369 results about "Plasma sample" patented technology

The invention relates to the technical field of aplastic anemia (AA) treatment research, discloses a biomarker method for predicting the curative effect of cyclosporine on aplastic anemia, and aims to detect plasma differential metabolites of patients with aplastic anemia by adopting a metabonomics technology, find potential biomarkers for treating AA patients and find the curative effect of cyclosporine on the AA patients. CsA) is used for treating the in-vivo metabolism of AA. The method is based on liquid chromatography-mass spectrometry (LC-MS) and gas chromatography-mass spectrometry (GC-MS) technologies, and comprises the following steps: collecting 5 plasma samples of AA patients, 5 plasma samples of healthy people and 5 plasma samples of patients in a stable period after treatment for comparative analysis; and screening differential compounds by adopting a multivariate statistical method, and further performing enrichment analysis on differential metabolites. Research of the method shows that in-vivo metabolites of AA patients and healthy people are obviously different, and the way related to immunity and energy metabolism may be a key target for treating AA; csA intervenes the occurrence and development of AA by regulating and controlling immune-related metabolic ways.

The invention provides an immunodetection method of a multi-index immune checkpoint detection kit, which belongs to the technical field of immunodetection and comprises three main stages of sample preparation, immune reaction and data analysis. The method comprises the following steps: firstly, carrying out centrifugal separation to obtain a plasma sample, and preparing a fluorescent microsphere coupled capture antibody and biotin labeled detection antibody compound; then carrying out immune reaction, forming a sandwich type immune complex through specific binding, and adding streptavidin marked by phycoerythrin for signal amplification. Detecting a fluorescence signal by adopting a flow cytometer to obtain an original data matrix; a contribution feature vector, a utility feature vector and an expression feature matrix are extracted through a feature decomposition algorithm, and a deep learning model of a total-score-total structure is established for data analysis. Finally, a detection report containing a quantitative result, an importance score and reliability evaluation is generated, and the technical problem that in the prior art, the analysis accuracy of a multi-index immune checkpoint detection result is insufficient is solved.

The invention discloses a colorectal cancer early-stage accurate diagnosis model based on plasma cfDNA multi-dimensional fragment omics and a construction method and application thereof. The method comprises the following steps: a) collecting and processing a sample; b) performing whole genome sequencing (WGS) and bioinformatics processing; c) fragment omics feature extraction; and d) constructing and optimizing a machine learning model. According to the method, cfDNA is extracted from a plasma sample of a colorectal cancer patient, the fragment size distribution and terminal sequence characteristics of the cfDNA are analyzed by utilizing a high-throughput sequencing technology, and then a specific cfDNA fragment mode related to CRC is identified through bioinformatics analysis. Based on the identified cfDNA fragment features, an economically feasible and highly sensitive diagnosis model is constructed, and early diagnosis of CRC is realized.

The invention discloses an eRNA molecular marker for auxiliary diagnosis of colorectal cancer and application of the eRNA molecular marker, and is characterized in that the eRNA molecular marker is eRNA eCOL4A1, and the nucleotide sequence of the eRNA molecular marker is shown as SEQ ID NO.1. The invention further provides application of the eRNA molecular marker in preparation of a kit for auxiliary diagnosis of colorectal cancer, and the eRNA molecular marker comprises a fluorescent quantitative PCR specific amplification primer for detecting the eRNA eCOL4A1 in a plasma sample, the nucleotide sequence of the upstream primer is 5 '-GGGCAGTGATGTGTAGATGAGTT-3', the nucleotide sequence of the downstream primer is 5 '-TGAACATCACATGGAGC-3', and the kit has the advantages that absolute quantitative detection of target molecules and early screening and identification of colorectal cancer can be rapidly and accurately completed only by a small amount of samples, and the kit is high in sensitivity, high in accuracy and rapid in detection.

The invention provides a glomerular senescence evaluation method, system and device, and relates to the technical field of glomerular senescence evaluation.The evaluation method mainly comprises the steps that based on a low-abundance proteomics result of an aged mouse plasma sample, core expression protein related to glomerular senescence is screened out, a prediction model aiming at glomerular senescence is constructed, and the prediction model is used for predicting the glomerular senescence; the prediction model comprises a glomerular senescence index; detecting core expression protein data of a to-be-detected plasma sample, and calculating the glomerular senescence index of the to-be-detected plasma sample according to the prediction model. According to the scheme, aiming at the specificity of glomerular senescence, core expression protein can be screened out and a prediction model can be constructed through methods such as low-abundance proteomics results, so that the glomerular senescence can be evaluated simply, conveniently, reliably and quickly; the scheme is helpful for follow-up efficient research and evaluation of anti-glomerular senescence drugs, and is helpful for follow-up efficient research and explanation of the effect of glomerular senescence in CKD progress.

A method for detecting the content of fluralana based on cat plasma relates to the technical field of detection of the content of fluralana, and comprises the following steps: extracting fluralana in a cat plasma sample by using an acetonitrile precipitation method, adding isotope deuterium-labeled fluralan-D4 as an internal standard, and quantifying the fluralana by using a UPLC-MS / MS method, verification parameters such as the quantitative range, the minimum quantitation limit, the intra-day and inter-day accuracy and precision of the analyte fluralana in the cat plasma and the selectivity and the recovery rate of the method all meet the requirements; after ULOQ is measured every time, an acetonitrile sample is continuously injected, the analyte residual quantity meets the requirement, the established method for measuring the flurala in the plasma through LC / MS / MS meets the requirement of the related guiding principle, the method is applied to the pharmacokinetics method of the flurala drops in the cat body, and the content of the flurala in the cat plasma sample can be accurately quantified.

The invention discloses a core-shell structure adsorbent and a preparation method and a kit thereof, as well as a detection method for the concentration of styrene metabolites in plasma. The core-shell structure adsorbent includes ferroferric oxide magnetic microspheres, petal-shaped titanium dioxide coated on the surface of the ferroferric oxide magnetic microspheres, and a quaternary amine-carbon 18 bifunctionalized oligomeric polymer compound modified on a partial area of ​​the surface of the petal-shaped titanium dioxide. The core of the adsorbent of the present invention is ferroferric oxide magnetic microspheres, and the adsorbent as a whole is magnetic, which can achieve rapid solid-liquid phase magnetic separation, improve the sample purification efficiency, the titanium dioxide component in the material can effectively adsorb the phospholipid components in the plasma, and the quaternary amine-carbon 18 bifunctionalized oligomeric polymer component can effectively adsorb impurities such as fat and inorganic anions in the plasma, thereby effectively reducing the matrix interference effect in the sample detection process, so as to achieve the purpose of quickly and accurately detecting the concentration of trace phenylglyoxylic acid and mandelic acid in the plasma sample.

Disclosed herein includes a method of detecting RhD incompatibility during pregnancy, comprising: a) extracting DNA from a blood sample of a pregnant mother; b) performing qPCR on the DNA to determine Ct values of at least one RhD exon and at least one internal control gene; and c) calculating a ΔCt value between the at least one RhD exon and at least one internal control gene.

The invention relates to a metabolic biomarker for predicting the cardiovascular disease risk of a patient with senile subclinical hypothyroidism and application of the metabolic biomarker. The marker comprises inosine, arachidonic acid, arginine, phenylalanine and glycocholic acid. According to the method, metabolite information of each plasma sample in a research queue is obtained by establishing an elderly SCH and concurrent CVD crowd queue and detecting by adopting a high performance liquid chromatography-mass spectrometry technology, and a targeted metabolic content map is established. According to the matrix expression of the metabolic marker, in combination with clinical follow-up visit data, a model is constructed by using machine learning Lasso-cox, and a clinical prediction model of the CVD risk of the elderly SCH patient is constructed to guide precise diagnosis and treatment of the elderly SCH. The invention further provides a kit containing the diagnostic marker suitable for predicting the CVD risk of the elderly SCH, and the kit can be used for predicting the CVD risk of the elderly SCH.

The invention relates to the technical field of medical detection, in particular to a method for detecting aldosterone, cortisol, deoxycorticosterone and cortisone in plasma through LC-MS / MS. The method comprises the following steps: (a) mixing a plasma sample with an internal standard solution to obtain a mixed solution; (b) adding the mixed solution into the magnetic bead suspension, sequentially carrying out adsorption, weak washing, strong washing and elution, and collecting an eluent; (c) carrying out liquid nitrogen blowing and redissolving on the eluent, and then carrying out LC-MS / MS detection; wherein the surfaces of the magnetic beads are modified with steroid adsorption groups, and the target detection objects are aldosterone, cortisol, deoxycorticosterone and cortisone. The detection method is convenient and simple, the detection efficiency is higher than that of a traditional method, and a feasible solution is provided for promoting popularization and application of the LC-MS / MS technology in clinical practice.

The invention discloses a colorectal cancer plasma circulating microbial marker, a reagent, a kit and application thereof, and belongs to the technical field of biomedical detection. The plasma circulating microbial marker for colorectal cancer comprises alternaria alternata, alophilous alophilous alophilous alophilous alophilous alophilous alophilous alophilous alophilous alophilous alophilous alophilous alophilous alophilous alophilous alophilous alophilous alophilous alophilous The colorectal cancer plasma circulating microbial marker can be used for early screening of colorectal cancer, has relatively high sensitivity and specificity, and remarkably improves the accuracy and reliability of detection; the limitation of traditional ctDNA detection is broken through, and the detection rate of early colorectal cancer is improved. The colorectal cancer plasma circulating microbial marker in a colorectal cancer plasma sample is detected through low-depth whole genome sequencing, the requirement for depth in an experiment is reduced, the cost can be greatly reduced while high sensitivity and specificity are guaranteed, and the method is more suitable for large-scale screening.

The invention discloses a method for annotating a vesicle cell subset based on monovesicle membrane proteomics, and belongs to the technical field of vesicle cell annotation. The method comprises the following steps: 1, carrying out exosome collection on a plasma sample to obtain a sample; 2, coding and labeling the antibody probe, and adding a protein tag and a labeled DNA sequence into the antibody probe to obtain a labeled antibody probe; 3, preparing a corresponding combined product; 4, adding a labeled antibody probe into the sample to obtain an exosome compound; step 5, capturing an exosome conjugate through CTB; 6, adding the binding product into the exosome conjugate to generate a sequence; 7, constructing a sequence library and sequencing to obtain a sequencing sequence; 8, removing a sequencing sequence with low expression quantity to obtain an exosome expression data matrix, and standardizing the exosome expression data matrix; 9, carrying out clustering analysis to find out an exosome core subgroup; and step 10, determining the source of the exosome core subgroup, and annotating the single vesicle subgroup.

A method of pre-screening a human subject for a clinical trial for treatment of tauopathy or an amyloidogenic disease. The method comprises obtaining a plasma sample from the subject and determining a concentration of p217+tau present in the plasma sample. The method further comprises indicating the subject for further screening for the clinical trial when the concentration of p217+tau present in the plasma sample is greater than or equal to a minimum threshold and less than or equal to a maximum threshold. The minimum threshold corresponds to an amount of p217+tau in plasma over which subjects present with mild cognitive impairment (MCI) and an increased accumulation of tau tangles in the brain as compared to a cognitively normal patient. The maximum threshold corresponds to an amount of p217+tau present in plasma over which subjects present with pathology of widespread accumulation of tau tangles in multiple regions of the brain.

The invention provides a metabolic marker combination for ovarian cancer diagnosis and application thereof, and belongs to the technical field of in-vitro diagnosis. The invention provides a metabolic marker combination for ovarian cancer diagnosis. The metabolic marker combination comprises phosphatidylcholine 34: 4, threonic acid, phosphatidylcholine 32: 2, pyroglutamic acid, phosphatidylcholine 36: 6 and ceramide d38: 2. According to the metabolic marker combination, plasma samples of a healthy subject and an ovarian cancer patient are analyzed, a group of biomarkers with significant difference are screened from the plasma samples, and the metabolic marker combination is a non-invasive, non-invasive and high-accuracy metabolic marker combination for distinguishing the healthy subject and the ovarian cancer patient. The method can be used for constructing a diagnostic model for distinguishing healthy subjects from ovarian cancer patients. The metabolic marker combination disclosed by the invention can be used for improving the diagnosis and evaluation capability of ovarian cancer patients, so that early discovery, early diagnosis and early intervention can be realized clinically, and the survival rate of the ovarian cancer patients is improved.

The invention relates to the field of biological medicine, and discloses application of LPC, PC and AA in children sepsis diagnosis and prognosis product development. According to the invention, a high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS / MS) technology is used, plasma samples of a child sepsis patient and a healthy control group are compared, the relationship between lipidome change and pSOFA score is analyzed, and specific lipid molecules closely related to disease severity and prognosis are identified. According to the invention, the following lipid molecules are highlighted as key biomarkers: lysophosphatidylcholine (LPC), phosphatidylcholine (PC) and arachidonic acid (AA). The change of the lipid molecules is closely related to the physiological state of a child sepsis patient, and the lipid molecules can be used for early diagnosis and evaluation of the state of the child sepsis, so that the treatment effect and the accuracy of prognosis evaluation are improved, and a new treatment strategy and a new management method are provided for clinic.

The invention discloses a novel high performance liquid chromatography-tandem mass spectrometry analysis method for detecting aspartatide in human plasma, teriparatide is used as an internal standard substance to be detected, a solid phase extraction method is adopted to extract aspartatide to be detected and internal standard teriparatide from a plasma sample, and a standard curve is linear in a range of 0.010-1.00 ng / mL. During the verification of the method, selectivity, matrix effect, recovery, sensitivity, linearity, accuracy and precision, stability and dilution reliability are assessed to meet standards. The method disclosed by the invention has specificity on determination of the to-be-detected substance, i.e., the aspartatide and the internal standard teriparatide in the human plasma, and a standard curve is linear in a range of 0.010-1.00 ng / mL. The quantitative lower limit of methodology is 0.01 ng / mL. The method has the advantages of good accuracy, reliability, high sensitivity, high specificity and reproducibility.

A device for detecting and / or quantifying functional C1-esterase inhibitor (fC1-INH), the device comprising: (i) a conjugate pad comprising a first zone and a second zone, on which a first agent and a second agent are immobilized, respectively, and (ii) a membrane, which is in communication with the conjugate pad, wherein the membrane comprises a third zone, on which a third agent is immobilized. The conjugate pad may further comprise a fourth zone for placing a biological sample, which flows through the device in the order of the first zone, the second zone, and the third zone.

The invention relates to the field of medical informatics, and provides a diabetic nephropathy risk prediction method and system based on a protein marker. The method comprises the following steps: detecting the concentration of a protein marker in a plasma sample of a diabetic to obtain plasma protein marker concentration data; performing longitudinal correlation analysis on the protein markers according to the plasma protein marker concentration data to obtain the kidney disease related protein markers; performing feature screening on the kidney disease related protein marker combination to obtain a core protein marker; establishing a nephropathy risk prediction model through the clinical parameters of the diabetic patient and the core protein marker combination; and outputting a nephropathy risk prediction result of the patient to be detected through the nephropathy risk prediction model. The advanced intervention of the diabetic nephropathy is realized, and the prediction accuracy of the diabetic nephropathy is improved.

Nucleic acid error suppression is provided. In various embodiments, DNA is extracted from a collection of plasma samples. A sequence library with duplex adapters is prepared by ligating a duplex adapter having a Unique Molecule Identifier (UMI) to an end of each of a plurality of strands of the extracted DNA and amplifying the extracted DNA with a first polymerase chain reaction (PCR). A subset of the whole genome library is selected and amplified with a second PCR to increase an amount of PCR duplicates. A plurality of duplex reads is sequenced from the amplified subset aligned to a host genome and denoised based on said alignment. A variant presence is detected in at least one of the plurality of duplex reads. A signature of the variant is determined, which is compared to a collection of disease-specific variant signatures. A disease type is determined based on the comparison.

The invention discloses a plasma proteome-based colorectal cancer precancerous lesion diagnosis model construction method, and aims to solve the problem that a current colorectal cancer diagnosis kit is insufficient in sensitivity and specificity when detecting an early stage (precancerous lesion / early cancer) through a proximity extension technology (PEA) and selecting a specific detection panel. Protein biomarkers in plasma samples of 80 patients with precancerous lesion (progression stage adenoma) and early cancer (Tis / T1 stage) in a discovery queue are identified. By adjusting potential clinical confounding factors, 15 key protein biomarkers are identified. In the discovery queue, four machine learning algorithms (Lasso regression, random forest, SVM and XGBoost) are adopted to diagnose early colorectal cancer lesions, and high diagnosis efficiency is realized through multiple machine learning algorithms. In a verification queue sample, the diagnosis model also shows an important diagnosis capability for patients with progression-stage adenoma or early-stage colorectal cancer, and has a potential clinical application value.

The invention discloses a brain-derived Tau protein single-molecule fluorescence immunoassay detection kit and a use method, the kit provided by the invention is composed of a BD-Tau magnetic bead reagent coated with a capture antibody, a BD-Tau calibrator, a BD-Tau quality control product, a biotinylated BD-Tau Detector reagent for detecting the antibody, a BD-Tau SBG reagent, an RGP reagent and a BD-Tau sample diluent, the magnetic bead concentration of the BD-Tau magnetic bead reagent is 0.04 mg / mL-0. 08mg / mL of carboxyl magnetic beads, the carboxyl magnetic beads are coated with Tau J5.H3 coated antibodies, the detection antibody in the BD-Tau Detector reagent of the biotinylated detection antibody is Tau12, the concentration of the detection antibody is 0.3 mu g / mL-0. 8mu g / mL, and the concentration of SBG in the BD-Tau SBG reagent is 40 pM-60 pM; the kit disclosed by the invention can be used by adopting any one of a one-step method, a two-step method or a three-step method to detect the content of the BD-Tau protein in a plasma sample, the detection limit is 0.050 pg / mL, and the detection range is 0.050 pg / mL-150 pg / mL; according to the invention, the specificity, accuracy and reliability of determination of the Alzheimer's disease are improved, and the problems of early diagnosis and early screening of the Alzheimer's disease are solved.

The invention discloses a specific metabolic marker combination for diagnosing ovarian cancer and application thereof, and belongs to the field of markers for detecting ovarian cancer. The invention discloses a specific metabolic marker combination for diagnosing ovarian cancer. The specific metabolic marker combination comprises phosphatidylcholine 36: 6, sphingomyelin d40: 2 and sphingomyelin d41: 2. According to the invention, a metabonomics technology is used to screen out a specific metabolism marker combination for diagnosing ovarian cancer, and the specific metabolism marker combination has high sensitivity in ovarian cancer diagnosis and has high diagnosis capability for ovarian cancer diagnosis. The specific metabolic marker combination also has high specificity in ovarian cancer diagnosis, but is not applicable to diagnosis of endometrial cancer and cervical cancer. In addition, the plasma sample acquisition mode has the advantages of non-invasiveness and convenience, and has a wide application prospect in the research of biomarkers.

The invention relates to the technical field of biological detection, in particular to a sample diluent as well as a preparation method and application thereof. The sample diluent comprises a dilution component, and the dilution component comprises the following raw materials in percentage by mass: 0.005%-0.02% of thermally denatured immunoglobulin G, 0.5%-2.0% of a protein protective agent, 0.5%-1.5% of a metal ion chelating agent, 0.1%-0.5% of an ampholytic surfactant and 0.5%-2.0% of a sugar alcohol compound. According to the sample diluent, through the interaction of all the components, the ability of the sample diluent to reduce the matrix effect of serum and plasma samples can be remarkably improved, so that the interference of non-specific reaction and matrix effect of serum and plasma on the detection process is reduced, and the accuracy of serum and plasma sample detection can be improved; and a more reliable and accurate experiment result can be obtained.

The invention relates to the technical field of hepatic failure treatment, and particularly discloses application of tsRNA-20 or a simulant thereof in preparation of drugs for treating chronic plus acute hepatic failure and / or promoting liver cell proliferation. Through tsRNA sequencing and qRT-PCR verification, down-regulated expression of the tsRNA-20 in a plasma sample and liver tissue in chronic and acute hepatic failure is determined, and cell experiments find that the tsRNA-20 regulates an ACPH / GRHL1 axis to promote liver cell proliferation. Specifically, it is found that tsRNA-20 is combined with an amidyl peptide hydrolase (ACPH), so that a Ras-ERK pathway is activated, nuclear translocation of a granulocyte-like transcription factor 1 (GRHL1) is promoted, and finally liver cell proliferation is enhanced. Therefore, when the tsRNA-20, the precursor tRNA-GIy-CCC thereof and the regulated objects ACPH and GRHL1 thereof are applied to treatment of the chronic and acute liver failure, the tsRNA-20, the precursor tRNA-GIy-CCC thereof and the regulated objects ACPH and GRHL1 thereof can be used as targets to be regulated to promote liver cell proliferation, so that liver regeneration is promoted, the treatment effect of the chronic and acute liver failure is improved, the lifetime of patients with liver diseases is prolonged, and the tsRNA-20, the precursor tRNA-GIy-CCC and the regulated objects ACPH and GRHL1 possibly become new targets for precise treatment. The clinical application value is relatively high.

The invention discloses a data processing method, device, system and equipment, a medium and a program product, and is applied to the technical field of data processing. The method comprises: acquiring a plasma sample of a user; the plasma sample is detected, expression data of biomarkers are obtained, the biomarkers comprise markers related to carotid plaque occurrence, and the expression data of the biomarkers comprise the expression quantity of the biomarkers in the plasma sample; and based on the expression data of the biomarker, determining a risk score value of the user, the risk score value being used for representing a risk probability of occurrence of the carotid plaque of the user within a preset time period. According to the method, the risk probability of carotid plaque occurrence of the user within the preset time can be judged.

The invention discloses a gallbladder malignant tumor protein diagnosis biomarker combination, a kit and application. The protein marker provided by the invention comprises CA1 and / or IGFBP6 (insulin-like growth factor binding protein 6). According to the invention, an LC-MS / MS mass spectrometry method is adopted, mass spectrometry is carried out on a large number of clinical plasma samples, and by calculating log2 difference multiples of corresponding protein molecule contents in the plasma of a gallbladder cancer patient and the plasma of a normal person, it is determined that two protein molecules (CA1 protein and IGFBP6 protein) have good inspection benefits; the kit can be used as a marker for early diagnosis of gallbladder cancer; therefore, the invention provides a non-invasive screening means based on plasma, and the non-invasive screening means is used for predicting the cholecystic malignant tumor and distinguishing the cholecystic carcinoma crowd from the non-cancer crowd. And materials are convenient to take, the blood sample amount is small, and the sensitivity is high. The invention can fill the blank that no protein marker combination with high diagnostic efficiency exists at present for the cholecystic malignant tumor, and has great clinical significance.

The invention discloses a plasma or serum exosome separation method which comprises the following steps: firstly, coupling an antibody for resisting four transmembrane protein CD81 on the surface of an exosome by using a magnetic bead to form an immunomagnetic bead; pretreating a serum / plasma sample, enriching exosomes, co-incubating with the immunomagnetic beads, washing the magnetic beads after incubation capture is completed, and washing off uncombined impurities; after being captured, the exosome can be directly cracked, the magnetic beads are removed for downstream experiments, or the magnetic beads are eluted to obtain the complete exosome. The exosome affinity antibody is matched with the magnetic beads, the plasma / serum sample exosome is separated, the unique affinity separation technology not only can remove high-abundance protein in the serum / plasma sample, but also can eliminate other vesicles with similar membrane structures with the exosome, so that the purity of the separated exosome is far higher than that of the exosome obtained by other separation methods.

本发明实施例公开了一种基于蛋白质组学的脓毒症休克患者液体管理策略预测方法。所述方法包括：收集脓毒症休克患者的血浆样本，检测蛋白质标志物的表达水平，所述蛋白质标志物为GAL、NFASC、MICB_MICA、MAP2K6、JCHAIN和CSF3的组合；基于亚组识别模型计算效益得分，获得脓毒症休克患者的液体管理策略结果。本发明通过收集脓毒症休克患者的临床数据和蛋白质表达数据，采用LASSO回归分析，构建基于上述蛋白质标志物的亚组识别模型，进而获得效益评分，基于效益评分能预测患者液体管理策略方案的适用性，为脓毒症休克患者的液体治疗提供了可靠的方案，实现个体化和精准的液体治疗，在临床具有较好的应用前景。

The application discloses a method for determining unbound concentration of lenvatinib, which comprises the following steps: sending standard curve working solution and quality control working solution into a liquid chromatography tandem mass spectrometry detection system to obtain a standard curve; adding a plasma sample into an ultrafiltration tube, centrifuging under the condition of a centrifugal force of 3000g for 15 min, and collecting an ultrafiltrate of the plasma sample; adding the ultrafiltrate of the plasma sample into blank plasma ultrafiltrate, mixing uniformly, taking supernatant into a collection plate, sending the collection plate into the liquid chromatography tandem mass spectrometry detection system to obtain a ratio of a peak area of lenvatinib to a peak area of an internal standard, and then bringing the area ratio into the standard curve to obtain the unbound concentration of lenvatinib in the plasma sample. The method for determining the unbound concentration of lenvatinib can accurately determine the unbound concentration of lenvatinib in plasma and overcome the prejudice of the prior art.

The present invention relates to plasma metabolite markers for gastric cancer detection and their applications. Based on the metabolomics method, the present invention screened and obtained 15 metabolite markers that can distinguish between health, gastric non-cancer diseases and gastric cancer by mass spectrometry analysis of plasma samples of gastric cancer patients, gastric non-cancerous diseases and healthy controls. Multivariate multi-classification ROC curve analysis showed that the AUC value reached 0.852, and the 15 differential metabolite markers had good diagnostic efficacy in distinguishing health, gastric non-cancerous diseases and gastric cancer. Further selecting 11, 7 or 4 combinations from the 15 markers also had the same good diagnostic effect. And the above combination was further confirmed in the validation group. The metabolite combination provided by the present invention can accurately predict whether it is a healthy group, a patient with a gastric non-cancerous disease, or a patient with gastric cancer, which will help in the early prevention, treatment and prognosis of gastric cancer, etc., with good treatment effect and reduced treatment cost.