Nov. 03, 2009
"We are now able to take a series of photographs at slightly different focal planes or levels through a single cell or group of cells. These photographs result in a consecutive record of the internal architecture of the cell or cells. This accomplishment we have called "optical sectioning". ... By means of this new development a transparent specimen such as a group of cells may be sectioned optically. ... Detail above or below the focal plane does not interfere."  moreNov. 03, 2009
In visualizing transparent biological cells and tissues, the phase contrast microscope and its related techniques have been a cornerstone of nearly every cell biology laboratory. However, phase contrast methods are inherently qualitative and lack in 3-D imaging capability. We introduce a novel tomographic microscopy for quantitative three-dimensional mapping of refractive index in live cells and tissues using a phase-shifting laser interferometric microscope with variable illumination angle. moreNov. 03, 2009
The development of instrumentation for microscopy has advanced enormously in recent years and one of the critical advancements has been the development of low voltage scanning electron microscopy (LVSEM) that allows high-resolution imaging of delicate biological structures with minimal coating requirements. LVSEM provides resolution at levels that previously could only be achieved with transmission electron microscopy (TEM). moreNov. 03, 2009
The appearance of hair is influenced by the 3D geometric arrangement of hair fibres. An accurate 3D representation of hair is needed for hair research to assess the effect of different treatments. X-ray microtomography (XRT) can be used for the 3D visualisation of hair arrays and the quantitative analysis of volume and shape attributes.
Introduction moreNov. 03, 2009
Modern optical microscopy has always represented an indispensable tool for biomedical research. One of the most relevant and successful transformations of the modern microscope is the ability to parallel an instrumental modification with the development of new assays for the determination of functional parameters. Instrument performances have been consequently optimized for the analysis of extremely heterogeneous targets, ranging from single molecules up to living organisms. moreNov. 03, 2009
Supernumerary or extra teeth also result from disturbances during the initiation and proliferation stages of dental development. The most common supernumerary tooth appears in the maxillary midline and is called a mesiodens. The maxillary midline is the most common location for a supernumerary tooth, which can be almost any shape.
Introduction moreNov. 03, 2009
Imaging of single DNA molecules has reached the best spatial resolution by means of dynamic force mode. Amplitude and Frequency Modulation modes at room and low temperature in UHV indicate semi-contact or non-contact as the best modes to achieve high resolution on such small biological molecules. A step forward to more quantitative results is single point force spectroscopy. The force and potential evaluation from the experimental curves evidences the contrast between substrate and DNA and suggests the Non Contact AFM as a possible tool for molecular recognition. moreNov. 03, 2009
Ever since the first human embryonic stem cell line was established, hopes have been raised that treatment for a wide range of cellular degenerative disease and injuries is imminent. While significant progress has been made in stem cell research in recent years, several hurdles remain to be overcome before stem cells can be used routinely in the clinic. In particular, the understanding of the mechanisms that control cell integration, differentiation and proliferation in recipient tissues is far from complete. more