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•KOH-super activated carbon (SAC) was first produced from Jatoba’s barks.•SAC was successfully applied in the paracetamol (PCT) adsorption.•The regenerated SAC (RSAC) was obtained ...after several thermal regeneration cycles.•SAC and RSAC showed SBET values of 2794 m² g−1 and 889 m² g−1, respectively.•A PCT adsorption mechanism was proposed based on the molecular orbital theory.
A super activated carbon (SAC) was produced by KOH-activation of a biomass waste for paracetamol (PCT) adsorption from aqueous solution and for adsorption-thermal regeneration cycles. The SAC and the regenerated SAC after five adsorption-regeneration cycles (RSAC-5th) were fully characterized by several techniques. The N2 physisorption showed that the SBET values of the SAC and RSAC-5th are remarkably different, being 2794 m² g−1 and 889 m² g−1, respectively. The XPS analysis demonstrated that the SAC surface is composed by oxygen containing-groups, whilst the RSAC-5th also presents nitrogen ones, provenient from the PCT molecules. The adsorption studies revealed that the maximum adsorption capacity (Qm) for the SAC (356.22 mg g−1) is higher than that for RSAC-5th (113.69 mg g−1). Also, the results demonstrated that the PCT adsorption is governed by both physisorption and chemisorption and the ab initio calculations showed the chemisorption mainly occurs in carboxylic groups.
An outbreak of extended spectrum β-lactamase-producing
Klebsiella pneumoniae (ESBLKp) infections in a neonatal intensive care unit (NICU) prompted a prospective investigation of colonization and ...infection with this pathogen. From August 1, 1997 to May 30, 1999, neonates admitted to the NICU for more than 24
h were screened for ESBLKp acquisition. Neonatal gastrointestinal screening was performed by means of faecal sampling within 48
h of admission and then weekly until discharge. Isolates were typed using pulsed-field gel electrophoresis (PFGE). Time-dependent proportional hazard models were used to identify independent effects of invasive procedures and antimicrobials after controlling for duration of stay at the NICU. During the study period, 464 neonates were admitted and 383 were regularly screened. Infections occurred in 13 (3.4%) neonates and 206 (53.8%) became colonized. Independent risk factors for colonization during the first nine days in the NICU were the antimicrobial combination cephalosporin plus aminoglycoside hazard rate (HR)=4.60; 95% CI: 1.48–14.31, and each NICU-day was associated with a 26% increase in the hazard rate for colonization (HR=1.26; 95% CI: 1.16–1.37). Previous colonization (HR=5.19; 95% CI: 1.58–17.08) and central vascular catheter use (HR=13.89; 95% CI: 2.71–71.3) were independent risk factors for infection. In an outbreak setting the proportion of neonates colonized with ESBLKp was observed to increase with the duration of stay and antimicrobial use, and once colonized, infants exposed to invasive devices may become infected.
A total of 278 Ixodes ticks, collected from Madeira Island and Setubal District, mainland Portugal, were examined by polymerase chain reaction (PCR) for the presence of Anaplasma phagocytophilum. Six ...(4%) of 142 Ixodes ricinus nymphs collected in Madeira Island and 1 nymph and 1 male (2%) of 93 I. ventalloi collected in Setubal District tested positive for A. phagocytophilum msp2 genes or rrs. Infection was not detected among 43 I. ricinus on mainland Portugal. All PCR products were confirmed by nucleotide sequencing to be identical or to be most closely related to A. phagocytophilum. To our knowledge, this is the first evidence of A. phagocytophilum in ticks from Setubal District, mainland Portugal, and the first documentation of Anaplasma infection in I. ventalloi. Moreover, these findings confirm the persistence of A. phagocytophilum in Madeira Island's I. ricinus.
A procedure involving bead-injection concept and sequential determination of copper and mercury ions in river-water samples is proposed. The method is based on the solid-phase extraction of both ...metal ions on the same beads surface (Chelex 100 resin) and in their subsequent reaction with the colorimetric reagents (APDC and Dithizone for copper and mercury ions, respectively). For this task, a resin mini-column is established in the optical path by the selection, introduction and trapping of a defined volume of the Chelex-100 resin beads suspension in the flow system. The passage of the sample solution through the resin mini-column promotes the sorption of Cu(II) ions and, making the APDC colorimetric reagent flows through the beads, the formation of the coloured complex on the solid phase surface occurs. The absorbance of the formed APDC–Cu complex is then monitored at 436
nm and the spent beads are discarded. Packing another resin mini-column in the flow cell and repeating the concentration step it is possible to carried out the mercury determination by using Dithizone as reagent. The absorbance of the Dithizone–Hg complex is monitored at 500
nm. After each measurement, the spent beads are wasted and a new portion of fresh one is trapped in the system, letting it ready for the next measurement. The bead injection system is versatile and can be used to concentrate different sample volumes, which permits the determination of a wide range of copper and mercury ions concentrations. When the sample-selected volumes are 100 and 1000
μl the analytical ranges were 5.0 up to 500.0
μg
l
−1 and 2.5 up to 30.0
μg
l
−1 for Cu(II) and Hg(II) ions, respectively. Under these conditions, the detection limit was estimated as 0.63 and 0.25
μg
l
−1 for copper and mercury ions determination. The system consumes 2
mg of Chelex 100 resin beads, 0.20
mg of APDC or 1.25
mg of Dithizone per determination and the traditional organic solvent extraction methodology, normally used in connection with APDC and Dithizone reagents, is not used here which permits to classify the present method as green.
We aimed to evaluate the effect of supplementation of ACP-118® extender with the antioxidant catalase (10 and 50 µg/ml) on Sapajus apella sperm motility, vigour, and plasma membrane integrity during ...the processes of seminal liquefaction, cooling, and freezing. Catalase did not affect any of the evaluated parameters after semen dilution or cooling. Cryopreserved sperm in the presence of 50 µg/ml catalase presented a plasma membrane integrity similar to that fresh sperm, however.
A new spectrophotometric method involving flow injection analysis and textile dye aggregation effect is proposed. The method is based on the aggregation effect of Blue Procion HEGN at pH 3, which ...relocates its maximum absorption wavelength from 620 to 776 nm, avoiding the interference of other blue textile dyes. For this task, a simple and robust flow injection system was designed, which became a very stable analytical method. When the system was applied to Blue Procion determination in effluent of textile industry, precise results were observed (RSD < 2% within 1.0 and 5.0 mg l-1 HEGN). The analytical frequency was 80 measurements per hour; the analytical curve was linear from 1.0 to 5.0 mg l-1 HEGN; the detection limit considering three times the standard deviation of the blank solution (n = 10) was estimated as 0.03 mg l-1 HEGN; and recoveries between 95% and 105% were found. The system consumes 20 mg of sodium citrate and 125 µl of the sample per determination. No baseline drift was observed during extended (5 h) operation periods.
Pulsed-field gel electrophoresis typing of 60 extended-spectrum beta-lactamase-producing Klebsiella pneumoniae (ESBLKp) isolates obtained in a neonatal intensive care unit during an outbreak ...indicated the dissemination of two major bacterial genotypes associated with colonization and invasive disease: one composed by aminoglycoside-resistant isolates and the other by aminoglycoside-susceptible isolates. A urease-negative phenotype was observed among aminoglycoside-resistant ESBLKp. Six pairs of isolates from gastrointestinal (GI) colonization and isolates from invasive disease that occurred 3-23 days later were shown to belong to the same genotype, reinforcing a direct association between colonization and subsequent disease. These data indicate that screening for ESBLKp GI colonization in an outbreak setting may be useful to detect neonates at a higher risk of invasive disease.
In recent years, the interest in the Aeromonas genus has been growing, due to its involvement in human infections, mainly those of gastroenteric nature. It has been described 13 species for the ...genus, in which 11 have been isolated from clinical material associated with infectious processes. Among these, we detach Aeromonas trota which according to A Carnahan et al. seems to be an agent of gastroenteritis in human beings and has been isolated exclusively from human faecal material. In this communication we report its isolation from a water environment. The strain of A. trota was isolated from a polluted estuary which surrounds "Ilha do Fundao" in Rio de Janeiro.
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