Electrochemically deposited sol-gel-derived silicate films as a viable alternative in thin-film design.

Sol-gel-derived silicate films were electrochemically deposited on conducting surfaces from a sol consisting of tetramethoxysilane (TMOS). In this method, a sufficiently negative potential is applied to the electrode surface to reduce oxygen to hydroxyl ions, which serves as the catalyst for the hydrolysis and condensation of TMOS. The electrodeposition process was followed by the electrochemical quartz crystal microbalance and cyclic voltammetry.

Eucommia (Eucommiaceae), a potential biothermometer for the reconstruction of paleoenvironments.

The living trees of Eucommia ulmoides, an endemic species in China, grow from 200 to 1700 m above sea level, within the geographic range from 102° E to 118° E and from 25° N to 35° N. Spring temperatures in these regions vary from 12.3°C to 20.

Molecular epidemiological analysis of community circulating respiratory syncytial virus in rural South Africa: Comparison of viruses and genotypes responsible for different disease manifestations.

Human respiratory syncytial virus (RSV) is a major cause of severe lower respiratory tract infection in children in both the industrialized and developing world. Most molecular epidemiological studies have, until now, focused on isolates from hospitalized infants in industrialized countries. Limited data have been available with regard to community circulating RSV, especially from Africa.

Revision of species of Minerisporites, Azolla and associated plant microfossils from deposits of the Upper Palaeocene and Palaeocene/Eocene transition in the Netherlands, Belgium and the USA.

Species of the megaspore genus Minerisporites Potonié, megaspore apparatuses of species of the water fern Azolla Lamarck, and some associated organic-walled microfossils recovered from deposits of the Upper Palaeocene and Palaeocene/Eocene transition in the southern part of the Netherlands and neighbouring Belgium are redescribed on the basis of an examination of specimens under scanning and transmission electron microscopes. Originally studied about 40 years ago by S.J.

Active case finding: understanding the burden of tuberculosis in rural South Africa.

Setting: The Agincourt demographic and health surveillance site in South Africa's rural Northern Province.

Objectives: To accurately assess the true burden of tuberculosis in a rural sub-district with a known high prevalence of human immunodeficiency virus.

Design: Data on hospital registrations of tuberculosis were combined with data from an ongoing demographic health and surveillance system to accurately describe the burden of tuberculosis in a well-defined community.

Assessing the potential for the stomatal characters of extant and fossil Ginkgo leaves to signal atmospheric CO2 change.

The stomatal density and index of fossil Ginkgo leaves (Early Jurassic to Early Cretaceous) have been investigated to test whether these plant fossils provide evidence for CO(2)-rich atmosphere in the Mesozoic. We first assessed five sources of natural variation in the stomatal density and index of extant Gingko biloba leaves: (1) timing of leaf maturation, (2) young vs. fully developed leaves, (3) short shoots vs.

Diffusion of redox probes in hydrated sol-gel-derived glasses.

Cyclic voltammetry and chronoamperometry have been used to characterize the translational mobility of eight different redox probes trapped in hydrated silica gel monoliths and evaluate the extent of surface interactions. The redox probes, selected for their size and charge, were introduced into a silica sol prepared by the acid-catalyzed hydrolysis of tetramethoxysilane along with an ultramicroelectrode (r = 13 microns) and a Ag/AgCl reference/counter electrode. Relative changes in the magnitude of the Faradaic current, the half-wave potential, E1/2, and the apparent diffusion coefficient (D) were evaluated for each redox probe as the sol gelled, aged, and dried.

Electrogenerated chemiluminescence of tris (2,2'-bipyridyl)ruthenium(II) ion-exchanged in nafion-silica composite films.

The voltammetry and electrogenerated chemiluminescence (ECL) of tris(2,2'-bipyridyl)ruthenium(II) (Ru(bpy)3 2+) ion-exchanged in Nafion and Nafion-silica composite materials have been investigated. The major goal of this work was to investigate and develop new materials and immobilization approaches for the fabrication of ECL-based sensors with improved reactivity and long-term stability. Nation-silica composite materials with varying contents of Nation (53-100 wt% relative to silica) were prepared via the two-step acid/base hydrolysis and condensation of tetramethoxysilane.

Electrochemiluminescence of ruthenium (II) tris(bipyridine) encapsulated in sol-gel glasses.

The electrogenerated chemiluminescence (ECL) of Ru(bpy)3 2+ and tripropylamine, tributylamine, triethylamine, trimethylamine, or sodium oxalate encapsulated within sol-gel-derived silica monoliths have been investigated using an immobilized ultramicroelectrode assembly. The major purpose of this study was to investigate the role of the reductant on the magnitude and stability of the ECL in this solid host matrix. For gel-entrapped Ru(bpy)3 2-/tertiary amines, the shape and intensity of the ECL-potential curves were highly dependent on scan rate.

Diversity of exine structure in Upper Carboniferous (Westphalian) selaginellalean megaspores.

Studies of wall structure in Mesozoic and Recent selaginellalean megaspores have been well documented. However, Palaeozoic examples have received minimal attention. The principal Palaeozoic megaspore genus of likely selaginellalean affinity is Triangulatisporites, extending from the Upper Devonian to the Upper Carboniferous.

Delivery of non-surgical oncology care.

The changes and options for future change in the provision of non-surgical oncology care within the UK are discussed in the context of the recommendations of the Calman report, the drive towards site specialization and the changing nature of the specialties of clinical and medical oncology. Options for the creation of an improved and more flexible service are discussed.

Evaluating computerized health information systems: hardware, software and human ware: experiences from the Northern Province, South Africa.

Despite enormous investment world-wide in computerized health information systems their overall benefits and costs have rarely been fully assessed. A major new initiative in South Africa provides the opportunity to evaluate the introduction of information technology from a global perspective and assess its impact on public health. The Northern Province is implementing a comprehensive integrated hospital information system (HIS) in all of its 42 hospitals.

Duplication of 8p23.1: a cytogenetic anomaly with no established clinical significance.

We present seven families with a cytogenetic duplication of the short arm of chromosome 8 at band 8p23.1. The duplication has been transmitted from parents to offspring in four of the seven families.

Ultrastructural interpretation of the Late Cretaceous megaspore Glomerisporites pupus and its associated microspores.

The ultrastructure of the Late Cretaceous (Santonian-?early Campanian) megaspore Glomerisporites pupus and its associated microspores has been examined in an attempt to resolve a number of problems concerning the interpretation of their morphology. The new observations presented are based on an analysis of entire, fragmentary, and thin-sectioned specimens under scanning and transmission electron microscopes. These add to, and partly correct, previous observations on this taxon.

Inv(10)(p11.2q21.2), a variant chromosome.

We present 33 families in which a pericentric inversion of chromosome 10 is segregating. In addition, we summarise the data on 32 families in which an apparently identical inv(10) has been reported in the literature. Ascertainment was through prenatal diagnosis or with a normal phenotype in 21/33 families.

Two enhancer domains control early aspects of the complex expression pattern of Msx1.

To understand how the complex embryonic expression pattern of the Msx1 gene is produced a transgenic analysis of 13 kb of DNA around the Msx1 locus was carried out. Most of the extensive expression pattern of the Msx1 gene was reproduced in transgenics using the LacZ gene fused to 5 kb of Msx1 5' flanking DNA. Two enhancer domains were identified which produced this pattern.

Unbalanced translocation in a mother and her son in one of two 5;10 translocation families.

We present two families with different distal long arm 5;10 translocations. In one family the propositus and his mother inherited the same derived chromosome 10 from the maternal grandfather who has a balanced t(5;10)(q35.3;q26.

Observation of individual chemical reactions in solution.

Discrete chemical reaction events occurring in solution have been observed by single photon detection of a bimolecular, chemiluminescent reaction. The reactants were generated from 9,10-diphenylanthracene in acetonitrile with potential pulses applied to an ultramicroelectrode. Electrogenerated radical ions of opposite sign react to yield the excited singlet state of the parent compound.

Stability studies on admixtures of 5-fluorouracil with carboplatin and 5-fluorouracil with heparin for administration in continuous infusion regimens.

The therapeutic index of several anticancer agents may be improved by replacing rapid infusion/bolus injection schedules with prolonged continuous infusion regimens. Admixtures of 5-fluorouracil (5FU) with carboplatin and 5FU with heparin were subjected to stability studies to establish the feasibility of administering these infusions on an in-patient and out-patient basis, respectively. In the first study the stability of carboplatin was determined in an admixture of carboplatin and 5FU for neoadjuvant treatment of in-patients with oesophageal carcinoma by 5-day infusion.

Intravenous pamidronate: infusion rate and safety.

In view of previous animal studies showing that pamidronate (Aredia) can cause renal damage, and human data indicating that pamidronate in doses of 60-90 mg is more effective in the control of tumor-induced hypercalcemia than when given at lower doses, we decided to investigate whether pamidronate 90 mg infused over 60 minutes at weekly intervals had any adverse effects on renal function in patients with bone metastases. Twelve patients, 7 female (all with breast cancer) and 5 male (4 with prostate cancer, 1 with bladder cancer) were entered into the trial. Each patient received weekly intravenous infusions of pamidronate 90 mg in 250 ml normal saline over 60 minutes for 4 weeks.

Vaccination coverage in Mhala and Elim in 1990--a health systems approach.

This paper assesses the implementation of the 1986 Gazankulu policy on immunisation in 2 of the homeland's 6 health wards, Mhala and Elim. Vaccination coverage was estimated using the cluster sampling technique recommended by the Expanded Programme on Immunisation of the World Health Organisation. Vaccination coverage of children aged 12-23 months who have received eight valid doses (as stipulated in the programme) is estimated at 25% in Mhala and 53% in Elim (P < 0.