The influence of weights is usually ignored in the study of nonlinear vibrations of plates.In this paper,the effect of structure weights on the nonlinear vibration of a composite circular plate with a rigid body is pr...The influence of weights is usually ignored in the study of nonlinear vibrations of plates.In this paper,the effect of structure weights on the nonlinear vibration of a composite circular plate with a rigid body is presented.The nonlinear governing equations are derived from the generalized Hamilton's principle and the von Kármán plate theory.The equilibrium configurations due to weights are determined and validated by the finite element method(FEM).A nonlinear model for the vibration around the equilibrium configuration is established.Moreover,the natural frequencies and amplitude-frequency responses of harmonically forced vibrations are calculated.The study shows that the structure weights introduce additional linear and quadratic nonlinear terms into the dynamical model.This leads to interesting phenomena.For example,considering weights increases the natural frequency.Furthermore,when the influence of weights is considered,the vibration response of the plate becomes asymmetrical.展开更多
A porous 3D cross-linked conductive network pierced by multi-wall carbon nanotubes(MWCNTs) was successfully designed from zeolitic imidazolate framework-8(ZIF-8). Zn@NPC@MWCNTs composites were tailored by the facile r...A porous 3D cross-linked conductive network pierced by multi-wall carbon nanotubes(MWCNTs) was successfully designed from zeolitic imidazolate framework-8(ZIF-8). Zn@NPC@MWCNTs composites were tailored by the facile regulating the mass ratios and thermal annealing treatment. Due to the combination of less eddy current loss and dielectric loss together with multiple reflection attenuation caused by a unique structure. With a 10 wt% filler loading, the Zn@NPC@MWCNTs composites carbonized at 800℃ show two high reflection loss(RL) values with different thicknesses. An RL value is-53.18 dB with 4.09 mm thickness in the C-Band(4-8 GHz), and a minimum RL can reach-74.83 d B(10.8 GHz)with a matching thickness of 2.749 mm. The effective absorption bandwidth is 4 GHz(from 8 to 12 GHz,RL ≤-10 d B), which just covers the full X-band. Low cost and easy preparation can also provide advantages to develop MOF-based materials as effective EMW absorbents.展开更多
INTRODUCTIONIt has been reported that renin-angiotensin systemexists in tissue and aldosterone can be synthesizedin extra-adrenal tissue including heart,bloodvessels and brain.Recent studies have broughtrich evidences...INTRODUCTIONIt has been reported that renin-angiotensin systemexists in tissue and aldosterone can be synthesizedin extra-adrenal tissue including heart,bloodvessels and brain.Recent studies have broughtrich evidences in favour of aldosterone as a strongstimulator of fibrogenesis and mitogenesis.展开更多
AIM: Angiotensin Ⅱ has pro-fibrotic function in the liver.Blockade of the renin-angiotensin-aldosterone-system (RAAS) attenuates hepatic fibrosis. The aim of the present study was to determine the mechanism of angiot...AIM: Angiotensin Ⅱ has pro-fibrotic function in the liver.Blockade of the renin-angiotensin-aldosterone-system (RAAS) attenuates hepatic fibrosis. The aim of the present study was to determine the mechanism of angiotensinconverting enzyme inhibitor (ACEI) on the progression of rat hepatic fibrosis.METHODS: Forty male Wistar rats were divided into three groups. Model group (Mo): The rats were injected subcutaneously with 40% of CCl4 0.25 mL/100 g. Perindopril group (Pe): The rats were injected subcutaneously with administrated. Control group (Nc): the rats were treated with olive oil only. After 4 and 6 wk, the rats were killed.The liver sections were stained with Masson. The protein expressions of AT1R, TGF-β1 and PDGF-BB were examined by Western blot. Nuclear factor κB (NF-κB) DNA binding activity was examined by EMSA (Electrophoretic gel mobility shift assay). Matrix metalloproteinase-2,9(MMP-2,9) activity was assessed by zymography. Serum laminin (LN) and hyaluronic acid (HA) were measured using radioimmunoassays.RESULTS: Using Western blot, we clearly provided direct evidence for the expression of AT1R in liver. The expression was up-regulated when fibrogenesis occurred. Perindopril treatment significantly reduced mean fibrosis score,protein levels of AT1R, TGF-β1 and PDGF-BB, serum levels of HA and LN, and the activity of MMP-2,9. NF-κB DNA binding activity markedly increased in model group, perindopril treatment considerably reduced NF-κB DNA binding activity.CONCLUSION: Perindopril attenuates CCl4-induced hepatic fibrogenesis of rat by inhibiting TGF-β1, PDGF-BB,NF-κB and MMP-2,9.展开更多
Toxicodendron is a genus in the Rhus complex of Anacardiaceae with a disjunct distribution between eastern Asia and North America, extending to southeastern Asia and the neotropics. Nuclear （internal transcribed spac...Toxicodendron is a genus in the Rhus complex of Anacardiaceae with a disjunct distribution between eastern Asia and North America, extending to southeastern Asia and the neotropics. Nuclear （internal transcribed spacer, external transcribed spacer, and NIA-i3） and chloroplast （ndhF and trnL-F） sequences were used to construct phylogenetic relationships of Toxicodendron. Phylogenetic analysis of these data strongly support Toxieodendron as a monophyletic group distinct from other genera of the Rhus complex, and the phylogeny does not fully corroborate classification at the sectional level. Two temperate disjunct lineages were detected, one from section Toxicodendron and the other between the eastern North American Toxicodendron vernix and the eastern Asian Toxicodendron vernieifluum. Their divergence times were estimated to be 13.46 （7.95-19.42） and 7.53 （2.76-12.86） mya, respectively. The disjunction between section Griffithii （taxa from warm temperate to tropical Asia） and Toxieodendron striatum （from the neotropics） was supported and their divergence time was estimated to be 20.84 （11.1 6-30.52） mya in the early Miocene. Our biogeographic results and the paleontological data support the Bering land bridge as the most likely route to explain the temperate disjunctions, yet the tropical disjunction in Toxicodendron seems to be best explained by the North Atlantic land bridge hypothesis.展开更多
Streptococcus mutans is a well-known cause of dental caries,due to its acidogenicity,aciduricity,and ability to synthesize exopolysaccharides in dental plaques.Intriguingly,not all children who carry S.mutans manifest...Streptococcus mutans is a well-known cause of dental caries,due to its acidogenicity,aciduricity,and ability to synthesize exopolysaccharides in dental plaques.Intriguingly,not all children who carry S.mutans manifest caries,even with similar characteristics in oral hygiene,diet,and other environmental factors.This phenomenon suggests that host susceptibility potentially plays a role in the development of dental caries;however,the association between host genetics,S.mutans,and dental caries remains unclear.Therefore,this study examined the influence of host gene-by-S.mutans interaction on dental caries.Genome-wide association analyses were conducted in 709 US children (<13 years old),using the dbGap database acquired from the center for oral health research in appalachia (COHRA) and the Iowa Head Start programmes (GEIRS).A generalized estimating equation was used to examine the gene-by-S.mutans interaction effects on the outcomes (decayed and missing/filled primary teeth due to caries).Sequentially,the COHRA and GEIRS data were used to identify potential interactions and replicate the findings.Three loci at the genes interleukin 32 (IL32),galactokinase 2 (GALK2),and CUGBP,Elav-like family member 4 (CELF4) were linked to S.mutans carriage,and there was a severity of caries at a suggestive significance level among COHRA children (P < 9×10?5),and at a nominal significance level among GEIRS children (P = 0.047–0.001).The genetic risk score that combined the three loci also significantly interacted with S.mutans (P < 0.000 1).Functional analyses indicated that the identified genes are involved in the host immune response,galactose carbohydrate metabolism,and food-rewarding system,which could potentially be used to identify children at high risk for caries and to develop personalized caries prevention strategies.展开更多
Plain reservoirs are shallow, and have low dams and widespread water surfaces.Therefore, wind-wave-induced damage to the dam is one of the important factors affecting the safety of the reservoir.To improve upon unsati...Plain reservoirs are shallow, and have low dams and widespread water surfaces.Therefore, wind-wave-induced damage to the dam is one of the important factors affecting the safety of the reservoir.To improve upon unsatisfactory plain reservoir wave-clipping schemes, a numerical method is proposed to predict and analyze waves in the reservoir in the presence of artificial islands, constructed from dredged sediment.The MIKE21 SW model is applied to a specific plain reservoir for finding the optimal artificial island parameters.The simulated wave height attenuation results are seen to agree well with empirically predicted values.Thus, the validity and reliability of the numerical model are established.Artificial islands at suitable locations in the reservoir can attenuate the wave heights by approximately 10%e30%, which justifies the efficacy of the clipping scheme making use of dredging and island construction.展开更多
The impacts of nighttime post-anthesis warming on rice productivity and grain quality in East China were evaluated for two cultivars, II You 128, an indica rice, and Wuyunjing 7, a japonica rice. Warming by 3.0 °...The impacts of nighttime post-anthesis warming on rice productivity and grain quality in East China were evaluated for two cultivars, II You 128, an indica rice, and Wuyunjing 7, a japonica rice. Warming by 3.0 °C stimulated the nighttime respiration rate and decreased the photosynthesis rate, resulting in significant decreases of 21.2% and 24.9% in aboveground biomass accumulation for II You 128 and Wuyunjing 7, respectively. Warming significantly reduced the rates of seed setting and grain filling, especially of inferior kernels(those lower in panicles), while the filling rate of superior kernels remained almost unchanged. As a result, 1000-grain weight and grain yield were respectively 3.7% and 30.0% lower for II You 128 and 12.8% and 34.3% for Wuyunjing 7 in warmed plots than in the unwarmed control. Nighttime warming also significantly reduced the grain milling and appearance quality of both varieties. More negative effects of warming on inferior than on superior kernels were found. The above results have important implications for rice variety cultivation in East China.展开更多
A new species of Rosaceae from Central China, Prunus sunhangii D. G. Zhang & T. Deng, sp. nov., is described and illustrated. The new species is placed in Prunus subgenus Cerasus by flower and fruit characteristic...A new species of Rosaceae from Central China, Prunus sunhangii D. G. Zhang & T. Deng, sp. nov., is described and illustrated. The new species is placed in Prunus subgenus Cerasus by flower and fruit characteristics. It is most similar to Prunus cerasoides, but differs by having longitudinally 2-lobed apical petals, an acuminate leaf apex, 17—25 stamens, white petals, dark black drupes, brown hypanthium, and different phenology. The phylogenetic placement of this species was assessed based on morphological and molecular data. Molecular analysis(cp DNA + ITS) corroborated its placement in subgenus Cerasus,specifically Prunus section Serrula.展开更多
基金Project supported by the National Natural Science Foundation of China(No.12002195)the National Science Fund for Distinguished Young Scholars of China(No.12025204)the Program of Shanghai Municipal Education Commission of China(No.2019-01-07-00-09-E00018)。
文摘The influence of weights is usually ignored in the study of nonlinear vibrations of plates.In this paper,the effect of structure weights on the nonlinear vibration of a composite circular plate with a rigid body is presented.The nonlinear governing equations are derived from the generalized Hamilton's principle and the von Kármán plate theory.The equilibrium configurations due to weights are determined and validated by the finite element method(FEM).A nonlinear model for the vibration around the equilibrium configuration is established.Moreover,the natural frequencies and amplitude-frequency responses of harmonically forced vibrations are calculated.The study shows that the structure weights introduce additional linear and quadratic nonlinear terms into the dynamical model.This leads to interesting phenomena.For example,considering weights increases the natural frequency.Furthermore,when the influence of weights is considered,the vibration response of the plate becomes asymmetrical.
基金supported by the Natural Science Foundation of Anhui Province (Grant No. 2008085MF217, Grant No. 2008085QF287)the University Natural Science Research Project of Anhui Province (Grant No. KJ2021A0912, Grant No. KJ2020A0091, Grant No. KJ2019A0714)+1 种基金the Program Fund for Excellent Young Talents of Higher Education Institutions of Anhui Province (Grant No. gxyq2020042)Anhui Province Key Laboratory of Simulation and Design for Electronic Information System (Grant No. 2019ZDSYSZB02)
文摘A porous 3D cross-linked conductive network pierced by multi-wall carbon nanotubes(MWCNTs) was successfully designed from zeolitic imidazolate framework-8(ZIF-8). Zn@NPC@MWCNTs composites were tailored by the facile regulating the mass ratios and thermal annealing treatment. Due to the combination of less eddy current loss and dielectric loss together with multiple reflection attenuation caused by a unique structure. With a 10 wt% filler loading, the Zn@NPC@MWCNTs composites carbonized at 800℃ show two high reflection loss(RL) values with different thicknesses. An RL value is-53.18 dB with 4.09 mm thickness in the C-Band(4-8 GHz), and a minimum RL can reach-74.83 d B(10.8 GHz)with a matching thickness of 2.749 mm. The effective absorption bandwidth is 4 GHz(from 8 to 12 GHz,RL ≤-10 d B), which just covers the full X-band. Low cost and easy preparation can also provide advantages to develop MOF-based materials as effective EMW absorbents.
基金the National Natural Science Foundation of China,No.39870331.
文摘INTRODUCTIONIt has been reported that renin-angiotensin systemexists in tissue and aldosterone can be synthesizedin extra-adrenal tissue including heart,bloodvessels and brain.Recent studies have broughtrich evidences in favour of aldosterone as a strongstimulator of fibrogenesis and mitogenesis.
基金Supported by the Natural Science Foundation of China, No.30270610
文摘AIM: Angiotensin Ⅱ has pro-fibrotic function in the liver.Blockade of the renin-angiotensin-aldosterone-system (RAAS) attenuates hepatic fibrosis. The aim of the present study was to determine the mechanism of angiotensinconverting enzyme inhibitor (ACEI) on the progression of rat hepatic fibrosis.METHODS: Forty male Wistar rats were divided into three groups. Model group (Mo): The rats were injected subcutaneously with 40% of CCl4 0.25 mL/100 g. Perindopril group (Pe): The rats were injected subcutaneously with administrated. Control group (Nc): the rats were treated with olive oil only. After 4 and 6 wk, the rats were killed.The liver sections were stained with Masson. The protein expressions of AT1R, TGF-β1 and PDGF-BB were examined by Western blot. Nuclear factor κB (NF-κB) DNA binding activity was examined by EMSA (Electrophoretic gel mobility shift assay). Matrix metalloproteinase-2,9(MMP-2,9) activity was assessed by zymography. Serum laminin (LN) and hyaluronic acid (HA) were measured using radioimmunoassays.RESULTS: Using Western blot, we clearly provided direct evidence for the expression of AT1R in liver. The expression was up-regulated when fibrogenesis occurred. Perindopril treatment significantly reduced mean fibrosis score,protein levels of AT1R, TGF-β1 and PDGF-BB, serum levels of HA and LN, and the activity of MMP-2,9. NF-κB DNA binding activity markedly increased in model group, perindopril treatment considerably reduced NF-κB DNA binding activity.CONCLUSION: Perindopril attenuates CCl4-induced hepatic fibrogenesis of rat by inhibiting TGF-β1, PDGF-BB,NF-κB and MMP-2,9.
基金supported bygrants from the National Basic Research Program of China (973 Program,grant no. 2007CB411601)the National Natural Science Foundation of China (grant nos.30625004 and 40771073 to H. Sun)+2 种基金the Yunnan Natural Science Foundation (grant no. 2008CC013)the John D. and Catherine T. MacArthur Foundation (to J.Wen)supported by the Laboratory of Analytical Biology of the National Museum of Natural History,Smithsonian Institution,Washington DC,USA
文摘Toxicodendron is a genus in the Rhus complex of Anacardiaceae with a disjunct distribution between eastern Asia and North America, extending to southeastern Asia and the neotropics. Nuclear （internal transcribed spacer, external transcribed spacer, and NIA-i3） and chloroplast （ndhF and trnL-F） sequences were used to construct phylogenetic relationships of Toxicodendron. Phylogenetic analysis of these data strongly support Toxieodendron as a monophyletic group distinct from other genera of the Rhus complex, and the phylogeny does not fully corroborate classification at the sectional level. Two temperate disjunct lineages were detected, one from section Toxicodendron and the other between the eastern North American Toxicodendron vernix and the eastern Asian Toxicodendron vernieifluum. Their divergence times were estimated to be 13.46 （7.95-19.42） and 7.53 （2.76-12.86） mya, respectively. The disjunction between section Griffithii （taxa from warm temperate to tropical Asia） and Toxieodendron striatum （from the neotropics） was supported and their divergence time was estimated to be 20.84 （11.1 6-30.52） mya in the early Miocene. Our biogeographic results and the paleontological data support the Bering land bridge as the most likely route to explain the temperate disjunctions, yet the tropical disjunction in Toxicodendron seems to be best explained by the North Atlantic land bridge hypothesis.
基金supported by the National Institute of Dental and Craniofacial Research (NIDCR) grant K23DE027412
文摘Streptococcus mutans is a well-known cause of dental caries,due to its acidogenicity,aciduricity,and ability to synthesize exopolysaccharides in dental plaques.Intriguingly,not all children who carry S.mutans manifest caries,even with similar characteristics in oral hygiene,diet,and other environmental factors.This phenomenon suggests that host susceptibility potentially plays a role in the development of dental caries;however,the association between host genetics,S.mutans,and dental caries remains unclear.Therefore,this study examined the influence of host gene-by-S.mutans interaction on dental caries.Genome-wide association analyses were conducted in 709 US children (<13 years old),using the dbGap database acquired from the center for oral health research in appalachia (COHRA) and the Iowa Head Start programmes (GEIRS).A generalized estimating equation was used to examine the gene-by-S.mutans interaction effects on the outcomes (decayed and missing/filled primary teeth due to caries).Sequentially,the COHRA and GEIRS data were used to identify potential interactions and replicate the findings.Three loci at the genes interleukin 32 (IL32),galactokinase 2 (GALK2),and CUGBP,Elav-like family member 4 (CELF4) were linked to S.mutans carriage,and there was a severity of caries at a suggestive significance level among COHRA children (P < 9×10?5),and at a nominal significance level among GEIRS children (P = 0.047–0.001).The genetic risk score that combined the three loci also significantly interacted with S.mutans (P < 0.000 1).Functional analyses indicated that the identified genes are involved in the host immune response,galactose carbohydrate metabolism,and food-rewarding system,which could potentially be used to identify children at high risk for caries and to develop personalized caries prevention strategies.
基金supported by the National Key Research and Development Program of China(Grants No.2016YFC0401603,2016YFC0401605,and 2016YFC0401607)the Central Public-interest Scientific Institution Basal Research Fund(Grants No.Y717012 and Y718007)
文摘Plain reservoirs are shallow, and have low dams and widespread water surfaces.Therefore, wind-wave-induced damage to the dam is one of the important factors affecting the safety of the reservoir.To improve upon unsatisfactory plain reservoir wave-clipping schemes, a numerical method is proposed to predict and analyze waves in the reservoir in the presence of artificial islands, constructed from dredged sediment.The MIKE21 SW model is applied to a specific plain reservoir for finding the optimal artificial island parameters.The simulated wave height attenuation results are seen to agree well with empirically predicted values.Thus, the validity and reliability of the numerical model are established.Artificial islands at suitable locations in the reservoir can attenuate the wave heights by approximately 10%e30%, which justifies the efficacy of the clipping scheme making use of dredging and island construction.
基金supported by the National Key Technology Support Program of China (2011BAD16B14)the Chinese Natural Science Foundation (30771278)the Program for New Century Excellent Talents in University (NCET-05-0492)
文摘The impacts of nighttime post-anthesis warming on rice productivity and grain quality in East China were evaluated for two cultivars, II You 128, an indica rice, and Wuyunjing 7, a japonica rice. Warming by 3.0 °C stimulated the nighttime respiration rate and decreased the photosynthesis rate, resulting in significant decreases of 21.2% and 24.9% in aboveground biomass accumulation for II You 128 and Wuyunjing 7, respectively. Warming significantly reduced the rates of seed setting and grain filling, especially of inferior kernels(those lower in panicles), while the filling rate of superior kernels remained almost unchanged. As a result, 1000-grain weight and grain yield were respectively 3.7% and 30.0% lower for II You 128 and 12.8% and 34.3% for Wuyunjing 7 in warmed plots than in the unwarmed control. Nighttime warming also significantly reduced the grain milling and appearance quality of both varieties. More negative effects of warming on inferior than on superior kernels were found. The above results have important implications for rice variety cultivation in East China.
基金supported by the Major Program of the National Natural Science Foundation of China (31590823)the National Natural Science Foundation of China (31700165)+4 种基金the National Key R & D Program of China (2017YFC0505200)the Strategic Priority Research Program of Chinese Academy of Sciences (XDA20050203)the Fund for Reserve Talents of Young and Middle-aged Academic and Technical Leaders of Yunnan Province (2014HB027)the CAS "Light of West China" Program, the Comprehensive Scientific Investigation of Biodiversity from the Wuling Mountains (2014FY110100)the survey on baseline resources of Wufeng Houhe National Nature Reserve in Hubei Province
文摘A new species of Rosaceae from Central China, Prunus sunhangii D. G. Zhang & T. Deng, sp. nov., is described and illustrated. The new species is placed in Prunus subgenus Cerasus by flower and fruit characteristics. It is most similar to Prunus cerasoides, but differs by having longitudinally 2-lobed apical petals, an acuminate leaf apex, 17—25 stamens, white petals, dark black drupes, brown hypanthium, and different phenology. The phylogenetic placement of this species was assessed based on morphological and molecular data. Molecular analysis(cp DNA + ITS) corroborated its placement in subgenus Cerasus,specifically Prunus section Serrula.
