We report a design and implementation of a field-programmable-gate-arrays(FPGA)based hardware platform,which is used to realize control and signal readout of trapped-ion-based multi-level quantum systems.This platform...We report a design and implementation of a field-programmable-gate-arrays(FPGA)based hardware platform,which is used to realize control and signal readout of trapped-ion-based multi-level quantum systems.This platform integrates a four-channel 2.8 Gsps@14 bits arbitrary waveform generator,a 16-channel 1 Gsps@14 bits direct-digital-synthesisbased radio-frequency generator,a 16-channel 8 ns resolution pulse generator,a 10-channel 16 bits digital-to-analogconverter module,and a 2-channel proportion integration differentiation controller.The hardware platform can be applied in the trapped-ion-based multi-level quantum systems,enabling quantum control of multi-level quantum system and highdimensional quantum simulation.The platform is scalable and more channels for control and signal readout can be implemented by utilizing more parallel duplications of the hardware.The hardware platform also has a bright future to be applied in scaled trapped-ion-based quantum systems.展开更多
Objective:To explore the expression and clinical significance of DKK-1 protein in patients with gastric cancers.Methods:Enzyme linked imtnuno sorbent assay was used to detect expressions of serum DKK-1 protein in 90 c...Objective:To explore the expression and clinical significance of DKK-1 protein in patients with gastric cancers.Methods:Enzyme linked imtnuno sorbent assay was used to detect expressions of serum DKK-1 protein in 90 cases of gastric cancers,50 cases of gastric benign disease and 40 healthy cases.The dynamic change in serum DKK-1 protein of gastric cancer patients who accepted radical operation for a month was also observed.Results:The expression of serum DKK-1 protein in gastric cancer groups was significantly higher than that in gastric benign group's(P<0.01) and in health control(P<0.01).Serum DKK 1 level was increased gradually along with the progress of the disease.Serum DKK 1 levels were significantly higher in patients at TNM staging Ⅲ and Ⅳ than patients at TNM staging Ⅰ andⅡ.Level of serum DKK-1 was related to microvascular invasion,differentiation degree and infiltration depth.Level of serum DKK-1 was significantly reduced in patients after radical surgery(P<0.01).Conclusions:The expression of serum DKK-1 protein in gastric cancer patients is increased.Level of serum DKK-1 is related to TNM staging,microvascular invasion,differentiation degree and infiltration depth.DKK-1 detection can be used as a reference index in monitoring gastric cancer progress and biological behavior.展开更多
Readout electronics is developed for a prototype spectrometer for in situ measurement of low-energy ions of30 e V/e–20 ke V/e in the solar wind plasma.A low-noise preamplifier/discriminator(A111F) is employed for eac...Readout electronics is developed for a prototype spectrometer for in situ measurement of low-energy ions of30 e V/e–20 ke V/e in the solar wind plasma.A low-noise preamplifier/discriminator(A111F) is employed for each channel to process the signal from micro-channel plate(MCP) detectors.A high-voltage(HV) supply solution based on a HV module and a HV optocoupler is adopted to generate a fast sweeping HV and a fixed HV.Due to limitation of telemetry bandwidth in space communication,an algorithm is implemented in an FPGA(field programmable gate array) to compress the raw data.Test results show that the electronics achieves a 1 MHz event rate and a large input dynamic range of 95 p C.A slew rate of 0.8 V/ls and an integral nonlinearity of 0.7-LSB for the sweeping HV,and a precision of less than 0.8 % for the fixed HV are obtained.A vacuum beam test shows an energy resolution of 12 ± 0.7 % full width at half maximum(FWHM) is achieved,and noise counts are less than10/sec,indicating that the performance meets the physical requirement.展开更多
Objective:To clone and express Rv3265c gene of Mycobacterium tuberculosis in Escherichia coli (E.coli) under optimistic conditions,obtain and identify protein expressed,analyze the structure and characteristics of the...Objective:To clone and express Rv3265c gene of Mycobacterium tuberculosis in Escherichia coli (E.coli) under optimistic conditions,obtain and identify protein expressed,analyze the structure and characteristics of the protein using bioinformatics methods for future applications.Methods: Rv3265c gene from Mycobacterium tuberculosis H37Rv was amplified by polymerase chain reaction,and was cloned into the pET-30a vector after purification and recovery.The recombinant plasmid was sequenced and expressed in E.coli BL21(DE3),and then purified and identified by western blotting.The essential physical-chemical properties of the protein were predicated by bioinformatics tools,including subcellular location,secondary structure,domains,antigenic epitopes,etc.Tertiary structure of the protein based on homology modeling was estabUshed,while multi-sequence homological alignment and phylogenetic analysis were preformed.Results:The recombinant protein was obtained in soluble fraction from expression system in E.coli B121(DE3) carrying pET30- Rv3265c plasmid,and Rv3265c gene was expressed correctly.Bioinformatics analysis showed the protein contained no signal peptide and transmembrane helices,located outside of membrane.Secondary structure analysis revealed it containedα-helix,extended strand and random coil,46.8%,14.6%,38.6%,respectively.Furthermore,it possessed six potential antigenic epitopes,one glycosyl transferase domain.A simple three-dimensional model of this protein was constructed by Swiss-model sever.Both sequences and structures were conservative and especial either in gene or in protein.Conclusions:Rv3265c gene might be a desirable molecular target for anti-tuberculosis drug and vaccine.The purified protein from expression will be utilized to study the kinetics of L-rhamnosyltransferase and to develope an enzyme assay for screening vaccine or drug.展开更多
A high performance fast-Fourier-transform (FFT) spectrum analyzer, which is developed for measure spin noise spectrums, is presented in this paper. The analyzer is implemented with a field-programmable-gate-arrays (FP...A high performance fast-Fourier-transform (FFT) spectrum analyzer, which is developed for measure spin noise spectrums, is presented in this paper. The analyzer is implemented with a field-programmable-gate-arrays (FPGA) chip for data and command management. An analog-to-digital-convertor chip is integrated for analog signal acquisition. In order to meet the various requirements of measuring different types of spin noise spectrums, multiple operating modes are designed and realized using the reprogrammable FPGA logic resources. The FFT function is fully managed by the programmable resource inside the FPGA chip. A 1 GSa/s sampling rate and a 100 percent data coverage ratio with non-dead-time are obtained. 30534 FFT spectrums can be acquired per second, and the spectrums can be on-board accumulated and averaged. Digital filters, multi-stage reconfigurable data reconstruction modules, and frequency down conversion modules are also implemented in the FPGA to provide flexible real-time data processing capacity, thus the noise floor and signals aliasing can be suppressed effectively. An efficiency comparison between the FPGA-based FFT spectrum analyzer and the software-based FFT is demonstrated, and the high performance FFT spectrum analyzer has a significant advantage in obtaining high resolution spin noise spectrums with enhanced efficiency.展开更多
Molecular qubits are promising as they can benefit from tailoring and versatile design of chemistry.It is essential to reduce the decoherence of molecular qubits caused by their interactions with the environment.Herei...Molecular qubits are promising as they can benefit from tailoring and versatile design of chemistry.It is essential to reduce the decoherence of molecular qubits caused by their interactions with the environment.Herein the dynamical decoupling(DD)technique is utilized to combat such decoherence.The coherence time for a transitionmetal complex(PPh_(4))_(2)[Cu(mnt)_(2)]is prolonged from 6.8μs to 1.4 ms.The ratio of the coherence time and the length ofπ/2 pulse,defined as the single qubit figure of merit(QM),reaches 1.4×10^(5),which is 40 times greater than what previously reported for this molecule.Our results show that molecular qubits,with milliseconds coherence time,are promising candidates for quantum information processing.展开更多
Recombinant human interferon a2b(rhIFNa2b)is widely used as an antiviral therapy agent for the treatment of hepatitis B and hepatitis C.The current identification test for rhIFNa2b is complex.In this study,an anti-rhI...Recombinant human interferon a2b(rhIFNa2b)is widely used as an antiviral therapy agent for the treatment of hepatitis B and hepatitis C.The current identification test for rhIFNa2b is complex.In this study,an anti-rhIFNa2b nanobody was discovered and used for the development of a rapid lateral flow strip for the identification of rhIFNa2b.RhIFNa2b was used to immunize an alpaca,which established a phage nanobody library.After five steps of enrichment,the nanobody I22,which specifically bound rhIFNa2b,was isolated and inserted into the prokaryotic expression vector pET28a.After subsequent purification,the physicochemical properties of the nanobody were determined.A semiquantitative detection and rapid identification assay of rhIFNa2b was developed using this novel nanobody.To develop a rapid test,the nanobody I22 was coupled with a colloidal gold to produce lateral-flow test strips.The developed rhIFNa2b detection assay had a limit of detection of 1 mg/mL.The isolation of I22 and successful construction of a lateral-flow immunochromatographic test strip demonstrated the feasibility of performing ligand-binding assays on a lateral-flow test strip using recombinant protein products.The principle of this novel assay is generally applicable for the rapid testing of other commercial products,with a great potential for routine use in detecting counterfeit recombinant protein products.展开更多
Recently,magnetism in two-dimensional(2 D)van der Waals(vd W)materials has attracted wide interests.It is anticipated that these materials will stimulate discovery of new physical phenomena and novel applications.The ...Recently,magnetism in two-dimensional(2 D)van der Waals(vd W)materials has attracted wide interests.It is anticipated that these materials will stimulate discovery of new physical phenomena and novel applications.The capability to quantitatively measure the magnetism of 2 D magnetic vd W materials is essential to understand these materials.Here we report on quantitative measurements of ferromagnetic-to-paramagnetic phase transition of an atomically thin(down to 11 nm)vd W magnet,namely Cr Br_(3),with a Curie point of 37.5 K.This experiment demonstrates that surface magnetism can be quantitatively investigated,which is useful for a wide variety of potential applications.展开更多
Objective:To explore the expression level of klk7 and E-cad in serum of patients with gastric cancer and to explore the relationship of klk7 and E-cad with gastric cancer clinical pathological characteristics.Method: ...Objective:To explore the expression level of klk7 and E-cad in serum of patients with gastric cancer and to explore the relationship of klk7 and E-cad with gastric cancer clinical pathological characteristics.Method: A total of 50 patients with gastric cancer, and 50 healthy persons were selected as the experimental group, benign gastric disease group and healthy group, respectively. A total of 24 patients in experimental group met surgery indications, and agreed to perform gastrectomy. They were divided into preoperative group and postoperative group. The serums levels of KLK7 and E-cad were detected by enzyme-linked immunosorbent assay.Results: The serum levels of KLK7 and E-cad were significantly higher than that of benign gastric disease group and normal control group. Compared with the experimental group after operation, MMP-2 and MMP-9 were decreased, KLK7 was significantly decreased and E-cad increased significantly after operation. Serum levels of KLK7 and E-cad in experimental group stage I were increased and stage IV decreased. Microvascular invasion was significantly correlated with serum KLK7 and E-cad. There was no significant correlation between tumor size, differentiation degree, depth and expression of KLK7 and E-cad. Serum KLK7 were significantly negatively correlated with E-cad expression in gastric cancer patients. Conclusions:KLK7 and E-cad are involved in the development and metastasis of gastric cancer. The serum expression of KLK7 and E-cad are significantly negatively correlated in patients with stomach cancer. There may be an antagonistic effect in gastric cancer development and metastasis. Serum level of KLK7 and E-cad can be used as indexes for progress monitoring.展开更多
As the most common internal modification of mRNA,Ne-methyladenosine(m^(6)A)and its regulators modulate gene expression and play critical roles in various biological and patholog-ical processes including tumorigenesis....As the most common internal modification of mRNA,Ne-methyladenosine(m^(6)A)and its regulators modulate gene expression and play critical roles in various biological and patholog-ical processes including tumorigenesis.It was reported previously that m^(6)A methyltransferase(writer),methyltransferase-like 3(METTL3)adds m^(6)A in primary microRNAs(pri-miRNAs)and fa-cilitates its processing into precursor miRNAs(pre-miRNAs).However,it is unknown whether m^(6)A modification also plays a role in the maturation process of pre-miRNAs and(if so)whether such a function contributes to tumorigenesis.Here,we found that YTHDF2 is aberrantly overexpressed in acute myeloid leukemia(AML)patients,especially in relapsed patients,and plays an onco-genic role in AML.Moreover,YTHDF2 promotes expression of miR-126-3p(also known as miR-126,as it is the main product of precursor miR-126(pre-miR-126)),a miRNA that was reported as an oncomiRNA in AML,through facilitating the processing of pre-miR-126 into mature miR-126.Mechanistically,YTHDF2 recognizes m^(6)A modification in pre-miR-126 and recruits AGO2,a regulator of pre-miRNA processing,to promote the maturation of pre-miR-126.YTHDF2 posi-tively and negatively correlates with miR-126 and miR-126's downstream target genes,respec-tively,in AML patients,and forced expression of miR-126 could largely rescue YTHDF2/Ythdf2 depletion-mediated suppression on AML cell growth/proliferation and leukemogenesis,indi-cating that miR-126 is a functionally important target of YTHDF2 in AML.Overall,our studies not only reveal a previously unappreciated YTHDF2/miR-126 axis in AML and highlight the ther-apeutic potential of targeting this axis for AML treatment,but also suggest that m^(6)A plays a role in pre-miRNA processing that contributes to tumorigenesis.展开更多
We herein report a simultaneous dehalogenation and hydrogenation(DHH)reaction in Sonogashira coupling involving hexahalogenobenzene C6X6(X=I,Br),in which a halogen on the aryl polyhalide substrate was substituted by a...We herein report a simultaneous dehalogenation and hydrogenation(DHH)reaction in Sonogashira coupling involving hexahalogenobenzene C6X6(X=I,Br),in which a halogen on the aryl polyhalide substrate was substituted by a hydrogen atom.First,a steric bulky terminal alkyne 5 was designed and synthesized to study the influence of the reaction conditions(e.g.,catalyst,solvent,temperature)and the halogens on the substrates C6X6 on the DHH reaction.Moreover,based on the optimized conditions,a terminal alkyne 6 with less steric hindrance was further synthesized to investigate the influence of alkyne on the DHH reaction.As a result,two aromatic polyynes 7 and 8 were were further studied and compared.The influence produced by the alkynes and aryl polyhalides substrate provide insights into Sonogashira coupling involving terminal alkyne with huge steric hindrance and polyhalogenated aromatic hydrocarbons.展开更多
基金the Strategic Priority Research Program of CAS(Grant No.XDC07020200)the National Key R&D Program of China(Grants No.2018YFA0306600)+5 种基金the National Natural Science Foundation of China(Grant Nos.11974330 and 92165206)the Chinese Academy of Sciences(Grant No.QYZDY-SSW-SLH004)the Innovation Program for Quantum Science and Technology(Grant Nos.2021ZD0302200 and 2021ZD0301603)the Anhui Initiative in Quantum Information Technologies(Grant No.AHY050000)the Hefei Comprehensive National Science Centerthe Fundamental Research Funds for the Central Universities。
文摘We report a design and implementation of a field-programmable-gate-arrays(FPGA)based hardware platform,which is used to realize control and signal readout of trapped-ion-based multi-level quantum systems.This platform integrates a four-channel 2.8 Gsps@14 bits arbitrary waveform generator,a 16-channel 1 Gsps@14 bits direct-digital-synthesisbased radio-frequency generator,a 16-channel 8 ns resolution pulse generator,a 10-channel 16 bits digital-to-analogconverter module,and a 2-channel proportion integration differentiation controller.The hardware platform can be applied in the trapped-ion-based multi-level quantum systems,enabling quantum control of multi-level quantum system and highdimensional quantum simulation.The platform is scalable and more channels for control and signal readout can be implemented by utilizing more parallel duplications of the hardware.The hardware platform also has a bright future to be applied in scaled trapped-ion-based quantum systems.
基金supported by Hainan Province Health Department Fund Projects No.2013-08
文摘Objective:To explore the expression and clinical significance of DKK-1 protein in patients with gastric cancers.Methods:Enzyme linked imtnuno sorbent assay was used to detect expressions of serum DKK-1 protein in 90 cases of gastric cancers,50 cases of gastric benign disease and 40 healthy cases.The dynamic change in serum DKK-1 protein of gastric cancer patients who accepted radical operation for a month was also observed.Results:The expression of serum DKK-1 protein in gastric cancer groups was significantly higher than that in gastric benign group's(P<0.01) and in health control(P<0.01).Serum DKK 1 level was increased gradually along with the progress of the disease.Serum DKK 1 levels were significantly higher in patients at TNM staging Ⅲ and Ⅳ than patients at TNM staging Ⅰ andⅡ.Level of serum DKK-1 was related to microvascular invasion,differentiation degree and infiltration depth.Level of serum DKK-1 was significantly reduced in patients after radical surgery(P<0.01).Conclusions:The expression of serum DKK-1 protein in gastric cancer patients is increased.Level of serum DKK-1 is related to TNM staging,microvascular invasion,differentiation degree and infiltration depth.DKK-1 detection can be used as a reference index in monitoring gastric cancer progress and biological behavior.
基金supported by the National Key Scientific Instrument and Equipment Development Projects of the National Natural Science Foundation of China(No.41327802)the Fundamental Research Funds for the Central Universities(WK2030040066)
文摘Readout electronics is developed for a prototype spectrometer for in situ measurement of low-energy ions of30 e V/e–20 ke V/e in the solar wind plasma.A low-noise preamplifier/discriminator(A111F) is employed for each channel to process the signal from micro-channel plate(MCP) detectors.A high-voltage(HV) supply solution based on a HV module and a HV optocoupler is adopted to generate a fast sweeping HV and a fixed HV.Due to limitation of telemetry bandwidth in space communication,an algorithm is implemented in an FPGA(field programmable gate array) to compress the raw data.Test results show that the electronics achieves a 1 MHz event rate and a large input dynamic range of 95 p C.A slew rate of 0.8 V/ls and an integral nonlinearity of 0.7-LSB for the sweeping HV,and a precision of less than 0.8 % for the fixed HV are obtained.A vacuum beam test shows an energy resolution of 12 ± 0.7 % full width at half maximum(FWHM) is achieved,and noise counts are less than10/sec,indicating that the performance meets the physical requirement.
基金Supported by Research Program in higher educational institutes of The Education Department of Hainan Province(No.Hj2010-21)Research Program of The Health Department of Hainan Province(No.2007-44)+1 种基金Natural Science Fund of Hainan Province(No.2008-30837)Cultivation Program of Hainan Medical University (HY2010-006)
文摘Objective:To clone and express Rv3265c gene of Mycobacterium tuberculosis in Escherichia coli (E.coli) under optimistic conditions,obtain and identify protein expressed,analyze the structure and characteristics of the protein using bioinformatics methods for future applications.Methods: Rv3265c gene from Mycobacterium tuberculosis H37Rv was amplified by polymerase chain reaction,and was cloned into the pET-30a vector after purification and recovery.The recombinant plasmid was sequenced and expressed in E.coli BL21(DE3),and then purified and identified by western blotting.The essential physical-chemical properties of the protein were predicated by bioinformatics tools,including subcellular location,secondary structure,domains,antigenic epitopes,etc.Tertiary structure of the protein based on homology modeling was estabUshed,while multi-sequence homological alignment and phylogenetic analysis were preformed.Results:The recombinant protein was obtained in soluble fraction from expression system in E.coli B121(DE3) carrying pET30- Rv3265c plasmid,and Rv3265c gene was expressed correctly.Bioinformatics analysis showed the protein contained no signal peptide and transmembrane helices,located outside of membrane.Secondary structure analysis revealed it containedα-helix,extended strand and random coil,46.8%,14.6%,38.6%,respectively.Furthermore,it possessed six potential antigenic epitopes,one glycosyl transferase domain.A simple three-dimensional model of this protein was constructed by Swiss-model sever.Both sequences and structures were conservative and especial either in gene or in protein.Conclusions:Rv3265c gene might be a desirable molecular target for anti-tuberculosis drug and vaccine.The purified protein from expression will be utilized to study the kinetics of L-rhamnosyltransferase and to develope an enzyme assay for screening vaccine or drug.
基金Project supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDC07020200)the National Key R&D Program of China(Grant Nos.2018YFA0306600 and 2016YFB0501603)+3 种基金the National Natural Science Foundation of China(Grant No.11927811)the Chinese Academy of Sciences(Grants Nos.GJJSTD20170001 and QYZDY-SSW-SLH004)Anhui Initiative in Quantum Information Technologies,China(Grant No.AHY050000)the Fundamental Research Funds for the Central Universities,China.
文摘A high performance fast-Fourier-transform (FFT) spectrum analyzer, which is developed for measure spin noise spectrums, is presented in this paper. The analyzer is implemented with a field-programmable-gate-arrays (FPGA) chip for data and command management. An analog-to-digital-convertor chip is integrated for analog signal acquisition. In order to meet the various requirements of measuring different types of spin noise spectrums, multiple operating modes are designed and realized using the reprogrammable FPGA logic resources. The FFT function is fully managed by the programmable resource inside the FPGA chip. A 1 GSa/s sampling rate and a 100 percent data coverage ratio with non-dead-time are obtained. 30534 FFT spectrums can be acquired per second, and the spectrums can be on-board accumulated and averaged. Digital filters, multi-stage reconfigurable data reconstruction modules, and frequency down conversion modules are also implemented in the FPGA to provide flexible real-time data processing capacity, thus the noise floor and signals aliasing can be suppressed effectively. An efficiency comparison between the FPGA-based FFT spectrum analyzer and the software-based FFT is demonstrated, and the high performance FFT spectrum analyzer has a significant advantage in obtaining high resolution spin noise spectrums with enhanced efficiency.
基金Supported by the National Key R&D Program of China(Grant Nos.2018YFA0306600 and 2016YFB0501603)the Chinese Academy of Sciences(Grant Nos.GJJSTD20170001,QYZDY-SSW-SLH004,and QYZDB-SSW-SLH005)+2 种基金Anhui Initiative in Quantum Information Technologies(Grant No.AHY050000)the Youth Innovation Promotion Association of Chinese Academy of Sciences for their supportthe support from Wuhan National High Magnetic Field Center(Grant No.2015KF06)。
文摘Molecular qubits are promising as they can benefit from tailoring and versatile design of chemistry.It is essential to reduce the decoherence of molecular qubits caused by their interactions with the environment.Herein the dynamical decoupling(DD)technique is utilized to combat such decoherence.The coherence time for a transitionmetal complex(PPh_(4))_(2)[Cu(mnt)_(2)]is prolonged from 6.8μs to 1.4 ms.The ratio of the coherence time and the length ofπ/2 pulse,defined as the single qubit figure of merit(QM),reaches 1.4×10^(5),which is 40 times greater than what previously reported for this molecule.Our results show that molecular qubits,with milliseconds coherence time,are promising candidates for quantum information processing.
基金support was provided by the National Science and Technology Major Project(Grant No.:2015ZX09501008)。
文摘Recombinant human interferon a2b(rhIFNa2b)is widely used as an antiviral therapy agent for the treatment of hepatitis B and hepatitis C.The current identification test for rhIFNa2b is complex.In this study,an anti-rhIFNa2b nanobody was discovered and used for the development of a rapid lateral flow strip for the identification of rhIFNa2b.RhIFNa2b was used to immunize an alpaca,which established a phage nanobody library.After five steps of enrichment,the nanobody I22,which specifically bound rhIFNa2b,was isolated and inserted into the prokaryotic expression vector pET28a.After subsequent purification,the physicochemical properties of the nanobody were determined.A semiquantitative detection and rapid identification assay of rhIFNa2b was developed using this novel nanobody.To develop a rapid test,the nanobody I22 was coupled with a colloidal gold to produce lateral-flow test strips.The developed rhIFNa2b detection assay had a limit of detection of 1 mg/mL.The isolation of I22 and successful construction of a lateral-flow immunochromatographic test strip demonstrated the feasibility of performing ligand-binding assays on a lateral-flow test strip using recombinant protein products.The principle of this novel assay is generally applicable for the rapid testing of other commercial products,with a great potential for routine use in detecting counterfeit recombinant protein products.
基金supported by the National Natural Science Foundation of China(Grant Nos.81788101,T2125011,and 11874338)the National Key R&D Program of China(Grant No.2018YFA0306600)+2 种基金Chinese Academy of Sciences(Grants Nos.XDC07000000,GJJSTD20200001,QYZDY-SSW-SLH004,and ZDZBGCH2021002)Anhui Initiative in Quantum Information Technologies(Grant No.AHY050000)Fundamental Research Funds for the Central Universities。
文摘Recently,magnetism in two-dimensional(2 D)van der Waals(vd W)materials has attracted wide interests.It is anticipated that these materials will stimulate discovery of new physical phenomena and novel applications.The capability to quantitatively measure the magnetism of 2 D magnetic vd W materials is essential to understand these materials.Here we report on quantitative measurements of ferromagnetic-to-paramagnetic phase transition of an atomically thin(down to 11 nm)vd W magnet,namely Cr Br_(3),with a Curie point of 37.5 K.This experiment demonstrates that surface magnetism can be quantitatively investigated,which is useful for a wide variety of potential applications.
文摘Objective:To explore the expression level of klk7 and E-cad in serum of patients with gastric cancer and to explore the relationship of klk7 and E-cad with gastric cancer clinical pathological characteristics.Method: A total of 50 patients with gastric cancer, and 50 healthy persons were selected as the experimental group, benign gastric disease group and healthy group, respectively. A total of 24 patients in experimental group met surgery indications, and agreed to perform gastrectomy. They were divided into preoperative group and postoperative group. The serums levels of KLK7 and E-cad were detected by enzyme-linked immunosorbent assay.Results: The serum levels of KLK7 and E-cad were significantly higher than that of benign gastric disease group and normal control group. Compared with the experimental group after operation, MMP-2 and MMP-9 were decreased, KLK7 was significantly decreased and E-cad increased significantly after operation. Serum levels of KLK7 and E-cad in experimental group stage I were increased and stage IV decreased. Microvascular invasion was significantly correlated with serum KLK7 and E-cad. There was no significant correlation between tumor size, differentiation degree, depth and expression of KLK7 and E-cad. Serum KLK7 were significantly negatively correlated with E-cad expression in gastric cancer patients. Conclusions:KLK7 and E-cad are involved in the development and metastasis of gastric cancer. The serum expression of KLK7 and E-cad are significantly negatively correlated in patients with stomach cancer. There may be an antagonistic effect in gastric cancer development and metastasis. Serum level of KLK7 and E-cad can be used as indexes for progress monitoring.
基金supported in part by the U.S.National Institutes of Health(NIH)grants R01 CA243386(J.C.),R01 CA271497,R01 CA214965(J.C.),R01 CA236399(J.C.),R01 DK124116(J.C)The Simms/Mann Family Foundation(J.C.).J.C.is a Leukemia&Lymphoma Society(LLS)Scholar and is supported by the LLS 2022 Scholar CDP Achievement Award.
文摘As the most common internal modification of mRNA,Ne-methyladenosine(m^(6)A)and its regulators modulate gene expression and play critical roles in various biological and patholog-ical processes including tumorigenesis.It was reported previously that m^(6)A methyltransferase(writer),methyltransferase-like 3(METTL3)adds m^(6)A in primary microRNAs(pri-miRNAs)and fa-cilitates its processing into precursor miRNAs(pre-miRNAs).However,it is unknown whether m^(6)A modification also plays a role in the maturation process of pre-miRNAs and(if so)whether such a function contributes to tumorigenesis.Here,we found that YTHDF2 is aberrantly overexpressed in acute myeloid leukemia(AML)patients,especially in relapsed patients,and plays an onco-genic role in AML.Moreover,YTHDF2 promotes expression of miR-126-3p(also known as miR-126,as it is the main product of precursor miR-126(pre-miR-126)),a miRNA that was reported as an oncomiRNA in AML,through facilitating the processing of pre-miR-126 into mature miR-126.Mechanistically,YTHDF2 recognizes m^(6)A modification in pre-miR-126 and recruits AGO2,a regulator of pre-miRNA processing,to promote the maturation of pre-miR-126.YTHDF2 posi-tively and negatively correlates with miR-126 and miR-126's downstream target genes,respec-tively,in AML patients,and forced expression of miR-126 could largely rescue YTHDF2/Ythdf2 depletion-mediated suppression on AML cell growth/proliferation and leukemogenesis,indi-cating that miR-126 is a functionally important target of YTHDF2 in AML.Overall,our studies not only reveal a previously unappreciated YTHDF2/miR-126 axis in AML and highlight the ther-apeutic potential of targeting this axis for AML treatment,but also suggest that m^(6)A plays a role in pre-miRNA processing that contributes to tumorigenesis.
基金supported by the National Natural Science Foundation of China(Grant no.21801031)the Natural Science Foundation Project of Chongqing,Chongqing Science and Technology Commission,China(Grant nos.2023NSCQ-MSX3187 and cstc2019jcyjmsxmX0404)+1 种基金the Scientific and Technological Research Program of Chongqing Municipal Education Commission(Grant no.KJQN202301524)the Foundation of Chongqing University of Science&Technology(Grant no.ckrc202212053).
文摘We herein report a simultaneous dehalogenation and hydrogenation(DHH)reaction in Sonogashira coupling involving hexahalogenobenzene C6X6(X=I,Br),in which a halogen on the aryl polyhalide substrate was substituted by a hydrogen atom.First,a steric bulky terminal alkyne 5 was designed and synthesized to study the influence of the reaction conditions(e.g.,catalyst,solvent,temperature)and the halogens on the substrates C6X6 on the DHH reaction.Moreover,based on the optimized conditions,a terminal alkyne 6 with less steric hindrance was further synthesized to investigate the influence of alkyne on the DHH reaction.As a result,two aromatic polyynes 7 and 8 were were further studied and compared.The influence produced by the alkynes and aryl polyhalides substrate provide insights into Sonogashira coupling involving terminal alkyne with huge steric hindrance and polyhalogenated aromatic hydrocarbons.