Singlet oxygen production by pyrano and furano 1,4-naphthoquinones in non-aqueous medium.

The influence of ring size on the photobehaviour of condensed 1,4-naphthoquinone systems, such as pyrano- and furano-derivatives (1 and 2, respectively) has been investigated. The absorption spectra for both families of naphthoquinones reveal clear differences; in the case of 2 they extend to longer wavelengths. A solvatochromic red shift in polar solvents is consistent with the π,π* character of the S(0)→ S(1) electronic transition in all cases.

[Conjoined twins: an experience of a tertiary hospital in Southeast Brazil].

Purpose: to analyze the occurrence of conjoined twins at a tertiary perinatology reference university hospital over a period of 25 years (January 1982 to January 2007) and to describe the successful separation of one of the pairs.

Methods: we consulted retrospectively the database of the University Hospital of the Medical School of Ribeirão Preto, University of São Paulo, Brazil, in order to determine the number of pairs of conjoined twins, their frequency, classification, gender, type of pregnancy resolution, attempted surgical separation, prenatal diagnosis and survival.

Results: we detected 14 pairs of conjoined twins (1/22,284 live births and 1/90 pairs of twin live births) born during this period (six males, seven females and one of indeterminate sex).

Hormonal assessment of women submitted to tubal ligation.

Sixteen fertile women aged 30-35 years with regular menstruations were studied before and 6 months after tubal ligation (TL). The diagnosis of ovulation was based on clinical ultrasonographic and hormonal parameters [follicle-stimulating hormone (FSH), luteinizing hormone (LH), E2 and P4]. The menstrual pattern did not vary before and after surgery.

Thin-section CT abnormalities and pulmonary gas exchange impairment in workers exposed to asbestos.

Purpose: To evaluate the relationship between abnormalities at thin-section computed tomography (CT) and indexes of pulmonary gas exchange impairment at rest and during moderate exercise in workers exposed to asbestos.

Materials And Methods: Eighty-two workers with long-term exposure to asbestos and abnormal thin-section CT findings underwent respiratory physiologic measurements at rest (lung diffusing capacity, Dlco) and during exercise (oxygen uptake-corrected alveolar-arterial pressure difference for oxygen, DeltaP[A-a]O(2)/VO(2)). CT results were compared with physiologic measurements of impairment in gas exchange (Dlco < 70% predicted value and/or DeltaP[A-a]O(2)/VO(2) > 20 mm Hg.