358 results about "Circular dichroism" patented technology

A method and apparatus for illuminating a subject with deep UV light and detecting 2-dimensional image information, e.g., a transmission image, fluorescence image, reflected light image, etc. The subject may be illuminated with a light pulse having a duration of 2 seconds or less and one or more components with a wavelength of between about 150 nm to about 300 nm. The light pulse may be arranged so as to minimize or eliminate any detrimental effect on the functioning of the subject, e.g., on a living cell. A concentration, mass, quantum yield, absorbance or other characteristics of one or more compounds in the subject may be determined based on one or more 2-dimensional images obtained of the subject. An illumination beam having left and right circularly polarized components may be generated, e.g., for circular dichroism analysis of a subject.

The present invention provides a bioapplicable material (or composition) or film-forming material (or composition), which is free from a risk of an infection by a pathogenic organism or a transmission of a causative factor, has a high safety. The material (or composition) comprises a collagen-like synthetic polypeptide having at least an amino acid sequence represented by the formula -Pro-Y-Gly- (wherein Y represents Pro or Hyp). The polypeptide may show positive Cotton effect at a wavelength in range of 220 to 230 nm and negative Cotton effect at a wavelength in range of 195 to 205 nm in a circular dichroism spectrum. At least part of the polypeptide may be capable of forming a triple helical structure. The polypeptide may be degradable with a collagenase.

The invention discloses a gold nanorod-silicon dioxide core-shell structure nanometer material. The core structure of the core-shell structure nanometer material is a chiral gold nanorod side-by-side assembly with the circular dichroism optical activity. The shell structure of the core-shell structure nanometer material is silicon dioxide. The core of the chiral gold nanorod side-by-side assembly is coated with the silicon dioxide shell layer, so that the nanometer material with the circular dichroism optical activity is obtained. According to the nanometer material, the side-by-side assembly structure is stable, the solution state is stable, and the circular dichroism optical activity is obviously improved, wherein the circular dichroism optical activity is improved by 4-6 times compared with a pure chiral gold nanorod, and the stability is kept as long as 6 months. A preparation method of the gold nanorod-silicon dioxide core-shell structure nanometer material is simple and low in cost. The obtained chiral gold nanorod side-by-side assembly-silicon dioxide core-shell structure nanometer material has various compositions and properties, is wide in application range and has the large development space.

The invention relates to polymer compositions comprising PCT (poly((cyclohexylene-dimethylene) terephthalate)) polymer and a fibrous glass filler having a non-circular cross-sectional aspect ratio of greater than at or about 4.

The invention relates to discrete precious metal nanoparticles with high plasmon circular dichroism response and a preparing method of the nanoparticles. The method comprises following steps: precious metal materials with anisotropy are adopted, chirality micromolecules are modified on the materials, a reducing agent and a precious metal saline solution are added into a solution of the obtained precious metal materials modified with the chirality micromolecules, standing is carried out for the reaction, a precious metal layer grows on the surface of the heavy metal materials modified with the chirality micromolecules, and the discrete precious metal nanoparticles with high plasmon circular dichroism response are obtained. The preparing method of the discrete precious metal nanoparticles is simple, gentle in reaction condition and easy and convenient to operate; the obtained discrete precious metal nanoparticles are very good in dispersion, for a single nanoparticle, a higher PCD signal is obtained, and the method is very suitable for detection, fundamental research(surface chemistry and PCD mechanism study) and the like.

Systems and methods for producing circular extinction (CE) contrast images of anisotropic samples. Microscope systems for determining circular extinction (CE), the differential transmission of left and right circularly polarized light resulting from circular dichroism (CD) of an anisotropic sample, include mechanically driven optical components and an image detector such as a monochromatic CCD camera to detect light intensities. In one aspect, optical components include a tunable filter, a rotatable linear polarizer and a variable retarder. The tunable filter is adjustable to provide light at a specific desired wavelength. The linear polarizer is adjustable to provide linearly polarized light with a specific wave vector, and the variable retarder is adjustable to produce near perfect circular polarized light at every selected wavelength. For example, in one aspect, the variable retarder includes a linear birefringent plate tiltable around one of its eigenmodes perpendicular to the wave vector of polarized light. The plate may be controllably tilted so that it functions as a perfect λ/4 plate at each wavelength.

The present invention provides an evaluation method and preparation process of injection containing a lipid A analog. Specifically, it provides, in an injection preparation containing a lipid A analog or a pharmacologically acceptable salt thereof, forecasting and evaluating methods of the pharmacokinetics of the lipid A analog, and quality evaluating method and preparation process of the injection, which each comprises measuring membrane fluidity and/or circular dichroism.

An apparatus and method that provide optical isolation by permitting substantially all forward-propagating light into a delivery fiber from an optical amplifier and substantially preventing backward-traveling light from the delivery fiber entering the optical amplifier without the use of a conventional optical isolator. Eliminating the isolator improves efficiency and reduces cost. Some embodiments use a delivery fiber having a non-circular core in order to spread a single-mode signal into multiple modes such that any backward-propagating reflection is inhibited from reentering the single-mode amplifier. Some embodiments amplify an optical signal in a gain fiber having an output end, output the forward-propagating amplified signal as a high-brightness optical beam (having a first Rayleigh range) into a removable delivery fiber having a non-circular waveguide, output the amplified signal from a distal end of the delivery fiber, and, without the use of a non-linear optical isolator, inhibit backward-propagating light from re-entering the gain fiber.

The invention relates to a double-layered nanostructure for regulating circular dichroism and a preparation method thereof. The double-layered nanostructure is a double-layered chiral structure comprising a plurality of gold nano units with the same structure being combined up and down, left and right, and each gold nano unit comprises an upper structure and a lower structure, the lower structurecomprises a lower bar, the upper structure comprises a metal rod and an upper bar located on the side of the metal bar. The angle between the metal bar and the upper bar is 90 degree, the metal bar and the lower bar are placed in parallel, and one end of the lower rod is perpendicular to one end of the upper rod near the metal rod in different surfaces; the preparation method of the double-layerednanostructure comprises the steps of preparing a substrate, coating photoresist, drying after coating, exposing a structure pattern through an electron beam, developing, photographic fixing, drying after photographic fixing, gold plating, stripping PMMA photoresist, blow-drying, plating SiO2 intermediate layer and the like. The circular dichroism produced by the double-layered nanostructure of the invention has a better effect and can also dynamically adjust a circular dichroism signal of the structure.

The invention relates to the field of biological detection and provides a chiral sensing element and equipment, a chiral representation method as well as a concentration representation method, so that the detection sensitivity of molecular chirality is improved; the equipment and detection cost is reduced, and the detection efficiency and accuracy are improved; meanwhile, high-sensitivity representation of concentration of biological molecules in a solution is realized. The chiral sensing equipment comprises the chiral sensing element, the chiral sensing element comprises an upper covering layer, a middle covering layer and a lower covering layer which have light transmission, as well as a microfluidic channel formed by the upper covering layer, the middle covering layer and the lower covering layer; a chiral nanostructure array is arranged on the lower covering layer in the microfluidic channel. The invention applies to detection of weak circular-dichroism signals.

The invention discloses a double helix chiral asymmetric planar meta-material circular dichroic device comprising a substrate 1 and a cladding layer 2 and a circular dichroic acting layer 3 which arearranged on the upper part of the substrate 1. The circular dichroic acting layer 3 has an array structure. The array structure is composed of a plurality of upper-and-lower-layer Archimedes helix array elements with certain scaling coefficient. The upper and lower layers of Archimedes helixes are made of chiral meta-material, the lower layer of Archimedes helix is covered by the cladding layer 2and the thickness of the cladding layer 2 is the same as the thickness of the lower layer of Archimedes helix, and the upper layer of Archimedes helix is arranged on the upper part of the cladding layer 2. Compared with the existing three-layer asymmetric planar meta-material structure, the circular dichroic performance can be greatly enhanced by the double helix chiral asymmetric planar meta-material and the meta-material has a brand-new working mechanism. The device has wide application prospect in the biological and optoelectronic field of molecular structure detection, display, laser, imaging and the like.

The invention provides an all-medium ultrathin two-dimensional circular polarization dichroic device and a preparation method thereof, for realizing the effects of directly generating circularly polarized light and distinguishing left and right rotation circularly polarized light. The structure comprises a substrate and a Z-shaped through hole which covers the substrate and is etched in a medium layer. According to the invention, the average circular dichroism of a polarizer at a waveband of 1.50[mu]m to 1.61[mu]m is more than 70%, the circular dichroism at a waveband of 1.53[mu]m can reach 98.3% to the maximum degree, and the all-medium ultrathin two-dimensional circular polarization dichroic device has the advantages of quite wide waveband, simple structure and easy manufacturing, and thereby having a quite large application value in future optical sensing systems, advanced nanometer photon devices and integrated optical systems.

The invention discloses a method for high-sensitivity detection of silver ions through circular dichroism, belonging to the technical field of analytic chemistry. The method comprises the following steps: respectively coupling gold nanoparticles with two different grain sizes and two specific nucleic acids rich in a cytosine (C) sequence to obtain AuNPs10nm-DNA1 and AuNPs25nm-DNA2, adding silver ions to cause AuNPs10nm-DNA1 and AuNPs25nm-DNA2 to generate C-Ag<+>-C mispairing identification, reducing through trisodium citrate, reacting AuNPs10nm-DNA1, AuNPs25nm-DNA2 and silver ions under the liquid environment to form a binary assembly so as to form plasma chirality, and causing the gold nanoparticles to generate a circular dichroism CD signal in a visible region. The CD signal intensity in the liquid environment is measured through the circular dichroism so as to measure the content of the silver ions. According to the invention, reaction is only performed in the liquid environment, a step of cleaning is unnecessary, one-step reaction is only required, the reaction condition is simplified, the sensitivity of detection is improved, and the leading level in the world is achieved.

The invention relates to an aeromagnetic field vector detecting device and a detecting method, a DFB laser which has the same lasing frequency with an alkali metal atom D1 wire is adopted as a pump light source, the light emitted by the DFB laser generates circular polarization pump light polarized alkali metal atoms with free adjustable laser power through an optical isolator, an optical attenuator, a polarizer and a lambda/4 wave plate, and the atom is made to have macroscopic magnetic moment. A detected weak magnetic field in a y axis direction makes the magnetic moment to generate Larmor precession on an xoz plane around the y axis. The polarization plane rotation of the linearly polarized light caused by circular dichroism of a polarized atom, the pump light is removed, the deflection angle gradually vibrates and attenuates to zero, a zero-cross detection device is adopted to detect the time difference between the time of removing the pump light and the first zero crossing point, the Larmor prescession frequency can be obtained, and a magnetic-field vector value is obtained by dividing the Larmor prescession frequency by a gyromagnetic ratio. According to the invention, the device and the method have the advantages of high magnetic-field vector detection precision, fast response frequency and good repeatability, and are suitable for aeromagnetic field vector detecting mobile platform magnetic measurement.

A highly efficient vacuum ultraviolet circular dichroism spectrometer is provided; the spectrometer suitable for laboratory use or for integration into a beam line at a synchrotron radiation facility. In one embodiment, a spectroscopic circular dichroism instrument is provided; the instrument configured so as to enable circular dichroism data to be simultaneously obtained for multiple wavelengths of light. The instrument may be further configured to operate in at least a portion of the vacuum ultraviolet wavelength region.

To obtain a monomer having a large torsion force, to obtain a liquid crystal polymer which is excellent in a film-forming property, can easily control a helical pitch of a cholesteric phase, can form a grandjean orientation in a good monodomain state by an orientation treatment in a short time such as few minutes, and can stably fix it in a glass state, and to obtain an optical element having a circular dichroism, represented by the following formula (a), comprising a solidified product of the liquid crystal polymer, which is thin and light, is hard to change the oriented state such as pitch, etc., at a practical temperature, and has excellent durability and storage stability. An optically active monomer represented by (wherein R1 represents a hydrogen atom or a methyl group, and A and B represent an organic group); a side chain type liquid crystal polymer having a structural unit comprising the optically active monomer; and an optical element showing a circular dichroism having a solidified layer of a grandjean oriented cholesteric liquid crystal phase comprising the liquid crystal polymer.

The invention describes a method to eliminate instrumental offset in measurement of optically active scattering and circular dichroism. The method uses the time-average measurement of the light that is systematically transformed by a series of optical devices. The optical devises perform the function of rotating linearly polarized light, interconverting left and right circular polarized light, converting circular polarized light to rotating linear polarized light and converting linear polarized light to alternating left and right circular polarized light.

The invention belongs to the technical field of metal nano materials, and particularly relates to a chiral nanostructure with adjustable circular dichroism and a preparation method thereof. A primary structure of the chiral nanostructure is an L-shaped structure, a gap exists between the long edge and the short edge of the L-shaped structure, the long edge of the L-shaped structure is made of metal, the short edge of the L-shaped structure is a two-layer structure perpendicular to the long edge, the bottom layer is made of silicon dioxide, and the upper layer is made of metal; the chiral nanostructure with the adjustable circular dichroism is formed by evaporating a medium layer on the long edge or the short edge of the primary structure, namely, the L-shaped structure. According to the chiral nanostructure with the adjustable circular dichroism and the preparation method thereof, the medium layer is added into a simple three-dimensional structure, the circular dichroism is achieved through a normal incidence mode of light, the circular dichroism is regulated and controlled through the position of the medium layer, and different requirements are met; precious metal material cost is greatly lowered, and the experiment cost is lowered; in addition, the chiral nanostructure is simple in preparation process, low in cost, more accurate in measurement signal due to normal incidence and capable of serving as a high-sensitivity biological sensor.

The invention discloses an ultra-sensitive detection method of ochratoxin A based on a gold core-silver satellite chiral assembly body, and belongs to the field of analytical chemistry. The method mainly comprises the following steps: (1) synthesizing gold nanoparticles with the particle size of 35 nm; (2) synthesizing silver nanoparticles with the particle size of 8 nm; (3) modifying aptamers on the gold nanoparticles; (4) modifying part of complementary sequences of aptamers on the silver nanoparticles; (5) assembling a gold core silver satellite structure; (6) performing circular dichroism spectrum detection, and creating a standard curve of gold and silver chiral signal superposition and ochratoxin A concentration. The invention provides a method for detecting ochratoxin A by a chiral signal of the gold core silver satellite structure. Compared with a conventional detection method, the method provided by the invention is low in cost, high in sensitivity, convenient and quick, and has a very good practical application prospect.

The invention discloses a method for detecting L-cysteine concentration by applying of a circular dichrorism, and belongs to the technical field of analytical chemistry. The L-cysteine and a reagent are mixed according to a certain volume ratio to generate self-assembly and form gold nanoparticle dimer, reactant is placed on a circular dichroism analyzer, signal strength at 525nm position of a main wave is detected, and therefore the concentration of the L-cysteine is measured. Compared with a traditional instrument, under a liquid environment, AuNPs and the L-cysteine are utilized to react to form the gold nanoparticle dimer, the chirality of the L-cysteine can be enlarged through the form of a binary assembly, and a CD signal is produced by the gold nanoparticle diamer in a visible region. The contents of the L-cysteine are measured by a manner that the CD signal intensity under the liquid environment is measured through the circular dichrorism. The method only can be carried out under the liquid environment, and a step of washing is not needed. Only one step of reaction is needed, reaction conditions are simplified, and sensitivity of detection is improved.

The invention relates to a circular dichroism enhancement device and a circular dichroism enhancement detection method based on a super-chiral light field. The circular dichroism enhancement device isformed by superposing a silicon dioxide substrate, a gold thin film, a magnesium fluoride nano-cylindrical array and a gold nano-cylindrical array from bottom to top. Vertically incident circularly-polarized light is going to the efficiently coupled into an optical resonant cavity formed by the gold thin film, the magnesium fluoride nano-cylindrical array and the gold nano-cylindrical array, andgenerates a super-chiral light field with the optical chiral density higher than that of ordinary circular polarization. When chiral molecules interact with the super-chiral light field and a resonance peak of the molecules is matched with the resonance wavelength of the resonant cavity, the circular dichroism of the chiral molecules can be greatly improved. In addition, through reducing a gap between the nano-cylindrical arrays, red shift of the resonance peak of the resonant cavity can be caused, thereby being conductive to further enhancing the optical chiral density of the light field in the resonant cavity and circular dichroism signals of the chiral molecules. The circular dichroism enhancement device and the circular dichroism enhancement detection method have the advantages of great circular dichroism signal intensity, high expandability and the like.

The invention provides a 6-DOF microchecker, which comprises at least three 2-DOF micro-drive apparatuses, wherein, the two 2-DOF micro-drive apparatuses have equal included angles and are horizontally and equally arranged on the circumference of a circular micro-plummer; each 2-DOF micro-drive apparatuses comprise two pairs of electromagnets and a micro-actuator rotor which is provided with an electromagnet armature; as for the two pairs of electromagnets, one pair is horizontally arranged and the other pair is vertically arranged, thereby the two pairs of electromagnets are symmetrically arranged in a cross shape; and the micro-actuator rotor is fixed on the circular micro-plummer and arranged on the center of the cross-shaped electromagnets. 6-DOF micromotion of the mocro-plummer is realized through high-precise control of the electromagnets to the micro-actuator rotor. The 6-DOF microchecker only needs to design a micro-actuator; the structure and the assembly technique of the microchecker are simple; and the development period is short.