In order to investigate how to enhance the teeth fracture resistance after the post and core treatment, an in vitro study was conducted to measure the fracture resistance of endodontically treated teeth restored with ...In order to investigate how to enhance the teeth fracture resistance after the post and core treatment, an in vitro study was conducted to measure the fracture resistance of endodontically treated teeth restored with cast post and core with two kinds of surface treatment technology and acid etching preparation on the dentinal surface. Sixty-four recently extracted human single-rooted first premolars were endodontically treated and sectioned approximately 1.5 mm above the cementoenamel junction to remove the coronal portion. Each specimen received a cast post, core build-up and a metal alloy crown restoration. All teeth were randomly divided into the smooth surface post, core repair group, the sand blasting surface post, and core repair group, each group was divided into 10 s, 30 s, 60 s acid corrosion treatment group and control group. In acid test groups, an acid etching solution was applied for 10, 30 and 60 seconds, respectively, to the root canal wall surface. Each specimen was embedded in acrylic resin block and tested in an electronic universal testing machine. Fracture loads results showed that canal acid etching could increase teeth fracture resistance strength both in smooth groups and sandblasting group, and achieved the best effect when acid etching for 30 s. Sand spray treatment on the surface of the cast metal post can improve the flexural strength of the teeth after postcrown restoration. Acid etching on the root canal wall surfaces and sand spray treatment on the surface of the cast metal post can improve the flexural strength of the root after post-crown restoration. Therefore, these two methods could be used to strengthen the tooth fracture resistance, and maintain the long-term therapeutic effect of cast post and core restoration.展开更多
AIM: To investigate the molecular mechanism for regulation of cholesterol metabolism by hepatitis C virus(HCV) core protein in Hep G2 cells.METHODS: HCV genotype 1b core protein was cloned and expressed in Hep G2 cell...AIM: To investigate the molecular mechanism for regulation of cholesterol metabolism by hepatitis C virus(HCV) core protein in Hep G2 cells.METHODS: HCV genotype 1b core protein was cloned and expressed in Hep G2 cells. The cholesterol content was determined after transfection. The expression of sterol regulatory element binding protein 2(SREBP2) and the rate-limiting enzyme in cholesterol synthesis(HMGCR) was measured by quantitative real-time PCR and immunoblotting after transfection. The effects of core protein on the SREBP2 promoter and 3'-untranslated region were analyzed by luciferase assay. We used different target predictive algorithms, micro RNA(mi RNA) mimics/inhibitors, and site-directed mutation to identify a putative target of a particular mi RNA.RESULTS: HCV core protein expression in Hep G2 cells increased the total intracellular cholesterol level(4.05 ± 0.17 vs 6.47 ± 0.68, P = 0.001), and this increase corresponded to an increase in SREBP2 and HMGCR m RNA levels(P = 0.009 and 0.037, respectively) and protein expression. The molecular mechanism studyrevealed that the HCV core protein increased the expression of SREBP2 by enhancing its promoter activity(P = 0.004). In addition, mi R-185-5p expression was tightly regulated by the HCV core protein(P = 0.041). Moreover, overexpression of mi R-185-5p repressed the SREBP2 m RNA level(P = 0.022) and protein expression. In contrast, inhibition of mi R-185-5p caused upregulation of SREBP2 protein expression. mi R-185-5p was involved in the regulation of SREBP2 expression by HCV core protein. CONCLUSION: HCV core protein disturbs the cholesterol homeostasis in Hep G2 cells via the SREBP2 pathway; mi R-185-5p is involved in the regulation of SREBP2 by the core protein.展开更多
A number of cold seeps have been discovered in the northern South China Sea(SCS) including the Haiyang 4 cold-seep area where Core 973-5 was collected. Intact polar lipids(IPLs) and core lipids(CLs) were analyzed sepa...A number of cold seeps have been discovered in the northern South China Sea(SCS) including the Haiyang 4 cold-seep area where Core 973-5 was collected. Intact polar lipids(IPLs) and core lipids(CLs) were analyzed separately in sediments from Core 973-5. The most abundant lipid biomarkers were isoprenoidal GDGTs(iso GDGTs), with Crenarchaeol and GDGT-0 predominating. IPL-iso GDGTs and CL-iso GDGTs were mainly derived from Thaumarchaeota. IPL-iso GDGTs were mainly produced and retained in situ thus containing most of the in situ microbiological information. Branched GDGTs were predominantly derived from generated in marine production, and mixed with some terrestrial inputs. All IPLs groups presented a high value in the sulfate-methane transition zone(SMTZ). Furthermore, IPL and CL-MI, IPL-R;showed the highest values within the SMTZ, while IPL and CL-R;had the lowest values at the SMTZ, suggesting that the contribution of Methanophila and methanogenic to GDGTs increased, while the contribution of ammonia-oxidizing Archaea to GDGTs decreased at the SMTZ.展开更多
AIM： TO examine whether 2＇-5＇oligoadenylate synthetase （OAS） gene promoter can be specifically activated by hepatitis C virus （HCV）-core protein. METHODS： Human embryo hepatic cell line L02 was transfected wit...AIM： TO examine whether 2＇-5＇oligoadenylate synthetase （OAS） gene promoter can be specifically activated by hepatitis C virus （HCV）-core protein. METHODS： Human embryo hepatic cell line L02 was transfected with pcDNA3.1-core plasmid and selected by G418. Expression of HCV-core was detected by reverse transcription polymerase chain reaction and Western blotting. The OAS promoter sequence was amplified from the genomic DNA and inserted into pGL3-basic vector. The resultant pGL3-OAS-Luci plasmid was transiently transfected into L02/core cells and luciferase activity was assayed. I^ESULTS： L02/core cell line stably expressing HCV- core protein was established. The pGL3-OAS-Luci construct exhibited significant transcriptional activity in the L02/core cells but not in the L02 cells. CONCLUSION： HCV-core protein activates the OAS gene promoter specifically and effectively. Utilization of OAS gene promoter would be an ideal strategy for developing HCV-specific gene therapy.展开更多
A theoretical analysis is presented to predict the nonlinear thermo-structural response of metallicsandwich panels with truss cores under through-thickness gradient temperature field, which is acommon service condit...A theoretical analysis is presented to predict the nonlinear thermo-structural response of metallicsandwich panels with truss cores under through-thickness gradient temperature field, which is acommon service condition for metallic thermal protection system （TPS）. The in-planetemperature distribution is assumed to be uniform, and through-thickness temperature field isdetermined by heat conduction. Two typical conditions are analyzed： nonlinear thermal bendingin fixed inside surface temperature, and thermal post-buckling in fixed temperature differencebetween two surfaces. Temperature-dependent mechanical properties are considered, andgradient shear stiffness and bending stiffness due to non-uniform temperature is included. Resultsindicate that the temperature-dependent material properties obviously affect bending resistance;however, the effect is negligible on post-buckling behavior. Influences of geometric parameters onthe thermo-structural behavior of the sandwich panel according to the present theoretical modelare discussed.展开更多
旗舰级的LGA2011平台三年来倒也升级了两代了,今年则会轮到Haswell-E架构登场了,还好这一次的升级力度还是挺大的,CPU要从6核升级到8核,主板要从X79升级到X99,就连主流的DDR3内存也要升级到全新的DDR4了,来了个三位一体的全方位换代。...旗舰级的LGA2011平台三年来倒也升级了两代了,今年则会轮到Haswell-E架构登场了,还好这一次的升级力度还是挺大的,CPU要从6核升级到8核,主板要从X79升级到X99,就连主流的DDR3内存也要升级到全新的DDR4了,来了个三位一体的全方位换代。这两年A M D无心恋战高性能处理器市场,Intel早已高处不胜寒,从Sandy Bridgge到Ivy Bridge再到Haswell,每代处理器升级最大的都是GPU性能。展开更多
Friction spun core yarn has two components: filament core and staple fiber sheath. Under axial rubbing action, the failure mode of the core yarn is the stripping of the sheath from the core. This paper introduces a me...Friction spun core yarn has two components: filament core and staple fiber sheath. Under axial rubbing action, the failure mode of the core yarn is the stripping of the sheath from the core. This paper introduces a method to test the anti - stripping property of the core yarn. With a modified Universal Testing Machine, the stripping resistance of friction spun core yarn can be continuously measured. Some factors Influencing the measurements are discussed in detail. The testing results are compared with those from a Y731 Yarn Abrasion Tester and fur - ther confirmed by weaving practice.展开更多
基金Funded by the Construction Engineering Special Fund of Taishan Scholars(No.201511106)the Youth Scientific Research Funds of School of Stomatology,Shandong University(No.2018QNJJ01)+1 种基金Shandong Medical and Health Science and Technology Development Plan(No.2017WS112)National Key Research and Development Program of China(No.2016YFC1102705)
文摘In order to investigate how to enhance the teeth fracture resistance after the post and core treatment, an in vitro study was conducted to measure the fracture resistance of endodontically treated teeth restored with cast post and core with two kinds of surface treatment technology and acid etching preparation on the dentinal surface. Sixty-four recently extracted human single-rooted first premolars were endodontically treated and sectioned approximately 1.5 mm above the cementoenamel junction to remove the coronal portion. Each specimen received a cast post, core build-up and a metal alloy crown restoration. All teeth were randomly divided into the smooth surface post, core repair group, the sand blasting surface post, and core repair group, each group was divided into 10 s, 30 s, 60 s acid corrosion treatment group and control group. In acid test groups, an acid etching solution was applied for 10, 30 and 60 seconds, respectively, to the root canal wall surface. Each specimen was embedded in acrylic resin block and tested in an electronic universal testing machine. Fracture loads results showed that canal acid etching could increase teeth fracture resistance strength both in smooth groups and sandblasting group, and achieved the best effect when acid etching for 30 s. Sand spray treatment on the surface of the cast metal post can improve the flexural strength of the teeth after postcrown restoration. Acid etching on the root canal wall surfaces and sand spray treatment on the surface of the cast metal post can improve the flexural strength of the root after post-crown restoration. Therefore, these two methods could be used to strengthen the tooth fracture resistance, and maintain the long-term therapeutic effect of cast post and core restoration.
基金Supported by Medical Specialty Development Projects of Beijing Municipal Administration of Hospitals,No.ZYLX201402Ministry of Education of The People’s Republic of China,No.20121107110012+1 种基金Beijing Municipal Commission of Education,No.11320016Collaborative Innovation Center of Infectious Diseases and Beijing Key Laboratory of Emerging Infectious Diseases,Beijing,China
文摘AIM: To investigate the molecular mechanism for regulation of cholesterol metabolism by hepatitis C virus(HCV) core protein in Hep G2 cells.METHODS: HCV genotype 1b core protein was cloned and expressed in Hep G2 cells. The cholesterol content was determined after transfection. The expression of sterol regulatory element binding protein 2(SREBP2) and the rate-limiting enzyme in cholesterol synthesis(HMGCR) was measured by quantitative real-time PCR and immunoblotting after transfection. The effects of core protein on the SREBP2 promoter and 3'-untranslated region were analyzed by luciferase assay. We used different target predictive algorithms, micro RNA(mi RNA) mimics/inhibitors, and site-directed mutation to identify a putative target of a particular mi RNA.RESULTS: HCV core protein expression in Hep G2 cells increased the total intracellular cholesterol level(4.05 ± 0.17 vs 6.47 ± 0.68, P = 0.001), and this increase corresponded to an increase in SREBP2 and HMGCR m RNA levels(P = 0.009 and 0.037, respectively) and protein expression. The molecular mechanism studyrevealed that the HCV core protein increased the expression of SREBP2 by enhancing its promoter activity(P = 0.004). In addition, mi R-185-5p expression was tightly regulated by the HCV core protein(P = 0.041). Moreover, overexpression of mi R-185-5p repressed the SREBP2 m RNA level(P = 0.022) and protein expression. In contrast, inhibition of mi R-185-5p caused upregulation of SREBP2 protein expression. mi R-185-5p was involved in the regulation of SREBP2 expression by HCV core protein. CONCLUSION: HCV core protein disturbs the cholesterol homeostasis in Hep G2 cells via the SREBP2 pathway; mi R-185-5p is involved in the regulation of SREBP2 by the core protein.
基金supported by the Natural Science Foundation of China(Grant Nos.40672005 and 41776066)。
文摘A number of cold seeps have been discovered in the northern South China Sea(SCS) including the Haiyang 4 cold-seep area where Core 973-5 was collected. Intact polar lipids(IPLs) and core lipids(CLs) were analyzed separately in sediments from Core 973-5. The most abundant lipid biomarkers were isoprenoidal GDGTs(iso GDGTs), with Crenarchaeol and GDGT-0 predominating. IPL-iso GDGTs and CL-iso GDGTs were mainly derived from Thaumarchaeota. IPL-iso GDGTs were mainly produced and retained in situ thus containing most of the in situ microbiological information. Branched GDGTs were predominantly derived from generated in marine production, and mixed with some terrestrial inputs. All IPLs groups presented a high value in the sulfate-methane transition zone(SMTZ). Furthermore, IPL and CL-MI, IPL-R;showed the highest values within the SMTZ, while IPL and CL-R;had the lowest values at the SMTZ, suggesting that the contribution of Methanophila and methanogenic to GDGTs increased, while the contribution of ammonia-oxidizing Archaea to GDGTs decreased at the SMTZ.
基金Supported by National Natural Science Foundation of China,No.30671846
文摘AIM： TO examine whether 2＇-5＇oligoadenylate synthetase （OAS） gene promoter can be specifically activated by hepatitis C virus （HCV）-core protein. METHODS： Human embryo hepatic cell line L02 was transfected with pcDNA3.1-core plasmid and selected by G418. Expression of HCV-core was detected by reverse transcription polymerase chain reaction and Western blotting. The OAS promoter sequence was amplified from the genomic DNA and inserted into pGL3-basic vector. The resultant pGL3-OAS-Luci plasmid was transiently transfected into L02/core cells and luciferase activity was assayed. I^ESULTS： L02/core cell line stably expressing HCV- core protein was established. The pGL3-OAS-Luci construct exhibited significant transcriptional activity in the L02/core cells but not in the L02 cells. CONCLUSION： HCV-core protein activates the OAS gene promoter specifically and effectively. Utilization of OAS gene promoter would be an ideal strategy for developing HCV-specific gene therapy.
基金The financial support from the National Natural Science Foundation of China (91016025, 11472276, 11602271, and 11332011)the Defense Industrial Technology Development Program of China (JCKY2016130B009)
文摘A theoretical analysis is presented to predict the nonlinear thermo-structural response of metallicsandwich panels with truss cores under through-thickness gradient temperature field, which is acommon service condition for metallic thermal protection system （TPS）. The in-planetemperature distribution is assumed to be uniform, and through-thickness temperature field isdetermined by heat conduction. Two typical conditions are analyzed： nonlinear thermal bendingin fixed inside surface temperature, and thermal post-buckling in fixed temperature differencebetween two surfaces. Temperature-dependent mechanical properties are considered, andgradient shear stiffness and bending stiffness due to non-uniform temperature is included. Resultsindicate that the temperature-dependent material properties obviously affect bending resistance;however, the effect is negligible on post-buckling behavior. Influences of geometric parameters onthe thermo-structural behavior of the sandwich panel according to the present theoretical modelare discussed.
文摘旗舰级的LGA2011平台三年来倒也升级了两代了,今年则会轮到Haswell-E架构登场了,还好这一次的升级力度还是挺大的,CPU要从6核升级到8核,主板要从X79升级到X99,就连主流的DDR3内存也要升级到全新的DDR4了,来了个三位一体的全方位换代。这两年A M D无心恋战高性能处理器市场,Intel早已高处不胜寒,从Sandy Bridgge到Ivy Bridge再到Haswell,每代处理器升级最大的都是GPU性能。
文摘Friction spun core yarn has two components: filament core and staple fiber sheath. Under axial rubbing action, the failure mode of the core yarn is the stripping of the sheath from the core. This paper introduces a method to test the anti - stripping property of the core yarn. With a modified Universal Testing Machine, the stripping resistance of friction spun core yarn can be continuously measured. Some factors Influencing the measurements are discussed in detail. The testing results are compared with those from a Y731 Yarn Abrasion Tester and fur - ther confirmed by weaving practice.
