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1.
Polymers (Basel) ; 13(10)2021 May 14.
Article in English | MEDLINE | ID: mdl-34069314

ABSTRACT

Developing a biomimetic material to wound care is an emerging need for the healing process. Poly (ε-caprolactone) (PCL) is a polymer with the necessary dressing's requirements often used in medicine. Their surface, physic-chemical and biological properties can be modified by adding bioactive compounds, such as andiroba seed oil (Carapa guianensis). This Amazonian natural plant has medicinal and pharmacological properties. For this purpose, PCL polymeric films incorporated with andiroba oil were investigated. The synthesis of hybrids materials was carried out in the solvent casting method. Thermal properties were evaluated using thermogravimetric analysis (TGA/DTGA) and differential scanning calorimetry (DSC). The solvent type on the surface and hydrophilicity of samples was studied using a scanning electron microscope (SEM). Additionally, contact angle measurements, functional groups analysis, fluid absorption capacity, and cell viability were performed. The results demonstrated the influences of andiroba oil under the morphology and thermal properties of the polymeric matrix; the hydrophilicity of the hybrid film obtained by acetic acid was reduced by 13%; the porosity decreased as the concentration of oil increased, but its higher thermal stability. The L929 cell line's proliferation was observed in all materials, and it presented nontoxic nature. It was demonstrated the ability of PCL hybrid film as a matrix for cell growth. Then, the materials were proved potential candidates for biomedical applications.

2.
J Environ Manage ; 270: 110868, 2020 Sep 15.
Article in English | MEDLINE | ID: mdl-32721313

ABSTRACT

Acai seed was used herein as an Amazon biomass waste for the synthesis of activated and modified carbon in order to find a possible use for the large volume of residues generated during the processing of this fruit and to add value to this residue. Activated carbon materials were used to remove Pb2+, Fe2+, and Mg2+ metal ions from water. The efficiency of removal of these ions by the acai seed activated carbon was compared with that by commercial activated carbon. Activated carbon materials were prepared by carbonization and chemical activation using two KOH impregnation ratios, namely 1:1 (ACK1) and 5:1 (ACK5), by mass. These samples were modified by treatment with nitric acid under microwave heating (ACK1-M) and (ACK5-M), respectively. The result of the elemental analysis indicated that this biomass has carbon and sulfur contents of 43.29% and 0.10% wt, respectively. The textural parameters showed that the obtained activated carbon samples presented high surface areas between 1462 and 2774 m2 g-1. Raman analysis revealed the different degrees of graphitization of the activated carbon materials. Boehm titration identified the presence of phenolic, carboxylic, and lactonic groups in samples that were confirmed by Fourier transform infrared spectroscopy. In the metal adsorption tests, ACK5-M showed better removal efficiency, reaching 86% removal for Pb2+, 69% for Fe2+, and 8% for Mg2+in 1 h of contact time; these results were superior to those obtained for commercial carbon. The results indicated that acai seed can be used for the production of activated carbon and can also be used for metal removal.


Subject(s)
Charcoal , Water Pollutants, Chemical/analysis , Adsorption , Biomass , Ions , Kinetics , Metals , Water
3.
Materials (Basel) ; 12(9)2019 May 02.
Article in English | MEDLINE | ID: mdl-31052534

ABSTRACT

Two bentonites from Paraíba (Northeastern Brazil) were impregnated with heteropoly phosphomolybdic H3PMo12O40 (HPMo). The materials produced were characterized by various techniques such as N2 adsorption-desorption (specific surface area, SSA), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Thermogravimetric analysis (TGA/DTG), Scanning Electron Microscopy (SEM) equipped with Dispersive Energy X-ray spectroscopy (EDS), ultraviolet-visible spectroscopy (UV-vis), acid-base titration analysis. The catalytic activity of these materials was tested in the esterification of a waste from palm oil deodorization and the main results obtained (about 93.3% of conversion) indicated that these materials have potential to act as heterogeneous solid acid catalysts. The prepared materials exhibited satisfactory catalytic performance even after a very simple recycling process in three reuse cycles, without significant loss of their activities.

4.
Bioresour Technol ; 102(17): 8314-7, 2011 Sep.
Article in English | MEDLINE | ID: mdl-21704520

ABSTRACT

The distillate produced by deodorization of palm oil (DDPO) is a waste that corresponds to 4% of the product formed in this process. DDPO is 83% free of fatty acids (FFA), making it a good material for biodiesel production. In this paper, a catalyst prepared from a waste material, Amazon flint kaolin, was used for the esterification of DDPO with methanol. Leached metakaolin treated at 950°C and activated with 4M sulfuric acid (labeled as MF9S4) offered maximum esterification activity (92.8%) at 160°C with a DDPO:methanol molar ratio of 1:60 and a 4-h reaction time. The influences of reaction parameters, such as the molar ratio of the reactants, alcohol chain length, temperature, time and the presence of glycerides and unsaponifiable matter, have also been investigated. Based on the catalytic results, esterification of DDPO using MF9S4 can be a cheaper alternative for production of sustainable fuels.


Subject(s)
Biofuels , Odorants , Plant Oils/metabolism , Refuse Disposal , Catalysis , Kinetics , Palm Oil , Temperature
5.
Bioresour Technol ; 102(10): 5873-7, 2011 May.
Article in English | MEDLINE | ID: mdl-21411317

ABSTRACT

Differential scanning calorimetry (DSC) and a Rancimat method apparatus were applied to evaluate the oxidative stability of buriti pulp oil (Mauritia flexuosa Mart), rubber seed oil (Hevea brasiliensis), and passion fruit oil (Passiflora edulis). The Rancimat measurements taken for the oxidative induction times were performed under isothermal conditions at 100°C and in an air atmosphere. The DSC technique involved the oxidation of oil samples in an oxygen-flow DSC cell. The DSC cell temperature was set at five different isothermal temperatures: 100, 110, 120, 130 and 140°C. During the oxidation reaction, an increase in heat was observed as a sharp exothermic curve. The value T(0) represents the oxidative induction time, which is determined from the downward extrapolated DSC oxidative curve verses the time axis. These curves indicate a good correlation between the DSC T(0) and oxidative stability index (OSI) values. The DSC method is useful because it consumes less time and less sample.


Subject(s)
Calorimetry, Differential Scanning/methods , Plant Oils/chemistry , Chromatography, Gas , Fatty Acids/analysis , Oxidation-Reduction , South America , Thermogravimetry
6.
Sex Transm Infect ; 79(5): 388-92, 2003 Oct.
Article in English | MEDLINE | ID: mdl-14573834

ABSTRACT

OBJECTIVES: (1) To assess risk factors for urethral infections with Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis among male clients of female sex workers (FSWs) in Benin; (2) to study the validity of LED testing of male urine samples compared to a highly sensitive gold standard (PCR) for the diagnosis of urethral infections with the organisms cited above. METHODS: Male clients of FSWs (n=404) were recruited on site at prostitution venues in Cotonou, Benin, between 28 May and 18 August 1998. A urine sample was obtained from each participant just before he visited the FSW, and tested immediately using a leucocyte esterase dipstick (LED) test. It was then tested for HIV using the Calypte EIA with western blot confirmation, and for C. trachomatis, N. gonorrhoeae, and T. vaginalis by PCR. After leaving the FSW's room, participants were interviewed about demographics, sexual behaviour, STI history and current symptoms and signs, and were examined for urethral discharge, genital ulcers, and inguinal lymphadenopathies. RESULTS: STI prevalences were: C. trachomatis, 2.7%; N. gonorrhoeae, 5.4%; either chlamydia or gonorrhoea 7.7%; T. vaginalis 2.7%; HIV, 8.4%. Lack of condom use with FSWs and a history of STI were independently associated with C. trachomatis and/or N. gonorrhoeae infection. Over 80% of these infections were in asymptomatic subjects. The overall sensitivity, specificity, positive and negative predictive values of the LED test for detection of either C. trachomatis or N. gonorrhoeae were 48.4%, 94.9%, 44.1%, and 95.7%, respectively. In symptomatic participants (n=22), all these parameters were 100% while they were 47.4%, 94.7%, 37.5%, and 96.4% in asymptomatic men (n=304). CONCLUSIONS: Since most STIs are asymptomatic in this population, case finding programmes for gonorrhoea and chlamydia could be useful. The performance characteristics of the LED test in this study suggest that it could be useful to detect asymptomatic infection by either C. trachomatis or N. gonorrhoeae in high risk men.


Subject(s)
Carboxylic Ester Hydrolases , Sex Work/statistics & numerical data , Sexually Transmitted Diseases/epidemiology , Urethral Diseases/diagnosis , Adolescent , Adult , Benin/epidemiology , Female , Humans , Male , Mass Screening/standards , Middle Aged , Multivariate Analysis , Reagent Kits, Diagnostic/standards , Risk Factors , Sexually Transmitted Diseases/transmission
7.
AIDS ; 14(16): 2523-34, 2000 Nov 10.
Article in English | MEDLINE | ID: mdl-11101064

ABSTRACT

OBJECTIVES: Male clients of female sex workers have rarely been specific targets for HIV/sexually transmitted diseases (STD) interventions in sub-Saharan Africa. We assessed the effectiveness of outreach methodology for contacting sexual partners of female sex workers for purposes of HIV/STD prevention in Cotonou, Benin. DESIGN AND METHODS: In collaboration with owners/managers, outreach personnel and female sex workers, 404 clients were recruited on-site at prostitution venues, and provided urine samples for leukocyte esterase dipstick (LED), STD and HIV testing before having sex with female sex workers. After having sex they underwent an interview and physical examination. No payment was made for study participation. Prostitution site personnel (n = 41) and boyfriends of female sex workers (n = 56) were also recruited. RESULTS: In all 68% of the clients approached agreed to participate. On-site LED testing and free STD treatment were important factors in participation. HIV-1 prevalence was several-fold higher than in the general population in Cotonou, at 8.4, 12.2 and 16.1% in clients, personnel and boyfriends respectively, and was associated with increasing age and lack of condom use with female sex workers. Condom use rates by clients with female sex workers were non-negligible but sub-optimal, and low with regular partners. Approximately one-third of clients with regular partners also had other non-female sex worker sex partners. Boyfriends of female sex workers are of particular concern due to high numbers of partners, very low condom use rates and high HIV prevalence. CONCLUSIONS: Study findings indicate that male sex partners of female sex workers form a 'bridging population' for HIV/STD transmission both to female sex workers, as well as from female sex workers to the general population of women, particularly regular female partners.


Subject(s)
HIV Infections/prevention & control , Risk-Taking , Sex Work , Sexual Partners , Sexually Transmitted Diseases/prevention & control , Adult , Benin/epidemiology , Condoms , Female , HIV Infections/epidemiology , Humans , Male , Middle Aged , Prevalence , Sexual Behavior , Sexually Transmitted Diseases/epidemiology
8.
Cir. vasc. angiol ; 7(4): 15-8, dez. 1991. ilus, tab
Article in Portuguese | LILACS | ID: lil-103829

ABSTRACT

É relatado um caso de fístula arteriovenosa traumática dos vasos mesentéricos superiores, causado por arma branca. Sinais de insuficiência cardíaca e hipertensäo portal estavam ausentes. Dor, emagrecimento e sopro abdominal foram os achados clínicos. O diagnóstico foi confirmado pela arteriografia seletiva da artéria mesentérica superior. O tratamento consistiu em pseudo-aneurismectomia, oclusäo da fístula e restauraçäo do fluxo arterial com interposiçäo de veia safena. No pós-operatório, o paciente apresentou icterícia. Após 3 meses permanece assintomático, recuperando peso.


Subject(s)
Arteriovenous Fistula/etiology , Mesenteric Arteries , Wounds, Gunshot/complications , Angiography , Mesenteric Arteries/surgery , Mesenteric Arteries , Arteriovenous Fistula/surgery , Arteriovenous Fistula , Jaundice/etiology , Postoperative Complications
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