Abstract:
Methods for diagnosis of non-small cell lung cancers by detection of endogenous peptides in exhaled breath condensate (EBC) are provided. Diagnostic peptides derived from dermcidin (DCD) are provided. A specific dermcidin-derived peptide E-R11, having the sequence ENAGEDPGLAR, is provided. E-R11 peptide levels in EBC, as measured by mass spectrometry (MS), are highly diagnostic of non-small cell lung cancers. A method for inhibiting growth of lung cancer cells by inhibiting DCD expression by RNA interference also is provided.
Abstract:
A method for analyzing a gaseous electronegative species comprises the steps of providing an analysis chamber; providing an electric field of known potential within the analysis chamber; admitting into the analysis chamber a gaseous sample containing the gaseous electronegative species; providing a pulse of free electrons within the electric field so that the pulse of free electrons interacts with the gaseous electronegative species so that a swarm of electrically charged particles is produced within the electric field; and, measuring the mobility of the electrically charged particles within the electric field.
Abstract:
Methods for determining the quality of a biomolecular microarray to determine suitability of the microarray for performing specific binding reactions, such as hybridization, are provided. Methods are based on staining a microarray with a solution of detectable nanoparticles that reversibly stain the biomolecules through an electrostatic interaction to select microarrays that meet quality standards for hybridization reactions. A gold nanoparticle solution based staining method for DNA microarrays is provided. Destaining methods allowing multiple rounds of hybridization of nanogold stained microarrays are provided. Microarrays selected by methods of the invention are provided.
Abstract:
Methods and apparatuses for portable mass spectrometry are disclosed. The apparatuses comprise at least one source of ionized analyte, at least one frequency scanning subsystem, at least one detector, and optionally at least one vacuum pump, and are portable. In some embodiments, the apparatuses comprise multiple sources of ionized analyte and/or are configured to obtain mass spectra of a large analyte, such as analyte with an m/z ratio of at least 105, or analyte with a molecular weight of at least 105 Da, as well as mass spectra of small molecule analyte. In some embodiments, the methods comprise obtaining mass spectra with a portable apparatus described above.
Abstract:
A novel system and methods for accelerating analytes including, without limitation, molecular ions, biomolecules, polymers, nano- and microparticles, is provided. The invention can be useful for increasing detection sensitivity in applications such as mass spectrometry, performing collision-induced dissociation molecular structure analysis, and probing surfaces and samples using accelerated analyte.
Abstract:
An air filtering device includes an inner seat member, an outer seat member, and a multi-layer filter medium. The inner seat member has opposed first and second sides and a plurality of first air passages extending therethrough from the first side to the second side. The outer seat member has opposed third and fourth sides and a plurality of second air passages extending therethrough from the third side to the fourth side. The multi-layer filter medium is sandwiched between the second side of the inner seat member and the third side of the outer seat member. The multi-layer filter medium has a polypropylene fabric layer, a far-infrared radiation material layer, and an activated carbon fiber layer connected to one another. The first air passages are registered with the second air passages.
Abstract:
An angled dual-polarity mass spectrometer includes a dual-polarity ion generator, a first mass analyzer, and a second mass analyzer. The dual-polarity ion generator includes an ion source to generate positive ions and negative ions from a sample, and electrodes to generate electric fields for guiding the negative ions into a beam of negative ions and guiding the positive ions into a beam of positive ions. The first mass analyzer can analyze the negative ions, and the second mass analyzer can analyze the positive ions. The central axes of the first and the second mass analyzers are at an angle between 0 to 179 degrees.
Abstract:
A mass spectrometer and methods for obtaining the mass spectrum of a single macromolecular or biomolecular ion in a mass spectrometer. The methods include creating single macromolecular or biomolecular primary ions in an ion trap by ionization of a macromolecule or biomolecule; ejecting half of the primary ions for detection with a first charge detector; ejecting half of the primary ions to impact upon a conversion dynode, thereby creating secondary ions for detection with charge amplification detector such as a channeltron or an electromultiplier or an MCP.
Abstract:
A dual-polarity mass spectrometer includes an ion source, a negative ion mass analyzer, and a positive ion mass analyzer to measure both the negative and positive ion spectra of a sample material simultaneously. The ion source includes a sample surface on which the sample material is positioned, the sample material providing positive ions and negative ions when excited by a laser beam or an energetic particle stream. A first extraction electrode is connected to a voltage higher than the sample surface to attract the negative ions from the sample electrode. A second extraction electrode is connected to a voltage lower than the sample surface to attract the positive ions from the sample electrode. The negative and positive ions are analyzed simultaneously by the negative ion mass analyzer and the positive ion mass analyzer, respectively.
Abstract:
Apparatus and methods of operation are described for determining, with isotopic selectivity, the number of noble gas atoms in a sample. The analysis is conducted within an evacuated chamber which can be isolated by a valve from a vacuum pumping system capable of producing a pressure of 10.sup.-8 Torr. Provision is made to pass pulses of laser beams through the chamber, these pulses having wavelengths appropriate for the resonance ionization of atoms of the noble gas under analysis. A mass filter within the chamber selects ions of a specific isotope of the noble gas, and means are provided to accelerate these selected ions sufficiently for implantation into a target. Specific types of targets are discussed. An electron measuring device produces a signal relatable to the number of ions implanted into the target and thus to the number of atoms of the selected isotope of the noble gas removed from the gas sample. The measurement can be continued until a substantial fraction, or all, of the atoms in the sample have been counted.Furthermore, additional embodiments of the apparatus are described for bunching the atoms of a noble gas for more rapid analysis, and for changing the target for repetitive cycling of the gas in the chamber. The number of repetitions of the cyclic steps depend upon the concentration of the isotope of interest, the separative efficiency of the mass filter, etc. The cycles are continued until a desired selectivity is achieved. Also described are components and a method of operation for a pre-enrichment operation for use when an introduction of a total sample would elevate the pressure within the chamber to levels in excess of those for operation of the mass filter, specifically a quadrupole mass filter.Specific examples of three noble gas isotope analyses are described.