A fast and inexpensive sensitive screening test for recognising potential wastewater contamination by the presence of highly toxic heavy metals is described. The test is based on the reaction of the ...toxic heavy metals Hg(II), Cd(II), Pb(II) and Ag(I) with 6-mercaptopurine (6-MP) to produce highly fluorescent complexes.
Optimum experimental conditions include a buffer of pH 7.2 (0.1
M citric acid/0.2
M Na
2HPO
4), a chelating reagent concentration of 6×10
−4
M and the addition of 10
−4
M of
o-phenanthroline. The fluorescence emitted by the complexes was measured at 380 and 540
nm for excitation and emission wavelengths, respectively.
Detection limits of 4, 3, 6 and 3
μg
l
−1 were achieved for Hg, Cd, Pb and Ag. Relative standard deviation (R.S.D.) were between ±2 and ±6% of the fluorescence signals for five identical samples. Potential interference effects from other heavy metals (Zn, Mn, Co, Fe, Ni and Cu), which could affect the response of the proposed screening test was investigated. Results showed that none of these metals give rise to noticeable fluorescence signals under the above described experimental conditions.
Finally, the capability of the proposed heavy metal screening test for the analysis of contaminated water samples is discussed.
and
are zoonotic, tick-borne pathogens that can cause febrile illnesses with or without other symptoms in humans, but may cause subclinical infections in animals. There are only a few reports on the ...occurrence of these pathogens in cattle and water buffalo in Southeast Asia, including the Philippines. In this study, molecular detection of
and
in the blood and in the
(
)
ticks of cattle and water buffalo from five provinces in Luzon Island of the Philippines was done. A total of 620 blood samples of cattle and water buffalo and 206 tick samples were collected and subjected to DNA extraction. After successful amplification of control genes, nested PCR was performed to detect
of
and
of
. No samples were positive for
, while 10 (cattle = 7, water buffaloes = 3), or 1.6% of blood, and five, or 1.8% of tick samples, were
-positive. Sequence analysis of the positive amplicons showed 99-100% similarity to reported
isolates. This molecular evidence on the occurrence of
in Philippine ruminants and cattle ticks and its zoonotic nature should prompt further investigation and surveillance to facilitate its effective control.
'Rickettsia' and 'Coxiella burnetii' are zoonotic, tick-borne pathogens that can cause febrile illnesses with or without other symptoms in humans, but may cause subclinical infections in animals. ...There are only a few reports on the occurrence of these pathogens in cattle and water buffalo in Southeast Asia, including the Philippines. In this study, molecular detection of Rickettsia and C. burnetii in the blood and in the 'Rhipicephalus' ('Boophilus') 'microplus' ticks of cattle and water buffalo from five provinces in Luzon Island of the Philippines was done. A total of 620 blood samples of cattle and water buffalo and 206 tick samples were collected and subjected to DNA extraction. After successful amplification of control genes, nested PCR was performed to detect 'gltA' of 'Rickettsia' and com1 of 'C. burnetii'. No samples were positive for 'Rickettsia', while 10 (cattle = 7, water buffaloes = 3), or 1.6% of blood, and five, or 1.8% of tick samples, were 'C. burnetii'-positive. Sequence analysis of the positive amplicons showed 99-100% similarity to reported 'C. burnetii' isolates. This molecular evidence on the occurrence of 'C. burnetii' in Philippine ruminants and cattle ticks and its zoonotic nature should prompt further investigation and surveillance to facilitate its effective control.
Heterocyclic α-diimines {2,2′-bipyridine (bpy), 4,4′-dimethyl-2,2′-bipyridine (4,4′-Me
2bpy), 1,10-phenantroline (phen), 4,7-dimethyl-1,10-phenantroline (4,7-Me
2phen) and ...2,9-dimethyl-1,10-phenantroline (2,9-Me
2phen)} react, in a wide range of conditions, with iron clusters of nuclearity one, two or three. Two kinds of compounds, Fe(CO)
3(α-diimine) (type
1) and Fe
2(CO)
7(α-diimine) (type
2), are afforded in all cases. We propose a reaction mechanism to explain this behaviour. The crystal structures of compounds Fe(CO)
3(bpy) (
1a), Fe(CO)
3(phen) (
1b), Fe
2(CO)
7(bpy) (
2a) and Fe
2(CO)
7(phen) (
2b) at 173 K were determined by single-crystal X-ray diffraction methods. In contrast, reaction of the pentanuclear iron cluster Fe
5C(CO)
15 with bpy led to the tetranuclear salt Fe(bpy)
3(μ-H)Fe
4C(CO)
12
2 (
3). The electronic structures of the mono- and di-iron derivatives with bpy and phen were analysed using the atoms in molecules (AIM) theory. Their comparative study seems to rule out the existence of FeFe bond in the dinuclear complexes.
We investigated the reaction of Fe(CO)
5, Fe
2(CO)
9 and Fe
3(CO)
12 in tetrahydrofuran with 2,2′-bipyridine (bpy), 1,10-phenantroline (phen) and their commercial dimethyl derivatives. In all cases, mixtures containing both mono-iron Fe(CO)
3(NN) and di-iron Fe
2(CO)
7(NN) derivatives (NN=α-diimine) were obtained. A reaction mechanism is proposed to explain this behaviour. The crystal structures of compounds Fe(CO)
3(bpy), Fe(CO)
3(phen), Fe
2(CO)
7(bpy) and Fe
2(CO)
7(phen) at 173 K were described, and a comparative theoretical study was performed on them in order to determine the existence of FeFe bond in the dinuclear complexes.
A invasão do espaço pessoal e territorial do paciente hospitalizado e seus efeitos, têm sido objeto de vários estudos à nível internacional. Considerando a sua importância e na busca de um ...instrumento de medida para realizar pesquisas nessa área, o presente trabalho teve como objetivo adaptar o instrumento "Anxiety due to territory and space intrusion questionaire" para a cultura brasileira. Descrevemos todas as etapas desse processo e utilizamos o software SPSS para a análise psicométrica.
The invasion of patient's territorial and personal space and its effects have been object of several international studies. In view of its importance and searching for an instrument of measure to develop research in this area, the present study aimed at adapting the instrument "anxiety due to territory and space intrusion questionnaire" to the brazilian culture. Authors fully described the phases of this process and utilized the software SPSS for the psychometric analysis.
La invasión del espacio personal y territorial del paciente hospitalizado y sus efectos han sido objeto de varios estudios a nivel internacional. Considerando su importancia y en la busqueda de un instrumento de medida para desarrollar las investigaciones en ésa área, el presente estudio tuvo como objetivo adaptar el instrumento "Anxiety due to territory and space instrusion questionnaire" para la cultura brasileña. Describimos todas las etapas de ése proceso y utilizamos el software SPSS para análisis psicométrico.
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