423 results about "Stable nuclide" patented technology

In a method of producing isotopes in a light water power reactor, one or more targets within the reactor may be irradiated under a neutron flux to produce one or more isotopes. The targets may be assembled into one or more fuel bundles that are to be loaded in a core of the reactor at a given outage. Power operations in the reactor irradiate the fuel bundles so as to generate desired isotopes, such as one or more radioisotopes at a desired specific activity or stable isotopes at a desired concentration.

The present invention relates to methods for measuring the proliferation and destruction rates of cells by measuring deoxyribonucleic acid (DNA) synthesis and/or destruction. In particular, the methods utilize non-radioactive stable isotope labels to endogenously label DNA synthesized through the de novo nucleotide synthesis pathway in a cell. The amount of label incorporated in the DNA is measured as an indication of cellular proliferation. The decay of labeled DNA over time is measured as an indication of cellular destruction. Such methods do not involve radioactivity or potentially toxic metabolites, and are suitable for use both in vitro and in vivo. Therefore, the invention is useful for measuring cellular proliferation or cellular destruction rates in humans for the diagnosis, prevention, or management of a variety of disease conditions in which cellular proliferation or cellular destruction is involved. The invention also provides methods for measuring proliferation or destruction of T cells in a subject infected with human immunodeficiency virus (HIV) and methods of screening an agent for a capacity to induce or inhibit cellular proliferation or destruction. In addition, the invention provides methods for measuring cellular proliferation in a proliferating population which utilize both radioactive isotope labels and stable isotopes to endogenously label DNA through the de novo nucleotide synthesis pathway.

The present invention relates to a method for preparing a radioactive film for local radioactive treatment. More particularly, the present invention relates to a method for preparing a radioactive film comprising the steps of; dissolving 0.1˜14.5 weight % of a stable nuclide and 13˜32.5 weight % of a film-forming base for the total amount of a solvent in the solvent; applying a stable nuclide solution on a release paper by a coater and drying; and irradiating a stable nuclide film with neutrons in a nuclear reactor. A method for preparing a radioactive film according to the present invention provides a radioactive film having a uniform distribution of radionuclides and an even thickness. Therefore, the therapeutic efficacy of the radioactive film for selective treatment of a lesion may be maximized by attaching the radioactive film on a patient's skin or a mucous membrane and by direct radioactive radiation.

The metabolic processes involved in the formation of any glucose-based metabolite of a metabolic network are determined. A precursor molecule is labeled with a stable carbon (¹³C) isotope at specific positions. The label is allowed to distribute and rearrange in the system. Metabolites are recovered and analyzed against a control system to determine a set of metabolic pathway substrate fluxes caused by changes to the test system relative to the control system such as the addition of compound being tested as a potential drug.

The present invention provides a novel NMR metabolomics method for observing an animal by labeling the animal itself. A labeled animal labeled with a stable isotope is produced by feeding an animal a labeled food labeled with the stable isotope. Metabolism of a biological substance in the animal is analyzed based on nuclear magnetic resonance data of the biological substance containing the stable isotope. The nuclear magnetic resonance data is acquired by performing NMR measurement on a body of the labeled animal, a portion of the body, or an extract.

Stable isotope labeling and neutron activation to measure biological functions are provided, as are the use and method of adding a chemical monitor to correct for neutron flux to sample vials prior to the addition of sample is presented, and the use of stable isotopes as a chemical bar code for vials and other items. Methods are provided also for measuring glomerular filtration rate and glomerular sieving function in a subject, and for measuring other physiological functions.

The invention provides a diagnostic test for gastrointestinal disorders by providing a safe, convenient, reliable method for measuring gastric emptying. In this test, a tracer amount of 13C-glutamine or 13C-glutamic acid is added to a liquid meal, or 13C-glutamic acid added to a solid meal. After digestion in the stomach, the meal is emptied into the small bowel, where the labeled 13C-tracer is immediately taken up and metabolized by the cells lining the small bowel. The released 13CO2 is detected in the breath. The measurement of rise in the level of 13CO2 as a function of time is correlated to the rate of gastric emptying.

The invention relates to the field of milk powder quality detection and more specifically relates to a method for distinguishing milk powder original production places through an elemental analysis-stable isotope mass spectrometry. The method is characterized by comprising the following steps: S1, obtaining samples of milk powder imported from a plurality of Countries; S2, respectively performingstable carbon and nitrogen isotope detection on a plurality of samples, performing stable hydrogen and oxygen isotope detection and performing analysis; S3, performing microelement analysis on the plurality of samples; S4, utilizing a principle component analysis method for performing principle component analysis on elements in the plurality of the samples and primarily distinguishing the samplesof the milk powder from different original production places; S5, utilizing original production place information of the plurality of samples and analysis data in the S3 and S4 and discriminant analysis to perform statistical modeling to obtain an original production place discrimination model coefficient matrix and corresponding original production place discrimination prediction accuracy; S6, bringing unknown samples into the model to perform original production place discrimination and finally judging original production place attributes. By means of the method, original production place traceability and discrimination can be primarily performed on the milk powder; thus, convenience is brought to checking of milk powder quality and fighting of counterfeit and shoddy products.

The invention relates to a preparation method for a cyclopropylamine spiro(hetero)cyclic compound and a composition containing the same, and application of the compound and the composition as an inhibitor for human lysine-specific demethylase (LSD1). The inhibitor is the cyclopropylamine spiro(hetero)cyclic compound as shown in a formula (I) which is described in the specification, or a pharmaceutically acceptable salt, predrug, solvate, polymorphic crystal or stable isotope derivative thereof. The compound can be used for treating or preventing diseases related to human lysine-specific demethylase, e.g., cancers and nerve diseases.

The invention is related to the instrumental analytical chemistry, further more to the stable isotope determination in food products. The present invention is referred to the alcohol thermal dehydration chamber, apparatus for “online” determination of isotopic composition of non-exchangeable hydrogen stable isotopes in ethanol samples, which comprises of: A) Alcohol thermal dehydration chamber, B) Detection device, which contains pyrolysis reactor and the Continuous Flow Isotope Spectrometer, and it is connected to the alcohol thermal dehydration chamber over C) System of valves, connectors and capillary tubes which are used for transfer of analyzed sample as for the purging of the alcohol thermal dehydration chamber; procedure for “online” determination of isotopic composition of non-exchangeable hydrogen stable isotopes in ethanol samples and procedure for “offline” preparation of ethene (ethylene) gas by means of alcohol thermal dehydration chamber and for the purpose of authenticity and geographical origin determination of wines, strong spirits, beer, fruit juices, honey and other food product which contain alcohol and/or fermentable sugars.

The invention relates to a low temperature rectification cascade system for rectifying CO to produce stable isotope 13C. The low temperature rectification cascade system is a cascade unit comprising n stage rectifying towers that are arranged horizontally; the rectifying towers comprise overhead condensers, tower bottom reboilers and rectifying columns; and the rectifying towers are connected through pipelines. Compared with the prior art, extraction sections are arranged in the horizontally cascaded rectifying towers so as to reduce the material conveying flow rate between cascaded rectifying towers, the automatic material flow between the rectifying towers can be achieved at the same time by changing the pressure distribution of the horizontal cascade system, the material is conveyed among the intermediate rectifying towers without power conveying equipment, and the cascade unit can be ensured to operate stably and continuously for a long time.

The invention discloses an analytical method of tilapia mossambica food source, which adopts stable isotope technology to analyze the tilapia mossambica food source and comprises the following steps: (1) collecting tilapia mossambica samples, collecting baits which tilapia mossambica probably ingests and processing the collected tilapia mossambica samples and the baits which are probably ingested; (2) carrying out the stable isotope determination on the processed tilapia mossambica samples and the baits which are probably ingested; and (3) data processing the stable isotope determination results, calculating and comparing the stable isotope numerical value of the tilapia mossambica samples with that of the baits which are probably ingested to obtain tilapia mossambica food source. The invention combines stable isotope technology and traditional stomach contents technology, in favor of improving analytic accuracy and precisely determining the nutrient source of tilapia mossambica, thus locating accurately the interrelation between the tilapia mossambica and other creature types and the flow of energy of the system.

The invention relates to an aquatic product producing area tracing method based on fatty acid carbon stable isotopes. The method includes the steps that A, preprocessing is performed, wherein collected aquatic products are processed, completely frozen, dried and ground into powder; B, total lipid extraction is performed, wherein 5.0 g of samples are taken, a chloroform and methanol solution is added, digestion stays overnight after oscillating extraction, filtering is performed, an extraction solution is washed with a sodium chloride solution, standing is performed so that layering can be achieved, a chloroform layer is collected, and after drying performed through anhydrous sodium sulfate, sample total lipid is acquired by means of concentration of a nitrogen blowing method; C, methyl esterification of fatty acid is performed, wherein a sulfuric acid-methyl alcohol methyl esterification method is adopted, a sulfuric acid-methyl alcohol solution is added into the total lipid, methyl esterification is performed in a water bath, n-hexane is added for oscillation after cooling, standing is performed so that layering can be achieved, supernatant is taken and placed in a bottle to be refrigerated and stored; D, the fatty acid C stable isotopes are measured, wherein fatty acid methyl ester samples are analyzed and identified through a gas chromatograph mass spectrometer; E, a result is analyzed, wherein by comparing fatty acid in different sea area samples, aquatic products in different sea areas and different varieties are identified.

Stable isotope atoms present in the form of stable isotope compounds, for example, 13C present in the form of 13CO, are separated by distillation using a distillation column packed orderly with a formed packing, and preferably by distillation using a distillation column packed with a "promoting-fluid-dispersion type" structured packing.

The invention relates to a Wuyi rock tea production place identification method through combination of four detection technologies, and belongs to the technical field of geographical indication product authenticity recognition. In the prior art, the single detection data cannot represent all production place traceability key information, the data matching problem exists when different types of the detection data are subjected to combined use in the metrology method, and other problems exist. A purpose of the present invention is to solve the problems in the prior art. According to the present invention, based on the partial least square discrimination model, the near infrared characteristic spectrum data, the stable isotope data, the trace element data and the amino acid data of the rock teas (produced inside and outside the geographical indication production place) from different production places are integrally fused, the analysis model is established, the sample is extracted, and the rock tea production place is objectively and accurately determined by using the model, wherein the recognition rate is high, achieves 100.0%, and is higher than the PLSDA determining result of the single data, and the recognition rate of the blind sample achieves 100%; and the method has the good application prospect, and can be used as the Wuyi rock tea production place traceability recognition technical method.

The invention relates to a method for measuring the hydrogen isotope ratio of ethanol in grape wine and belongs to the technical field of stable isotope analysis. The method comprises the steps that (1) hydrogen isotope is used for forming a known to-be-tested water treatment sample; (2) acetone is used for diluting a fermentation ethanol sample treated by water, and the mixture is mixed for use; (3) a liquid sample injection needle is used for sample injection, and gas chromatography equipped with a molecular sieve capillary chromatographic column is used for separating ethanol, acetone, water and other hydrogen compounds; (4) an on-line cracking device is used for converting ethanol into hydrogen; (5) CF-IMRS is used for measuring the hydrogen delta D produced by the ethanol; (6) correction computation of delta DSMOW of sample ethanol is performed according to the delta D measured value of an ethanol isotopic reference material. According to the method for measuring the hydrogen isotope ratio of ethanol in grape wine, GC-TC-IRMS is used for measuring the hydrogen isotopic compositions of the fermentation ethanol, and the technical difficulty of series of pretreatment of ethanol purification before measurement of fermentation ethanol hydrogen isotope in the past is solved; advance of the ethanol hydrogen isotope measurement technology can be promoted, and a technical method is provided for source identification of fermentation ethanol, sugar mixing detection of a plant source product and study of metabolic pathways in future.

The invention relates to a rapid determination method for oxygen stable isotope of ethanol in an alcoholic beverage, and belongs to the technical field of stable isotope analysis. The method comprises the following steps: 1) using acetone to dilute an alcoholic beverage, and mixing for stand-by; 2) injecting a sample by a liquid injection needle, and using a GC with molecular sieve chromatographic capillary column to separate ethanol, acetone, water and other oxygen-containing compounds; 3) converting ethanol into CO with an on-line pyrolysis device; 4) determining delta 18O in CO produced by ethanol by CF-IRMS; and 5) based on a measured delta 18 O value of an isotopic reference material, correcting and calculating delta 18OVSMOW of the ethanol sample. The invention utilizes GC-TC-IRMS to realize rapid determination of oxygen stable isotope of ethanol in alcoholic beverage, and solves series of existing technical problems in pretreatment, such as ethanol purification before determination of oxygen stable isotope of alcohol in alcoholic beverage. The project can promote technological progress of ethanol oxygen isotope determination, and also provides technical methods for the future research on authentication and metabolic path of alcoholic beverage or biofuel.

Methods for incorporating a stable isotope into a protein or peptide fragment are disclosed. The methods include providing isolated isotope-labeled protein or peptide fragments and analyzing the isolated labeld fragments. In another aspect of the invention, methods for quantitatively comparing peptides in two protein or peptide fragment mixtures are provided. In these methods, protein levels are measured using stable-isotope coded protein or peptide fragments.

The invention discloses a stable isotopic abundance ratio real-time online monitoring device and a stable isotopic abundance ratio real-time online monitoring method. A wavelength scanning off-axis integrated cavity spectrum technology is utilized for performing precision measurement on isotopic abundance ratio of an object element, and the device comprises a laser device, a laser controller, a signal generator, an angle adjustable prism, a wavemeter, an off-axis integrated cavity, a temperature and pressure controller, a piezoelectric ceramic controller, an off-axis parabolic mirror, a photoelectric detector, a lock-in amplifier and a signal processing system for acquiring A/D (analog/digital) and terminal signals. The method disclosed by the invention is performed on the basis of the off-axis integrated cavity laser absorption spectrum technology and is further combined with wavelength scanning, cavity regulation, temperature, pressure and wavelength precision control technology, so that the stable isotopic abundance ratio real-time online monitoring can be realized, and trace gas concentration and isotopic abundance ratio measurement can be simultaneously performed; furthermore, the preparation of a sample is not required, so that the measurement frequency is greatly improved; and the device has the advantages of simplicity in operation, no need of calibration, almost no drift during a long period of time, good stability, low power, convenience in carrying, mounting and field experiments and large dynamic range.