638 results about "Density gradient" patented technology

Blood plasma of pregnant women contains fetal and (generally>90%) maternal circulatory extracellular DNA. Most of said fetal DNA contains ≦500 base pairs, said maternal DNA having a greater size. Separation of circulatory extracellular DNA of <500 base pairs results in separation of fetal from maternal DNA. A fraction of a blood plasma or serum sample of a pregnant woman containing, due to size separation (e.g. by chromatography, density gradient centrifugation or nanotechnological methods), extracellular DNA substantially comprising ≦500 base pairs is useful for non-invasive detection of fetal genetic traits (including the fetal RhD gene in pregnancies at risk for HDN; fetal Y chromosome-specific sequences in pregnancies at risk for X chromosome-linked disorders; chromosomal aberrations; hereditary Mendelian genetic disorders and corresponding genetic markers; and traits decisive for paternity determination) by e.g. PCR, ligand chain reaction or probe hybridization techniques, or nucleic acid arrays.

Matrixes doped with semiconductor nanocrystals are provided. In certain embodiments, the semiconductor nanocrystals have a size and composition such that they absorb or emit light at particular wavelengths. The nanocrystals can comprise ligands that allow for mixing with various matrix materials, including polymers, such that a minimal portion of light is scattered by the matrixes. The matrixes of the present invention can also be utilized in refractive index matching applications. In other embodiments, semiconductor nanocrystals are embedded within matrixes to form a nanocrystal density gradient, thereby creating an effective refractive index gradient. The matrixes of the present invention can also be used as filters and antireflective coatings on optical devices and as down-converting layers. Processes for producing matrixes comprising semiconductor nanocrystals are also provided. Nanostructures having high quantum efficiency, small size, and/or a narrow size distribution are also described, as are methods of producing indium phosphide nanostructures and core-shell nanostructures with Group II-VI shells.

An anode with an anode body with a first side and a second side opposite to said first side. First flutes are on the first side and second flutes on the second side. The first flutes and said second flutes are offset or have different depths.

Matrixes doped with semiconductor nanocrystals are provided. In certain embodiments, the semiconductor nanocrystals have a size and composition such that they absorb or emit light at particular wavelengths. The nanocrystals can comprise ligands that allow for mixing with various matrix materials, including polymers, such that a minimal portion of light is scattered by the matrixes. The matrixes are optionally formed from the ligands. The matrixes of the present invention can also be utilized in refractive index matching applications. In other embodiments, semiconductor nanocrystals are embedded within matrixes to form a nanocrystal density gradient, thereby creating an effective refractive index gradient. The matrixes of the present invention can also be used as filters and antireflective coatings on optical devices and as down-converting layers. Processes for producing matrixes comprising semiconductor nanocrystals are also provided. Nanostructures having high quantum efficiency, small size, and/or a narrow size distribution are also described, as are methods of producing indium phosphide nanostructures and core-shell nanostructures with Group II-VI shells.

A coalescer filter element for the separation of water from hydrocarbon fluids, such as kerosene, jet fuel, diesel fuel, and gasoline under surfactant conditions such as thermal stability additive and dispersant. Coalescer fibrous material has hydrophobic properties which resist surfactant coating of the fibers thereby allowing breakdown of water emulsion in the hydrocarbon fluids. The coalescer has a negative media density gradient in the liquid flow direction.

The present invention relates to an absorbent material that can be used as an absorbent core in absorbent articles such as sanitary napkins, pantiliners, incontinence products, disposable diapers, etc. The material of the present invention is a nonwoven sheet, consisting of cellulosic fibers, optionally superabsorbent polymeric material, containing no binders, latexes, etc, relying on hydrogen bonding to produce the necessary structure. The material contains density gradients which direct fluid into the material and distribute it providing more effective fluid transport and efficient utilization of storage capacity. The material consists of two regions. In the first region, the material has a low-density stratum adjacent to one surface, overlaying at least one higher density stratum adjacent to the opposite surface of the sheet. These strata create a density gradient in the thickness direction (Z-direction) of the sheet. The second region consists of a fluid distribution structure that has a higher density than at least the lower density of the strata comprising the first region. The fluid distribution structure is in direct fluid communication with the adjacent strata in the first region, along their boundaries.

Various modifications to a porous substrate, such as employed in lateral flow assay devices, to regulate or modify the flow rate and/or flow path pattern of a fluid through the porous substrate is described. The lateral flow assay device has a porous substrate matrix in fluid communication with a flow-rate control zone having a number of flow-rate control devices arranged as features in or on a substrate surface or laminates thereof in a body. The flow-rate control devices may include: a density gradient, porosity gradient, ion affinity gradient, micro-channels, and combinations thereof.

A wearing article absorption of body fluids has an inner sheet, an outer sheet and a body fluid absorbent first panel underlying the inner sheet. The inner sheet and the first panel are formed in central regions thereof with a void to be filled with a hydrophobic second panel which is elastically compressible and liquid-pervious. A plurality of narrow strips, each comprising water-absorbent fibers compressed to a high density, and a hydrophobic and liquid-pervious spacer member underlying the narrow strips are interposed between the second panel and the outer sheet.

The invention relates to a base comprising a closed cell foam core sheet having a closed cell foam layer with a density gradient between the center of the core and the surfaces of the core. The invention also relates to a method of making such a base by adding a first concentration of a first blowing agent to a first polymer to form a first mixture, adding a second concentration of a second blowing agent to a second polymer to form a second mixture, and extruding the mixtures to form the closed cell foam core sheet. The invention also relates to a method of making such a closed cell foam core sheet base comprising the steps of adding a blowing agent to a polymer to form a mixture, melting the mixture, extruding the mixture from a die, and rapidly quenching the mixture against a high heat transfer surface.

The invention belongs to the field of allogenic mesenchymal stem cells, and particularly relates to a preparation method of allogenic mesenchymal stem cells by CRISPR (clustered regularly interspaced short palindromic repeats) technique editing and IGF (insulin-like growth factor) optimization and application of the allogenic mesenchymal stem cells in treating myocardial infarction. The preparation method comprises the following steps: carrying out separation by density gradient centrifugation to obtain allogenic single karyocytes, and carrying out adherent culture to obtain mesenchymal stem cells; designing a mesenchymal stem cell surface antigen B2M-gRNA and an inflammatory factor TNF-alpha-gRNA; establishing recombinant slow virus particles, and transfecting the mesenchymal stem cells; optimizing the mesenchymal stem cells by using IGF-1; and preparing drugs for treating myocardial infarctions by using the modified and optimized mesenchymal stem cells. The CRISPR/Cas9 technique is utilized to remove the antigens capable of causing immunological rejection and the inflammatory factors capable of causing inflammatory reaction on the mesenchymal stem cell surface, and the IGF-1 is utilized to enhance the apoptosis resistance of the mesenchymal stem cells and promote the homing of the mesenchymal stem cells, thereby providing a new technical scheme for preparing drugs for treating cardiovascular diseases in clinic. The prepared allogenic mesenchymal stem cells can not cause immunological rejection after cell transplantation.

The present invention is a method to manufacture shaped foam article. Specifically, the present invention is a method of extruding a styrenic polymer with a blowing agent to form a foam polymer plank having a density gradient and shaping the surface of the foam plank having the lowest density by passing the foam plank through one or more sets of rolls. Preferably, the foam has a vertical compressive balance (Rv) equal to or greater than 0.4 and more preferably, the foam has a cell gas pressure less than 1 atmosphere and/or an open cell content of equal to or less than 20 percent.

A system and method for automatic scale selection in real-time image and video processing and computer vision applications. In one aspect, a non-parametric variable bandwidth mean shift technique, which is based on adaptive estimation of a normalized density gradient, is used for detecting one or more modes in the underlying data and clustering the underlying data. In another aspect, a data-driven bandwidth (or scale) selection technique is provided for the variable bandwidth mean shift method, which estimates for each data point the covariance matrix that is the most stable across a plurality of scales. The methods can be used for detecting modes and clustering data for various types of data such as image data, video data speech data, handwriting data, etc.

An extrusion system utilizes single or tandem extruders and a mixer-cooler to extrude a foamable extrudate through a die in a sealable chamber. The foamable extrudate is shaped and calibrated within the chamber. The die is mounted on the end of a gel tube projecting through a gland seal in a fixed bulkhead forming the upstream end of the chamber. The gel tube and mixer-cooler are mounted on a movable carriage, movement of which may be used to adjust the die with respect to shaping and calibrating equipment inside the chamber. The mixer-cooler achieves a selected narrow range of uniform viscosity of the melt at the die depending on the size of the product and density. The chamber is preferably a vacuum chamber producing low density foams. The product exits the chamber to atmosphere on a continuous basis through a submerged orifice in a water baffle immersion seal. The mixer-cooler enables a large size low density product to be produced with uniform cellular structure without cell collapse or density gradients, as the product is subjected to the pressure and temperature transformations passing from the chamber to atmosphere through the water. The seal includes the submerged orifice with a free wheeling guiding system upstream of the orifice. Immediately ahead of the guiding system, the parameters of the foam extrudate are sensed to control the configuration of the orifice on a continuous basis. Before the extrudate passes into the water baffle seal it moves over a floating dancer roll, the position of which controls a haul-off such as a vacuum belt at the tail end of the system. This avoids pushing on the extrudate.

The present invention is related to a method for separating a first population of cells from a second population of cells in a sample by discontinuous density gradient separation using dense particles to target the first population of cells and a density separation medium (DSM) that is at least about 0.001 g/cm³ higher than the density of the second population of cells.

An electromagnetic transducer, such as an audio loudspeaker, having an underhung voice coil disposed in a magnetically tapered air gap. The taper provides asymmetry in the magnetic flux field. As the voice coil moves in one direction, the motor becomes stronger and more efficient, and as the voice coil moves in the other direction, the motor becomes weaker and less efficient. This results in an increase in even-order harmonics. The magnetic taper may result from a geometric taper of one or both of the opposing steel pieces which form the gap, or it may result from one or both of them having an at least partially laminated structure. The geometric taper provides a magnetic reluctance gradient along the height of the magnetic air gap. The laminated structure provides a magnetic reluctance gradient through the thickness of the laminated member (e.g. top plate). The magnetic reluctance gradient produces a magnetic flux density gradient along the height of the magnetic air gap.

The invention relates to the field of the protective structures of spacecrafts, and discloses a lightweight filled composite protective structure for space debris, comprising a first layer of protective screen which is a corrugated board, a second layer of protective screen which is a corrugated board/density gradient metal foam; and spacing is left among the first layer of protective screen, the second layer of protective screen and a stiffener structure. The first layer of protective screen is in a corrugated shape, and the corrugated protective screen can effectively decompose debris cloud produced when the space debris with different incident angles collide with the protective structure at high speed, so that the damage energy is scattered. The corrugated surface plate of the second layer of protective screen decomposes the debris cloud again produced when the space debris collide with the first layer of protective structure, and a density gradient metal foam filling layer can further crush and melt the hit space debris, reduce the speed of the cloud debris, and minimize the damage to the external structure of a spacecraft and a sub-system.