Abstract: A heater integrated gas chromatography (GC) column device according to the present invention is capable of precisely and uniformly controlling a temperature by having a high thermal conductivity, and raising and lowering a temperature at a high speed by having a low thermal mass, such that a measuring time is significantly decreased. The GC column is in contact with a bobbin with a homogeneous temperature distribution, and thus a temperature is homogeneously distributed in each GC column. Further, the heater integrated GC column device according to the present invention has the above-described effects and may have a smaller size.

Abstract: Apparatus and methods for high performance liquid chromatography. The apparatus includes a preparation loop comprising two linear stepping pumps, a sample loop comprising a sample injector, a chromatography column, and a detector device. The detector device can include a flash lamp, a flow cell, and a light sensor comprising an entrance slit, a grating; and a charge-coupled device array.

Abstract: An apparatus for scanning and detecting analytes in real time as they move through a separation conduit is provided. The apparatus may include a detector mounted on a scanner containing a separation conduit positions under the scanner such that the scanner may move back and forth along the conduit, producing time and space data of the column as the analyte moves through and providing information regarding elution of the analyte in real time. A method for real time analysis of analytes as they move through a separation conduit is also provided.

Abstract: A detector for liquid chromatography has light sources that generate light in an ultraviolet region and in a near-infrared region; a flow cell, through which sample liquid flows; an optical system to let light generated from the light sources become incident on the flow cell concurrently; a detection element that detects light in the ultraviolet region that passes through the flow cell; a detection element that detects light in the near-infrared region that passes through the flow cell; and an arithmetic operation part that performs arithmetic operation of a first signal value obtained from the detection element and of a second signal value obtained from the detection element. The arithmetic operation part combines the first signal value and the second signal value to calculate a signal value with a reduced baseline fluctuation resulting from a mobile phase during a gradient analysis.

Abstract: An ultraviolet-visible spectrophotometry (UV/Vis) high-performance liquid chromatography (HPLC) photometer includes a nano flow cell in which a light source feeds a reference light channel and a sample light channel, a reference photodiode for evaluating the reference light channel, and a sample photodiode for evaluating the sample light channel, which extends through the nano flow cell. To create a photometer whose signal evaluation is improved, respective effective exposure times of the sample photodiode and the reference photodiode are settable separately from one another.

Abstract: An analyzing device includes a feeder connected to a container in which a sample is contained for sucking the sample from the container and feeding the sample, and a controller for performing control for feeding from the feeder to a measurer. In measuring the sample, the controller performs control so that results of a plurality of times of measurement are obtained with respect to the single container in which the sample is contained, without changing the container. This arrangement allows quick accuracy check.

Abstract: The invention provides novel, simple, reliable and effective methods for separating various lipids from biological samples. In certain embodiments, the invention provides HILIC-based UHPLC separation methods. In one embodiment, the methods of the invention offer an efficient and rapid separation of ether glycophospholipids (e.g., plasmalogens) from their diacyl or monoacyl counterparts within the same lipid class. In certain instances, the invention relates to the use of a Waters ACQUITY UPLC® system.

Abstract: A pulsed ion multifunctional detector used for both high performance liquid chromatograph and ion chromatograph, and experiment chromatograms attached also show that the detector has excellent multipurpose function in liquid chromatograph. The casing of the instrument is provided with a sample solution inlet, a sample solution outlet, a power supply socket, a liquid crystal display, an operation keyboard and a detection signal output interface. In the casing is provided a detection electromechanical member, which includes a central controller, a detection cell, a preposed subtracting module, a polarity transformation module, a noise processing module and an output amplifier module. The pulsed ion multifunctional detector can sensitively and accurately measure ion current of sample ionized directly in the detection cell, and subtract baseline background generated by various mobile phases and automatically eliminate dynamic noise and drift of the instrument.

Abstract: A sensor system utilizing flexible electronics for on-line real-time high-sensitivity sampling, monitoring, and analysis of a parameter or analyte of interest in a fluid or in or on a solid is provided. The flexible substrate sensor system comprises a plurality of sensors, a flexible substrate, a network, and a connection between the sensors and the network, wherein the network reads out or collects information from the sensors. The network can be onboard, connected by via a physical connection to the sensors and the flexible substrate, or external to the sensors and flexible substrate, connected via a telemetric or wireless connection to the sensors. The flexible substrate sensor system can be deployed in systems that conduct or distribute fluids or solids, such as distribution systems (municipal water systems, oil or gas pipeline systems), industrial systems (production facilities, piping, and storage systems), and large structures (dams, bridges, walkways, buildings).

Abstract: This invention relates to methods and apparatus of a combination of laser wave mixing technology with diagnostic flow technologies with embodiments describing supercritical fluid chromatography. The combination of these technologies along with minute detection levels have not yet been seen in the field.

Abstract: A liquid chromatography device includes a sample inlet valve to which a sample to be analyzed is introduced, and a trap valve fluid-communicating with a solid phase extraction column and a reverse phase liquid chromatography column. The device further includes a solvent dividing unit dividing flow of a solvent discharged from the sample inlet valve into the first solvent inlet port and the second solvent inlet port of the trap valve. The liquid chromatography device improves resolution and increases reproducibility by allowing the sample injecting direction and the sample eluting direction to be opposite to each other.

Abstract: The invention provides methods for rapid and quantitative extraction and detection of coenzyme Q10 in a sample readily adaptable to high throughput screening methods. The invention further provides reagents and kits for practicing the methods of the invention.

Abstract: A non-electrolytic method and apparatus for treating an aqueous sample stream including analyte ions and matrix ions of opposite charge, for pretreatment or suppression. The apparatus includes an ion exchange membrane capable of passing only ions of opposite charge to the analyte ions, a sample stream flow channel, a first aqueous stream ion receiving flow channel adjacent one side of the sample stream flow channel and separated therefrom by the first ion exchange membrane, and stationary flow-through ion exchange packing disposed in the sample stream flow channel. The ion receiving channel has an ion exchange capacity for the matrix ions less than about 25% of the ion exchange capacity for the matrix ions.

Abstract: For the simplified use of a test strip holder, a device having a holding or positioning device is provided, comprising a mixing chamber, a lid for closing the mixing chamber, and an obvious fluid opening for a fluid passage from the mixing chamber to the test strip holder. This allows for the test strip holder to be inserted into the device in a simple way and a sample can be prepared in the mixing chamber of the device. The device is provided with a mixing chamber that can be closed, wherein a reaction partner, for example a gold conjugate, can be dissolved in the sample for increasing the sensitivity of the test strip.

Abstract: Flow through pressure sensors for use in fluid chromatography systems include a planar device formed from diffusion bonding of a plurality of metallic sheets and at least one sensing element. The planar device has a top surface, a bottom surface and a flow through channel. A diaphragm formed from a portion of one of the top or bottom surfaces is located adjacent to a sensing region of the flow through channel and is attached to the sensing element. The diaphragm is sized to deflect a distance in response to fluid pressure in the sensing region, which has an internal volume of less than about 25 microliters. The diaphragm and attached sensing element form a pressure sensor that measures strain or deflection of the diaphragm to calculate a pressure within the sensing region.

Abstract: A detection cell for a chromatography system includes a cell body having an inlet, an outlet, and a counter electrode, a working electrode, a sample flow passageway extending between the inlet and the outlet and in fluid contact with the counter and working electrodes, and a palladium/noble metal reference electrode system. A method of using the detection cell is also described.

Abstract: The present invention pertains to a method of ion chromatography wherein a specialized electrodeionization (EDI) apparatus is used for simultaneous ion suppression of cations from a flowing base containing an anion sample of interest and ion suppression of anions from a flowing acid containing a cation sample of interest. The methods described herein allow for the ion suppression of samples containing chloride, nitrate, and other electrochemically active anions, as well as sodium, potassium, and other electrochemically active cations, without causing damage to the suppressor.

Abstract: A method for analyzing a multi-channel chromatogram is realized for accurately resolving overlapping peaks on a multi-channel chromatogram to permit analysis of the composition of a sample. First, components of overlapping peaks are specified. A data matrix Dij is determined, and compressed in the wavelength direction to obtain a data matrix vector Di. Next, the two-dimensional data is deconvoluted, final standard deviation s0 is registered, and the deconvoluted two-dimensional data is reconvoluted to a retention intensity matrix. A quantitative spectral intensity matrix is computed, components are identified, and the identified components are quantified. Subsequently, an eigenvalue problem is solved, and the number n of components is estimated. The deconvolution and computation of the eigenvalue problem are iteratively executed until the peaks are isolated. Then, elution profiles are calculated, the components are identified, and the identified components are quantified.

Abstract: A fluid separation system (10) for separating compounds of a sample fluid in a mobile phase comprises a detector (50) adapted to detect separated compounds by providing an optical stimulus signal to the sample fluid and receiving a response signal to the optical stimulus signal. The detector (50) comprises a light source (100) adapted to provide an output light beam (230) as the optical stimulus signal. The light source (100) comprises a plurality of light emitting elements (200, 200A, 200Z) each adapted to emit a light beam (210, 210A1, 210A2, 210Z1, 210Z2) having a respective wavelength, and a diffracting element (220). The plurality of light emitting elements (200, 200A, 200Z) are arranged that emitted light beams (210, 210A1, 210A2, 210Z1, 210Z2) impinging, on the diffracting element (220) are diffracted by the diffracting element (220) to form the output light beam (230).

Abstract: A fluid separation conduit cartridge comprising a fluid separation conduit is disclosed. In certain embodiments the fluid separation conduit is potted to provide operation at increased pressures. In other embodiments, the fluid separation conduit cartridge has one or more memory units. The memory units are operative to store data such as, for example, cartridge usage and test results.

Abstract: This invention discloses a kind of quality control method and application of Ganoderma lucidium spore oil fat emulsion. Which includes Ganoderma lucidium spore oil 2˜25%, emulsifier 0.5˜10%, isosmotic agent 0.2˜5%, the remaining content is water and the final pH of Fat emulsion is adjusted to 6˜9. The quality control method of this invention can accurately determine the content of 1,2-oleic-3-palmitic triglyceride and glycerol trioleate in the preparation, and accurately determine the ergosterol content, which serves as the method and basis for quality control of this product. Fingerprints are utilized to grasp the product quality from the overall characteristics of Chromatogram. This invention has clearly defined active ingredients, with excellent bioactivity, and is capable of tumor treatment, while improving the organism's immunity, as well as the life quality of tumor patients undergoing radiotherapy and chemotherapy, and relieving the drug toxicity after treatment.

Abstract: The present invention pertains to a method of ion chromatography wherein a specialized electrodeionization (EDI) apparatus is used for (1) the preparation of a pure acid or pure base for use as an eluent in a chromatographic separation column and/or (2) for ion suppression (or neutralization) of the acid or base after it has been used to elute ions from a chromatographic separation column. Methods for trace ion removal, acid and base neutralization, and ion suppression using a specialized EDI apparatus are also described. The methods described herein allow for the ion suppression of samples containing chloride, nitrate, and other electrochemically active anions, without causing damage to the suppressor.

Abstract: An apparatus for liquid chromatography which detects ingredients by an electrolytic device, wherein the apparatus can detect many kinds of substances in high sensitivity by making possible to apply a wider range of electrolyzing voltage than former apparatus. The electrolytic device provided in the apparatus for liquid chromatography has a working electrode which is formed an electrically conductive diamond film on at least one side surface of an electrically conductive plate, a spacer plate of electrical insulating material which is 0.05 to 0.5 mm in thickness and has a hole, and a counter electrode which is facing to the diamond-formed surface of the working electrode while being put the spacer between the electrodes. Furthermore, an eluate inlet hole, an eluate outlet hole and a reference electrode are opened to a cavity formed by the hole of the spacer plate, and the eluate in the electrolytic device is pressurized to 1.0 to 15.0 kg/cm2.

Abstract: A method and system of screening or selecting a mobile phase eluent for a chromatography column is provided. A sample for chromatographic analysis or purification is combined with a solvent and passed through a membrane. A pressure measurement is taken of the sample/solvent combination in the system prior to the membrane. The pressure measurement may be compared to a second pressure and an appropriate solvent may be selected based on the relationship between the first measured pressure and the second pressure.

Abstract: A chromatography detector 11 includes a base substrate having a main surface 12a and a column flow path 15 formed on the main surface 12a, and a substrate block 13 and 14, which has a detection space 18 communicating with an outlet of the column flow path 15 and is stacked on the main surface 12a of the base substrate 12 so as to close a top surface of the column flow path 15.

Abstract: A contactless detection cell (1) for detecting an electrical property of one or more sample compounds in a flow path is described. The contactless detection cell (1) comprises a transmitter electrode (3) adapted for capacitively coupling an AC current into a detection channel (4) of the flow path, and a receiver electrode (5) adapted for receiving the AC current that has been coupled into the detection channel (4). An inner cross-section (IDDET) in at least a section of the detection channel is different than an inner cross-section (IDSEP) of the flow path (2) towards the detection channel (4).

Abstract: An apparatus for liquid chromatography comprises a liquid chromatography separation column on a substrate, wherein the separation column is coupled to a heater on the substrate. A chip-based temperature controlled liquid chromatography device comprises a substrate, a thermal isolation zone, and a separation column thermally isolated from the substrate by the thermal isolation zone. An apparatus for chip-based liquid chromatography comprising a cooling device is provided. A temperature gradient liquid chromatography system comprises a chip-based temperature controlled liquid chromatography device, a fluidic coupling, and an electrical interface. Methods of making and methods of using of chip-based temperature gradient liquid chromatography devices are also provided.

Abstract: A portable analytical system for detecting organic chemicals in water comprising a miniature preconcentrator and a SAW detector, the latter being characterized by a nanoporous carbon coating that provides improved response compared to prior art polymer coatings, particularly when detecting low concentrations of trihalomethane chemicals, such as chloroform and bromoform.

Abstract: 2-Deoxy-2-D-glucose (2-DG) concentration and purity can be measured in a sample of crystalline or liquid by HPLC with accuracy and precision suitable for analysis of active pharmaceutical ingredient and drug product.

Abstract: An apparatus for liquid chromatography which detects ingredients by an electrolytic device, wherein the apparatus can detect many kinds of substances in high sensitivity by making possible to apply a wider range of electrolyzing voltage than former apparatus. The electrolytic device provided in the apparatus for liquid chromatography has a working electrode which is formed an electrically conductive diamond film on at least one side surface of an electrically conductive plate, a spacer plate of electrical insulating material which is 0.05 to 0.5 mm in thickness and has a hole, and a counter electrode which is facing to the diamond-formed surface of the working electrode while being put the spacer between the electrodes. Furthermore, an eluate inlet hole, an eluate outlet hole and a reference electrode are opened to a cavity formed by the hole of the spacer plate, and the eluate in the electrolytic device is pressurized to 1.0 to 15.0 kg/cm2.

Abstract: Provided is a rosuvastatin triol and its use as a reference standard for analysis of rosuvastatin. Also provided are methods for preparation of rosuvastatin.

Abstract: A method and apparatus for monitoring and controlling nano-scale flow rate of fluid in the operating flow path of a HPLC system provide fluid flow without relying on complex calibration routines to compensate for solvent compositions gradients typically used in HPLC. The apparatus and method are used to correct the flow output of a typical, analytical-scale (0.1-5 mL/min) HPLC pump to enable accurate anti precise flow delivery at capillary (<0.1 mL/min) and nano-scale (<?L/min) HPLC flow rates.

Abstract: The invention relates to a method and apparatus for determining a total concentration of a component in a sample, including a reactor for oxidizing or reducing the sample, a chromatographic column coupled to the reactor for separating the component in the sample, and an electrochemical gas sensor coupled to the chromatographic column for detecting the component. In further embodiments, a filter may be used instead of or in addition to the column. Moreover, multiple sensors may be used instead of or in addition to the column for simultaneously detecting multiple components.

Abstract: The preparative liquid chromatograph uses a plurality of detectors including a mass spectrometer, and a chromatogram generator is provided for generating a plurality of chromatograms each corresponding to each of the plurality of detectors. The plurality of chromatograms are converted into a respective binary signal by comparing the chromatogram with a predetermined threshold, and a logical operator performs a binary operation on the plurality of respective binary signals, whereby a resultant binary signal is generated. A separation controller controls the fraction collector of the preparative liquid chromatograph based on the resultant binary signal to separate components from a sample. When “AND” is used as the binary operation, the resultant binary signal is “1” only when all the respective binary signals are “1”. This assures a high precision, high purity separation where an impurity mingling is minimized.

Abstract: Systems and methods for analyzing a plurality of samples in parallel include a plurality of liquid phase separation regions, a plurality of microfluidic storage regions, and a common mass spectrometer. Samples are separated in parallel in the separation regions to yield a plurality of output streams that are stored in the storage regions. The contents of each storage region, or at least a representative portion thereof, are sequentially discharged, ionized, and directed to the inlet of a mass spectrometer. In this manner, multiple separations are conducted in parallel with outputs provided serially to a common mass spectrometer without any loss of data. Microfluidic storage regions minimize diffusion between bands of separated samples. Portions of separated samples may be directed to fraction collectors.

Abstract: The present invention relates to microfabrication and utilization of microscale electrophoresis devices as well as the separation and detection of biomolecules in microscale electrophoresis devices. The device of the present invention utilizes novel fabrication and detection methods.

Abstract: A hyphenated technique based on the combination of high performance liquid chromatography (HPLC), electrochemical (coulometric) oxidation (EC) and electrospray ionization (ESI)- or atmospheric pressure chemical ionization (APCI)-mass spectrometry (MS), allows access of selected groups of low and medium polarity analytes to ESI- or APCI-mass spectrometry after HPLC by electrochemical treatment of the sample.

Abstract: A system for automatically performing liquid chromatography analysis of low volume liquid chemical samples at nanosecond flow rates using an analysis column that integrates a pre-concentration trapping column and a chromatography separation column terminating at an electrospray nozzle of an online mass spectrometer. The analysis column consists of a capillary having an inside diameter of between 75 and 125 microns packed throughout with a porous bed of micron particles. A branch outlet positioned 10 to 16 centimeters upstream from the nozzle divides the analysis column into an upstream pre-concentration trap and a downstream separation column. An autosampler delivers low volume liquid samples to the upstream inlet via a two-position valve. Feed connections couple the autosampler to upstream inlet when the valve is open to inject a liquid sample into the pre-concentration trap at a maximum loading flow rate in the range from 0.5 to 50 microliters/minute.

Abstract: A method to collect a plurality of target zones from a plurality of channels. The method includes introducing a plurality of compound mixtures into a plurality of microchannels on a microfabricated chip or a capillary tube. Optical signal measured at a detector window provides a signal of the position of a target zone. When a target zone has migrated to the location of a detector window, the detector senses an optical signal from the target zone and signals the system to disconnect a driving force from that channel. Once a plurality of zones in a plurality of channels are aligned, the driving force is reconnected and the zones are coeluted into a collection container.

Abstract: This invention relates to an apparatus and method for the simultaneous and rapid determination of CoQ10 and CoQ10H2 concentrations in human samples using HPLC-EC. The electrochemical reactions are monitored at electrodes that measure the current produced by the reduction of the hydroquinone group of CoQ10 or by the oxidation of the hydroquinol group of CoQ10H2.

Abstract: High throughput liquid chromatography systems include multiple separation columns and multiple flow-through detection regions in sensory communication with a common radiation source and a multi-channel detector. Preferred detector types include a multi-anode photomultiplier tube, a charge-coupled device detector, a diode array, and a photodiode array. In certain embodiments, separation columns are microfluidic and integrated into a unitary microfluidic device. The optical path through a detection region is preferably coaxial with the path of eluate flow along a flow axis through a detection region. On-board or off-board detection regions may be provided.

Abstract: Method allowing control of an evaporative light scattering detector which is coupled to a liquid chromatography column, substantially independently of the elution conditions for the chromatographic separation. A given adjustable constant calibrated volume of the flow which originates from the chromatography column is removed at a given adjustable frequency, this flow being constituted by an eluent which contains compounds to be analysed which have been dissolved therein, and the volume removed in this manner is transferred to a secondary circuit, to which the evaporative light scattering detector is connected, by being conveyed by means of an auxiliary pump with a specific carrier fluid which is independent of the eluent having a predetermined flow, and the successive fractions of the flow which originates from the chromatography column are mixed with the carrier fluid which conveys these fractions upstream of the evaporative light scattering detector.

Abstract: To economically perform preparatory chromatography, a plurality of pumps each having a corresponding one of a plurality of pistons and a corresponding one of a plurality of cylinders are driven by one motor to draw and pump solvent simultaneously into corresponding columns. To form a gradient, the pumps are connected to two-way valves that are connected alternately to a first solvent and a second solvent, whereby the time said valve is in a first position controls the amount of solvent drawn from the first reservoir into said pumps and the amount of time in said second position controls the amount of said second solvent drawn from the second reservoir into said pumps and the solvent is mixed in the pumping systems. The detectors are photodiodes mounted to light guides in the flow cells that generate signals related to light absorbance and communicate with a controller, whereby the controller receives signals indicating solute between the light guides and causes collection of solute.

Abstract: A reconfigurable multi-mode post-column analysis system improves resolution of liquid chromatography detection data by providing a parking or MS/MS detection mode in which flow of column eluent is substantially reduced to provide greater analysis time within a single eluting detection peak. A micro switching valve unit is reconfigurable between normal (MS) mode that passes column eluent directly to an MS unit, and a peak parking (or MS/MS) mode, in which normal mode column flow is interrupted, and the gradient halted, while more slowly flowing the detection peak of interest through the MS unit. A micro syringe pump contributes to the substantially lower MS/MS flow rate. A MS control unit controls micro switching valve valves to reconfigure between MS and MS/MS modes. After a detection peak, MS mode is reestablished, and the system primary pump returns to normal mode flow rate and gradient conditions. Mode changes can be carried out for each chromatogram detection peak.

Abstract: To economically perform preparatory chromatography, a plurality of pumps each having a corresponding one of a plurality of pistons and a corresponding one of a plurality of cylinders are driven by one motor to draw and pump solvent simultaneously into corresponding columns. To form a gradient, the pumps are connected to two-way valves that are connected alternately to a first solvent and a second solvent, whereby the time said valve is in a first position controls the amount of solvent drawn from the first reservoir into said pumps and the amount of time in said second position controls the amount of said second solvent drawn from the second reservoir into said pumps and the solvent is mixed in the pumping systems. The detectors are photodiodes mounted to light guides in the flow cells that generate signals related to light absorbance and communicate with a controller, whereby the controller receives signals indicating solute between the light guides and causes collection of solute.

Abstract: High throughput liquid chromatography systems include multiple separation columns and multiple flow-through detection regions in sensory communication with a common radiation source and a multi-channel detector. Preferred detector types include a multi-anode photomultiplier tube, a charge-coupled device detector, a diode array, and a photodiode array. In certain embodiments, separation columns are microfluidic and integrated into a unitary microfluidic device. The optical path through a detection region is preferably coaxial with the path of eluate flow along a flow axis through a detection region. On-board or off-board detection regions may be provided.

Abstract: A method and an apparatus for efficiently analyzing an organic macromolecular component contained in a sample with high precision are provided. The method and the apparatus for analyzing the organic macromolecular component are based on a flow analysis method with a measuring system including a sample introduction section, a preparation section, and a measuring section, and include the steps of supplying a sample together with a carrier solution into the measurement system through the introduction section, leading the sample to the preparation section and separating an organic macromolecular component from the sample, and leading the separated organic macromolecular component to the measuring section for analysis.

Abstract: A method and apparatus for efficiently analyzing an organic macromolecular component contained in a sample with high precision are provided. The method and apparatus for analyzing the organic macromolecular component are based on a flow analysis method with a measuring system including a sample introducing section, a preparing section, and a measuring section, composed of steps of supplying a sample with a carrier solution into the measurement system through the introducing section, leading the sample to the preparing section and separating an organic macromolecular component in the sample, and leading the separated organic macromolecular component to the measuring section and analyzing. Herein, the step of separating the organic macromolecular component includes steps of the organic macromolecular component in the sample being adsorbed on a resin and introducing an eluant into the preparing section and eluting the organic macromolecular component adsorbed on the resin.

Abstract: An apparatus and method for electrochemically modifying the retention of a species on a chromatography material is disclosed. The apparatus comprises a housing having an effluent flow channel adapted to permit fluid flow therethrough. The effluent flow channel comprises chromatography material. The apparatus further comprises first and second electrodes positioned such that at least a portion of the chromatography material is disposed between the first and second electrodes, and fluid flow through the apparatus is between, and in contact with, the first and second electrodes.

Abstract: A method for the separation of hydrogen ion, characterized in that a substance having a conjugate base (A−) of an acid (HA) as a functional group is used as a stationary phase, and an electrolyte containing a cation having a larger ion exchanging force than that of hydrogen ion is used as an eluent. The method allows the selective separation of hydrogen ion and the quantitative analysis thereof with high precision.