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1.
J Environ Manage ; 370: 122713, 2024 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-39368380

RESUMO

This study investigates the effectiveness of coagulation-flocculation and sedimentation (CFS) for separating microalgae, focusing on the use of various Moringa oleifera extracts as natural coagulants. We examined photobioreactor effluent (PBR) both with and without microplastic PVC (MP-PVC) contamination, referred to as PBR R2 and PBR R1, respectively. Utilising response surface methodology, we identified optimal conditions for the removal of microalgae and MP-PVC. Validation tests demonstrated that the aqueous extract of delipidated Moringa oleifera powder (AEDMOP) achieved high removal efficiencies, with coagulant dosages of 630 mg L-1 for PBR R1 and 625 mg L-1 for PBR R2. Both conditions showed microalgae removal efficiencies exceeding 83% for turbidity, colour, OD540 nm, OD680 nm, and OD750 nm, and 63% for OD254 nm. Interestingly, the optimised conditions for PBR R2 required slightly less coagulant, likely due to the additional particulate matter from MP-PVC. While extracellular polymeric substances (EPS) exhibited a marginal effect on flocculation, further investigation into their role in CFS is necessary. Our findings highlight the potential of AEDMOP for efficient microalgae separation, even in the presence of microplastics.

2.
World J Microbiol Biotechnol ; 40(1): 6, 2023 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-37932532

RESUMO

Urinary tract infections (UTIs) are a significant cause of morbidity in healthcare systems and are prominently associated with applying urethral catheters, particularly in surgeries. Polyvinyl chloride (PVC) is extensively utilized in the fabrication of catheters. Biofilms, complex polymeric constructions, provide a protective milieu for cell multiplication and the enhancement of antibiotic resistance. Strategies to counteract biofilm development on medical apparatuses' surfaces incorporate antimicrobial agents such as N,N-dodecyl, and methyl polyethylenimine (DMPEI). This research endeavored to characterize the morphology of PVC and PVC-DMPEI surfaces utilizing Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) and to gauge hydrophobicity through contact angle measurements. Employing Escherichia coli, Staphylococcus aureus, and Candida albicans in adhesion assays enabled the assessment of DMPEI's efficacy in preventing microbial adherence to PVC. Butanol successfully solubilized 2 mg.mL-1 DMPEI without altering the PVC structure. SEM results substantiated the formation of a DMPEI layer on the PVC surface, which led to decreased surface roughness, as validated by AFM, and increased hydrophilicity, as demonstrated by contact angle evaluations. E. coli, S. aureus, and C. albicans exhibited significant adhesion reduction, 89.3%, 94.3%, and 86.6% on PVC-DMPEI surfaces. SEM visualizations confirmed reduced cellular colonization on PVC-DMPEI and highlighted considerable morphological modifications in E. coli. Consequently, DMPEI films effectively minimize the adhesion of E. coli, S. aureus, and C. albicans on PVC surfaces. DMPEI, with its potential as a protective coating for innovative medical devices, promises to inhibit biofilm adherence effectively.


Assuntos
Escherichia coli , Polietilenoimina , Polietilenoimina/farmacologia , Staphylococcus aureus , Catéteres , Biofilmes , Candida albicans
3.
Materials (Basel) ; 16(21)2023 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-37959529

RESUMO

PVC is widely used in packaging, electrical insulation, and medical devices due to its versatility owing to its resistance, incombustible and barrier properties as well as affordable cost. In the present study, bibliometric and co-occurrence analyses are proposed to identify trends, gaps, future directions, and challenges regarding process system engineering (PSE) applied to the production process of PVC using VOSviewer as a tool for analyzing the data obtained from SCOPUS. A mapping of different topics alluding to simulation of PVC production was provided to gain a better insight into the development of the topic and its progression. The findings indicate that the literature on this topic falls into five different clusters: modeling and simulation of PVC production, process control and optimization, and optimization strategies of the process. From a co-occurrence study we identified that mathematics and statistics applied to polymer chemistry, separation phenomena, and polymer production are the main areas of interest for further research. The trends suggest that Monte Carlo and numerical simulation can contribute to a deeper understanding of PVC's properties and behavior. In addition, the focus on plastics and microplastics reflects concerns about the environmental impact. A bibliometric study evidenced that PSE provides the tools for improvement in PVC production processes by employing advanced process engineering techniques. Modelling and new algorithms for simulation methods of continuous polymerization processes are important to enhance accuracy and efficiency across various applications. The study also proposes a research agenda for future researchers working in the field of the use of PSE applied to the PVC production process.

4.
Polymers (Basel) ; 15(13)2023 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-37447548

RESUMO

The new demands for sustainable operation in the chemical industry due to increasing environmental regulations and agreements have generated the need to adapt existing processes to more intelligent production. The plastics sector is in a complex position due to its contribution to economic development and the climate crisis. Therefore, environmental assessment has become an important tool due to the benefits it provides by quantifying the environmental performance of processes, allowing it to balance operational and environmental needs. Polyvinyl chloride (PVC) is one of the most globally used polymers thanks to its resistance, flexibility, and cost-effectiveness. The polymer is synthetized by suspension polymerization, which is characterized by high productivity and controllability. However, it presents problems associated with intensive energy consumption and the emission of toxic substances and greenhouse gases. Therefore, an environmental assessment of the suspension PVC production process was performed using the waste reduction algorithm (WAR). The potential environmental impact (PEI) was quantified using the generation rate and the output velocity for four cases and three different fuels. It was found that the process transforms raw materials with high impacts, such as VCM, into substances with lower PEI, such as PVC. However, the process has a high generation of PEI due to the effects of energy consumption (-2860, -2410, 3020, and 3410 for cases 1-4, respectively). The evaluation of the toxicological impacts shows that the ATP category is the only one that presents a positive generation value (75 PEI/day); the product contributes to the formation and emission of impacts. The atmospheric categories showed that the energy consumption of the process is the most critical aspect with a contribution of 91% of the total impacts emitted. The AP and GWP categories presented the highest values. It was determined that the most suitable fuel is natural gas; it has lower impacts than liquid and solid fuels (coal). Additionally, it can be concluded that the PVC production process by suspension is environmentally acceptable compared to the polyethylene or polypropylene processes, with output impacts 228 and 2561 times lower, respectively.

5.
MethodsX ; 9: 101710, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35601957

RESUMO

This paper proposes and develops a protocol for measuring the aerobic granulation potential of sludge, aiming to provide an affordable and simple alternative that can facilitate the development of aerobic granulation technology. In this sense, the protocol comprises a set of parameters and considerations that interact to create a controlled environment and stimulate cell population clustering. All of this is done in the context of procedural simplicity, low cost, and the speed at which results are obtained. The protocol is essentially a three-stage method: preparation of the substrate, adaptation of the inoculum, and implementation of the protocol. Simple parameters were measured to evaluate the granulation process: SVI, settling velocity, and morphological parameters. The protocol was validated according to optimal ranges and criteria previously established in the literature. For this purpose, an activated sludge inoculum from a domestic wastewater treatment plant was submitted to the protocol, obtaining an optimal response of the biomass (SVI5 =13.90 mL g-1, settling velocity= 25,79 m h-1, Diameter > 0.2 mm) in a relatively short time (7 d). The results show that this protocol can constitute a tool for evaluation and decision-making using traditional laboratory equipment and is applicable at different scales.

6.
Chemosphere ; 287(Pt 3): 132344, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34826954

RESUMO

Chlorinated paraffins (CPs) are chemicals with multipurpose applications. Their global production has increased despite their adverse impacts on the environment and human health. In 2017, short-chain chlorinated paraffins (SCCPs) were listed as persistent organic pollutants (POPs) in the Stockholm Convention. Yet, specific exemptions were granted for their applications despite the recycling prohibition for products containing SCCPs. Therefore, we aimed to produce the first Brazilian inventory of SCCPs following its respective guidance to evaluate the applicability of the SCCP inventory guidance and to provide technical insights regarding SCCPs in the update of the Brazilian National Implementation Plan (NIP). Moreover, we performed a review of SCCP occurrence in Brazil to fulfil data gaps in the inventory development. We identified and consulted nationwide stakeholders and assessed foreign trade data of CPs and products that might contain CPs in relevant amounts. The Brazilian production of CPs was discontinued in 1994. However, CPs are still imported and used in the country. CPs have been mostly applied as plasticizers, flame retardants and lubricants in Brazil. The import of products containing CPs also pose a significant route of CP entrance into Brazil. Thus, the current end-of-life management of CP-containing products is a bottleneck towards the Convention implementation. The guidance application was feasible and useful despite the low engagement of stakeholders. To assess foreign trade of CPs and CP-containing products, we recommend the use of more specific tracking codes. Besides, the review of SCCP occurrence is not a demanded part for an inventory but was a useful complementation.


Assuntos
Hidrocarbonetos Clorados , Parafina , Brasil , China , Monitoramento Ambiental , Humanos , Hidrocarbonetos Clorados/análise , Parafina/análise
7.
Arq. Inst. Biol. (Online) ; 89: e00372020, 2022. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1416900

RESUMO

The objective of this work is to evaluate the use of modified atmosphere and chitosan as an alternative to chemical treatment in postharvest conservation of 'Tainung 1' papaya under refrigeration. The experiment comprised of completely randomized blocks with four replications, one fruit per replication, with a 2 × 4 × 4 factorial design as follows: two types of packaging (with or without polyvinyl chloride [PVC] stretchable film, thickness of 17 µm), four treatments (control, 2% chitosan, 4% chitosan, and prochloraz fungicide with 33.75 g a.i.·100 L­1), and four storage periods (0, 7, 14, and 21 days) at 10 °C and relative humidity (RH) of 90 ± 5%. The variables evaluated were mass loss (ML), external appearance, titratable acidity (TA), soluble solids (SS), vitamin C, reducing sugars (RS), and total sugars (TS). The storage of 'Formosa' papaya under refrigeration at 10 °C and RH of 90 ± 5% associated with PVC provided a low percentage of ML and longer conservation time of apparent quality (up to 7 days) in relation to fruits with no storage in PVC. The external appearance of fruits was preserved for up to 14 days by the PVC + 4% chitosan treatment and for up to 21 days by the PVC + prochloraz fungicide treatment. The treatment PVC + 4% chitosan associated with refrigeration is efficient in maintaining fruit quality. It is, for up to 14 days, a viable alternative to the use of prochloraz fungicide for postharvest conservation of 'Formosa' papaya.


Assuntos
Cloreto de Polivinila , Carica , Quitosana , Alimentos Resfriados , Conservação de Alimentos/métodos
8.
J. health sci. (Londrina) ; 23(2): 145-148, 20210621.
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1283131

RESUMO

After a visit to a hydrotherapy laboratory, limited resources for use in lower limbs were noted. For this reason, the goal is to design a water bike from low-cost material. The process took place in three phases: (1) project carried out, (2) prototype construction and (3) bicycle construction. The confection was divided into six parts; the materials used were polyvinyl chloride (PVC) tubes for the construction of sewer system. In addition to PVC materials, other products were used: two plastic pedals; a gel saddle, a seat post, two cranksets, a pipe clamp, a central shaft, two industrial bearings, three 40-millimeter aluminum cylinders and four suction cups. The final product was measured 69 centimeters (cm) in width, 59.05 cm in length; as the seat can be adjusted, the height varies. The prototype ranges from 73 to 102 cm in height and supports up to 85 kilograms (kg). It is concluded that although there is a limitation as to the design of the final product due to the limited formats of the PVC connections and as to the adaptations that must be made so that the final product can support a considerable weight, it is feasible to make a low-cost water exercise bike using PVC as the main material that can be used in the pool. It is noteworthy, however, that this product will still be tested to ascertain functionality as for equipment for clinical practice. (AU)


Após a visita em um laboratório de hidroterapia denotou-se a limitação de recursos para membros inferiores. Devido a isso, o objetivo é elaborar uma bicicleta aquática de material de baixo custo. O processo se deu em três fases: (1) design realizado, (2) produção do protótipo e a (3) construção da bicicleta. A confecção foi dividida em seis partes; os materiais utilizados foram tubos de Policloreto de vinila (PVC) para esgoto predial. Além de materiais de PVC foram utilizados outros produtos: dois pedais de plástico; um selim de gel, um canote, dois pedivelas, uma braçadeira de tubo, um eixo central, dois rolamentos industriais, três cilindros de alumínios 40 milímetros e quatro ventosas. O produto final teve como medida 69 centímetros (cm) de largura, 59,05 cm de comprimento; como o banco pode ser regulado, a altura varia. o protótipo varia entre 73 a 102 cm de altura e suporta até 85 quilogramas. Conclui-se então que embora haja limitação quanto ao design do produto final por conta dos limitados formatos das conexões de PVC e quanto à adaptações que devem ser feitas para que o produto final consiga suportar um peso considerável, é viável a confecção de uma bicicleta ergométrica aquática de baixo custo utilizando o PVC como material principal e que pode ser utilizada na piscina. Destaca-se, entretanto, que este produto ainda será testado para averiguar a funcionalidade quanto equipamento para a prática clínica. (AU)

9.
Braz J Microbiol ; 52(3): 1397-1404, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33852152

RESUMO

Planctomycetes are bacteria found in several environments, such as mangroves. In the coastline of the State of Sao Paulo (Brazilian Southeast), mangroves occur in different stages of environmental contamination, promoted by the proximity to the city and industrial activities. One of these mangroves (located in the city of Bertioga) is characterized by the high impact due to past petroleum and ongoing urban contamination. We isolated five bacteria affiliated to Planctomycetes from this mangrove and further subjected them to phenotypical and genetic analysis. The tolerance for salinity was demonstrated by the cultivation under distinct concentrations of NaCl. The ability of this bacterium to use diverse carbon sources was revealed by the use of 30 C-sources from a total of 31 tests. We found the isolate Rhodopirellula sp. MGV very closely affiliated to species of the genus Rhodopirellula, harboring a genome with 7.16 Mbp and 55.3% of GC. The annotation of the 77 contigs resulted in 6.284 CDS, with a remarkable occurrence of sequences associated with aromatic carbon metabolism. In conclusion, we present the isolation and characterization of a Planctomycetes from mangroves, suggesting its participation in the degradation of hydrocarbons present in the contaminated mangroves studied.


Assuntos
Hidrocarbonetos , Planctomycetales , Poluição Química da Água , Bactérias , Brasil , Carbono , Genômica , Hidrocarbonetos/metabolismo , Filogenia , Planctomycetales/genética , Planctomycetales/metabolismo , Áreas Alagadas
10.
Arch Environ Occup Health ; 76(7): 450-454, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33357049

RESUMO

Phthalates are esters of phthalic acid used in a broad array of consumer products and food contact surfaces. Phthalates are known endocrine disruptors and oxidant stressors, and exposure has been associated with premature birth, asthma, obesity, insulin resistance and endometriosis. Though many industrializing countries are known to manufacture phthalates, few studies have examined exposure to phthalates in this context, let alone in rural communities where phthalate-containing products are widely used. We evaluated the presence of 16 phthalate metabolites in third trimester pregnant women in three rural communities near the largest lake in Mexico, Lake Chapala, by liquid chromatography coupled to tandem mass spectrometry in 90 urine samples. Phthalate metabolites were found in all samples, where the highest concentration was 1830 ng/mL in mono-ethyl phthalate (mEP), and it was present in 98.9% of all samples. These findings suggest the need for further research on the effect of endocrine disrupting chemicals in developing countries, and public health guidance on opportunities for prevention.


Assuntos
Disruptores Endócrinos/urina , Ácidos Ftálicos/urina , Gestantes , Adolescente , Adulto , Disruptores Endócrinos/metabolismo , Exposição Ambiental/análise , Exposição Ambiental/estatística & dados numéricos , Feminino , Humanos , México , Ácidos Ftálicos/metabolismo , Gravidez , Terceiro Trimestre da Gravidez , População Rural , Adulto Jovem
11.
Braz. arch. biol. technol ; Braz. arch. biol. technol;64: e21200132, 2021. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1153298

RESUMO

HIGHLIGHTS Arsenic is considered as one of the highly hazardous elements in the environment and a serious carcinogen for the human health. An enzymatic method has been described by using arsenite oxidase for arsenic detection. Residual activity of the immobilized enzyme was 43% of the initial activity after being recycled 10 times.


Abstract Arsenic is considered as one of the highly hazardous elements in the environment and a serious carcinogen for the human health. More attention has taken towards the arsenic due to its presence in ground water in India, China, Bangladesh, Inner Mongolia and several other regions of the world. It's been a challenge to remove arsenic due to the lack of its efficient detection approach in the complicated environmental matrix. The proposed method describes an enzymatic method for arsenic determination using arsenite oxidase, which catalyzes the oxidation of arsenite to arsenate. Hence, a colorimetric PVC strip with immobilized arsenite oxidase has been developed to detect the arsenic concentration and also having potential for the field-testing. The influence of the optimal conditions i.e. pH, temperature, storage stability, and reusability of free and immobilized enzyme were evaluated and compared. The results have shown that the stabilities were significantly enhanced compared with free counterpart. Residual activity of the immobilized enzyme was 43% of the initial activity after being recycled 10 times. We approve that this novel low cost immobilized carrier presents a new approach in large scale applications and expected to act as a model for establishment of indigenous arsenic sensor in miniature form.


Assuntos
Humanos , Arsênio/análise , Cloreto de Polivinila/análise , Poluentes Químicos da Água/análise , Água Subterrânea/análise , Enzimas Imobilizadas/análise , Oxirredutases , Biodegradação Ambiental
12.
Rice (N Y) ; 13(1): 67, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32930888

RESUMO

BACKGROUND: The root system plays a major role in plant growth and development and root system architecture is reported to be the main trait related to plant adaptation to drought. However, phenotyping root systems in situ is not suited to high-throughput methods, leading to the development of non-destructive methods for evaluations in more or less controlled root environments. This study used a root phenotyping platform with a panel of 20 japonica rice accessions in order to: (i) assess their genetic diversity for a set of structural and morphological root traits and classify the different types; (ii) analyze the plastic response of their root system to a water deficit at reproductive phase and (iii) explore the ability of the platform for high-throughput phenotyping of root structure and morphology. RESULTS: High variability for the studied root traits was found in the reduced set of accessions. Using eight selected traits under irrigated conditions, five root clusters were found that differed in root thickness, branching index and the pattern of fine and thick root distribution along the profile. When water deficit occurred at reproductive phase, some accessions significantly reduced root growth compared to the irrigated treatment, while others stimulated it. It was found that root cluster, as defined under irrigated conditions, could not predict the plastic response of roots under drought. CONCLUSIONS: This study revealed the possibility of reconstructing the structure of root systems from scanned images. It was thus possible to significantly class root systems according to simple structural traits, opening up the way for using such a platform for medium to high-throughput phenotyping. The study also highlighted the uncoupling between root structures under non-limiting water conditions and their response to drought.

13.
Braz. j. infect. dis ; Braz. j. infect. dis;24(4): 337-342, Jul.-Aug. 2020. tab, graf
Artigo em Inglês | LILACS, Coleciona SUS | ID: biblio-1132461

RESUMO

Abstract Objective To evaluate the clinical and epidemiological profile of bacterial meningitis and meningococcal disease in pediatric patients admitted to a Brazilian Secondary Public Hospital. Methods A descriptive observational study was conducted. Microbiologically proven bacterial meningitis or meningococcal disease diagnosed from 2008 to 2018 were included. Results A total of 90 patients were diagnosed with proven bacterial meningitis. There were 64 confirmed cases of meningococcal disease. The prevalence was higher in boys (n=38), median age 30 months (1-185). The main clinical manifestations were: meningococcal meningitis (n=27), meningococcemia without meningitis (n=14), association of meningococcemia with meningitis (n=13), and fever without a known source in infants (n=7).Admissions to intensive care unit were necessary for 45 patients. Three deaths were notified. Serogroup C was the most prevalent (n=32) followed by serogroup B (n=12).Pneumococcal meningitis was identified in 21 cases; out of the total, 10 were younger than two years. The identified serotypes were: 18C, 6B, 15A, 28, 7F, 12F, 15C, 19A and 14. Pneumococcal conjugate 10-valent vaccine covered four of the nine identified serotypes.Haemophilus influenzae meningitis serotype IIa was identified in three patients, median age 4 months (4-7). All of them needed intensive care. No deaths were notified. Conclusion Morbidity and mortality rates from bacterial meningitis and meningococcal disease remain high, requiring hospitalization and leading to sequelae. Our study observed a reduced incidence of bacterial disease over the last decade, possibly reflecting the impact of vaccination.


Assuntos
Criança , Humanos , Lactente , Meningites Bacterianas/epidemiologia , Brasil/epidemiologia , Vacinas Pneumocócicas , Hospitais Gerais , Meningite Meningocócica , Meningite Pneumocócica
14.
Polymers (Basel) ; 11(9)2019 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-31514277

RESUMO

In this work, a quantitative spectroscopic study of the bleaching phenomena occurring in plasticized formulations containing poly(vinyl chloride) was performed, proposing a general methodology to comparatively analyze the effect of degrading conditions on the polyene accumulation behaviors (PABs) exhibited by a set of tested formulations. In the study, a set of environmental indexes (temperature (T*), UV energy (UV*), and days with rain) were proposed, which allowed for the suitable globalization of the changing environmental conditions occurring throughout the different degrading periods. A procedure to numerically describe the PAB, followed by each formulation undergoing each degrading condition was also proposed, which required only two primary fitting parameters and four secondary fitting parameters. Then, the combined effects of certain environmental conditions on the PABs were studied, quantifying the stabilizing effects of the rain and the combined decrement on the T* and UV* indexes. Finally, on the basis of the proposed fitting equation and the values of its fitting parameters, the relative importance of the dehydrochlorination reactions as compared with the photo-oxidative reactions simultaneously occurring in the studied systems was estimated.

15.
Talanta ; 152: 371-7, 2016 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-26992533

RESUMO

In this work, a method for poly(vinyl chloride) (PVC) analysis by inductively coupled plasma optical emission spectrometry (ICP-OES) was developed. Samples were digested by microwave-induced combustion (MIC) and thirteen elements (Ba, Cd, Co, Cu, Fe, Mg, Mn, Mo, Ni, Pb, Sr, V and Zn) were determined by ICP-OES. Operational conditions of MIC were investigated allowing quantitative determination of all the analytes and suitable results were achieved using a 3 mol L(-1) HNO3 solution. Microwave-assisted wet digestion (MAWD) using closed quartz vessels and a single reaction chamber microwave digestion system (MAWD-SRC), were also evaluated for PVC digestion for results comparison. All the evaluated sample preparation methods were considered suitable for PVC digestion but MIC was preferable due to the possibility of using diluted HNO3 instead of concentrated reagents and due to the better digestion efficiency. The residual carbon content (RCC) in digests obtained by MIC was significantly lower in comparison with the values obtained after MAWD and by MAWD-SRC. Accuracy for the proposed method was better than 94% for all analytes by comparison of results with those obtained by neutron activation analysis (NAA). Using MIC, it was possible to digest a relatively high sample mass (500 mg) and up to 8 samples in less time (25 min) in comparison with MAWD and MAWD-SRC (about 60 min for both methods). The efficiency of digestion by MIC was higher 99% and lower limits of detection (as low as 0.1 µg g(-1)) were obtained avoiding the use of concentrated acids that is of great concern according to the current green chemistry recommendations.


Assuntos
Fenômenos Ópticos , Gases em Plasma/química , Cloreto de Polivinila/química , Análise Espectral/métodos , Metais Pesados/análise , Micro-Ondas , Análise Espectral/instrumentação
16.
Int J Pharm ; 488(1-2): 20-8, 2015 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-25891254

RESUMO

Acrylic acid (AAc) and poly(ethylene glycol) methacrylate (PEGMA) were singly and dually grafted onto poly(vinyl chloride) (PVC) urinary catheters with the aim of preventing biofouling by endowing the catheters with the ability to load and release antimicrobial agents and to avoid bacteria adhesion. The polymers were grafted applying an oxidative pre-irradiation ((60)Co source) method in two steps. Grafting percentage and kinetics were evaluated by varying the absorbed pre-irradiation dose, reaction time, monomer concentration, and reaction temperature. Catheters with grafting percentages ranging from 8 to 207% were characterized regarding thermal stability, surface hydrophilicity, mechanical properties, swelling, and lubricity. The modified catheters proved to have better compatibility with fibroblast cells than PVC after long exposure times. Furthermore, grafted catheters were able to load ciprofloxacin and sustained its release in urine medium for several hours. Ciprofloxacin-loaded catheters inhibited the growth of Escherichia coli and Staphylococcus aureus in the catheter surroundings and prevented bacteria adhesion.


Assuntos
Acrilatos/química , Antibacterianos/farmacologia , Ciprofloxacina/farmacologia , Metacrilatos/química , Polietilenoglicóis/química , Cloreto de Polivinila/química , Cateteres Urinários , Infecções Relacionadas a Cateter/prevenção & controle , Estabilidade de Medicamentos , Escherichia coli/efeitos dos fármacos , Interações Hidrofóbicas e Hidrofílicas , Staphylococcus aureus/efeitos dos fármacos , Propriedades de Superfície
17.
Food Chem ; 169: 73-9, 2015 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-25236200

RESUMO

A preconcentration system has been developed to determine inorganic selenium species. Selenium was retained by a column filled with polyvinyl chloride (PVC) with lanthanum hydroxide co-precipitation. Speciation was achieved by selective photoreduction previous Se preconcentration. The retention pH was optimized at 10.0. Two multivariate calibrations and a central composite design were employed for optimization of the system. Sample, reagents and acid flow rates are significant variables affecting the system. Employing HG-ICP-OES as detection, the optimized system reached a detection limit of 0.03µg/L, and an enhancement factor of 14875 (25 for preconcentration system, 595 for hydride generation). To verify the method' accuracy, two certified reference materials, BCR® 414 Plankton & IRMM-804 Rice Flour, were analysed. The system was applied to inorganic selenium speciation in several Argentinean beverages to estimate their selenium contribution to diet.


Assuntos
Bebidas/análise , Espectrometria de Massas/métodos , Compostos de Selênio/análise , Compostos de Selênio/isolamento & purificação , Extração em Fase Sólida/métodos , Argentina , Calibragem , Limite de Detecção , Selênio/análise
18.
Vet. Not. (Online) ; 21(1): 48-53, Jan-Jun. 2015. tab
Artigo em Português | VETINDEX | ID: biblio-1502437

RESUMO

Central venous pressure (CVP) is an important parameter for monitoring in various clinical and experimental situations. In veterinary patients, depending on the clinical or surgical approach, the temperament of the animal and your clinical status, the measurement of PVC cannot be performed properly. Thus, the measurement of the jugular venous pressure (JVP) and/or cephalic (CfVP) may be an method for estimating the systemic venous pressure in animals. Thus, this study aimed to determine and to correlate the measures of the JVP and PVCf obtained of healthy dogs. For this 10 healthy dogs were used. All animals were subjected to physical, hematologic, electrocardiographic and echocardiographic evaluation. Any kind of sedation or anesthesia was used. The results showed JVP average values between 4 and -2 cm of water and CfPV between 2 and 16 cm of water. No correlation between JVP and the CfPV was found.


A pressão venosa central (PVC) é um importante parâmetro de monitorização nas mais diversas situações clínicas e experimentais. Em pacientes veterinários, dependendo da abordagem clínica ou cirúrgica, do temperamento do animal e de seu estado clínico, a aferição da PVC não pode ser realizada adequadamente. Assim, é possível que a medição das pressões venosas jugular (PVJ) e/ou cefálica (PVCf) possa ser capaz de estimar a pressão venosa central em animais. Desse modo, este estudo objetivou determinar e correlacionar as medidas da PVJ e da PVCf obtidas de cães saudáveis. Para isso foram utilizados 10 cães saudáveis. Todos os animais foram submetidos a avaliação física, hematológica, eletrocardiográfica e ecocardiográfica. Não foi utilizado qualquer tipo de sedação ou anestesia. Os resultados demonstraram valores médios da PVJ entre -2 e 4 cm de H2O e da PVCf entre 2 a 16 cm de H2O. Não foi observada correlação entre a PVJ e a PVCf.


Assuntos
Animais , Cães , Hemodinâmica , Pressão Venosa , Pressão Venosa Central , Voluntários Saudáveis , Catéteres , Eletrocardiografia Ambulatorial
19.
Vet. Not. ; 21(1): 48-53, Jan-Jun. 2015. tab
Artigo em Português | VETINDEX | ID: vti-481053

RESUMO

Central venous pressure (CVP) is an important parameter for monitoring in various clinical and experimental situations. In veterinary patients, depending on the clinical or surgical approach, the temperament of the animal and your clinical status, the measurement of PVC cannot be performed properly. Thus, the measurement of the jugular venous pressure (JVP) and/or cephalic (CfVP) may be an method for estimating the systemic venous pressure in animals. Thus, this study aimed to determine and to correlate the measures of the JVP and PVCf obtained of healthy dogs. For this 10 healthy dogs were used. All animals were subjected to physical, hematologic, electrocardiographic and echocardiographic evaluation. Any kind of sedation or anesthesia was used. The results showed JVP average values between 4 and -2 cm of water and CfPV between 2 and 16 cm of water. No correlation between JVP and the CfPV was found.(AU)


A pressão venosa central (PVC) é um importante parâmetro de monitorização nas mais diversas situações clínicas e experimentais. Em pacientes veterinários, dependendo da abordagem clínica ou cirúrgica, do temperamento do animal e de seu estado clínico, a aferição da PVC não pode ser realizada adequadamente. Assim, é possível que a medição das pressões venosas jugular (PVJ) e/ou cefálica (PVCf) possa ser capaz de estimar a pressão venosa central em animais. Desse modo, este estudo objetivou determinar e correlacionar as medidas da PVJ e da PVCf obtidas de cães saudáveis. Para isso foram utilizados 10 cães saudáveis. Todos os animais foram submetidos a avaliação física, hematológica, eletrocardiográfica e ecocardiográfica. Não foi utilizado qualquer tipo de sedação ou anestesia. Os resultados demonstraram valores médios da PVJ entre -2 e 4 cm de H2O e da PVCf entre 2 a 16 cm de H2O. Não foi observada correlação entre a PVJ e a PVCf.(AU)


Assuntos
Animais , Cães , Voluntários Saudáveis , Pressão Venosa Central , Pressão Venosa , Hemodinâmica , Catéteres , Eletrocardiografia Ambulatorial
20.
Waste Manag ; 33(12): 2771-80, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24011434

RESUMO

Solid waste, including municipal waste and its management, is a major challenge for most cities and among the key contributors to climate change. Greenhouse gas emissions can be reduced through recovery and recycling of resources from the municipal solid waste stream. In São Paulo, Brazil, recycling cooperatives play a crucial role in providing recycling services including collection, separation, cleaning, stocking, and sale of recyclable resources. The present research attempts to measure the greenhouse gas emission reductions achieved by the recycling cooperative Cooperpires, as well as highlight its socioeconomic benefits. Methods include participant observation, structured interviews, questionnaire application, and greenhouse gas accounting of recycling using a Clean Development Mechanism methodology. The results show that recycling cooperatives can achieve important energy savings and reductions in greenhouse gas emissions, and suggest there is an opportunity for Cooperpires and other similar recycling groups to participate in the carbon credit market. Based on these findings, the authors created a simple greenhouse gas accounting calculator for recyclers to estimate their emissions reductions.


Assuntos
Efeito Estufa/prevenção & controle , Reciclagem/estatística & dados numéricos , Algoritmos , Brasil , Conservação de Recursos Energéticos , Gerenciamento de Resíduos
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