This study investigated the mechanism underlying electroacupuncture therapy for vascular dementia through electroacupuncture at the acupoints of Baihui （DU20）, Dazhui （DU14）, and bilateral Shenshu （BL23） in a ra...This study investigated the mechanism underlying electroacupuncture therapy for vascular dementia through electroacupuncture at the acupoints of Baihui （DU20）, Dazhui （DU14）, and bilateral Shenshu （BL23） in a rat model of vascular dementia produced by bilateral middle cerebral artery occlusion. Morris water maze test showed that electroacupuncture improved the learning ability of vascular dementia rats. Western blot assay revealed that the expression of p70 ribosomal protein S6 kinase and ribosomal protein S6 in vascular dementia rats was significantly increased after electroacupuncture, compared with the model group that was not treated with acupuncture. The average escape latency was also shortened after electroacupuncture, and escape strategies in the spatial probe test improved from edge and random searches, to linear and trending swim pathways. The experimental findings indicate that electroacupuncture improves learning and memory ability by up-regulating expression of p70 ribosomal protein S6 kinase and ribosomal protein S6 in the hippocampus of vascular dementia rats.展开更多
BACKGROUND Systemic lupus erythematosus(SLE)is an autoimmune disease characterized by systemic involvement and multiple autoantibodies in the serum.Patients with protein C(PC)and protein S(PS)deficiency are prone to t...BACKGROUND Systemic lupus erythematosus(SLE)is an autoimmune disease characterized by systemic involvement and multiple autoantibodies in the serum.Patients with protein C(PC)and protein S(PS)deficiency are prone to thrombosis.In contrast,patients with primary hyperfibrino-lysis tend to bleed.CASE SUMMARY A 52-year-old female patient with bilateral pleural effusion was diagnosed with"tuberculous pleurisy"and treated with anti-tuberculosis drugs and prednisone.The coagulation-related laboratory results showed decreased fibrinogen,PC activity,PS activity,and antithrombinШactivity.The immune-related laboratory results showed positive antinuclear antibody,anti-Smith antibody,anticardiolipin antibody(ACL),anti-β2-glycoprotein I antibody(aβ2GPI)and direct Coomb’s test and decreased complement 3 and complement 4.Thoracoscopy was performed and bloody pleural fluid was drained.Pathology of the pleural biopsy showed lymphocytes,plasma cells,and a few eosinophils in adipose and fibrous connective tissue.Results of whole exome sequencing of blood showed no genetic mutations suggesting the presence of hereditary hematological diseases.The patient was finally diagnosed with SLE and primary hyperfibrinolysis,and was treated with prednisolone,hydroxychloroquine,and compound cyclophosphamide.CONCLUSION PC and PS deficiency in SLE might be related to ACL and aβ2GPI.SLE and primary hyperfibrinolysis can coexist in one patient,with both a risk of thrombosis and a risk of bleeding.展开更多
The ribosomal protein S29 also known as RPS29, is not only a component of the 40S subunit of ribosome, but also involved in embryonic development, oncogenesis and other pathologic conditions. However, rare commercial ...The ribosomal protein S29 also known as RPS29, is not only a component of the 40S subunit of ribosome, but also involved in embryonic development, oncogenesis and other pathologic conditions. However, rare commercial antibody against RPS29 restricts the discovery of precise physiological and pathological function of this protein. In this study, the whole RPS29 gene was inserted into plasmid pGEX-6p-1 to express glutathione＇s transferase （GST） fusion proteins in Escherichia eoli （E. coli） strain BL21. High yields of soluble recombinant proteins were obtained. Mice were immunized with the recombinant RPS29 protein. The serum from the immunized mice could specially react with purified recombinant RPS29 proteins and native RPS29 proteins in CCE cells by western blotting, immunofluorescence staining and flow cytometric analysis. Further more the polyclonal antibodies also reacted specifically with human cell strain ECV304, which showed typical cytoplasmatic fluorescence. The polyclonal antibodies we prepared would be an available tool for studying the roles of RPS29 in embryonic development and human diseases.展开更多
A 76-year-old woman was diagnosed as having left lilac deep vein thrombosis due to a hereditary deficiency of protein S, seventeen members of her family were studied with the measurements of total protein S (TPS), fre...A 76-year-old woman was diagnosed as having left lilac deep vein thrombosis due to a hereditary deficiency of protein S, seventeen members of her family were studied with the measurements of total protein S (TPS), free protein S (FPS), protein C (PC) and anti-thrombin-Ⅲ(AT-Ⅲ). The results showed that the level of FPS of thepatient was only 7%, while that of TPS 137.1%. Her secondson had a low FPS level (13.4%) too, and his TPS level was 48.1%. PC and AT-Ⅲwere all normal It was thus the first case of hereditary PS dificiency reported in China.展开更多
The Tyro3, Axl and Mer (TAM) receptor tyrosine kinases are activated by endogenous ligands, protein S1 (PROS1) and growth arrest-specific gene 6 (Gas6), and those have important effects on cell biology. These receptor...The Tyro3, Axl and Mer (TAM) receptor tyrosine kinases are activated by endogenous ligands, protein S1 (PROS1) and growth arrest-specific gene 6 (Gas6), and those have important effects on cell biology. These receptors (Rs) can be shad from the cell membrane and their soluble(s) forms can be found in plasma. We investigated the fluctuation and interactive role of sTAMRs and its ligands in patients with hepatocellular carcinoma (HCC), hepatitis groups, and healthy normal adult controls (NC). The measurement cases were 45 patients with HCC group (stage 1 in 4, stage 2 in 8, stage 3 in 16, and stage 4 in 17), 4 patients with fulminant hepatitis (FH), 14 patients with acute hepatitis (AH), 10 patients with chronic hepatitis (CH), 16 patients with liver cirrhosis (LC), and 20 NCs matched by age. Plasma levels of three sTAMRs and their ligands were measured by ELISA. In comparison with NCs, Gas6, des-γ-carboxy Gas6, and sTAMRs levels were significantly higher in HCC patients, but free PROS1 levels were significantly lower. The sTyro3 and sAxl levels peaked HCC stages 2 and 3 respectively, and gradually decreased afterwards while maintaining high levels. sMer levels increased with the progression of HCC. Gas6 and des-γ-carboxy Gas6 levels gradually increased, and PROS1 levels decreased with the progression of HCC. Gas6 levels were positively correlated with sAxl levels, whereas sMer levels were negatively correlated with free PROS1 levels. sTAMRs and Gas6 levels increased in parallel to the progression of HCC fibrosis. Through the progression of HCC, Axl played the major role in TAMRs activation. However, sTYro3 continued increasing rapidly from the early stage, and that of Mer increased throughout the progression. Roles of Axl may be changed in Mer, because des-γ-carboxy Gas6 levels increasing with Gas6 in the advanced stage of HCC cannot send a signal to Axl.展开更多
PC and PS antigens were measured in 370 cases of 12 different diseases and 14 women at third trimester of pregnancy. The PC level was found significantly raised in coronary heart disease, diabetes, nephrotic syndrome,...PC and PS antigens were measured in 370 cases of 12 different diseases and 14 women at third trimester of pregnancy. The PC level was found significantly raised in coronary heart disease, diabetes, nephrotic syndrome, stroke, aplastic anemia and the third trimester of pregnancy, decreased in chronic hepatitis, acute fulminant hepatitis, cirrhosis and deep vein thrombosis (DVT) and no change in acute hepatitis, primary liver carcinoma, Buerger’s disease and leukemia. Total PS was increased in type Ⅱdiabetes, acute lymphocytic leukemia and DVT, and decreased in Berger’s disease, liver diseases, aplastic anemia and the third trimester of pregnancy. In majority of the cases, the total PS and free PS changed parallelly except in Buerger’s disease, DVT and preeclampsia. No correlation was found between PC and PS, PC and AT-Ⅲ.展开更多
To editor:Thrombophilia is a group of blood clotting disorders that increase the risk of venous thromboembolism(VTE),which is primarily caused by genetic mutations in proteins involved in the coagulation cascade.These...To editor:Thrombophilia is a group of blood clotting disorders that increase the risk of venous thromboembolism(VTE),which is primarily caused by genetic mutations in proteins involved in the coagulation cascade.These mutations include Factor V Leiden,prothrombin G20210A,protein S deficiency(PSD),antithrombin III deficiency,and methyltetrahydrofolate reductase.Among these,PSD contribute to a significant proportion of thromboembolic events in pregnant women,particularly in those with additional risk factors such as obesity,advanced maternal age,or a history of VTE.1 This correspondence aims to present a series of clinical cases of PSD in pregnant women,highlighting treatment strategies,especially in a hospital in a low-and middle-income country(LMIC)with limited access to advanced therapeutic options.Written informed consent was obtained from all patients involved in this study.We had treated six pregnant women diagnosed with PSD.Among these cases,four had a history of adverse obstetric outcomes,including abortion,preterm birth,or intrauterine fetal death,while the other two cases had recurrent miscarriages(Supplementary Table 1,http://links.lww.com/MFM/A72).These women were identified after the diagnosis of PSD,and each case was carefully monitored throughout pregnancy.展开更多
BACKGROUND Upper gastrointestinal hemorrhage is a life-threatening manifestation of cow’s milk protein allergy(CMPA).We analyze the clinical characteristics of a case of milk protein allergy manifested as severe uppe...BACKGROUND Upper gastrointestinal hemorrhage is a life-threatening manifestation of cow’s milk protein allergy(CMPA).We analyze the clinical characteristics of a case of milk protein allergy manifested as severe upper gastrointestinal hemorrhage.CASE SUMMARY The hospital admitted a 2-month-old male infant due to“melena for 6 days,he-matemesis twice”.The main symptom was melena,initially occurring once or twice per day,then gradually increasing to five or six times per day at their peak.During the course of the illness,the infant vomited blood,but there were no re-ports of vomiting,fever,pale complexion,dyspnea,wheezing,or difficulty brea-thing.Laboratory tests showed hemoglobin level of 87 g/L,platelet count of 349×109/L,and eosinophil percentage of 0.031.Coagulation studies were normal.After avoiding certain foods and feeding with an amino acid formula for 2 weeks,a repeat gastroscopy revealed less bleeding.After six weeks,a positive oral food challenge test confirmed a severe CMPA.At the 4-month follow-up,there was no gastrointestinal bleeding,and the infant was growing and developing well.CONCLUSION The manifestations of milk protein allergy are diverse and nonspecific,with gas-trointestinal bleeding being less common,especially in infants.When infants present with unexplained massive hematemesis,it’s critical to investigate the possibility of CMPA.展开更多
BACKGROUND Tacrolimus(FK506)is a key calcineurin inhibitor used to prevent organ transplant rejection and is effective in improving graft survival.However,it is linked to hyperglycemia and insulin resistance,contribut...BACKGROUND Tacrolimus(FK506)is a key calcineurin inhibitor used to prevent organ transplant rejection and is effective in improving graft survival.However,it is linked to hyperglycemia and insulin resistance,contributing to new-onset diabetes after transplantation and negatively affecting islet function.AIM To study the effects of tacrolimus on the insulin signaling pathway of hepatocytes.METHODS HL7702 cells were treated with different concentrations of tacrolimus(0.1 mg/L,1 mg/L,5 mg/L)for 24 hours.The proteins involved in insulin signaling were detected by Western blotting.RESULTS Compared with the control group,phosphorylation of insulin receptor substrate(IRS)1 at Ser 307 and Ser 323 were increased significantly when the tacrolimus concentration reached 1 and 5 mg/L.Phosphorylation of IRS1 at Ser 1101 was also increased,although not significantly.However,phosphorylation of Ribosomal protein S6 kinase beta-1 at Thr 389 was decreased significantly.The levels of phosphorylated glycogen synthase kinase 3αSer 21 and Ser 9 were increased.Surprisingly,phosphorylation of glycogen synthase at Ser 641 was increased.There was no significant change in the activity of glycogen phosphorylase.CONCLUSION Tacrolimus has no direct effect on hepatic glucose metabolism,but inhibits IRS1-mediated insulin signaling.This may be one of the underlying mechanisms by which tacrolimus induces insulin resistance.展开更多
Lateral flow immunoassay(LFIA)has become popular in laboratories,at-home testing,and medical diagnostics due to its minimal cost and user-friendliness.Nevertheless,conventional test strips based on colloidal gold can ...Lateral flow immunoassay(LFIA)has become popular in laboratories,at-home testing,and medical diagnostics due to its minimal cost and user-friendliness.Nevertheless,conventional test strips based on colloidal gold can only obtain qualitative or semi-quantitative results with low sensitivity.In this work,AuFe_(3)O_(4) dumbbell-like nanoparticles were synthesized and used as the LFIA labelling marker for highly sensitive colorimetric-photothermal dual-mode detection of SARS-CoV-2 spike(S)protein.The unique dumbbell structure of Au-Fe_(3)O_(4) NPs makes it possible to combine the best features of both Au NPs and Fe_(3)O_(4) NPs.The increased surface area of these NPs enhances their LSPR effect and photothermal effect,which achieves signal amplification to increase sensitivity.The Au-Fe_(3)O_(4) NPs modified with S protein antibody could identify S protein in samples,which were recognized and accumulated on T-line by another antibody,generating color band for qualitative colorimetric detection.The T-line was irradiated by laser to obtain temperature change for quantitative detection of photothermal.In optimized conditions,the detection limit was 1.22 pg/m L,three orders of magnitude more sensitive than colorimetric detection.Finally,the approach was performed on SARS-CoV-2 pseudovirus samples and outperformed traditional colloidal gold strips.This LFIA platform exhibits significant promise for practical implementation,as it can satisfy the need for low-cost,high-sensitivity,and home-based quantitative detection for respiratory infectious diseases.展开更多
基金supported by the National Natural Science Foundation of China, No. 81001541
文摘This study investigated the mechanism underlying electroacupuncture therapy for vascular dementia through electroacupuncture at the acupoints of Baihui （DU20）, Dazhui （DU14）, and bilateral Shenshu （BL23） in a rat model of vascular dementia produced by bilateral middle cerebral artery occlusion. Morris water maze test showed that electroacupuncture improved the learning ability of vascular dementia rats. Western blot assay revealed that the expression of p70 ribosomal protein S6 kinase and ribosomal protein S6 in vascular dementia rats was significantly increased after electroacupuncture, compared with the model group that was not treated with acupuncture. The average escape latency was also shortened after electroacupuncture, and escape strategies in the spatial probe test improved from edge and random searches, to linear and trending swim pathways. The experimental findings indicate that electroacupuncture improves learning and memory ability by up-regulating expression of p70 ribosomal protein S6 kinase and ribosomal protein S6 in the hippocampus of vascular dementia rats.
文摘BACKGROUND Systemic lupus erythematosus(SLE)is an autoimmune disease characterized by systemic involvement and multiple autoantibodies in the serum.Patients with protein C(PC)and protein S(PS)deficiency are prone to thrombosis.In contrast,patients with primary hyperfibrino-lysis tend to bleed.CASE SUMMARY A 52-year-old female patient with bilateral pleural effusion was diagnosed with"tuberculous pleurisy"and treated with anti-tuberculosis drugs and prednisone.The coagulation-related laboratory results showed decreased fibrinogen,PC activity,PS activity,and antithrombinШactivity.The immune-related laboratory results showed positive antinuclear antibody,anti-Smith antibody,anticardiolipin antibody(ACL),anti-β2-glycoprotein I antibody(aβ2GPI)and direct Coomb’s test and decreased complement 3 and complement 4.Thoracoscopy was performed and bloody pleural fluid was drained.Pathology of the pleural biopsy showed lymphocytes,plasma cells,and a few eosinophils in adipose and fibrous connective tissue.Results of whole exome sequencing of blood showed no genetic mutations suggesting the presence of hereditary hematological diseases.The patient was finally diagnosed with SLE and primary hyperfibrinolysis,and was treated with prednisolone,hydroxychloroquine,and compound cyclophosphamide.CONCLUSION PC and PS deficiency in SLE might be related to ACL and aβ2GPI.SLE and primary hyperfibrinolysis can coexist in one patient,with both a risk of thrombosis and a risk of bleeding.
基金Supported by the National Natural Science Foundation of China(30800983,30700418 and 30972596)the Natural Science Foundation of Chongqing(2008BB5113 and 2009BB5015) the Scientific Research Foundation of Third Military Medical University(2009XHG03 and 2009XYY04)
文摘The ribosomal protein S29 also known as RPS29, is not only a component of the 40S subunit of ribosome, but also involved in embryonic development, oncogenesis and other pathologic conditions. However, rare commercial antibody against RPS29 restricts the discovery of precise physiological and pathological function of this protein. In this study, the whole RPS29 gene was inserted into plasmid pGEX-6p-1 to express glutathione＇s transferase （GST） fusion proteins in Escherichia eoli （E. coli） strain BL21. High yields of soluble recombinant proteins were obtained. Mice were immunized with the recombinant RPS29 protein. The serum from the immunized mice could specially react with purified recombinant RPS29 proteins and native RPS29 proteins in CCE cells by western blotting, immunofluorescence staining and flow cytometric analysis. Further more the polyclonal antibodies also reacted specifically with human cell strain ECV304, which showed typical cytoplasmatic fluorescence. The polyclonal antibodies we prepared would be an available tool for studying the roles of RPS29 in embryonic development and human diseases.
文摘A 76-year-old woman was diagnosed as having left lilac deep vein thrombosis due to a hereditary deficiency of protein S, seventeen members of her family were studied with the measurements of total protein S (TPS), free protein S (FPS), protein C (PC) and anti-thrombin-Ⅲ(AT-Ⅲ). The results showed that the level of FPS of thepatient was only 7%, while that of TPS 137.1%. Her secondson had a low FPS level (13.4%) too, and his TPS level was 48.1%. PC and AT-Ⅲwere all normal It was thus the first case of hereditary PS dificiency reported in China.
文摘The Tyro3, Axl and Mer (TAM) receptor tyrosine kinases are activated by endogenous ligands, protein S1 (PROS1) and growth arrest-specific gene 6 (Gas6), and those have important effects on cell biology. These receptors (Rs) can be shad from the cell membrane and their soluble(s) forms can be found in plasma. We investigated the fluctuation and interactive role of sTAMRs and its ligands in patients with hepatocellular carcinoma (HCC), hepatitis groups, and healthy normal adult controls (NC). The measurement cases were 45 patients with HCC group (stage 1 in 4, stage 2 in 8, stage 3 in 16, and stage 4 in 17), 4 patients with fulminant hepatitis (FH), 14 patients with acute hepatitis (AH), 10 patients with chronic hepatitis (CH), 16 patients with liver cirrhosis (LC), and 20 NCs matched by age. Plasma levels of three sTAMRs and their ligands were measured by ELISA. In comparison with NCs, Gas6, des-γ-carboxy Gas6, and sTAMRs levels were significantly higher in HCC patients, but free PROS1 levels were significantly lower. The sTyro3 and sAxl levels peaked HCC stages 2 and 3 respectively, and gradually decreased afterwards while maintaining high levels. sMer levels increased with the progression of HCC. Gas6 and des-γ-carboxy Gas6 levels gradually increased, and PROS1 levels decreased with the progression of HCC. Gas6 levels were positively correlated with sAxl levels, whereas sMer levels were negatively correlated with free PROS1 levels. sTAMRs and Gas6 levels increased in parallel to the progression of HCC fibrosis. Through the progression of HCC, Axl played the major role in TAMRs activation. However, sTYro3 continued increasing rapidly from the early stage, and that of Mer increased throughout the progression. Roles of Axl may be changed in Mer, because des-γ-carboxy Gas6 levels increasing with Gas6 in the advanced stage of HCC cannot send a signal to Axl.
文摘PC and PS antigens were measured in 370 cases of 12 different diseases and 14 women at third trimester of pregnancy. The PC level was found significantly raised in coronary heart disease, diabetes, nephrotic syndrome, stroke, aplastic anemia and the third trimester of pregnancy, decreased in chronic hepatitis, acute fulminant hepatitis, cirrhosis and deep vein thrombosis (DVT) and no change in acute hepatitis, primary liver carcinoma, Buerger’s disease and leukemia. Total PS was increased in type Ⅱdiabetes, acute lymphocytic leukemia and DVT, and decreased in Berger’s disease, liver diseases, aplastic anemia and the third trimester of pregnancy. In majority of the cases, the total PS and free PS changed parallelly except in Buerger’s disease, DVT and preeclampsia. No correlation was found between PC and PS, PC and AT-Ⅲ.
文摘To editor:Thrombophilia is a group of blood clotting disorders that increase the risk of venous thromboembolism(VTE),which is primarily caused by genetic mutations in proteins involved in the coagulation cascade.These mutations include Factor V Leiden,prothrombin G20210A,protein S deficiency(PSD),antithrombin III deficiency,and methyltetrahydrofolate reductase.Among these,PSD contribute to a significant proportion of thromboembolic events in pregnant women,particularly in those with additional risk factors such as obesity,advanced maternal age,or a history of VTE.1 This correspondence aims to present a series of clinical cases of PSD in pregnant women,highlighting treatment strategies,especially in a hospital in a low-and middle-income country(LMIC)with limited access to advanced therapeutic options.Written informed consent was obtained from all patients involved in this study.We had treated six pregnant women diagnosed with PSD.Among these cases,four had a history of adverse obstetric outcomes,including abortion,preterm birth,or intrauterine fetal death,while the other two cases had recurrent miscarriages(Supplementary Table 1,http://links.lww.com/MFM/A72).These women were identified after the diagnosis of PSD,and each case was carefully monitored throughout pregnancy.
基金Supported by the Excellent Medical Talents Training Program of the First Affiliated Hospital of Guangxi Medical University,Difficult and Critical illness Center,Pediatric Clinical Medical Research Center of Guangxi,No.Gui Ke AD22035219the Key Laboratory of Children’s Disease Research in Guangxi’s Colleges and Universities,Education Department of Guangxi Zhuang Autonomous Region.
文摘BACKGROUND Upper gastrointestinal hemorrhage is a life-threatening manifestation of cow’s milk protein allergy(CMPA).We analyze the clinical characteristics of a case of milk protein allergy manifested as severe upper gastrointestinal hemorrhage.CASE SUMMARY The hospital admitted a 2-month-old male infant due to“melena for 6 days,he-matemesis twice”.The main symptom was melena,initially occurring once or twice per day,then gradually increasing to five or six times per day at their peak.During the course of the illness,the infant vomited blood,but there were no re-ports of vomiting,fever,pale complexion,dyspnea,wheezing,or difficulty brea-thing.Laboratory tests showed hemoglobin level of 87 g/L,platelet count of 349×109/L,and eosinophil percentage of 0.031.Coagulation studies were normal.After avoiding certain foods and feeding with an amino acid formula for 2 weeks,a repeat gastroscopy revealed less bleeding.After six weeks,a positive oral food challenge test confirmed a severe CMPA.At the 4-month follow-up,there was no gastrointestinal bleeding,and the infant was growing and developing well.CONCLUSION The manifestations of milk protein allergy are diverse and nonspecific,with gas-trointestinal bleeding being less common,especially in infants.When infants present with unexplained massive hematemesis,it’s critical to investigate the possibility of CMPA.
文摘BACKGROUND Tacrolimus(FK506)is a key calcineurin inhibitor used to prevent organ transplant rejection and is effective in improving graft survival.However,it is linked to hyperglycemia and insulin resistance,contributing to new-onset diabetes after transplantation and negatively affecting islet function.AIM To study the effects of tacrolimus on the insulin signaling pathway of hepatocytes.METHODS HL7702 cells were treated with different concentrations of tacrolimus(0.1 mg/L,1 mg/L,5 mg/L)for 24 hours.The proteins involved in insulin signaling were detected by Western blotting.RESULTS Compared with the control group,phosphorylation of insulin receptor substrate(IRS)1 at Ser 307 and Ser 323 were increased significantly when the tacrolimus concentration reached 1 and 5 mg/L.Phosphorylation of IRS1 at Ser 1101 was also increased,although not significantly.However,phosphorylation of Ribosomal protein S6 kinase beta-1 at Thr 389 was decreased significantly.The levels of phosphorylated glycogen synthase kinase 3αSer 21 and Ser 9 were increased.Surprisingly,phosphorylation of glycogen synthase at Ser 641 was increased.There was no significant change in the activity of glycogen phosphorylase.CONCLUSION Tacrolimus has no direct effect on hepatic glucose metabolism,but inhibits IRS1-mediated insulin signaling.This may be one of the underlying mechanisms by which tacrolimus induces insulin resistance.
基金supported by the Natural Scientific Foundation of Shandong(Nos.ZR2023MC039,ZR2022JQ07)the National Natural Science Foundation of China(No.21876206)+1 种基金the Fundamental Research Funds for the Central Universities(No.21CX06014A)the Taishan Scholarship of Shandong Province(No.tsqn202211080)。
文摘Lateral flow immunoassay(LFIA)has become popular in laboratories,at-home testing,and medical diagnostics due to its minimal cost and user-friendliness.Nevertheless,conventional test strips based on colloidal gold can only obtain qualitative or semi-quantitative results with low sensitivity.In this work,AuFe_(3)O_(4) dumbbell-like nanoparticles were synthesized and used as the LFIA labelling marker for highly sensitive colorimetric-photothermal dual-mode detection of SARS-CoV-2 spike(S)protein.The unique dumbbell structure of Au-Fe_(3)O_(4) NPs makes it possible to combine the best features of both Au NPs and Fe_(3)O_(4) NPs.The increased surface area of these NPs enhances their LSPR effect and photothermal effect,which achieves signal amplification to increase sensitivity.The Au-Fe_(3)O_(4) NPs modified with S protein antibody could identify S protein in samples,which were recognized and accumulated on T-line by another antibody,generating color band for qualitative colorimetric detection.The T-line was irradiated by laser to obtain temperature change for quantitative detection of photothermal.In optimized conditions,the detection limit was 1.22 pg/m L,three orders of magnitude more sensitive than colorimetric detection.Finally,the approach was performed on SARS-CoV-2 pseudovirus samples and outperformed traditional colloidal gold strips.This LFIA platform exhibits significant promise for practical implementation,as it can satisfy the need for low-cost,high-sensitivity,and home-based quantitative detection for respiratory infectious diseases.
