Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Abdominal imaging 12 (1987), S. 289-295 
    ISSN: 1432-0509
    Keywords: Cancer, rectal ; Cancer, staging ; Endosonography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Transrectal ultrasonography (US) scanning facilitates the ultrastructural differentiation of the various histologic layers of the rectal wall. In particular, the muscularis propria is represented by the 4th sonographic layer. Rectal carcinoma appears on US as a low echogenic area that suddenly interrupts the regular sequence of parietal layers. Sixty-five patients suffering with carcinoma of the lower two-thirds of the rectum underwent pre-operative linear endosonography for staging. The reliability of such a method in assessing the extra-rectal spread was evaluated in our study, at the end of which 55 sonographic/histologic correlations were obtained. Four false-negative and 1 false-positive determinations of the presence or absence of extrarectal spread proved that sonography has a sensitivity and specificity of 91%, with a positive predictive value of 97% and a negative predictive value of 71%. Lower results are obtained in lymph node staging: enlarged lymph nodes are seen in only 11/22 C1/C2 patients (11 false negatives) while we were aware of 3 false positives.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1662-0356
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Natural Sciences in General , Technology
    Notes: Transport and surface interactions of proteins in nanopore membranes play a key role inmany processes of biomedical importance. Although the use of porous materials provides a largesurface-to-volume ratio, the efficiency of the operations is often determined by transport behavior,and this is complicated by the fact that transport paths (i.e., the pores) are frequently of moleculardimensions. Under these conditions, wall effects become significant, with the mobility of moleculesbeing affected by hydrodynamic interactions between protein molecules and the wall. Modeling oftransport in pores is normally carried out at the continuum level, making use of such parameters ashindrance coefficients; these in turn are typically estimated using continuum methods applied at thelevel of individual diffusing particles. In this work we coupled experimental evidences to manyscalemolecular simulations for the analysis of hen egg-white lysozyme adsorption/diffusionthrough a microfabricated silicon membrane, having pores of nanometric size in only onedimension. Our joint efforts allowed us a) to elucidate the specific mechanisms of interactionbetween the biopolymer and the silicon surface, and b) to derive molecular energetic and structuralparameters to be employed in the formulation of a mathematical model of diffusion, thus filling thegap between the nano- and the macroscale
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    [s.l.] : Nature Publishing Group
    Nature 425 (2003), S. 905-905 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] The blood contains a treasure trove of previously unstudied biomarkers that could reflect the ongoing physiologic state of all tissues. Every cell in the body leaves a record of its physiological state in the products it sheds to the blood, either as waste or as signals to neighbouring cells. What ...
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 76 (1994), S. 7246-7255 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A method is developed that yields the residual stress, the orientation distribution coefficients, the average crystallite dimension, the microstrain, and the crystal structure parameters from x-ray diffraction data in a single-step procedure. To this end, a general approach is introduced that combines the equations of micromechanics with the harmonic description of texture. All relationships are cast into a Rietveld-like format, which incorporates a microstructure model derived from line-broadening methods. In this manner, data collected over the whole x-ray-diffraction pattern at different tilting of the sample can be fitted directly. The associated fitting parameters are the crystal structure and microstructure, the texture coefficients, and the micromechanical properties and fields. © 1994 American Institute of Physics.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 63 (1988), S. 4460-4468 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The effective thermoelectromechanical properties of an aggregate of 6mm crystals exhibiting transverse isotropy are determined by averaging the corresponding crystal properties over all orientations. The orientation distribution function is expressed in terms of symmetric generalized spherical harmonics and is employed as a weighting function in the averaging procedures, which are applicable to any physical property. The averaging is carried out under a generalized Voigt-type assumption. The physical relevance of the odd-order texture coefficients is demonstrated through their relation to pyro- and piezoelectric phenomena. The discussion is centered on the determination of the physical behavior of zinc oxide, dedicating particular attention to thin films.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Biomedical microdevices 1 (1999), S. 113-119 
    ISSN: 1572-8781
    Keywords: bioseparation ; filter ; MEMS ; micromachining ; BioMEMS
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Technology
    Notes: Abstract For successful size separation in biomedical applications, the filter used must meet several strict criteria. Not only must it have precisely-machined sub-100 nm pores (〈5% variation), but it must also be able to handle large and small volumes with very high reduction ratios (〉104). In this paper, we will present a bulk-micromachined, direct-bonded silicon nanofilter that can remove particles as small as 44 nm. In doing so, we will describe the fabrication, the gas and liquid characterization, and the filtrations studies done on 44 nm and 100 nm beads.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1572-8781
    Keywords: BioMEMS ; nanotechnology ; microfabrication ; membranes ; silicon
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Technology
    Notes: Abstract The ability to create well-defined and controlled interfaces has been an area of great interest over the last few years, particularly in the biomedical arena. This paper will describe the development of technology for the fabrication of nanopore membranes, and their operation in biological environments. With monodisperse pores sizes as small as 10 nanometers, these membranes offer advantages in their reproducibility, and their ability to be integrated with controlled biochemical surface modification protocols. A comprehensive review of results in the areas of nanopore and biocapsule microfabrication technologies, biocompatibility of nanomembrane materials, biologically appropriate post-processing protocols (bonding, sterilization), surface modification protocols, and appropriate mass transport models will be presented. The results point to the potential of using such technologies for therapeutic applications including immunoisolation biocapsules, drug delivery devices, and targeted biorecognition platforms.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Biomedical microdevices 1 (1998), S. 81-89 
    ISSN: 1572-8781
    Keywords: self-assembled ; surface modification ; silicon ; PEG ; ESCA ; hemocompatibility
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Technology
    Notes: Abstract A simple hemocompatibility-enhancing technique for immobilizing a self-assembled polyethylene glycol multilayer onto silicon surfaces is introduced. It involves the functionalization of PEG by SiCl3 groups on its chain ends, and the reaction of the PEG organosilicon derivatives with hydroxylated groups on silicon surfaces. Surface properties of the treated surfaces were characterized by contact angle measurement, electron spectroscopy for chemical analysis, and ellipsometry. The coated PEG self-assembled molecular film showed effective suppression in both plasma protein adsorption and platelet adhesion to silicon surfaces.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 1572-8781
    Keywords: BioMEMS ; microfabricated biocapsule; immunoisolation ; insulinoma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Technology
    Notes: Abstract This study examines the viability and functionality of two insulinoma cell lines, RIN (1048) and βTC6F7, encapsulated within microfabricated biocapsules. Surface and bulk micromachining are integrated in the biocapsule fabrication process, resulting in a diffusion membrane with uniform pore size distribution as well as mechanical and chemical stability, surrounded by an anisotropically-etched silicon wafer, which serves as the encapsulation cavity. Insulinoma cells (4500 cells/biocapsule) were enclosed within these microfabricated biocapsules and subjected to a static incubation study after either implantation in BALB-C mice or incubation in vitro. Examination of retrieved microfabricated biocapsules revealed an insulin stimulatory index of approximately 1.5 for encapsulated RIN cells and 3.6 for encapsulated βTC6F7 cells for biocapsules with 18 nm pore sized microfabricated membranes, similar to indices of biocapsules incubated in vitro. There was an 80% decrease in cell stimulatory response between in vitro and in vivo 66 nm-biocapsules as compared to 20% for 18 nm-biocapsules, indicating that the immunoisolatory effectiveness depends greatly on achieving uniform pore sizes in the size range of 18 nm or smaller. The present study demonstrates the feasibility of using microfabricated biocapsules for the immunoisolation of insulinoma cells lines. The microfabricated biocapsule may serve as an alternative to conventional polymeric based biocapsules for possible use as in vivo insulin secreting bioreactor.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Biomedical microdevices 2 (1999), S. 5-7 
    ISSN: 1572-8781
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...