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Biomedical subjects

H M Meyer

Publications and source records attributed to H M Meyer.

At least 19 recordsLinked to original sources
PubMed2006

Formation of ultrasharp vertically aligned Cu-Si nanocones by a DC plasma process.

We report an effective method for the production of ultrasharp vertically oriented silicon nanocones with tip radii as small as 5 nm. These silicon nanostructures were shaped by a high-temperature acetylene and ammonia dc plasma reactive ion etch (RIE) process. Thin-film copper deposited onto Si substrates forms a copper silicide (Cu3Si) during plasma processing, which subsequently acts as a seed material masking the single-crystal cones while the exposed silicon areas are reactive ion etched. In this process, the cone angle is sharpened continually as the structure becomes taller. Furthermore, by lithographically defining the seed material as well as employing an etch barrier material such as titanium, the cone location and substrate topography can be controlled effectively.

Acetylene↗
PubMed2004

Experimental secondary electron spectra under SEM conditions.

Secondary electron spectra have been collected from both pure elements and from compounds examined under conditions approximating those found in a scanning electron microscope. Despite the presence of substantial surface contamination these spectra are found to be reproducible and characteristic of the underlying material. Typically the peak in such spectra is found to be at an energy of about 5 eV, and 50% of the total secondary electron emission falls within the range 0-12 eV. These data may be of value for the design of detectors for scanning microscopy and might have applications for microanalysis.

Journal Article↗
PubMed1997

A specific alpha-tubulin is associated with the initiation of parthenogenesis in 'Salmon' wheat lines.

The 'Salmon system' consists of isogenic but alloplasmic wheat lines with either sexual or autonomous embryo development. Using two-dimensional gel electrophoresis these lines have been screened for proteins potentially involved in the initiation of parthenogenesis. A temporally altered expression of the polypeptide 'P 115.1' in the sexual and parthenogenetic 'Salmon' lines seems to be related with the autonomous embryo formation. Around anthesis when most of the egg cells begin the parthenogenetic development, the polypeptide 'P 115.1' was present in ovaries of the parthenogenetic lines but not in ovaries of the sexual line. Moreover, this polypeptide is only expressed in the ovaries of amphidiploid parthenogenetic plants containing differentiated embryo sacs. It is absent from ovaries of the analogous polyhaploid plants, which lack any embryo sac structure within their ovules. Furthermore, the polypeptide was neither detectable in meristematic tissue of root tips nor in leaves. N-terminal amino acid sequencing identified 'P 115.1' as an alpha-tubulin. Thus, 'P 115.1' apparently represents an embryo sac-specific isoform of alpha-tubulin involved in the initiation of embryo development.

Amino Acid Sequence↗
PubMed1996

A pollen allergen-encoding gene is expressed in wheat ovaries.

To isolate genes specifically expressed at the initiation of plant embryo development we have applied a sensitive subtractive hybridization technique for three isogenic wheat lines of the so-called 'Salmon system' with either zygotic or autonomous embryo development. Here we present a gene sequence showing a high homology to grass pollen allergens of type II/III thought to be expressed in pollen tissue only. Surprisingly, the pollen allergen-like sequence, designated Tri a III, is also expressed in gynoecia of the sexual, male fertile wheat line '(aestivum)-Salmon', whereas the two parthenogenetic and male sterile wheat lines '(caudata)-Salmon' and '(kotschyi)-Salmon' completely lack any Tri a III transcript. Our data suggest a positive correlation between the expression of this clone and the manifestation of male fertility. Northern and in situ hybridization analysis revealed that, in addition to its presence in pollen, Tri a III is expressed in the parenchymatous tissue of '(aestivum)-Salmon' ovaries exclusively at the day of anthesis. This precise temporal and spatial expression pattern suggests a more general function of the pollen allergen-like sequence Tri a III not limited to the exhibition of allergens in pollen grains.

Allergens↗
PubMed1980

Rabies vaccine.

Explore the source record for details and available documents.

Costs and Cost Analysis↗
PubMed1978

Review of existing vaccines for influenza.

The problems of producing and distributing influenza vaccines are described as well as effectiveness and adverse reactions. It appears that Guillain-Barré (GBS) is likely to be encountered with the use of any of the inactivated influenza vaccines.

Antibodies, Viral↗
PubMed1977

Summary of clinical trials of influenza virus vaccines in adults.

Trials in approximately 3,900 adults were conducted with influenza A/New Jersey/76, A/Victoria/75, and B/Hong Kong/72 virus vaccines. Subjects were observed following a standard protocol, and serologic testing was performed in a single laboratory. The data indicate that prior experience of the population with earlier influenza viruses ("priming") is a determinant in response to vaccination. Thus, participants older than 25 years showed good serologic response following a single inoculation of A/New Jersey/76 virus, while younger persons responded poorly. Serological responses to A/Victoria/75 and B/Hong Kong/72 viruses were, in contrast, equally good in the younger and older adults. Whole-virus vaccines were measurably more reactive than split-virus vaccines, a finding more easily discernined in unprimed populations. In the unprimed persons, a single dose of split-virus vaccine was less immunogenic than a single dose of whole-virus vaccine. The presence of preexisting antibodies appeared to reduce systemic reactivity. For adequate immunization of a totally unprimed population, a single relatively large and reactive dose of whole-virus vaccine or two, properly spaced, smaller nonreactive doses of either whole-virus vaccine or split-virus vaccine would be required.

Adolescent↗
PubMed1977

Antibody persistence after primary immunization with trivalent oral poliovirus vaccine.

Five years after primary infant immunization with trivalent oral poliovirus vaccine, employing either a three-dose primary series as recommended by the U.S. Public Health Service Advisory Committee on Immunization Practices (ACIP) or a four-dose series as recommended by the Committee on Infectious Diseases of the American Academy of Pediatrics. 115 children were serologically tested for persistence of neutralizing antibodies by the microneutralization test. Of the 57 individuals immunized according to the ACIP recommendation, antibody persistence was demonstrated in 92% for type 1 poliovirus, 98% for type 2, and 84% for type 3. Of those 58 individuals originally receiving a four-dose primary infant immunization series, the persistence of antibody was 98% to type 1, 98% to type 2, and 87% to type 3. Twenty-one of 24 negative sera showed neutralizing ability when tested by a more sensitive plaque reduction test. Thus, individuals completing either immunization schedule demonstrated satisfactory persistence of neutralizing antibody to all three poliovirus types over a five-year period.

Antibodies, Viral↗
PubMed1976

Regulatory approach toward vaccines against cancer: the benefit/risk ratio.

Decisions regarding investigational new drug applications for testing of all biologicals to be used in humans, including those designed to prevent or treat cancers, must be considered in terms of benefit/risk ratios. In order for a regulatory organization to make the appropriate decision regarding the testing of new biologicals in humans, it must have an extremely broad dialog within the critical scientific public and the general public, which are represented on committees functioning in the Bureau of Biologics. There must be a generaly consensus regarding the benefit/risk ratio of proposed new biologicals for scientific progress and the effective regulation of biologicals.

Humans↗