Aim: To compare the contents of nucleosides from natural Cordyceps sinensis and cultured Cordyceps mycelia, and to study the effect of humidity and heat on the content of nucleosides. Methods: The contents of nucleos...Aim: To compare the contents of nucleosides from natural Cordyceps sinensis and cultured Cordyceps mycelia, and to study the effect of humidity and heat on the content of nucleosides. Methods: The contents of nucleosides were determined by using high performance capillary electrophoresis (HPCE). Beckman P/ACE System 5010 apparatus equipped with a UV detector and a Beckman untreated fused-silica capillary (57 cm 75 mm, 50 cm effective length) was used. Before sample injection, the capillary was rinsed with 1 molL-1 sodium hydroxide solution and running buffer for 5 min, respectively. A voltage of 20 kV was applied for the separation. Pressure injection was 586 kPa for 6 seconds, and the wavelength of detector was 254 nm. The running time was 20 min at 20 oC. The effect of humidity and heat on the contents of nucleosides from natural Cordyceps sinensis and cultured Cordyceps mycelia was observed for 1, 3, 5 and 10 days at temperature 40 oC, and relative humidity 75%. Results: The content of nucleosides from natural Cordyceps sinensis was higher than that from cultured Cordyceps mycelia. But the contents of nucleosides from freshly collected natural Cordyceps sinensis were very low, even below the limit of quantitation. The contents of nucleosides from natural Cordyceps sinensis were significantly increased by humidity and heat, but this phenomenon was not observed in cultured Cordyceps mycelia. Conclusion: There are differences between the nucleosides from natural Cordyceps sinensis and cultured Cordyceps mycelia. The nucleosides in natural Cordyceps sinensis may be derived from the degradation of nucleic acids. This implies that adenosine being used for the quality control of natural Cordyceps sinensis may have to be reconsidered.展开更多
Eleven tertiarv alkaloids were isolated from Corvdalis decumbens rhizome Their structures were identified as protopine(Ⅶ),allocryptopine(Ⅷ),cryptopine (Ⅸ),muramine(ⅩⅦ);(+)-tetrahydropalmatine(Ⅲ),(+)-kikemanine (...Eleven tertiarv alkaloids were isolated from Corvdalis decumbens rhizome Their structures were identified as protopine(Ⅶ),allocryptopine(Ⅷ),cryptopine (Ⅸ),muramine(ⅩⅦ);(+)-tetrahydropalmatine(Ⅲ),(+)-kikemanine (Ⅳ),(一)-scoulerine (ⅩⅧ),(十)-bulbo- capnine (ⅩⅨ),and(一)一capnoidine(Ⅰ),(一)一bicuculline(Ⅴ),(+) coriumidine(ⅩⅣ), respecti vely。 Among these,cryptopine,muramine,(+)-kikemanine,(-)-scoulerine,(一)capnoidine,(一)一bicuculline were isolated for the first time from this plant展开更多
目的:评价半夏白术天麻汤治疗血管性头痛的临床疗效。方法:检索EMBASE、PUBMED、MEDLINE、AMED、CINAHL、Cochrane图书馆、中国知网数据库、重庆维普中文科技期刊数据库、中国生物医学文献数据库、万方数据库和中国中医药期刊文献数据库...目的:评价半夏白术天麻汤治疗血管性头痛的临床疗效。方法:检索EMBASE、PUBMED、MEDLINE、AMED、CINAHL、Cochrane图书馆、中国知网数据库、重庆维普中文科技期刊数据库、中国生物医学文献数据库、万方数据库和中国中医药期刊文献数据库,筛选从建库至2015年5月1日的半夏白术天麻汤治疗血管性头痛的随机对照试验研究。应用Cochrane评价员手册进行偏倚风险评价,Jadad评分法进行质量评价,应用Rev Man 5.3软件进行Meta分析。结果:符合纳入标准的文献共3篇。Meta分析结果:半夏白术天麻汤治疗血管性头痛治疗组与对照组比较,临床疗效总有效率比值比(odds ratio,OR)为6.25,95%可信区间(confidence interval,CI)为[2.28,17.16],差异有统计学意义(P=0.0004);显效率OR为4.81,95%CI为[2.51,9.22],差异有统计学意义(P<0.00001)。纳入研究未有不良反应报道。结论:半夏白术天麻汤治疗血管性头痛有较好临床疗效,但由于本系统评价纳入研究的样本总体质量较低,研究的数量和样本量均较小,尚需要更多高质量、多中心、大样本、严格设计的随机对照试验深入研究。展开更多
Variation in the location of the South Asian High (SAH) in early boreal summer is strongly influenced by elevated surface heating from the Tibetan Plateau (TP) and the Iranian Plateau (IP). Based on observationa...Variation in the location of the South Asian High (SAH) in early boreal summer is strongly influenced by elevated surface heating from the Tibetan Plateau (TP) and the Iranian Plateau (IP). Based on observational and ERA-Interim data, diagnostic analyses reveal that the interannual northwestward-southeastwaxd (NW-SE) shift of the SAH in June is more closely correlated with the synergistic effect of concurrent surface thermal anomalies over the TP and IP than with each single surface thermal anomaly over either plateau from the preceding May. Concurrent surface thermal anomalies over these two plateaus in May are characterized by a negative correlation between sensible heat flux over most parts of the TP (TPSH) and IP (IPSH). This anomaly pattern can persist till June and influences the NW-SE shift of the SAH in June through the release of latent heat (LH) over northeastern India. When the IPSH is stronger (weaker) and the TPSH is weaker (stronger) than normal in May, an anomalous cyclone (anticyclone) appears over northern India at 850 hPa, which is accompanied by the ascent (descent) of air and anomalous convergence (divergence) of moisture flux in May and June. Therefore, the LH release over northeastern India is strengthened (weakened) and the vertical gradient of apparent heat source is decreased (increased) in the upper troposphere, which is responsible for the northwestward (southeastward) shift of the SAH in June.展开更多
In this study, the East Asian summer climate changes under the 1.5 ℃ global warming (1.5 GW) target in 30 simulations derived from 15 coupled models within the Coupled Model Intercomparison Program phase 5 (CMIP5...In this study, the East Asian summer climate changes under the 1.5 ℃ global warming (1.5 GW) target in 30 simulations derived from 15 coupled models within the Coupled Model Intercomparison Program phase 5 (CMIP5) are examined. Compared with the current summer climate (1975-2005), both surface air temperature and precipitation increase significantly over the East Asian continent during the 1.5 GW period (average period 2021-2051). In northeastern China this is particularly pronounced with regional averaged precipitation increases of more than 7.2%, which is greater than that for the whole East Asian continent (approximately 4.2%). Due to stronger enhancement of precipitation north of 40°N, the leading empirical orthogonal function (EOF) mode of summer precipitation over the East Asian continent changes from tripolar-like mode to dipole mode. As there is stronger surface warming over the East Asian continent than that over surrounding ocean, the land-sea thermal contrast is enhanced during the 1.5 GW period. As a result, the monsoon circulation in the lower troposphere is significantly strengthened, which causes the increased summer precipitation over the East Asian continent. In addition, larger interannual variabilities of East Asian summer monsoon circulation and associated precipitation are also suggested for the 1.5 GW period.展开更多
The first two series(RMM1 and RMM2) of RMM Index(all-Season Real-time Multivariate MJO Index) are computed to obtain the interannual variation of the preceding winter(preceding December to current February) MJO streng...The first two series(RMM1 and RMM2) of RMM Index(all-Season Real-time Multivariate MJO Index) are computed to obtain the interannual variation of the preceding winter(preceding December to current February) MJO strength,according to which active(or inactive) years of preceding winter MJO are divided.By utilizing the data provided by NCEP/NCAR,CMAP and China's 160 stations from 1979 to 2008,we studied the preceding winter MJO strength and discovered that the summer precipitation in the basin are of significantly negative correlation,i.e.when the preceding winter MJO is relatively active,the summer precipitation in the basin decreases,and vise verse.We also analyzed the causes.When the preceding winter MJO is relatively active,its release of potential heat facilities Inter-Tropical Convergence Zone(ITCZ) to strengthen and locate northward in winter and propagate northeastward.This abnormal situation lasts from winter to summer.In mid-May,ITCZ jumps northward to the South China Sea,the western Pacific subtropical high withdraws eastward,and the South China Sea summer monsoon sets off and strengthens.In summer,ITCZ propagates to South China Sea-subtropical western Pacific,the zonal circulation of subtropical Pacific strengthens,and a local meridional circulation of the South China Sea to the basin area forms,giving rise to the East Asia Pacific teleconnection wave-train.An East Asian monsoon trough and the Meiyu front show opposite features from south to north,the East Asian summer monsoon strengthens and advances northward.As a result,the summer monsoon is weakened as the basin is controlled by the subtropical high continually,with less rain in summer.On the contrary,when the preceding winter MJO is inactive,ITCZ weakens and is located southward,the subtropical high is located southward in summer,and the basin is in a region of ascending airflow with prevailing southwest wind.The East Asian monsoon trough and EASM weaken so that summer monsoon is reduced in the basin where precipitation increases.展开更多
The distributions of dimethylsulfide (DMS) and its precursor dimethylsulfoniopropionate (DMSP) in surface water of the Yellow Sea and the Bohai Sea were studied during June 2011. The mean concentrations and ranges...The distributions of dimethylsulfide (DMS) and its precursor dimethylsulfoniopropionate (DMSP) in surface water of the Yellow Sea and the Bohai Sea were studied during June 2011. The mean concentrations and ranges of DMS, dissolved DMSP (DMSPd), and particulate DMSP (DMSPp) in surface waters were 6.85 (1.60-12.36), 7.25 (2.28-19.05) and 61.87 (6.28-224.01) nmol/L, respectively. There were strong correlations between DMSPp and chlorophyll a in the Bohai Sea and the North Yellow Sea, respectively, and concentrations of DMS and DMSP were high, with a relatively high proportion of dinoflagellates, in the region of the South Yellow Sea Cold Water Mass. Results show that phytoplankton biomass and species composition were important factors that controlled the distribution of DMS and DMSP. Complex environmental factors, including nutrients, transparency, and terrestrial runoff, might also influence the variability in DMS and DMSP. Biological production and consumption rates of DMS in the Bohai Sea were higher than those in the Yellow Sea. DMS production rates were closely correlated with DMSPd concentrations. DMS and DMSP exhibited obvious diel variations, with high concentrations occurring in the late afternoon (16:00-19:00) and low concentrations occurring during the night, implying that the intensity of solar radiation had a significant influence on these variations. Size distributions of chlorophyll a and DMSPp were also investigated and large nanoplankton (5-20 μm), mainly diatoms, contributed significantly to chlorophyll a and DMSPp at most stations. The average sea-to-air flux of DMS in the study area was estimated to be 11.07 μmol/(m^2·d) during the summer.展开更多
Features of atmospheric circulation and thermal structures are discussed using the NCAR/NCEP data to reveal the reasons for the late onset and anomalous southward persistence of the South China Sea Summer Monsoon(SCSS...Features of atmospheric circulation and thermal structures are discussed using the NCAR/NCEP data to reveal the reasons for the late onset and anomalous southward persistence of the South China Sea Summer Monsoon(SCSSM) in 2005.The results show that three factors are crucial.First,a strong Arabian High overlaps with a high-latitude blocking high and channels strong cold air to southern Asia.Second,the Tibetan Plateau has a bigger snow cover than usual in spring and the melting of snow cools down the surface.Third,the Somali Jet breaks out at a much later date,being not conducive to convection over Indochina.The former two factors restrict atmospheric sensible heating over the Tibetan Plateau and nearby regions while the third one limits latent heating over Indochina.All of the factors slow down atmospheric warming and postpone the onset of SCSSM.Long after the onset of SCSSM,strong cold air over India advances the Southwest Monsoon northward slowly,resulting in weaker convection and latent heating over the Tibetan Plateau and nearby areas.The negative feedback conversely inhibits further northward movement of Southwest Monsoon.展开更多
文摘Aim: To compare the contents of nucleosides from natural Cordyceps sinensis and cultured Cordyceps mycelia, and to study the effect of humidity and heat on the content of nucleosides. Methods: The contents of nucleosides were determined by using high performance capillary electrophoresis (HPCE). Beckman P/ACE System 5010 apparatus equipped with a UV detector and a Beckman untreated fused-silica capillary (57 cm 75 mm, 50 cm effective length) was used. Before sample injection, the capillary was rinsed with 1 molL-1 sodium hydroxide solution and running buffer for 5 min, respectively. A voltage of 20 kV was applied for the separation. Pressure injection was 586 kPa for 6 seconds, and the wavelength of detector was 254 nm. The running time was 20 min at 20 oC. The effect of humidity and heat on the contents of nucleosides from natural Cordyceps sinensis and cultured Cordyceps mycelia was observed for 1, 3, 5 and 10 days at temperature 40 oC, and relative humidity 75%. Results: The content of nucleosides from natural Cordyceps sinensis was higher than that from cultured Cordyceps mycelia. But the contents of nucleosides from freshly collected natural Cordyceps sinensis were very low, even below the limit of quantitation. The contents of nucleosides from natural Cordyceps sinensis were significantly increased by humidity and heat, but this phenomenon was not observed in cultured Cordyceps mycelia. Conclusion: There are differences between the nucleosides from natural Cordyceps sinensis and cultured Cordyceps mycelia. The nucleosides in natural Cordyceps sinensis may be derived from the degradation of nucleic acids. This implies that adenosine being used for the quality control of natural Cordyceps sinensis may have to be reconsidered.
文摘Eleven tertiarv alkaloids were isolated from Corvdalis decumbens rhizome Their structures were identified as protopine(Ⅶ),allocryptopine(Ⅷ),cryptopine (Ⅸ),muramine(ⅩⅦ);(+)-tetrahydropalmatine(Ⅲ),(+)-kikemanine (Ⅳ),(一)-scoulerine (ⅩⅧ),(十)-bulbo- capnine (ⅩⅨ),and(一)一capnoidine(Ⅰ),(一)一bicuculline(Ⅴ),(+) coriumidine(ⅩⅣ), respecti vely。 Among these,cryptopine,muramine,(+)-kikemanine,(-)-scoulerine,(一)capnoidine,(一)一bicuculline were isolated for the first time from this plant
文摘目的:评价半夏白术天麻汤治疗血管性头痛的临床疗效。方法:检索EMBASE、PUBMED、MEDLINE、AMED、CINAHL、Cochrane图书馆、中国知网数据库、重庆维普中文科技期刊数据库、中国生物医学文献数据库、万方数据库和中国中医药期刊文献数据库,筛选从建库至2015年5月1日的半夏白术天麻汤治疗血管性头痛的随机对照试验研究。应用Cochrane评价员手册进行偏倚风险评价,Jadad评分法进行质量评价,应用Rev Man 5.3软件进行Meta分析。结果:符合纳入标准的文献共3篇。Meta分析结果:半夏白术天麻汤治疗血管性头痛治疗组与对照组比较,临床疗效总有效率比值比(odds ratio,OR)为6.25,95%可信区间(confidence interval,CI)为[2.28,17.16],差异有统计学意义(P=0.0004);显效率OR为4.81,95%CI为[2.51,9.22],差异有统计学意义(P<0.00001)。纳入研究未有不良反应报道。结论:半夏白术天麻汤治疗血管性头痛有较好临床疗效,但由于本系统评价纳入研究的样本总体质量较低,研究的数量和样本量均较小,尚需要更多高质量、多中心、大样本、严格设计的随机对照试验深入研究。
基金supported by the National Natural Science Foundation of China (Grant Nos.91437219,41275075 and 41175005)the National Basic Research Program of China (Grant No.2013CB430203)
文摘Variation in the location of the South Asian High (SAH) in early boreal summer is strongly influenced by elevated surface heating from the Tibetan Plateau (TP) and the Iranian Plateau (IP). Based on observational and ERA-Interim data, diagnostic analyses reveal that the interannual northwestward-southeastwaxd (NW-SE) shift of the SAH in June is more closely correlated with the synergistic effect of concurrent surface thermal anomalies over the TP and IP than with each single surface thermal anomaly over either plateau from the preceding May. Concurrent surface thermal anomalies over these two plateaus in May are characterized by a negative correlation between sensible heat flux over most parts of the TP (TPSH) and IP (IPSH). This anomaly pattern can persist till June and influences the NW-SE shift of the SAH in June through the release of latent heat (LH) over northeastern India. When the IPSH is stronger (weaker) and the TPSH is weaker (stronger) than normal in May, an anomalous cyclone (anticyclone) appears over northern India at 850 hPa, which is accompanied by the ascent (descent) of air and anomalous convergence (divergence) of moisture flux in May and June. Therefore, the LH release over northeastern India is strengthened (weakened) and the vertical gradient of apparent heat source is decreased (increased) in the upper troposphere, which is responsible for the northwestward (southeastward) shift of the SAH in June.
基金This research was supported by the National Key R&D Program of China (2017YFA0603802), the National Natural Science Foundation of China (41661144005 and 41320104007), and the CAS-PKU Joint Research Program. We would like to thanks the IPCC for providing the CMIP5 datasets (http://www.ipccdata.org/sim/gcm_monthly/AR5/Reference-Archive.html).
文摘In this study, the East Asian summer climate changes under the 1.5 ℃ global warming (1.5 GW) target in 30 simulations derived from 15 coupled models within the Coupled Model Intercomparison Program phase 5 (CMIP5) are examined. Compared with the current summer climate (1975-2005), both surface air temperature and precipitation increase significantly over the East Asian continent during the 1.5 GW period (average period 2021-2051). In northeastern China this is particularly pronounced with regional averaged precipitation increases of more than 7.2%, which is greater than that for the whole East Asian continent (approximately 4.2%). Due to stronger enhancement of precipitation north of 40°N, the leading empirical orthogonal function (EOF) mode of summer precipitation over the East Asian continent changes from tripolar-like mode to dipole mode. As there is stronger surface warming over the East Asian continent than that over surrounding ocean, the land-sea thermal contrast is enhanced during the 1.5 GW period. As a result, the monsoon circulation in the lower troposphere is significantly strengthened, which causes the increased summer precipitation over the East Asian continent. In addition, larger interannual variabilities of East Asian summer monsoon circulation and associated precipitation are also suggested for the 1.5 GW period.
基金Joint Project of Natural Science Foundation of China and Yunnan Province (U0833602)
文摘The first two series(RMM1 and RMM2) of RMM Index(all-Season Real-time Multivariate MJO Index) are computed to obtain the interannual variation of the preceding winter(preceding December to current February) MJO strength,according to which active(or inactive) years of preceding winter MJO are divided.By utilizing the data provided by NCEP/NCAR,CMAP and China's 160 stations from 1979 to 2008,we studied the preceding winter MJO strength and discovered that the summer precipitation in the basin are of significantly negative correlation,i.e.when the preceding winter MJO is relatively active,the summer precipitation in the basin decreases,and vise verse.We also analyzed the causes.When the preceding winter MJO is relatively active,its release of potential heat facilities Inter-Tropical Convergence Zone(ITCZ) to strengthen and locate northward in winter and propagate northeastward.This abnormal situation lasts from winter to summer.In mid-May,ITCZ jumps northward to the South China Sea,the western Pacific subtropical high withdraws eastward,and the South China Sea summer monsoon sets off and strengthens.In summer,ITCZ propagates to South China Sea-subtropical western Pacific,the zonal circulation of subtropical Pacific strengthens,and a local meridional circulation of the South China Sea to the basin area forms,giving rise to the East Asia Pacific teleconnection wave-train.An East Asian monsoon trough and the Meiyu front show opposite features from south to north,the East Asian summer monsoon strengthens and advances northward.As a result,the summer monsoon is weakened as the basin is controlled by the subtropical high continually,with less rain in summer.On the contrary,when the preceding winter MJO is inactive,ITCZ weakens and is located southward,the subtropical high is located southward in summer,and the basin is in a region of ascending airflow with prevailing southwest wind.The East Asian monsoon trough and EASM weaken so that summer monsoon is reduced in the basin where precipitation increases.
基金Supported by the National Natural Science Foundation of China(Nos.41320104008,41030858,41306069)the National Natural Science Foundation for Creative Research Groups(No.41221004)+3 种基金the Specialized Research Fund for the Doctoral Program of Higher Education of China(No.20110132120010)the Cheung Kong Scholars Program of Chinathe Taishan Scholar Program of Shandong Provincethe Fundamental Research Funds for the Central Universities
文摘The distributions of dimethylsulfide (DMS) and its precursor dimethylsulfoniopropionate (DMSP) in surface water of the Yellow Sea and the Bohai Sea were studied during June 2011. The mean concentrations and ranges of DMS, dissolved DMSP (DMSPd), and particulate DMSP (DMSPp) in surface waters were 6.85 (1.60-12.36), 7.25 (2.28-19.05) and 61.87 (6.28-224.01) nmol/L, respectively. There were strong correlations between DMSPp and chlorophyll a in the Bohai Sea and the North Yellow Sea, respectively, and concentrations of DMS and DMSP were high, with a relatively high proportion of dinoflagellates, in the region of the South Yellow Sea Cold Water Mass. Results show that phytoplankton biomass and species composition were important factors that controlled the distribution of DMS and DMSP. Complex environmental factors, including nutrients, transparency, and terrestrial runoff, might also influence the variability in DMS and DMSP. Biological production and consumption rates of DMS in the Bohai Sea were higher than those in the Yellow Sea. DMS production rates were closely correlated with DMSPd concentrations. DMS and DMSP exhibited obvious diel variations, with high concentrations occurring in the late afternoon (16:00-19:00) and low concentrations occurring during the night, implying that the intensity of solar radiation had a significant influence on these variations. Size distributions of chlorophyll a and DMSPp were also investigated and large nanoplankton (5-20 μm), mainly diatoms, contributed significantly to chlorophyll a and DMSPp at most stations. The average sea-to-air flux of DMS in the study area was estimated to be 11.07 μmol/(m^2·d) during the summer.
基金National Key Fundamental Research Development Project (2004CB418302)
文摘Features of atmospheric circulation and thermal structures are discussed using the NCAR/NCEP data to reveal the reasons for the late onset and anomalous southward persistence of the South China Sea Summer Monsoon(SCSSM) in 2005.The results show that three factors are crucial.First,a strong Arabian High overlaps with a high-latitude blocking high and channels strong cold air to southern Asia.Second,the Tibetan Plateau has a bigger snow cover than usual in spring and the melting of snow cools down the surface.Third,the Somali Jet breaks out at a much later date,being not conducive to convection over Indochina.The former two factors restrict atmospheric sensible heating over the Tibetan Plateau and nearby regions while the third one limits latent heating over Indochina.All of the factors slow down atmospheric warming and postpone the onset of SCSSM.Long after the onset of SCSSM,strong cold air over India advances the Southwest Monsoon northward slowly,resulting in weaker convection and latent heating over the Tibetan Plateau and nearby areas.The negative feedback conversely inhibits further northward movement of Southwest Monsoon.