AIM To study whether Helicobacter pylori is naturally transformable. METHODS Transformation was performed in BHI broth supplemented with horse serum and yeast extract. Genomic DNA extracted from a metronidazole...AIM To study whether Helicobacter pylori is naturally transformable. METHODS Transformation was performed in BHI broth supplemented with horse serum and yeast extract. Genomic DNA extracted from a metronidazole resistant H. pylori strain was added to H. pylori broth culture. The mixture was incubated at microaerophilic atmosphere. The DNA treated cells were plated on blood agar containing 8mg/L metronidazole to select for transformants. Sterile distilled water was used as a negative DNA control. The DNA profiles of transformants were compared with that of their parent strains by randomly amplified polymorphic DNA (RAPD) fingerprinting. RESULTS Transformation of H. pylori with DNA from a metronidazole resistant strain as a marker was demonstrated. Out of the 12 strains of H. pylori tested, 9 (75%) strains were found to be transformable. The transformation frequencies ranged from 3 4×10 -6 to 2 4×10 -4 . By RAPD, DNA fingerprints of the transformants and their parent strains showed no change in DNA profiles though transformants were all resistant to metronidazole as compared with their metronidazole sensitive parent strains. CONCLUSION Helicobacter pylori is naturally transformable which might be one of the ways that H. pylori develops resistance to metronidazole.展开更多
Abstract: The authors found five sodium (Na+) and chloride (Cl-.) hyperaccumulating halophytes in the Temperate Desert of Xinjiang, China and studied two of them (Suaeda salsa (L.) Pall. and Kalidium folium (Pall.) Mo...Abstract: The authors found five sodium (Na+) and chloride (Cl-.) hyperaccumulating halophytes in the Temperate Desert of Xinjiang, China and studied two of them (Suaeda salsa (L.) Pall. and Kalidium folium (Pall.) Moq.). K. folium and S. salsa had a NaCl content of 32.1% and 29.8%, respectively, on a dry weight basis. X-ray microanalysis of the Na+ in the vacuole, apoplasts and cytoplasm of the two plants indicated a ratio of 7.3:5.6:1.0 in K. folium and 7.3:6.6:1.0 in S. salsa. These data show that K. folium and S. salsa both have a high Na+ and Cl- accumulating capacity, which is related to high activity of tonoplast H+-ATPase and H+-PPase.展开更多
Purpose We aimed to analyse the correlation between prostaglandin D2 synthase(PTGDS)and a diffuse large B-cell lymphoma(DLBCL)prognosis.Methods We retrospectively collected two hundred paraffin-embedded tissue specime...Purpose We aimed to analyse the correlation between prostaglandin D2 synthase(PTGDS)and a diffuse large B-cell lymphoma(DLBCL)prognosis.Methods We retrospectively collected two hundred paraffin-embedded tissue specimens that were pathologically diagnosed as DLBCL in the Fujian Tumour Hospital between January 2014 and December 2018.An abundance of paraffin-embedded tumour tissues were obtained.Twenty patients with lymphocyte-rich,benign,tissue-reactive,hypertrophic tonsillitis were selected as controls.Wax blocks were selected for primary cases and the controls were screened by professional pathologists.The levels of prostaglandin D2 synthase(PTGDS)and the EMT-related molecules,E-cadherin and vimentin,were detected by immunohistochemistry in clinical samples.A chi-square test revealed the correlations between PTGDS expression and clinicopathological characteristics,including age,sex,primary site,clinical stage,immunotyping,and International Prognostic Index(IPI)score.The Kaplan–Meier survival analysis was performed,and the diagnostic value was evaluated by receiver operating characteristic(ROC)curve analysis.Results A total of 138 cases(69%)were found to be PTGDS positive(>30%positive cells).PTGDS staining was negative(<30%positive cells)in 62 cases(31%).We collected the corresponding clinicopathological information and found that PTGDS expression was not significantly related to the patients’age,tumour stage,presence of extranodal invasion,or IPI score.According to the follow-up data,patients with low PTGDS expression had poor progression-free survival(PFS)and overall survival(OS),with 2-year PFS and OS rates of 41.7%and 50%,respectively.The 2-year PFS and OS rates of PTGDS-positive patients were 89.3%and 92.9%,respectively(P<0.0001),and the differences were significant.Conclusion We found that the expression level of PTGDS is significantly correlated with the prognosis of diffuse large B-cell lymphoma.展开更多
The poor cycling stability of graphite in traditional ester electrolyte limits its applications as anodes for potassium ion batteries(KIBs).Herein,we demonstrate that the introduction of cyclic ether co-solvents into ...The poor cycling stability of graphite in traditional ester electrolyte limits its applications as anodes for potassium ion batteries(KIBs).Herein,we demonstrate that the introduction of cyclic ether co-solvents into ester electrolytes can remarkably enhance the cycling stability of graphite anodes.The graphite anode in ester electrolyte with cyclic ether could achieve a reversible capacity of 196.1 m Ah g^(-1) after 100 cycles at 0.3 C(1 C=280 m A g^(-1)),about three times higher than those in ester electrolytes with or without linear ether.Compared with the SEI formed in ester electrolytes,the addition of tetrahydrofuran promotes the generation of K_(2)CO_(3) and ethylene oxide oligomers(PEO),of which the K_(2)CO_(3) is expected to be more conductive and PEO is mechanically robust.The more uniform,conductive and stable solid electrolyte interphases(SEIs)on graphite in electrolytes with cyclic ethers contribute to the enhancement of the electrochemical performances of graphite.This work provides a novel design of commercialized electrolytes to achieve high-performance anodes for KIBs,which potentially accelerates the development of KIBs.展开更多
A new laboratory evaluation method for the coating blade was developed, and the tribological properties of coating blades with different Ti-based coatings were studied by UMT-2 tribometer. Comparison between the areas...A new laboratory evaluation method for the coating blade was developed, and the tribological properties of coating blades with different Ti-based coatings were studied by UMT-2 tribometer. Comparison between the areas of scratches before and after the cutting experiment was used to evaluate the cutting performance of the blades. Results showed that friction coefficient of TiA1CrN/TiA1N coating was significantly lower than that of TiA1SiN coating. Analysis of the worn surface revealed that the TiA1SiN and TiAICrN/TiA1N coatings in the dry turning process exhibited sign of inhornogeneous adhesive wear and abrasive wear. TiA1CrN/TiA1N coating has a longer working life and better anti-wear property because of its duplex coating.展开更多
A novel ultra-broadband polarization splitter based on a dual-core photonic crystal fiber(DC-PCF)is designed.The full-vector finite element method and coupled-mode theory are employed to investigate the characteristic...A novel ultra-broadband polarization splitter based on a dual-core photonic crystal fiber(DC-PCF)is designed.The full-vector finite element method and coupled-mode theory are employed to investigate the characteristics of the polarization splitter.According to the numerical results,a graphene-filled layer not only broadens the working bandwidth but also reduces the size of the polarization splitter.Furthermore,the fluorine-doped region and the germanium-doped region can broaden the bandwidth.Also,the 4.78 mm long polarization splitter can achieve an extinction ratio of-98.6 d B at a wavelength of 1550 nm.When extinction ratio is less than-20 d B,the range of the wavelength is 1027 nm-1723 nm with a bandwidth of 696 nm.Overall,the polarization splitter can be applied to all-optical network communication systems in the infrared and near-infrared wavelength range.展开更多
The network structures of smart substations and the characteristics of industrial Ethernet switches are analyzed.The testing technologies of network systems based on smart substations are specifically elaborated.A vie...The network structures of smart substations and the characteristics of industrial Ethernet switches are analyzed.The testing technologies of network systems based on smart substations are specifically elaborated.A viewpoint is proposed that special testing policy&method of smart substation networks should be followed,so that the results can reveal the real network data exchange performance of the whole station.This view ensures the safety and stability of smart substations and lays a foundation for future upgrades and expansions.展开更多
Available model of 3D-quantitative structure-activity relationship (3D-QSAR, the method of TopomerCoMFA) has been used to establish relationship between antioxidant performances of lubricating oil (trimethylolpropane ...Available model of 3D-quantitative structure-activity relationship (3D-QSAR, the method of TopomerCoMFA) has been used to establish relationship between antioxidant performances of lubricating oil (trimethylolpropane trioleate, TMPTO) with 15 kinds of amine additives and its molecular structure. Correlation coefficient of the cross-validation (include internal q2 and external qpred 2 ) and conventional correlation coefficient showed the model to be both stable and good predictive. The electron-donating group and larger steric effects group are adopted at the para-position or meta-position of amido on the benzene ring, and suitably decreasing the branch chain near the para-position, these indicate that the antioxidant performance of amine additives can be enhanced. The results not only can help us understanding the rule of antioxidant performance, but also providing guidance(s) to predict antioxidant performance of existing amine additives and to design or modify new amine additives in lubricating oil.展开更多
The design of existing tribometer mainly focuses on normal pressure and environmental conditions, and aims to measure the effect of load and speed on material performance. The effect of gas pressure and environmental ...The design of existing tribometer mainly focuses on normal pressure and environmental conditions, and aims to measure the effect of load and speed on material performance. The effect of gas pressure and environmental condition on performance of materials is usually not considered. Thus, data from friction tests are not precise. In this paper, a new atmosphere tribometer is developed to study the tribological behavior of materials under severe rugged atmosphere. A fail-safe analysis is performed through reproducibility, comparability, and sensitivity tests. The tribometer allows tests to be performed in block-circle disc line contact, pin-circle disc line contact, and block-circle disc face contact configurations at controlled atmosphere and gas pressure. A self-centering plant is designed to settle the poor contact problem. A pin-on-disk test is conducted, and the test results indicate that the proposed design is efficient. A combined sealing style is introduced to control gas leaks. Compared with other sealing styles, the combined sealing is found to meet the experiment requirements best. And the reproducibility, comparability, and sensitivity tests validate the performance of the tribometer. The designed atmosphere tribometer reliably simulates the friction test under extremely harsh conditions, enhances the ability for material tribological properties test, and ensures accuracy of the tribological data.展开更多
文摘AIM To study whether Helicobacter pylori is naturally transformable. METHODS Transformation was performed in BHI broth supplemented with horse serum and yeast extract. Genomic DNA extracted from a metronidazole resistant H. pylori strain was added to H. pylori broth culture. The mixture was incubated at microaerophilic atmosphere. The DNA treated cells were plated on blood agar containing 8mg/L metronidazole to select for transformants. Sterile distilled water was used as a negative DNA control. The DNA profiles of transformants were compared with that of their parent strains by randomly amplified polymorphic DNA (RAPD) fingerprinting. RESULTS Transformation of H. pylori with DNA from a metronidazole resistant strain as a marker was demonstrated. Out of the 12 strains of H. pylori tested, 9 (75%) strains were found to be transformable. The transformation frequencies ranged from 3 4×10 -6 to 2 4×10 -4 . By RAPD, DNA fingerprints of the transformants and their parent strains showed no change in DNA profiles though transformants were all resistant to metronidazole as compared with their metronidazole sensitive parent strains. CONCLUSION Helicobacter pylori is naturally transformable which might be one of the ways that H. pylori develops resistance to metronidazole.
基金国家重点基础研究发展计划(973计划)，the Foundation of Excellent Young/Scientists of Shandong Province
文摘Abstract: The authors found five sodium (Na+) and chloride (Cl-.) hyperaccumulating halophytes in the Temperate Desert of Xinjiang, China and studied two of them (Suaeda salsa (L.) Pall. and Kalidium folium (Pall.) Moq.). K. folium and S. salsa had a NaCl content of 32.1% and 29.8%, respectively, on a dry weight basis. X-ray microanalysis of the Na+ in the vacuole, apoplasts and cytoplasm of the two plants indicated a ratio of 7.3:5.6:1.0 in K. folium and 7.3:6.6:1.0 in S. salsa. These data show that K. folium and S. salsa both have a high Na+ and Cl- accumulating capacity, which is related to high activity of tonoplast H+-ATPase and H+-PPase.
基金supported by the Natural Science Foundation of Fujian Province(no.2020J011119)supported by the Natural Science Foundation of Fujian Province(no.2022J011046).
文摘Purpose We aimed to analyse the correlation between prostaglandin D2 synthase(PTGDS)and a diffuse large B-cell lymphoma(DLBCL)prognosis.Methods We retrospectively collected two hundred paraffin-embedded tissue specimens that were pathologically diagnosed as DLBCL in the Fujian Tumour Hospital between January 2014 and December 2018.An abundance of paraffin-embedded tumour tissues were obtained.Twenty patients with lymphocyte-rich,benign,tissue-reactive,hypertrophic tonsillitis were selected as controls.Wax blocks were selected for primary cases and the controls were screened by professional pathologists.The levels of prostaglandin D2 synthase(PTGDS)and the EMT-related molecules,E-cadherin and vimentin,were detected by immunohistochemistry in clinical samples.A chi-square test revealed the correlations between PTGDS expression and clinicopathological characteristics,including age,sex,primary site,clinical stage,immunotyping,and International Prognostic Index(IPI)score.The Kaplan–Meier survival analysis was performed,and the diagnostic value was evaluated by receiver operating characteristic(ROC)curve analysis.Results A total of 138 cases(69%)were found to be PTGDS positive(>30%positive cells).PTGDS staining was negative(<30%positive cells)in 62 cases(31%).We collected the corresponding clinicopathological information and found that PTGDS expression was not significantly related to the patients’age,tumour stage,presence of extranodal invasion,or IPI score.According to the follow-up data,patients with low PTGDS expression had poor progression-free survival(PFS)and overall survival(OS),with 2-year PFS and OS rates of 41.7%and 50%,respectively.The 2-year PFS and OS rates of PTGDS-positive patients were 89.3%and 92.9%,respectively(P<0.0001),and the differences were significant.Conclusion We found that the expression level of PTGDS is significantly correlated with the prognosis of diffuse large B-cell lymphoma.
基金financially supported by the National Natural Science Foundation of China(U21A2081,22075074,22179014)the Outstanding Young Scientists Research Funds from Hunan Province(2020JJ2004)+2 种基金the Major Science and Technology Program of Hunan Province(2020WK2013)the Natural Science Foundation of Hunan Province(2021JJ40047)the State Key Laboratory of Materials Processing and Die&Mould Technology,Huazhong University of Science and Technology(P2022-020)。
文摘The poor cycling stability of graphite in traditional ester electrolyte limits its applications as anodes for potassium ion batteries(KIBs).Herein,we demonstrate that the introduction of cyclic ether co-solvents into ester electrolytes can remarkably enhance the cycling stability of graphite anodes.The graphite anode in ester electrolyte with cyclic ether could achieve a reversible capacity of 196.1 m Ah g^(-1) after 100 cycles at 0.3 C(1 C=280 m A g^(-1)),about three times higher than those in ester electrolytes with or without linear ether.Compared with the SEI formed in ester electrolytes,the addition of tetrahydrofuran promotes the generation of K_(2)CO_(3) and ethylene oxide oligomers(PEO),of which the K_(2)CO_(3) is expected to be more conductive and PEO is mechanically robust.The more uniform,conductive and stable solid electrolyte interphases(SEIs)on graphite in electrolytes with cyclic ethers contribute to the enhancement of the electrochemical performances of graphite.This work provides a novel design of commercialized electrolytes to achieve high-performance anodes for KIBs,which potentially accelerates the development of KIBs.
基金supported by the National Natural Science Foundation of China(Grant No.51075308)
文摘A new laboratory evaluation method for the coating blade was developed, and the tribological properties of coating blades with different Ti-based coatings were studied by UMT-2 tribometer. Comparison between the areas of scratches before and after the cutting experiment was used to evaluate the cutting performance of the blades. Results showed that friction coefficient of TiA1CrN/TiA1N coating was significantly lower than that of TiA1SiN coating. Analysis of the worn surface revealed that the TiA1SiN and TiAICrN/TiA1N coatings in the dry turning process exhibited sign of inhornogeneous adhesive wear and abrasive wear. TiA1CrN/TiA1N coating has a longer working life and better anti-wear property because of its duplex coating.
基金Project supported by the State Key Laboratory of Luminescence and Applications(Grant No.SKLA-2020-01)。
文摘A novel ultra-broadband polarization splitter based on a dual-core photonic crystal fiber(DC-PCF)is designed.The full-vector finite element method and coupled-mode theory are employed to investigate the characteristics of the polarization splitter.According to the numerical results,a graphene-filled layer not only broadens the working bandwidth but also reduces the size of the polarization splitter.Furthermore,the fluorine-doped region and the germanium-doped region can broaden the bandwidth.Also,the 4.78 mm long polarization splitter can achieve an extinction ratio of-98.6 d B at a wavelength of 1550 nm.When extinction ratio is less than-20 d B,the range of the wavelength is 1027 nm-1723 nm with a bandwidth of 696 nm.Overall,the polarization splitter can be applied to all-optical network communication systems in the infrared and near-infrared wavelength range.
文摘The network structures of smart substations and the characteristics of industrial Ethernet switches are analyzed.The testing technologies of network systems based on smart substations are specifically elaborated.A viewpoint is proposed that special testing policy&method of smart substation networks should be followed,so that the results can reveal the real network data exchange performance of the whole station.This view ensures the safety and stability of smart substations and lays a foundation for future upgrades and expansions.
基金supported by the National Basic Research Program of China(Grant No.2013CB632303)the National Natural Science Foundation of China(Grant No.51505341)
文摘Available model of 3D-quantitative structure-activity relationship (3D-QSAR, the method of TopomerCoMFA) has been used to establish relationship between antioxidant performances of lubricating oil (trimethylolpropane trioleate, TMPTO) with 15 kinds of amine additives and its molecular structure. Correlation coefficient of the cross-validation (include internal q2 and external qpred 2 ) and conventional correlation coefficient showed the model to be both stable and good predictive. The electron-donating group and larger steric effects group are adopted at the para-position or meta-position of amido on the benzene ring, and suitably decreasing the branch chain near the para-position, these indicate that the antioxidant performance of amine additives can be enhanced. The results not only can help us understanding the rule of antioxidant performance, but also providing guidance(s) to predict antioxidant performance of existing amine additives and to design or modify new amine additives in lubricating oil.
基金supported by National Basic Research Program of China (973 Program, Grant No. 2007CB607603)National Science and Technology Major Project of China (2010ZX04 014-071)
文摘The design of existing tribometer mainly focuses on normal pressure and environmental conditions, and aims to measure the effect of load and speed on material performance. The effect of gas pressure and environmental condition on performance of materials is usually not considered. Thus, data from friction tests are not precise. In this paper, a new atmosphere tribometer is developed to study the tribological behavior of materials under severe rugged atmosphere. A fail-safe analysis is performed through reproducibility, comparability, and sensitivity tests. The tribometer allows tests to be performed in block-circle disc line contact, pin-circle disc line contact, and block-circle disc face contact configurations at controlled atmosphere and gas pressure. A self-centering plant is designed to settle the poor contact problem. A pin-on-disk test is conducted, and the test results indicate that the proposed design is efficient. A combined sealing style is introduced to control gas leaks. Compared with other sealing styles, the combined sealing is found to meet the experiment requirements best. And the reproducibility, comparability, and sensitivity tests validate the performance of the tribometer. The designed atmosphere tribometer reliably simulates the friction test under extremely harsh conditions, enhances the ability for material tribological properties test, and ensures accuracy of the tribological data.
