In this study, the washing action provided by domestic sewage was used to recover and even enhance the treatment performance of SAARBs treating mature landfill leachate. Three SAARB columns were operated for 300 d after which a "Recirculation-Washing-Recirculation" sequence was followed. In the first recirculation period (22 d), removal of chemical oxygen demand (COD) and total nitrogen (TN) decreased from ca. 90% and 60%, respectively, initially to about 75% and less than 20%, respectively. Thereafter, washing (20 d) of the SAARBs was accomplished by applying domestic sewage. In the subsequent second recirculation period (30 d), the SAARBs were operated at the same hydraulic loading as used initially, but achieved high (ca. 90%) COD and relatively high (ca. 59%-76%) TN removal, including degradation of refractory organic matter such as humic- and fulvic-like substances. Overall, the mechanisms of the treatment performance recovery (including organics degradation and nitrification-denitrification) using domestic sewage can be attributed to three main effects: (1) some accumulated pollutants were washed out, thereby leading to recovery of the adsorption ability of aged refuse; (2) the inhibition of bio-refractory organics stress on microbial activities was mitigated by domestic sewage washing; and (3) the wash out of some accumulated salts (e.g., chloride and sulfate ions) probably helped the microbial activity recover.


Assuntos
Filtração/métodos , Membranas Artificiais , Eliminação de Resíduos/métodos , Esgotos , Poluentes Químicos da Água/isolamento & purificação , Benzopiranos/metabolismo , Análise da Demanda Biológica de Oxigênio , Reatores Biológicos , Desnitrificação , Filtração/instrumentação , Filtração/normas , Substâncias Húmicas/microbiologia , Microbiota , Esgotos/microbiologia
4.
Indoor Air ; 30(2): 315-325, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31845406

RESUMO

High-efficiency filtration in residential forced-air heating, ventilation, and air conditioning (HVAC) systems protects equipment and can reduce exposure to particulate matter. Laboratory tests provide a measure of the nominal efficiency, but they may not accurately reflect the in situ efficiency of the filters because of variations in system conditions and changes in filter performance over time. The primary focus of this paper is to evaluate the effective filtration efficiency, which is inclusive of any loading and system impacts, in 21 occupied residential homes through in-duct concentration measurements. We considered the role of filter media by testing both electret and non-electret media, as well as the role of loading by considering new and used filters. The results show that filters with higher nominal efficiency generally had higher effective filtration efficiency in the same home. In terms of performance change, there is no significant difference in efficiency between initial and 3-month non-electret filters, but the efficiency of electret filters generally decreased over time. However, both nominal efficiency and performance change were vastly overshadowed by the wide variety in loading and system conditions across homes, making it hard to predict filter efficiency in a given home without in situ measurements.


Assuntos
Ar Condicionado/métodos , Filtros de Ar , Poluição do Ar em Ambientes Fechados/análise , Ventilação/métodos , Poluição do Ar em Ambientes Fechados/estatística & dados numéricos , Monitoramento Ambiental , Filtração/instrumentação , Calefação/instrumentação
5.
Chemosphere ; 245: 125604, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31855755

RESUMO

Environmental pollution caused by antimony (Sb) has attracted worldwide attention recently. Here, we employed a flow-through electro-Fenton system for the rapid and efficient detoxification of highly toxic Sb(III). A FeOCl modified carbon nanotube (CNT) filter served as functional cathode, where FeOCl as nanocatalyst promoted the generation of HO by facilitating effective Fe3+/Fe2+ cycling. Upon application of a proper potential, an ultra-rapid conversion of Sb(III) to less toxic Sb(V) can be achieved in situ just by a single-pass filtration (>99% within 2 s). Compared with the conventional batch reactor, the proposed system demonstrated ultra-rapid Sb(III) detoxification kinetics due to the convection-enhanced mass transport. The proposed flow-through E-Fenton system works effectively across a wide pH range (e.g., 3-9). EPR technique and radical quenching experiments indicate that HO and HO2 were the dominant radical species responsible for Sb(III) detoxification. At -0.4 V vs. Ag/AgCl, a >96.4% Sb(III) conversion efficiency still can be achieved when challenged with 500 µg L-1 Sb(III)-spiked tap water. The as-produced Sb(V) can be removed effectively by another Sb(V)-specific CNT filter functionalized with nanoscale iron oxides. The outcome of this research provides a promising strategy by integrating state-of-the-art electro-Fenton, membrane separation, carboncatalysis and nanotechnology for detoxification of Sb(III) and other similar heavy metal ions in polluted water.


Assuntos
Antimônio/química , Técnicas Eletroquímicas/métodos , Filtração/métodos , Peróxido de Hidrogênio/química , Ferro/química , Poluentes Químicos da Água/química , Antimônio/isolamento & purificação , Eletrodos , Compostos Férricos/química , Filtração/instrumentação , Radical Hidroxila/química , Compostos de Ferro/química , Cinética , Nanotubos de Carbono/química , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/métodos
6.
PLoS One ; 14(12): e0226354, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31856253

RESUMO

The self-cleaning screen filter is one of the most common types used in drip irrigation systems. Backwashing pressure difference and backwashing time for two screen filters with one geometry and two different screens (178 µm and 124 µm) using two water qualities (tap water and sand-water mixture) were studied in a total of 88 runs (42 runs for tap water, 22 and 24 filtration cycles for sand-water mixture and backwashing, respectively). The backwashing pressure difference and backwashing time were calculated using the experimental data, and the results were largely in the range of measured values. Three constraint conditions (flowrate, sand condition and filtration time) of backwashing pressure difference were analysed, and the optimal values of backwashing pressure difference were given as 60.0 and 70.0 kPa for 178 µm and 124 µm filters, respectively. The backwashing time of the screen filter should be an optimal value that ensures that the pressure difference between the internal and external surfaces of the screen decreased to the initial value, and the sand concentration of the backwashed outlet decreased to a small, stable value. Based on the results of the backwashing experiment and prototype observation, the optimal backwashing time was given as 30 to 45 s for both screen filters.


Assuntos
Filtração/instrumentação , Reatores Biológicos , Pressão , Fatores de Tempo , Qualidade da Água
7.
Nat Commun ; 10(1): 5762, 2019 12 17.
Artigo em Inglês | MEDLINE | ID: mdl-31848349

RESUMO

Perfluorinated alkyl substances, such as perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), are toxic materials that are known to globally contaminate water, air, and soil resources. Strategies for the simultaneous detection and removal of these compounds are desired to address this emerging health and environmental issue. Herein, we develop a type of guanidinocalix[5]arene that can selectively and strongly bind to PFOS and PFOA, which we use to demonstrate the sensitive and quantitative detection of these compounds in contaminated water through a fluorescent indicator displacement assay. Moreover, by co-assembling iron oxide nanoparticle with the amphiphilic guanidinocalix[5]arene, we are able to use simple magnetic absorption and filtration to efficiently remove PFOS and PFOA from contaminated water. This supramolecular approach that uses both molecular recognition and self-assembly of macrocyclic amphiphiles is promising for the detection and remediation of water pollution.


Assuntos
Ácidos Alcanossulfônicos/análise , Calixarenos/química , Caprilatos/análise , Fluorcarbonetos/análise , Tensoativos/química , Poluentes Químicos da Água/análise , Absorção Fisico-Química , Ácidos Alcanossulfônicos/isolamento & purificação , Caprilatos/isolamento & purificação , Monitorização de Parâmetros Ecológicos/métodos , Poluição Ambiental/prevenção & controle , Compostos Férricos/química , Filtração/instrumentação , Filtração/métodos , Fluorcarbonetos/isolamento & purificação , Nanopartículas de Magnetita/química , Água/análise , Água/química , Poluentes Químicos da Água/isolamento & purificação , Poluição Química da Água/prevenção & controle
8.
Radiol Med ; 124(12): 1238-1252, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31630332

RESUMO

Cardiovascular computer tomography (CT) in pediatric congenital heart disease (CHD) patients is often challenging. This might be due to limited patient cooperation, the high heart rate, the complexity and variety of diseases and the need for radiation dose minimization. The recent developments in CT technology with the introduction of the third-generation dual-source (DS) dual-energy (DE) CT scanners well suited to respond to these challenges. DSCT is characterized by high-pitch, long anatomic coverage and a more flexible electrocardiogram-synchronized scan. DE provides additional clinical information about vascular structures, myocardial and lung perfusion and allows artifacts reduction. These advances have increased clinical indications and modified CT protocol for pediatric CHD patients. In our hospital, DSCT with DE technology has rapidly become an important imaging technique for both pre- and postoperative management of pediatric patients with CHDs. The aim of this article is to describe the state-of-the-art in DSCT protocol with DE technology in pediatric CHD patients, providing some case examples of our experience over an 18-month period.


Assuntos
Cardiopatias Congênitas/diagnóstico por imagem , Imagem Radiográfica a Partir de Emissão de Duplo Fóton/métodos , Tomografia Computadorizada por Raios X/métodos , Artefatos , Criança , Pré-Escolar , Meios de Contraste/administração & dosagem , Filtração/instrumentação , Frequência Cardíaca , Humanos , Lactente , Recém-Nascido , Movimentos dos Órgãos , Doses de Radiação , Imagem Radiográfica a Partir de Emissão de Duplo Fóton/instrumentação , Respiração , Tomografia Computadorizada por Raios X/instrumentação
9.
J Med Eng Technol ; 43(4): 248-254, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31478761

RESUMO

Postpartum haemorrhage (PPH), the leading cause of maternal mortality, is particularly problematic in low resource settings where access to safe blood supplies and definitive medical treatment is limited. We describe the continued development of an autotransfusion device designed to treat PPH by collection, filtration and infusion of maternal blood. Previous study has demonstrated that the device effectively moves blood through a filtration apparatus and removes up to 97% of aerobic bacteria but had poor anaerobic bacteria reduction. In this study, we investigate the filtration efficacy of the device using configurations comprised of three different leukocyte depletion filter designs: the Pall Leukoguard RS leukocyte reduction filter (PLRF), the Haemonetics BPF4™ (BPF4) leukocyte reduction filter, and the Haemonetics SCRC Leukotrap® (SCRC) filter. All configurations performed well with reductions ranging from 49 to 98%. Configurations containing 2 Haemonetics SCRC Leukotrap®filters (configuration 5 and 6) consistently reduced anaerobic bacteria by at least 73%. These results indicate that utilising a combination of SCRC and PLRF filters confers a high level of microbial filtration with improved removal of anaerobic organisms.


Assuntos
Transfusão de Sangue Autóloga/instrumentação , Filtração/instrumentação , Bactérias Anaeróbias , Feminino , Humanos , Leucócitos , Hemorragia Pós-Parto/terapia , Gravidez
10.
Undersea Hyperb Med ; 46(4): 447-459, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31509901

RESUMO

Introduction: The mining and tunneling industries are historically associated with hazardous exposures that result in significant occupational health concerns. Occupational respiratory exposures causing pneumoconiosis and silicosis are of great concern, silicosis being non-curable. This work demonstrates that compressed-air workers (CAWs) performing tunnel hyperbaric interventions (HIs) may be at risk for hazards related to bentonite exposure, increasing the likelihood of developing harmful illnesses including cancer. Bentonite dust inhalation may result in respiratory levels of silica exceeding acceptable industrial hygiene standards. Methods: A qualitative observational exposure assessment was conducted on CAWs while they were performing their HI duties. This was followed by quantitative data collection using personal and area air sample techniques. The results were analyzed and interpreted using standard industrial hygiene principles and guidelines from NIOSH and OSHA. Results: Our work suggests bentonite dust exposure may be an emerging particulate matter concern among CAWs in the tunneling industry. Aerosolized bentonite particles may have potential deleterious effects that include pneumoconiosis and silicosis. Silicosis can result in the development of pulmonary carcinoma. Conclusions: The modern tunneling industry and required hyperbaric interventional tasks represent a potential public health and occupational concern for CAWs. This paper introduces the modern tunneling industry and the duties of CAWs, the hazardous environment in which they perform their duties, and describes the risks and potential harmful health effects associated with these hazardous exposures.


Assuntos
Bentonita/toxicidade , Ar Comprimido , Materiais de Construção/toxicidade , Poeira , Arquitetura de Instituições de Saúde , Exposição Ocupacional/efeitos adversos , Poluentes Ocupacionais do Ar/química , Poluentes Ocupacionais do Ar/toxicidade , Bentonita/química , Indústria da Construção , Materiais de Construção/análise , Segurança de Equipamentos , Filtração/instrumentação , Humanos , Pressão , Pesquisa Qualitativa , Dispositivos de Proteção Respiratória , Estados Unidos , United States Occupational Safety and Health Administration/normas
11.
Environ Sci Pollut Res Int ; 26(30): 30731-30754, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31494849

RESUMO

Surfactants widely exist in various kinds of wastewaters which could be treated by pressure-driven membrane separation (PDMS) techniques. Due to the special characteristics of surfactants, they may affect the performance of membrane filtration. Over the last two decades, there are a number of studies on treating wastewaters containing surfactants by PDMS. The current paper gives a review of the roles of surfactants in PDMS processes. The effects of surfactants on membrane performance were discussed via two aspects: influence of surfactants on membrane fouling and enhanced removal of pollutants by surfactants. The characteristics of surfactants in solution and at solid-liquid interface were summarized. Surfactants in membrane filtration processes cause membrane fouling mainly through adsorption, concentration polarization, pore blocking, and cake formation, and fouling degree may be influenced by various factors (feed water composition, membrane properties, and operation conditions). Furthermore, surfactants may also have a positive effect on membrane performance. Enhanced removal of various kinds of pollutants by PDMS in the presence of surfactants has been summarized, and the removal mechanism has been revealed. Based on the current reports, further studies on membrane fouling caused by surfactants and enhanced removal of pollutants by surfactant-aided membrane filtration were also proposed.


Assuntos
Filtração/métodos , Membranas Artificiais , Tensoativos/química , Eliminação de Resíduos Líquidos/instrumentação , Eliminação de Resíduos Líquidos/métodos , Adsorção , Incrustação Biológica , Filtração/instrumentação , Águas Residuárias/química , Poluentes Químicos da Água/química , Purificação da Água/métodos
12.
J Agric Food Chem ; 67(39): 10977-10983, 2019 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-31490679

RESUMO

In this study, an analytical method was developed and validated for simultaneous determination of five diamide insecticides (chlorantraniliprole, cyantraniliprole, flubendiamide, cyclaniliprole, and tetrachlorantraniliprole) in food matrices. Determination of the latter two diamide compounds is first reported. Samples were cleaned up by multiplug filters containing carbon nanotubes (CNT) or hydrophilic-lipophilic balanced copolymers (HLB) and classic dispersive solid phase extraction (d-SPE) procedures, respectively. The CNT multiplug filter performed the best in terms of process rapidity and cleanup efficiency; thus, it was finally chosen for sample cleanup. Instrumental analysis was completed in 5 min using ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Mean recoveries of the five diamides ranged from 84.3 to 110.0%, with intraday and interday relative standard deviations (RSD) of less than 13.5%. Limits of quantitation (LOQ) of all analytes ranged from 0.005 to 0.01 mg kg-1 in different matrices. The results indicate this method is reliable for monitoring the five diamide insecticides in various foods.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Diamida/química , Filtração/métodos , Contaminação de Alimentos/análise , Inseticidas/química , Resíduos de Praguicidas/química , Espectrometria de Massas em Tandem/métodos , Diamida/isolamento & purificação , Filtração/instrumentação , Inseticidas/isolamento & purificação , Nanotubos de Carbono/química , Resíduos de Praguicidas/isolamento & purificação
13.
Molecules ; 24(18)2019 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-31540285

RESUMO

Studies on the functionalization of materials used for the construction of filtering facepiece respirators (FFRs) relate to endowing fibers with biocidal properties. There is also a real need for reducing moisture content accumulating in such materials during FFR use, as it would lead to decreased microorganism survival. Thus, in our study, we propose the use of superabsorbent polymers (SAPs), together with a biocidal agent (biohalloysite), as additives in the manufacturing of polypropylene/polyester (PP/PET) multifunctional filtering material (MFM). The aim of this study was to evaluate the MFM for stability of the modifier's attachment to the polymer matrix, the degree of survival of microorganisms on the nonwoven, and its microorganism filtration efficiency. Scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy were used to test the stability of the modifier's attachment. The filtration efficiency was determined under conditions of dynamic aerosol flow of S. aureus bacteria. The survival rates (N%) of the following microorganisms were assessed: Escherichia coli and Staphylococcus aureus bacteria, Candida albicans yeast, and Aspergillus niger mold using the AATCC 100-2004 method. FTIR spectrum analysis confirmed the pre-established composition of MFM. The loss of the active substance from MFM in simulated conditions of use did not exceed 0.02%, which validated the stability of the modifier's attachment to the PP/PET fiber structure. SEM image analysis verified the uniformity of the MFM structure. Lower microorganism survival rates were detected for S. aureus, C. albicans, and E. coli on the MFM nonwoven compared to control samples that did not contain the modifiers. However, the MFM did not inhibit A. niger growth. The MFM also showed high filtration efficiency (99.86%) against S. aureus bacteria.


Assuntos
Desinfetantes/farmacologia , Viabilidade Microbiana/efeitos dos fármacos , Polipropilenos/síntese química , Aspergillus niger/efeitos dos fármacos , Aspergillus niger/crescimento & desenvolvimento , Candida albicans/efeitos dos fármacos , Candida albicans/crescimento & desenvolvimento , Desinfetantes/química , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Filtração/instrumentação , Microscopia Eletrônica de Varredura , Polímeros , Polipropilenos/química , Dispositivos de Proteção Respiratória/microbiologia , Espectroscopia de Infravermelho com Transformada de Fourier , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento
14.
Chemosphere ; 237: 124544, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31549656

RESUMO

This study evaluated the effects of co-existing cations (Na+ or Ca2+) on the lamellar structure of cross-linked graphene oxide (GO) layers and GO modified membrane performance in terms of their fouling behaviours and retention for single-model organic matter, namely, bull serum albumin (BSA), sodium alginate (SA), humic acid (HA) and tannic acid (TA). In the absence of co-existing cations, the GO layers mitigated membrane fouling for large molecules (SA, BSA, and HA) but led to severer pore blocking for small molecules (TA) compared with pristine membrane. Na+ and Ca2+ altered the performance impacts of the GO modified membrane due to different interactions with the cross-linked GO layers. Low concentrations of Na+ (<0.4 mM) enlarged interlayer spacing of the GO layers and caused a decrease in flux after physical cleaning, but the GO layers maintained the uniform lamellar structure. High concentrations of Na+ (>0.4 mM) promoted the aggregation of cross-linked GO layers through charge shielding and reduced the uniformity of lamellar structure, which weakened the antifouling performance for large molecules and promoted the passage of small molecules through the membrane. However, Ca2+ complexed with GO sheets and reinforced the uniform lamellar structure of the GO layers, leading to a better antifouling performance for the filtration of large molecules than the pristine membrane but aggravated TA fouling.


Assuntos
Cátions Bivalentes/química , Filtração/métodos , Grafite/química , Membranas Artificiais , Purificação da Água/instrumentação , Alginatos/química , Incrustação Biológica/prevenção & controle , Reagentes para Ligações Cruzadas/química , Filtração/instrumentação , Substâncias Húmicas , Óxidos/química , Tamanho da Partícula , Polivinil/química , Soroalbumina Bovina/química , Purificação da Água/métodos
15.
Strabismus ; 27(2): 78-87, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31379274

RESUMO

Purpose: The purpose of this study is to determine whether the Sbisa bar (Sbisa Ophthalmic Instruments) (referred to in this article as the BF(Sbisa) bar) and Bagolini Filter bar (C.O.I. Vision) (referred to in this article as the BF(new) bar) are repeatable and comparable, for measuring density of suppression or strength of abnormal binocular single vision (BSV), in a pediatric population. Methods: Using a spot photometer, percentage light transmittance of filters on two BF(Sbisa) bars and two BF(new) bars was measured. Thirty-three participants aged 5-12 years with unilateral strabismus were recruited. Density of suppression or strength of abnormal BSV was measured with two of each bar, in addition to a repeated measure with one of each bar. Results: Light transmittance did not reduce consistently with increasing filter number (the number assigned to each filter by the manufacturer). Using data as filter numbers, a BF(Sbisa) bar was not comparable to a BF(new) bar (ᵶ = -3.936, p < 0.001, r = -0.28); different BF(Sbisa) bars were not comparable (ᵶ = -3.103, p = 0.005, r = -0.22) but different BF(new) bars were comparable (ᵶ = -1.165, p = 1.285, r = -0.08). Using light transmittance values, a BF(Sbisa) bar was comparable to a BF(new) bar (ᵶ = -0.385, p = 3.535, r = -0.03); different BF(Sbisa) bars were comparable (ᵶ = -1.476, p = 0.720, r = -0.10) but different BF(new) bars were not comparable (ᵶ = -3.354, p < 0.001, r = -0.24). The BF(Sbisa) and BF(new) bars were not repeatable using filter numbers (ᵶ = -3.648, p < 0.001, r = -0.26 and ᵶ = -3.099, p = 0.005, r = -0.22, respectively) or light transmittance values (ᵶ = -3.743, p < 0.001, r = -0.27 and ᵶ = -2.727, p = 0.025, r = -0.19, respectively). An order effect existed using filter numbers (ᵶ = -4.473, p < 0.001, r = -0.32) and light transmittance values (ᵶ = -4.525, p < 0.001, r = -0.32). Conclusion: There is a need for the production of bars with consistently reducing and comparable light transmittance of filters if measurement of density of suppression or strength of abnormal BSV with filter bars is to continue, because the current bars show inconsistencies, particularly at lower filter numbers. In the meantime, the bars are limited by their lack of comparability or repeatability. Using only BF(new) bars is preferable to using BF(Sbisa) bars or a mixture of the two types of bar because two different BF(new) bars may be comparable using filter number readings, but filter number readings from different BF(Sbisa) bars or from a BF(Sbisa) and BF(new) bar are not comparable. As the BF(Sbisa) and BF(new) bars are currently labeled, a second measure of density of suppression or strength of abnormal BSV is not recommended within 2 min of an initial measurement, because the measurement procedure seems to cause a reduction in suppression or abnormal BSV that does not recover with repeated measurements 2 min apart.


Assuntos
Ambliopia/terapia , Diplopia/prevenção & controle , Óculos , Filtração/instrumentação , Luz , Ortóptica/instrumentação , Criança , Pré-Escolar , Estudos Transversais , Feminino , Humanos , Fotometria , Estudos Prospectivos , Visão Binocular/fisiologia
16.
Optom Vis Sci ; 96(7): 513-522, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31274740

RESUMO

SIGNIFICANCE: We investigated, for safety and awareness, ultraviolet and high-energy violet light-blocking protection provided by assorted types of eyewear. Ultraviolet and high-energy violet light-filtering efficiency varied and did not correlate with price or advertised claims. Standardization of methods and specifications for lens spectral transmission evaluation is recommended. PURPOSE: Studies have linked exposure of high-energy visible blue light to effect and damage on retinal epithelial cells, photoreceptors, and ganglion cells. "Blue light" is more accurately differentiated into "high-energy visible blue-violet light" and "circadian rhythm blue-turquoise light." This study measured and compared spectral transmission of ultraviolet and high-energy violet light of low-, medium-, and high-priced sunglasses. METHODS: Sunglasses and lens blanks were obtained from the University of Texas Medical Branch Optical Shop and vendors. Groups were based on promotional, retail, designer sunglasses, or "blue blocker" lenses. The percent transmittance of ultraviolet/visible spectral scans (800 to 350 nm) was measured using an Agilent Cary 50 spectrophotometer. High-energy violet/blue light was defined as 400 to 450 nm. RESULTS: Promotional sunglasses (tinted polycarbonate) blocked 100% ultraviolet and 67 to 99.8% high-energy violet blue light. Retail sunglasses filtered out 95 to 100% ultraviolet A and 67% high-energy violet light. The tested designer sunglasses varied widely in their optical transmissibility with respect to their ultraviolet A and high-energy violet light-blocking properties, with some not blocking ultraviolet A. Clear and colorless Kodak Total Blue provided maximal high-energy violet protection, whereas clear Essilor Crizal Prevencia provided less high-energy violet blocking between 400 and 450 nm. CONCLUSIONS: The ultraviolet and high-energy violet (400 to 450 nm) light-filtering efficiency varied between sunglasses and clear lenses and did not correlate with price or advertised claims. Standardization of methods and specifications for lens spectral transmission evaluation is recommended.


Assuntos
Óculos , Filtração/instrumentação , Luz , Proteção Radiológica/instrumentação , Raios Ultravioleta , Humanos , Cristalino/efeitos da radiação , Lesões por Radiação/prevenção & controle , Proteção Radiológica/normas , Retina/efeitos da radiação , Análise Espectral
17.
J Environ Sci (China) ; 84: 166-173, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31284908

RESUMO

The primary purpose of this study was to investigate the effect of a catalyzed continuously regenerating trap (CCRT) system composed of a diesel oxidation catalyst (DOC) and a catalyzed diesel particulate filter (CDPF) on the main gaseous and particulate emissions from an urban diesel bus, as well as the durability performance of the CCRT system. Experiments were conducted based on a heavy chassis dynamometer, and a laboratory activity test as well as X-ray photoelectron spectroscopy (XPS) test were applied to evaluate the changes of the aged CCRT catalyst. Results showed that the CCRT could reduce the CO by 71.5% and the total hydrocarbons (THC) by 88.9%, and meanwhile promote the oxidation of NO. However, the conversion rates for CO and THC dropped to 25.1% and 55.1%, respectively, after the CCRT was used for one year (~60,000 km), and the NO oxidation was also weakened. For particulate emissions, the CCRT could reduce 97.4% of the particle mass (PM) and almost 100% of the particle number (PN). The aging of the CCRT resulted in a reduced PM trapping efficiency but had no observable effect on the PN; however, it increased the proportion of nucleation mode particles. The activity test results indicated that the deterioration of the CCRT was directly relevant to the increase in the light-off temperatures of the catalyst for CO, C3H8 and NO2. In addition, the decreased concentrations of the active components Pt2+ and Pt4+ in the catalyst are also important factors in the CCRT deterioration.


Assuntos
Filtração/instrumentação , Emissões de Veículos/prevenção & controle , Monóxido de Carbono/análise , Catálise , Hidrocarbonetos/análise , Óxidos de Nitrogênio/análise , Material Particulado/análise , Emissões de Veículos/análise
18.
Nutr Hosp ; 36(4): 764-768, 2019 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-31271291

RESUMO

Introduction: Objective: we found a black precipitate during the infusion of a parenteral nutrition without lipids. The objective of this study is to check the composition of the precipitate and the influence of the type of amino acids in its formation. Methods: four PN bags were prepared with the following composition: 1 l of amino acids solution, 150 g glucose, 60 mEq potassium, 217 mEq chloride, 105 mEq sodium, 15 mEq magnesium, 15 mEq calcium, 18.63 mmol phosphorus and trace elements (Addamel®). Each bag was prepared using a different type of amino acids solution with different amount of cysteine per litre: Tauramin® 10% (0.5 g/l), Primene® 10% (1.89 g/l), Tauramin® 12.6% (0.62 g/l) or Synthamin® 10% (0 g/l). Tauramin® 10% and Primene® 10% were packaged in glass containers whereas Tauramin® 12.6% and Synthamin® 10%, in plastic. The contents of each bag were filtered using Pall NEO96E 0.2 micron filters. A 2.25% area of each filter was observed by scanning electron microscopy at 100x magnification. The analysis by energy dispersive spectroscopy (EDS) was performed at 1,000x magnification. Results: in the Primene® 10% and Tauramin® 10% filters, a greater amount of precipitate was observed than with Tauramin® 12.6% and Synthamin® 10%. The percentage of copper and sulphur in each area of the filters studied was, respectively, 22.9% and 11.5% (Primene® 10%), 19.3% and 9.6% (Tauramin® 10%), 3.7% and 0% (Tauramin® 12.6%), 2.5% y 0% (Synthamin® 10%). Conclusions: the observed precipitate contains copper and sulphur. Precipitate formation occurs in high cysteine content amino acids solutions packaged in glass containers. It is important to use filters in the administration of PN to ensure that this type of precipitates are retained and do not pass to the patient. Key words.


Assuntos
Aminoácidos/química , Precipitação Química , Cobre/análise , Cisteína , Eletrólitos/química , Glucose/química , Soluções de Nutrição Parenteral/química , Nutrição Parenteral , Enxofre/análise , Cor , Filtração/instrumentação , Soluções/química , Análise Espectral/métodos , Oligoelementos
19.
Environ Int ; 131: 104998, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31330365

RESUMO

The omnipresence of filterable bacteria that can pass through 0.22-µm membrane filters demands a change in the sterile filtration practice. In this study, we identified that filterable bacteria enriched from a surface water are members of the Bacteroidetes, Proteobacteria, Spirochaetae, Firmicutes, and Actinobacteria. Filterable bacteria displayed superior filterability during the entire bacterial growth phase, especially at the exponential phase. Maximal passage percentages were comparable at different cell densities, and achieved earlier at high cell density. Furthermore, filter retention for the investigated bacteria is independent of liquid temperature. However, cultivation temperature could affect the growth of some specific filterable bacteria and lead to variability in the passage percentage. Additionally, membrane materials, pore size and filtering flux greatly affected the passage of filterable bacteria. The majority of filterable Hylemonella and SAR324 could pass through 0.1-µm polyvinylidene fluoride and polyethersulfone filters but could not pass through 0.1-µm polycarbonate and mixed cellulose esters filters. Taken together, our results demonstrated that the ultra-small size of filterable bacteria, membrane characteristics and filtration operational conditions could challenge the validity of the 0.22/0.1-µm sterilizing grade filters in providing bio-safety barriers.


Assuntos
Bactérias/isolamento & purificação , Filtração , Microbiologia da Água , Purificação da Água/métodos , Abastecimento de Água , Filtração/instrumentação , Esterilização
20.
Food Chem ; 300: 125168, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31330368

RESUMO

This study reports a clear-cut relationship of the technological use of specific filter aids with highly variable vanadium levels in beer, wine, and fruit juices. First, the previously reported broad range of vanadium levels was confirmed in 68 commercial beverages by ICP-MS. Since cloudy apple juices exhibited significantly lower vanadium amounts than clear apple juices, filter aids used for clarification were analyzed and found to contain substantial and highly variable amounts of vanadium, particularly in all analyzed diatomite (38-368 mg vanadium per kg filter aid), but not in perlite products (<4 mg/kg). Subsequent pilot-scale precoat filtration experiments (170 L/batch) proved vanadium to be released from diatomite (Kieselguhr), increasing its levels from ca. 2.1-2.6 µg/kg unfiltered to 27-201 µg/kg filtered juice, depending on the use of diatomites high or low in vanadium. Thus, filter aid selection was shown to modulate the vanadium concentrations in clarified beverages.


Assuntos
Bebidas/análise , Filtração/instrumentação , Vanádio/análise , Óxido de Alumínio , Cerveja/análise , Terra de Diatomáceas/análise , Terra de Diatomáceas/química , Filtração/métodos , Contaminação de Alimentos/análise , Sucos de Frutas e Vegetais/análise , Malus , Dióxido de Silício , Vinho/análise
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