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Studied the similarity of behaviors among group members and the effects of a risk-reduction intervention aimed at AIDS/HIV prevention with 76 groups of African-American urban adolescents (n=382 youth) studied over 18 months. Data support the usefulness of HIV prevention through groups of friends. (SLD)

Annual tuberculosis screening of inner-city children may not be necessary. Researchers estimated the rate of tuberculosis transmission by performing Mantoux injection tuberculosis testing of 1,433 children from a low income, urban area of Baltimore, Maryland. Forty percent of the children returned to have their test read by a health care professional, which yielded five positive test results. The prevalence rate of TB was a low 0.8%, suggesting that annual TB screening in this population is not necessary. The American Academy of Pediatrics stated in 1996 that annual TB testing is unnecessary., Background. In January 1994, the American Academy of Pediatrics recommended that annual screening with the purified protein derivative tuberculin skin test, Mantoux method, be used for tuberculosis screening in high-risk children. This test has a better sensitivity and specificity than the previously used multiple puncture test, and patients need to return for a reading done by palpation by a health care professional. Objective. To estimate the prevalence of reactivity to purified protein derivative tuberculin in an urban primary care clinic whose patients meet high-risk criteria and to determine if annual screening is warranted, to determine the adherence to return to the clinic for reading of the skin test, and to describe the characteristics of patients who have tuberculosis infection and disease. Research Design. Cross-sectional study. Setting. Inner-city, hospital-based primary care pediatric clinic in Baltimore, MD. Subjects. A total of 1433 consecutive children attending this clinic from March through September, 1994, who were at risk for tuberculosis because of frequent exposure to poor and medically indigent city dwellers. Methods. The Mantoux test (5TU intradermal injection of purified protein derivative) was administered to children at annual health supervision visits. Patients were tracked to determine those who resumed for a reading by a health care professional and find those with a positive Mantoux test. The charts of children with a positive test were reviewed. Results. Five hundred seventy-three (40%) patients resumed for a reading by a health care professional. Five patients had a positive Mantoux test, giving a prevalence rate of 0.8% of reactivity to purified protein derivative tuberculin. One child with a positive Mantoux test also had chest radiograph findings consistent with tuberculosis disease but was asymptomatic. Conclusions. In our city with a low prevalence of disease, children whose only risk factor for tuberculosis was exposure to poor and medically indigent city dwellers did not represent a high-risk group. Our results are supportive of the 1996 American Academy of Pediatrics screening statement that annual screening is not warranted. Sixty percent of children did not return for a reading of the Mantoux test by a health care professional. Alternative strategies that are more convenient for parents are needed to obtain accurate readings by health care professionals when skin testing is deemed necessary., Pediatrics 1997;99:529-533; tuberculosis infection, disease, pediatrics, children, screening, Mantoux, tuberculin skin test, PPD, high risk, urban, resident continuity clinic. ABBREVIATIONS. AAP, American Academy of Pediatrics; PPD, purified protein derivative; MPT, [...]

The article informs that plastics are now the material of choice for a wide range of applications, from inexpensive packaging to durable, high-performance products. It mentions that advanced recycling of plastic has the potential to overcome technical challenges posed by mechanical recycling, paving the way toward a more circular economy.

Equilibrium and dynamic separations for the three xylene and two hydroxynaphthalenes (naphthol) isomers were experimentally obtained with beta-cyclodextrin (β-CD) on mesoporous glass bead and silica gel supports. β-CD-support attachment was either by direct covalent bonding or through tethering with 3-glycidoxypropyltrimethoxysilane. The obtained guest/host separation selectivity ratios were as high as 4.1/1.0 for 1-naphthol from 2-naphthol. Maximum separation ratios were 2.4/1.0 for m-xylene from p-xylene and 0.75/1.0 for o-xylene from p-xylene. β-CD tethering decreased the separation efficiencies of the xylene and naphthol isomers over those obtained by β-CD covalent bonding. Molecular mechanics and semi-empirical methods were used to determine the mechanisms for the above guest-host separation efficiencies. The three mechanisms evaluated were guest-host inclusion energy, charge transfer and steric hindrance. Computational results show that the steric hindrance of the guest entering the host was the controlling mechanism. Levels of steric hindrance were determined by guest-host overlap of electrostatic potential surfaces. A key component concept was used to develop a model for predicting separation selectivities for other guests with β-CD and other guest-host combinations. This model is based on a linear correlation between component/key component selectivity ratios and component/key component electrostatic potential overlap ratios. [ABSTRACT FROM AUTHOR]