Attachment of Algal Cells to Zwitterionic Self-Assembled Monolayers Comprised of Different Anionic Compounds.

The influence of zwitterionic self-assembled monolayers on settlement and removal of algae was studied. The monolayers were constructed either from zwitterionic thiols or from solutions of positively and negatively charged thiols. The cationic component was composed of quaternary ammonium terminated thiols and the anionic component contained sulfate or carboxylate termination. During assembly, all surfaces showed a strong tendency for equilibration of the surface charge. Settlement and adhesion assays with zoospores of Ulva linza and the diatom Navicula incerta, and field tests of the initial surface colonization revealed the relevance of charge equilibration for the biological inertness of the prepared surfaces.

[Access to the pediatric ambulatory service at a university hospital]. / Acesso a ambulatório pediátrico de um hospital universitário.

INTRODUCTION: In Brazil, one can verify an imbalance between the increase in the need for health care and its supply. The consolidation of the National Health System which recommends universality and equity in care, makes this issue important in the field of health service evaluation. Two pediatric services in a university hospital, one general and the other specialized are studied and compared in terms of their clients' access. METHOD: Questionnaires were applied to 221 users of the general pediatrics outpatient departments of one of the specialties with a view to studying and comparing socioeconomic and several other variables related to the access to these and other health services. RESULTS: A high level of difficulty in the users' locomotion from local health services to the hospital was noted. Of the patients attended, 40% did not receive any kind of care before their arrival and were dependent exclusively on State-run health services. The clients of the specialty were different as regards several variables when compared to the users of the general outpatients' department. The fact that they are at a better socioeconomic level and are less dependent on State-run services brings out the social inequalities involved. CONCLUSION: Socioeconomic conditions, as well as organizational aspects of the service, are seen to be both causes and consequences of social inequality verified.