Colorectal cancer(CRC),ranking as the third most common malignant tumor globally,continues to have high incidence and mortality rates.In China,the incidence of CRC has been increasing in recent years,imposing a heavy ...Colorectal cancer(CRC),ranking as the third most common malignant tumor globally,continues to have high incidence and mortality rates.In China,the incidence of CRC has been increasing in recent years,imposing a heavy economic burden on society[1].Low prevalence of early screening leads to the majority of patients being diagnosed at an advanced stage.Current main treatment methods,such as surgery,chemotherapy,targeted therapy,and immunotherapy,have limited effectiveness for these patients and are prone to recurrence and metastasis.Moreover,the interplay of various pathogenic factors including genetic,environmental,and lifestyle factors increases the difficulty of CRC prevention and treatment[1].展开更多
AIM: To explore the effect of Obtusifolin on retinal pigment epithelial cell growth under hypoxia.METHODS: In vitro chemical hypoxia model of ARPE-19 cells was established using cobalt chloride(CoCl2). Cell viability ...AIM: To explore the effect of Obtusifolin on retinal pigment epithelial cell growth under hypoxia.METHODS: In vitro chemical hypoxia model of ARPE-19 cells was established using cobalt chloride(CoCl2). Cell viability was tested by cell counting kit-8(CCK-8) assay. Western blot and real-time quantitative polymerase chain reaction were applied to detect proteins and mRNAs respectively. Flow cytometry was used to examine the cell cycle. Secretion of vascular endothelial growth factor(VEGF) was tested by using enzyme linked immunosorbent assay(ELISA).RESULTS: Under the chemical hypoxia model established by CoCl2, hypoxia inducible factor-1α(HIF-1α) mRNA and protein levels was up-regulated. Cell viability was increased and the proportion of S phase was higher. Obtusifolin could reduce cell viability under hypoxic conditions and arrest cells in G1 phase. Obtusifolin reduced the expression of Cyclin D1 and proliferating cell nuclear antigen(PCNA) in the hypoxic environment and increased the expression of p53 and p21. The levels of VEGF, VEGFR2 and eNOS proteins and mRNA were significantly increased under hypoxia while Obtusifolin inhibited the increasing.CONCLUSION: Obtusifolin can inhibit cell growth under hypoxic conditions and down-regulate HIF-1/VEGF/eNOS secretions in ARPE-19 cells.展开更多
Objective To construct a morphine tolerance model in primarily cultured striatal neurons, and screen the differentially expressed genes in this model using suppression subtractive hybridization （SSH）. Methods Sbtra...Objective To construct a morphine tolerance model in primarily cultured striatal neurons, and screen the differentially expressed genes in this model using suppression subtractive hybridization （SSH）. Methods Sbtracted cDNA libraries were constructed using SSH from normal primarily cultured striatal neurons and long-term morphine treated striatal neurons （10^-5 mol/L for 72 hours）. To check reliability of the cell culture model, RT-PCR was performed to detect the cAMP-responsive element-binding protein （CREB） mRNA expression. The subtracted clones were prescreened by PCR. The clones containing inserted fragments from forward libraries were sequenced and submitted to GenBank for homology analysis. And the expression levels of genes of interest were confirmed by RT-PCR. Results CREB mRNA expression showed a significant increase in morphine treated striatal neurons （62.85± 1.98） compared with normal striatal neurons （28.43 ± 1.46, P〈0.01）. Thirty-six clones containing inserted fragments were randomly chosen for sequence analysis. And the 36 clones showed homology with 19 known genes and 2 novel genes. The expression of 2 novel genes, mitochondrial carrier homolog 1 （Mtchl ; 96.81±2.04 vs. 44.20±1.31, P〈0.01） and thyrnoma viral proto-oncogene 1 （Akt1 ; 122.10±2.17 vs 50.11±2.01, P〈0.01）, showed a significant increase in morphine-treated striatal neurons compared with normal striatal neurons. Conclusions A reliable differential cDNA library of striatal neurons treated with long-term morphine is constructed. Mtchl and Aktl might be the candidate genes for the development of morphine tolerance.展开更多
The optical properties of tri-group（B, Al, Ga, In） doped（6,6） SiC nanotubes（SiCNTs） are studied from first principles. The results show that the main absorption and dispersion of SiCNTs caused by the intrinsic t...The optical properties of tri-group（B, Al, Ga, In） doped（6,6） SiC nanotubes（SiCNTs） are studied from first principles. The results show that the main absorption and dispersion of SiCNTs caused by the intrinsic transition appear in the ultraviolet-visible region（below 500 nm）, and the tri-group doping increases the minimum dielectric constant value resulting in enhanced transmittance. In addition, the tri-group doping can introduce a weak absorption and dispersion region in the near-mid-infrared region, and the response peak blue shifts as the diameter of the doping atom increases. Comparative studies of reflectance, absorptivity, and transmittance show that the key factors affecting the transmittance of SiCNTs are reflectance（or refractive index） rather than absorption coefficient.展开更多
Based on the transport theory and the polarization relaxation model,the effects of hydrogen and hydroxyl passivation on the conductivity and dielectric properties of silicon carbide nanowires(SiCNWs)with different siz...Based on the transport theory and the polarization relaxation model,the effects of hydrogen and hydroxyl passivation on the conductivity and dielectric properties of silicon carbide nanowires(SiCNWs)with different sizes are numerically simulated.The results show that the variation trend of conductivity and band gap of passivated SiCNWs are opposite to the scenario of the size effect of bare SiCNWs.Among the influencing factors of conductivity,the carrier concentration plays a leading role.In the dielectric properties,the bare SiCNWs have a strong dielectric response in the blue light region,while passivated SiCNWs show a more obvious dielectric response in the far ultraviolet-light region.In particular,hydroxyl passivation produces a strong dielectric relaxation in the microwave band,indicating that hydroxyl passivated SiCNWs have a wide range of applications in electromagnetic absorption and shielding.展开更多
According to the one-dimensional quantum state distribution, carrier scattering, and fixed range hopping model, the structural stability and electron transport properties of N-, P-, and As-doped SiC nanowires(N-SiCNWs...According to the one-dimensional quantum state distribution, carrier scattering, and fixed range hopping model, the structural stability and electron transport properties of N-, P-, and As-doped SiC nanowires(N-SiCNWs, P-SiCNWs, and As-SiCNWs) are simulated by using the first principles calculations. The results show that the lattice structure of NSiCNWs is the most stable in the lattice structures of the above three kinds of doped SiCNWs. At room temperature,for unpassivated SiCNWs, the doping effect of P and As are better than that of N. After passivation, the conductivities of all doped SiCNWs increase by approximately two orders of magnitude. The N-SiCNW has the lowest conductivity. In addition, the N-, P-, As-doped SiCNWs before and after passivation have the same conductivity–temperature characteristics,that is, above room temperature, the conductivity values of the doped SiCNWs all increase with temperature increasing.These results contribute to the electronic application of nanodevices.展开更多
Silicon carbide nanosheets(SiCNSs)have a very broad application prospect in the field of new two-dimensional(2D)materials.In this paper,the interlayer interaction mechanism of bilayer SiCNSs(BL-SiCNSs)and its effect o...Silicon carbide nanosheets(SiCNSs)have a very broad application prospect in the field of new two-dimensional(2D)materials.In this paper,the interlayer interaction mechanism of bilayer SiCNSs(BL-SiCNSs)and its effect on optical properties are studied by first principles.Taking the charge and dipole moment of the layers as parameters,an interlayer coupling model is constructed which is more convenient to control the photoelectric properties.The results show that the stronger the interlayer coupling,the smaller the band gap of BL-SiCNSs.The interlayer coupling also changes the number of absorption peaks and causes the red or blue shift of absorption peaks.The strong interlayer coupling can produce obvious dispersion and regulate the optical transmission properties.The larger the interlayer distance,the smaller the permittivity in the vertical direction.However,the permittivity of the parallel direction is negative in the range of 150-300 nm,showing obvious metallicity.It is expected that the results will provide a meaningful theoretical basis for further study of SiCNSs optoelectronic devices.展开更多
文摘Colorectal cancer(CRC),ranking as the third most common malignant tumor globally,continues to have high incidence and mortality rates.In China,the incidence of CRC has been increasing in recent years,imposing a heavy economic burden on society[1].Low prevalence of early screening leads to the majority of patients being diagnosed at an advanced stage.Current main treatment methods,such as surgery,chemotherapy,targeted therapy,and immunotherapy,have limited effectiveness for these patients and are prone to recurrence and metastasis.Moreover,the interplay of various pathogenic factors including genetic,environmental,and lifestyle factors increases the difficulty of CRC prevention and treatment[1].
文摘AIM: To explore the effect of Obtusifolin on retinal pigment epithelial cell growth under hypoxia.METHODS: In vitro chemical hypoxia model of ARPE-19 cells was established using cobalt chloride(CoCl2). Cell viability was tested by cell counting kit-8(CCK-8) assay. Western blot and real-time quantitative polymerase chain reaction were applied to detect proteins and mRNAs respectively. Flow cytometry was used to examine the cell cycle. Secretion of vascular endothelial growth factor(VEGF) was tested by using enzyme linked immunosorbent assay(ELISA).RESULTS: Under the chemical hypoxia model established by CoCl2, hypoxia inducible factor-1α(HIF-1α) mRNA and protein levels was up-regulated. Cell viability was increased and the proportion of S phase was higher. Obtusifolin could reduce cell viability under hypoxic conditions and arrest cells in G1 phase. Obtusifolin reduced the expression of Cyclin D1 and proliferating cell nuclear antigen(PCNA) in the hypoxic environment and increased the expression of p53 and p21. The levels of VEGF, VEGFR2 and eNOS proteins and mRNA were significantly increased under hypoxia while Obtusifolin inhibited the increasing.CONCLUSION: Obtusifolin can inhibit cell growth under hypoxic conditions and down-regulate HIF-1/VEGF/eNOS secretions in ARPE-19 cells.
基金Supported by the National Natural Science Foundation of China (81070961,30770676,and 30870932)the Natural Science Foundation of Shandong Province (ZR2009DZ004)the Science and Technology Bureau Foundation of Shandong Province (2006GG2202037)
文摘Objective To construct a morphine tolerance model in primarily cultured striatal neurons, and screen the differentially expressed genes in this model using suppression subtractive hybridization （SSH）. Methods Sbtracted cDNA libraries were constructed using SSH from normal primarily cultured striatal neurons and long-term morphine treated striatal neurons （10^-5 mol/L for 72 hours）. To check reliability of the cell culture model, RT-PCR was performed to detect the cAMP-responsive element-binding protein （CREB） mRNA expression. The subtracted clones were prescreened by PCR. The clones containing inserted fragments from forward libraries were sequenced and submitted to GenBank for homology analysis. And the expression levels of genes of interest were confirmed by RT-PCR. Results CREB mRNA expression showed a significant increase in morphine treated striatal neurons （62.85± 1.98） compared with normal striatal neurons （28.43 ± 1.46, P〈0.01）. Thirty-six clones containing inserted fragments were randomly chosen for sequence analysis. And the 36 clones showed homology with 19 known genes and 2 novel genes. The expression of 2 novel genes, mitochondrial carrier homolog 1 （Mtchl ; 96.81±2.04 vs. 44.20±1.31, P〈0.01） and thyrnoma viral proto-oncogene 1 （Akt1 ; 122.10±2.17 vs 50.11±2.01, P〈0.01）, showed a significant increase in morphine-treated striatal neurons compared with normal striatal neurons. Conclusions A reliable differential cDNA library of striatal neurons treated with long-term morphine is constructed. Mtchl and Aktl might be the candidate genes for the development of morphine tolerance.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11574261 and 51132002the Natural Science Foundation of Hebei Province under Grant No A2015203261
文摘The optical properties of tri-group（B, Al, Ga, In） doped（6,6） SiC nanotubes（SiCNTs） are studied from first principles. The results show that the main absorption and dispersion of SiCNTs caused by the intrinsic transition appear in the ultraviolet-visible region（below 500 nm）, and the tri-group doping increases the minimum dielectric constant value resulting in enhanced transmittance. In addition, the tri-group doping can introduce a weak absorption and dispersion region in the near-mid-infrared region, and the response peak blue shifts as the diameter of the doping atom increases. Comparative studies of reflectance, absorptivity, and transmittance show that the key factors affecting the transmittance of SiCNTs are reflectance（or refractive index） rather than absorption coefficient.
基金supported by the National Natural Science Foundation of China(Grant No.11574261)the Natural Science Foundation of Hebei Province,China(Grant No.A2021203030).
文摘Based on the transport theory and the polarization relaxation model,the effects of hydrogen and hydroxyl passivation on the conductivity and dielectric properties of silicon carbide nanowires(SiCNWs)with different sizes are numerically simulated.The results show that the variation trend of conductivity and band gap of passivated SiCNWs are opposite to the scenario of the size effect of bare SiCNWs.Among the influencing factors of conductivity,the carrier concentration plays a leading role.In the dielectric properties,the bare SiCNWs have a strong dielectric response in the blue light region,while passivated SiCNWs show a more obvious dielectric response in the far ultraviolet-light region.In particular,hydroxyl passivation produces a strong dielectric relaxation in the microwave band,indicating that hydroxyl passivated SiCNWs have a wide range of applications in electromagnetic absorption and shielding.
基金Project supported by the National Natural Science Foundation of China(Grant No.11574261)the Natural Science Foundation of Hebei Province,China(Grant No.A2015203261)。
文摘According to the one-dimensional quantum state distribution, carrier scattering, and fixed range hopping model, the structural stability and electron transport properties of N-, P-, and As-doped SiC nanowires(N-SiCNWs, P-SiCNWs, and As-SiCNWs) are simulated by using the first principles calculations. The results show that the lattice structure of NSiCNWs is the most stable in the lattice structures of the above three kinds of doped SiCNWs. At room temperature,for unpassivated SiCNWs, the doping effect of P and As are better than that of N. After passivation, the conductivities of all doped SiCNWs increase by approximately two orders of magnitude. The N-SiCNW has the lowest conductivity. In addition, the N-, P-, As-doped SiCNWs before and after passivation have the same conductivity–temperature characteristics,that is, above room temperature, the conductivity values of the doped SiCNWs all increase with temperature increasing.These results contribute to the electronic application of nanodevices.
基金supported by Hebei Natural Science Foundation(Grant No.A2021203030)the National Natural Science Foundation of China(Grant No.11574261).
文摘Silicon carbide nanosheets(SiCNSs)have a very broad application prospect in the field of new two-dimensional(2D)materials.In this paper,the interlayer interaction mechanism of bilayer SiCNSs(BL-SiCNSs)and its effect on optical properties are studied by first principles.Taking the charge and dipole moment of the layers as parameters,an interlayer coupling model is constructed which is more convenient to control the photoelectric properties.The results show that the stronger the interlayer coupling,the smaller the band gap of BL-SiCNSs.The interlayer coupling also changes the number of absorption peaks and causes the red or blue shift of absorption peaks.The strong interlayer coupling can produce obvious dispersion and regulate the optical transmission properties.The larger the interlayer distance,the smaller the permittivity in the vertical direction.However,the permittivity of the parallel direction is negative in the range of 150-300 nm,showing obvious metallicity.It is expected that the results will provide a meaningful theoretical basis for further study of SiCNSs optoelectronic devices.
