SAUR(SMALL AUXIN UP RNA)基因家族是促进下胚轴伸长的重要下游基因,然而在高温诱导的下胚轴伸长中SAURs受调控的分子机制尚有很多不明之处。热形态建成被定义为高等植物在最适温度和逆境高温之间的温和高温范围内发生的一系列形态变化...SAUR(SMALL AUXIN UP RNA)基因家族是促进下胚轴伸长的重要下游基因,然而在高温诱导的下胚轴伸长中SAURs受调控的分子机制尚有很多不明之处。热形态建成被定义为高等植物在最适温度和逆境高温之间的温和高温范围内发生的一系列形态变化。其中,高温诱导的下胚轴伸长是研究最为透彻的一个。该研究以拟南芥Col野生型、hy5突变体、35 S::HY5-HA/Col过表达植物和烟草为材料,采用抑制剂NPA处理实验、定量RT-PCR、染色质免疫共沉淀和双荧光素酶报告基因检测方法探索了高温调控SAUR1/2/3/4的分子机制。结果表明:(1)热形态建成信号转导通路中生长素处于HY5(ELONGATED HYPOCOTYL 5)的下游。(2)在20℃和29℃中,HY5抑制了SAUR1/2/3/4的转录。(3)在常温和高温中,HY5与SAUR1/2/3/4的启动子区染色质含有E-box的部分结合且这些结合被高温所抑制。(4)HY5对SAUR1/2/3/4的调控依然需要生长素的参与。综上认为,高温通过影响HY5与SAUR1/2/3/4启动子染色质的结合强度来调控这4个基因的转录,并且此调控过程需要生长素。该研究结果为高温调控下胚轴伸长下游基因的分子机制提供了新的见解。展开更多
With the globalization of the economy,maritime trade has surged,posing challenges in the supervision of marine vessel activities.An automatic identification system(AIS)is an effective means of shipping traffic service...With the globalization of the economy,maritime trade has surged,posing challenges in the supervision of marine vessel activities.An automatic identification system(AIS)is an effective means of shipping traffic service,but many uncertainties exist regarding its data quality.In this study,the AIS data from Haiyang(HY)series of satellites were used to assess the data quality,analyze the global ship trajectory distribution and update frequencies from 2019 to 2023.Through the analysis of maritime mobile service identity numbers,we identified 340185 unique vessels,80.1%of which adhered to the International Telecommunication Union standards.Approximately 49.7%of ships exhibit significant data gaps,and 1.1%show inconsistencies in their AIS data sources.In the central Pacific Ocean at low latitudes and along the coast of South America(30°-60°S),a heightened incidence of abnormal trajectories of ships has been consistently observed,particularly in areas associated with fishing activities.According to the spatial distribution of ship trajectories,AIS data exhibit numerous deficiencies,particularly in high-traffic regions such as the East China Sea and South China Sea.In contrast,ship trajectories in the polar regions,characterized by high latitudes,are relatively comprehensive.With the increased number of HY satellites equipped with AIS receivers,the quantity of trajectory points displays a growing trend,leading to increasingly complete trajectories.This trend highlights the significant potential of using AIS data acquired from HY satellites to increase the accuracy of vessel tracking.展开更多
为了明确除草活性菌株HY-021对藜(Chenopodium album L.)的侵染作用机理,利用电镜扫描技术观察该菌株接种藜后对藜叶片的侵染过程,并使用生理指标测定法对接种后藜植株体内活性物质含量变化进行了测定。结果表明,HY-021菌株的菌丝通过...为了明确除草活性菌株HY-021对藜(Chenopodium album L.)的侵染作用机理,利用电镜扫描技术观察该菌株接种藜后对藜叶片的侵染过程,并使用生理指标测定法对接种后藜植株体内活性物质含量变化进行了测定。结果表明,HY-021菌株的菌丝通过气孔侵入叶片组织,并寄生繁殖产孢,逐渐破坏组织,同时叶片表面开始失绿并伴随着病斑的形成,最终导致植株不能进行光合作用而死亡。HY-021菌株接种于藜植株后体内MDA含量逐渐升高,SOD、CAT、POD的活性呈现出先上升后下降的趋势。表明该菌株对植株生理防御机制中的酶有多方面的影响,接种后引起植物广泛的代谢变化。可溶性蛋白质含量总体上高于对照,表明受到菌株侵染后,可溶性蛋白质含量增加,植物的抵御能力增强。展开更多
Idiopathic acute pancreatitis is a diagnostic challenge for gastroenterologists.The possibility of finding a cause for pancreatitis usually relies on how far the diagnostic study is taken.Endoscopic explorations such ...Idiopathic acute pancreatitis is a diagnostic challenge for gastroenterologists.The possibility of finding a cause for pancreatitis usually relies on how far the diagnostic study is taken.Endoscopic explorations such as endoscopic retrograde cholangiopancreatography and endoscopic ultrasonography can help to determine the cause of pancreatitis.Furthermore,microscopic bile examination and magnetic resonance cholangiopancreatography can also be helpful in the work up of these patients.In this article an approximation to the diagnostic approach to patients with idiopathic acute pancreatitis is made,taking into account the reported evidence with which to choose between the different available explorations.展开更多
In this paper, the effect of adding different concentrations of kinetic inhibitors on the induction time of hydrogen sulfide hydrate formation in a reactor equipped with automatic adjustable temperature controller is ...In this paper, the effect of adding different concentrations of kinetic inhibitors on the induction time of hydrogen sulfide hydrate formation in a reactor equipped with automatic adjustable temperature controller is studied. A novel method namely ＂sudden cooling＂ is used for performing the relevant measurements, in which the induction time of H2S hydrate in the presence/absence of PVP and L-tyrosine with different concentrations （100, 500, and 1000 ppm） is determined. As a result, PVP with the concentration of 1000 ppm in aqueous solution is detected as a more suitable material for increasing the induction time of H2S hydrate formation among the investigated kinetic hydrate inhibitors.展开更多
基金The National Key R&D Program of China under contract Nos 2021YFC2803305 and 2024YFC2816301the Fundamental Research Funds for the Central Universities of China under contract No.2042022dx0001.
文摘With the globalization of the economy,maritime trade has surged,posing challenges in the supervision of marine vessel activities.An automatic identification system(AIS)is an effective means of shipping traffic service,but many uncertainties exist regarding its data quality.In this study,the AIS data from Haiyang(HY)series of satellites were used to assess the data quality,analyze the global ship trajectory distribution and update frequencies from 2019 to 2023.Through the analysis of maritime mobile service identity numbers,we identified 340185 unique vessels,80.1%of which adhered to the International Telecommunication Union standards.Approximately 49.7%of ships exhibit significant data gaps,and 1.1%show inconsistencies in their AIS data sources.In the central Pacific Ocean at low latitudes and along the coast of South America(30°-60°S),a heightened incidence of abnormal trajectories of ships has been consistently observed,particularly in areas associated with fishing activities.According to the spatial distribution of ship trajectories,AIS data exhibit numerous deficiencies,particularly in high-traffic regions such as the East China Sea and South China Sea.In contrast,ship trajectories in the polar regions,characterized by high latitudes,are relatively comprehensive.With the increased number of HY satellites equipped with AIS receivers,the quantity of trajectory points displays a growing trend,leading to increasingly complete trajectories.This trend highlights the significant potential of using AIS data acquired from HY satellites to increase the accuracy of vessel tracking.
文摘为了明确除草活性菌株HY-021对藜(Chenopodium album L.)的侵染作用机理,利用电镜扫描技术观察该菌株接种藜后对藜叶片的侵染过程,并使用生理指标测定法对接种后藜植株体内活性物质含量变化进行了测定。结果表明,HY-021菌株的菌丝通过气孔侵入叶片组织,并寄生繁殖产孢,逐渐破坏组织,同时叶片表面开始失绿并伴随着病斑的形成,最终导致植株不能进行光合作用而死亡。HY-021菌株接种于藜植株后体内MDA含量逐渐升高,SOD、CAT、POD的活性呈现出先上升后下降的趋势。表明该菌株对植株生理防御机制中的酶有多方面的影响,接种后引起植物广泛的代谢变化。可溶性蛋白质含量总体上高于对照,表明受到菌株侵染后,可溶性蛋白质含量增加,植物的抵御能力增强。
文摘Idiopathic acute pancreatitis is a diagnostic challenge for gastroenterologists.The possibility of finding a cause for pancreatitis usually relies on how far the diagnostic study is taken.Endoscopic explorations such as endoscopic retrograde cholangiopancreatography and endoscopic ultrasonography can help to determine the cause of pancreatitis.Furthermore,microscopic bile examination and magnetic resonance cholangiopancreatography can also be helpful in the work up of these patients.In this article an approximation to the diagnostic approach to patients with idiopathic acute pancreatitis is made,taking into account the reported evidence with which to choose between the different available explorations.
文摘In this paper, the effect of adding different concentrations of kinetic inhibitors on the induction time of hydrogen sulfide hydrate formation in a reactor equipped with automatic adjustable temperature controller is studied. A novel method namely ＂sudden cooling＂ is used for performing the relevant measurements, in which the induction time of H2S hydrate in the presence/absence of PVP and L-tyrosine with different concentrations （100, 500, and 1000 ppm） is determined. As a result, PVP with the concentration of 1000 ppm in aqueous solution is detected as a more suitable material for increasing the induction time of H2S hydrate formation among the investigated kinetic hydrate inhibitors.
