以三峡水库长江干流库区超微型真核浮游生物为研究对象,在三峡水库干流库区设置2个采样点(CJ01,CJ05),分别在2015春季(4月)、夏季(8月)、秋季(10月)和冬季(12月)进行季度采样;采用Illumina Miseq PE250高通量测序平台对8个样本的18S r ...以三峡水库长江干流库区超微型真核浮游生物为研究对象,在三峡水库干流库区设置2个采样点(CJ01,CJ05),分别在2015春季(4月)、夏季(8月)、秋季(10月)和冬季(12月)进行季度采样;采用Illumina Miseq PE250高通量测序平台对8个样本的18S r DNA进行测序。结果显示,三峡水库长江干流库区超微型真核浮游生物群落主要的类群有隐藻、纤毛虫以及领鞭毛虫等,此外还有大量未分类物种。群落结构存在时空演化,其时空演化以时间为主。三峡水库长江干流库区群落物种丰富度和多样性从春季开始逐渐增加,到冬季后开始降低。水体温度(WT)、化学需氧量(COD)与春季群落成正相关,与秋季群落成负相关。总磷(TP)、磷酸盐(P-PO4)、溶解氧(DO)、氧化还原电位(ORP)与秋季群落成正相关,与春夏季群落成负相关。展开更多
Responses of Prochlorococcus (Pro), Synechococcus (Syn), pico-eukaryotes (Euk) and heterotrophic bacteria (Bact) in pelagic marine ecosystems to external nutrient perturbations were examined using nitrogen- (N), phosp...Responses of Prochlorococcus (Pro), Synechococcus (Syn), pico-eukaryotes (Euk) and heterotrophic bacteria (Bact) in pelagic marine ecosystems to external nutrient perturbations were examined using nitrogen- (N), phosphorus- (P), iron- (Fe), and cobalt- (Co) enriched incubations in the South China Sea in November 1997. Variations in abundance of the 4 groups of microorganism and cellular pigment content of the autotrophs during incubation were followed by flow-cytometric measurements for seven days. During the incubation, Syn and Euk showed a relatively higher demand on Fe and N, while Pro required higher levels of Co and P. The Fe was inadequate for all the organisms in the deep euphotic zone (75 m) of the study area. The experimental results also implied that biological interaction among the organisms played a role in the community structure shift during the incubation. It seemed that besides the effects of temperature, there are some other physical and chemical limitations as well as impacts from biological interactions on Pro distribution in coast waters.展开更多
Abstract Picoplankton distribution was investigated in different water masses of the East China Sea in November, 2006 and February, 2007. The autumn and winter cruises crossed three major water masses： the coastal wa...Abstract Picoplankton distribution was investigated in different water masses of the East China Sea in November, 2006 and February, 2007. The autumn and winter cruises crossed three major water masses： the coastal water mass （CWM）, the mixed water mass （MWM）, which forms on the continental shelf, and the Kuroshio water mass （KWM）. Picoplankton composition was resolved into four main groups by flow cytometry, namely Synechococcus, Prochlorococcus, picoeukaryotes, and heterotrophic bacteria. The average abundances of Synechococcus, picoeukaryotes, and heterotrophic bacteria were （0.63＋ 10.88）~ 103, （1.61＋1.16）x103, （3.39~1.27）x105 cells/mL in autumn and （6.45~8.60）x103, （3.23~2.63）x103, （3.76~1.37）x 105 cells/mL in winter, respectively. Prochlorococcus was not found in the CWM and seldom observed in surface samples in either season. However, Prochlorococcus was observed in the MWM and KWM （approximately 103 cells/mL） in both auttman and winter. Synechococcus distribution varied considerably among water masses, with the highest levels in KWM and lowest levels in CWM. The depth-averaged integrated abundance of Synechococcus was approximately 5-fold higher in KWM than in CWM, which may be due primarily to water temperature. In the MWM, Synechococcus was resolved as two subgroups; the presence of both subgroups was more common in autumn. Picoeukaryote abundance varied less among water masses than Synechococcus, and heterotrophic bacteria depth-averaged integrated abundance exhibited the smallest seasonal variations with respect to water mass. Correlation analysis showed that relationships between picoplankton abundances and environmental factors （temperature, nutrients, and chlorophyll a） differed among the three water masses, suggesting that the three water masses have different effects on picoplankton distribution （particularly Synechococcus）.展开更多
OBJECTIVE: To review the major progress in primary angle closure glaucoma (PACG). METHODS: Contents of this article were selected from the original papers or reviews related to primary angle closure glaucoma published...OBJECTIVE: To review the major progress in primary angle closure glaucoma (PACG). METHODS: Contents of this article were selected from the original papers or reviews related to primary angle closure glaucoma published in Chinese and foreign journals. A total of 76 articles were selected from several hundred original articles or reviews. The content of selected articles is in accordance with our purpose and the authors are authorized scientists in the study of glaucoma. RESULTS: Primary angle closure glaucoma is the most common type of glaucoma in the Sino-Mongoloid population. PACG in Chinese can be classified into three types depending on the mechanism of angle closure: 1. Multimechanism: 54.8% of Chinese PACG is caused by co-existing factors. The pattern of angle closure appears to mainly be creeping closure. After iridectomy, almost 40% of the cases still manifest a positive response to the darkroom provocative test and progressive synechial closure or recurrent angle closure may occur. Several mechanisms are involved in this form of PACG such as pupillary blocking component, iris crowding component and anterior positioned ciliary body. These factors can coexist in the follow patterns: pupillary blocking and iris crowding coexist; pupillary blocking and anterior positioned ciliary body coexist or three of them co-exist. 2. Pupillary block: (38.1% of Chinese PACG) is caused by iris bombe due to pupillary block with acute or subacute attack. It responds well to iridectomy or laser iridotomy. 3. Non-pupillary blocking: (7.8% of Chinese PACG). They usually have a deeper anterior chamber, and tend to be younger (below 40 years of age). Angle closure in this form of PACG is caused by: iris crowding mechanism or/and anteriorly positioned ciliary body against iris root to angle. It is critical to distinguish multi-mechanism PACG from other types. The initial treatment for this type of PACG is also iridectomy, but after the pupillary block component is eliminated by iridectomy, the residual non-pupillary blocking components should be highlighted by a diagnostic treatment procedure or by a ultrasound biomicroscopy (UBM) provocative test. Finally, the role of UBM in the observation and evaluation of the mechanism of angle closure is discussed and future research directions on PACG in Asians are proposed. CONCLUSION: Chinese eyes have been recognized to be prone to the development of creeping angle closure. There is some direct evidence that creeping angle closure is caused by multiple mechanisms. Further study on this topic is needed.展开更多
文摘以三峡水库长江干流库区超微型真核浮游生物为研究对象,在三峡水库干流库区设置2个采样点(CJ01,CJ05),分别在2015春季(4月)、夏季(8月)、秋季(10月)和冬季(12月)进行季度采样;采用Illumina Miseq PE250高通量测序平台对8个样本的18S r DNA进行测序。结果显示,三峡水库长江干流库区超微型真核浮游生物群落主要的类群有隐藻、纤毛虫以及领鞭毛虫等,此外还有大量未分类物种。群落结构存在时空演化,其时空演化以时间为主。三峡水库长江干流库区群落物种丰富度和多样性从春季开始逐渐增加,到冬季后开始降低。水体温度(WT)、化学需氧量(COD)与春季群落成正相关,与秋季群落成负相关。总磷(TP)、磷酸盐(P-PO4)、溶解氧(DO)、氧化还原电位(ORP)与秋季群落成正相关,与春夏季群落成负相关。
文摘Responses of Prochlorococcus (Pro), Synechococcus (Syn), pico-eukaryotes (Euk) and heterotrophic bacteria (Bact) in pelagic marine ecosystems to external nutrient perturbations were examined using nitrogen- (N), phosphorus- (P), iron- (Fe), and cobalt- (Co) enriched incubations in the South China Sea in November 1997. Variations in abundance of the 4 groups of microorganism and cellular pigment content of the autotrophs during incubation were followed by flow-cytometric measurements for seven days. During the incubation, Syn and Euk showed a relatively higher demand on Fe and N, while Pro required higher levels of Co and P. The Fe was inadequate for all the organisms in the deep euphotic zone (75 m) of the study area. The experimental results also implied that biological interaction among the organisms played a role in the community structure shift during the incubation. It seemed that besides the effects of temperature, there are some other physical and chemical limitations as well as impacts from biological interactions on Pro distribution in coast waters.
基金Supported by the National Basic Research Program of China(973 Program)(No.2011CB409804)the National Natural Science Foundation of China for Creative Research Groups(No.41121064)the Knowledge Innovation Program of China(No.KZCX2-YW-Q07-02)
文摘Abstract Picoplankton distribution was investigated in different water masses of the East China Sea in November, 2006 and February, 2007. The autumn and winter cruises crossed three major water masses： the coastal water mass （CWM）, the mixed water mass （MWM）, which forms on the continental shelf, and the Kuroshio water mass （KWM）. Picoplankton composition was resolved into four main groups by flow cytometry, namely Synechococcus, Prochlorococcus, picoeukaryotes, and heterotrophic bacteria. The average abundances of Synechococcus, picoeukaryotes, and heterotrophic bacteria were （0.63＋ 10.88）~ 103, （1.61＋1.16）x103, （3.39~1.27）x105 cells/mL in autumn and （6.45~8.60）x103, （3.23~2.63）x103, （3.76~1.37）x 105 cells/mL in winter, respectively. Prochlorococcus was not found in the CWM and seldom observed in surface samples in either season. However, Prochlorococcus was observed in the MWM and KWM （approximately 103 cells/mL） in both auttman and winter. Synechococcus distribution varied considerably among water masses, with the highest levels in KWM and lowest levels in CWM. The depth-averaged integrated abundance of Synechococcus was approximately 5-fold higher in KWM than in CWM, which may be due primarily to water temperature. In the MWM, Synechococcus was resolved as two subgroups; the presence of both subgroups was more common in autumn. Picoeukaryote abundance varied less among water masses than Synechococcus, and heterotrophic bacteria depth-averaged integrated abundance exhibited the smallest seasonal variations with respect to water mass. Correlation analysis showed that relationships between picoplankton abundances and environmental factors （temperature, nutrients, and chlorophyll a） differed among the three water masses, suggesting that the three water masses have different effects on picoplankton distribution （particularly Synechococcus）.
文摘OBJECTIVE: To review the major progress in primary angle closure glaucoma (PACG). METHODS: Contents of this article were selected from the original papers or reviews related to primary angle closure glaucoma published in Chinese and foreign journals. A total of 76 articles were selected from several hundred original articles or reviews. The content of selected articles is in accordance with our purpose and the authors are authorized scientists in the study of glaucoma. RESULTS: Primary angle closure glaucoma is the most common type of glaucoma in the Sino-Mongoloid population. PACG in Chinese can be classified into three types depending on the mechanism of angle closure: 1. Multimechanism: 54.8% of Chinese PACG is caused by co-existing factors. The pattern of angle closure appears to mainly be creeping closure. After iridectomy, almost 40% of the cases still manifest a positive response to the darkroom provocative test and progressive synechial closure or recurrent angle closure may occur. Several mechanisms are involved in this form of PACG such as pupillary blocking component, iris crowding component and anterior positioned ciliary body. These factors can coexist in the follow patterns: pupillary blocking and iris crowding coexist; pupillary blocking and anterior positioned ciliary body coexist or three of them co-exist. 2. Pupillary block: (38.1% of Chinese PACG) is caused by iris bombe due to pupillary block with acute or subacute attack. It responds well to iridectomy or laser iridotomy. 3. Non-pupillary blocking: (7.8% of Chinese PACG). They usually have a deeper anterior chamber, and tend to be younger (below 40 years of age). Angle closure in this form of PACG is caused by: iris crowding mechanism or/and anteriorly positioned ciliary body against iris root to angle. It is critical to distinguish multi-mechanism PACG from other types. The initial treatment for this type of PACG is also iridectomy, but after the pupillary block component is eliminated by iridectomy, the residual non-pupillary blocking components should be highlighted by a diagnostic treatment procedure or by a ultrasound biomicroscopy (UBM) provocative test. Finally, the role of UBM in the observation and evaluation of the mechanism of angle closure is discussed and future research directions on PACG in Asians are proposed. CONCLUSION: Chinese eyes have been recognized to be prone to the development of creeping angle closure. There is some direct evidence that creeping angle closure is caused by multiple mechanisms. Further study on this topic is needed.
