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Studies on the movement, home range, and habitat use of greylag geese (Anser anser) based on satellite tracking
No full text营养和能量有效的积累对候鸟能否顺利完成迁徙具有重要意义。2015年8月至10月在内蒙古图牧吉湿地,利用卫星跟踪技术对灰雁的活动特征、生境利用等方面进行了研究,以期阐明灰雁在秋季如何有效积累能量以满足迁徙前的生理需求。我们采用增强型植被指数(EVI)分析了灰雁的生境特征,运用核密度分析法(KDE)计算了日间和夜间活动区面积,以及对不同月份的平均活动距离进行了分析。结果表明,8至10月间,灰雁活动位点的EVI值逐月递减,并且逐渐向南移动,趋向于水域集中,增加了对湖泊的利用,同时减少了对草地的利用;灰雁的活动区面积逐月递增,日间活动区面积大于夜间;灰雁在日间、夜间及平均活动距离均呈递增的趋势,每天凌晨及黄昏都出现较长时间的活动。由于8至10月间气温逐渐降低,从草地中可以获取的潜在食物资源减少,灰雁通过逐渐向水域较为丰富的区域移动,活动区面积逐渐增大,增加活动距离提高食物的获取量等确保获取足够的食物和能量满足迁徙的需求
Analysis of Anthocyanins and Flavonoids Components in Blueberry Extract by UPLC-TOF MS
No full text使用超高效液相色谱/飞行时间质谱,分别在TOF/MS全扫描和Q-TOF/MS碎片扫描两种模式下分析不同厂家生产的蓝莓提取物中的的花青素和黄酮类活性成分。首先依据高分辨精确质量在"待筛查化合物数据表"中查出可能的化合物,再结合二级质谱的子离子碎裂特征对化合物进行定性分析,结合参考文献,从蓝莓提取物中共鉴定出19个花青素类化合物、8个黄酮类化合物。同时,本文还对蓝莓提取物中的花青素苷和黄酮苷的质谱裂解规律进行了探讨。这一分析方法方便快捷、灵敏度高、准确性好,可将其推广至其它天然活性成分的无对照品筛查研究之中
Hydrogen production by corn straw in micro-aerobic conditions
No full text以玉米秸秆为原料,通过小试实验研究了不同的预处理方式和通氧量对微氧条件下发酵产氢的影响,放大实验对比了微氧发酵和厌氧发酵过程中产气、产氢、pH、碱度、挥发性脂肪酸(VFA)以及微生物种群的变化。小试实验表明,经过稀酸预处理的玉米秸秆产氢效果最好,最佳通氧量确定为280mL/(kg·d)。放大实验表明,微氧发酵的最大产气量、最大产氢量、累计产气量和累计产氢量均高于厌氧发酵,并且产气和产氢时间延长了6h。引起pH和碱度变化的原因主要是VFA的积累,特别是乙酸和丁酸。能够鉴定到科及以下的微氧发酵产氢优势种有肠球菌属(Enterococcus sp.)、拟杆菌属(Bacteroides oleiciplenus)、柠檬酸杆菌属(Citrobacter sp.)、消化链球菌科(Peptoclostridium difficile)、肠杆菌属(Escherichia sp.)、乳杆菌属(Lactobacillus mucosae)、梭状芽孢杆菌科(Clostridia)、梭菌属(Clostridium baratii)、双歧杆菌属(Bifidobacterium animalis)
Plants regulate the effects of experimental warming on the soil microbial community in an alpine scrub ecosystem
No full textInformation on how soil microbial communities respond to warming is still scarce for alpine scrub ecosystems. We conducted a field experiment with two plant treatments (plant removal or undisturbed) subjected to warmed or unwarmed conditions to examine the effects of warming and plant removal on soil microbial community structures during the growing season in a Sibiraea angustata scrubland of the eastern Qinghai Tibetan Plateau. The results indicate that experimental warming significantly influenced soil microbial biomass carbon (MBC) and microbial biomass nitrogen (MBN), but the warming effects were dependent on the plant treatments and sampling seasons. In the plant-removal plots, warming did not affect most of the microbial variables, while in the undisturbed plots, warming significantly increased the abundances of actinomycete and Gram-positive bacterial groups during the mid-growing season (July), but it did not affect the fungi groups. Plant removal significantly reduced fungal abundance throughout the growing season and significantly altered the soil microbial community structure in July. The interaction between warming and plant removal significantly influenced the soil MBC and MBN and the abundances of total microbes, bacteria and actinomycete throughout the growing season. Experimental warming significantly reduced the abundance of rare taxa, while the interaction between warming and plant removal tended to have strong effects on the abundant taxa. These findings suggest that the responses of soil microbial communities to warming are regulated by plant communities. These results provide new insights into how soil microbial community structure responds to climatic warming in alpine scrub ecosystems
Temporal-spatial pattern of organic carbon sequestration by Chinese lakes since 1850
No full textIn the last century, lakes in China have been subject to forcing by climate change, intensification of agriculture, and urban expansion, though their effects on lake OC sequestration are poorly understood. We compiled dry mass and OC burial rates from 82 Pb-210-dated lake sediment records in China. The average post-1950 focusing-corrected lake mass accumulation rate (MARFC) of 256 +/- 56 g m(-2) yr(-1) (median +/- SE) and focusing-corrected OC accumulation rate (CAR(FC)) of 8 +/- 3 g C m(-2) yr(-1) were significantly higher than the 1850-1900 rates (p<0.05). However, the magnitude of increase in CARFC was most marked in the subtropical lakes of the East Plain (EP) and on the Yunnan-Guizhou Plateau (YG), where the post-1950 CAR(FC) was about three times that of the 1850-1900 (p<0.05), due to the agricultural intensification and urban expansion in recent decades. Moreover, MARFC was significantly higher in the EP than that on the Mongolia-Xinjiang Plateau (MX) for all time periods (p< 0.05). Lake CAR(FC) in YG was significantly higher than rates in the Qinghai-Tibetan Plateau (QTP) for the post-1950 and MX for the 1850-1900 (p<0.05). Regression analyses showed that the controls on lake CAR(FC) varied among regions, with catchment climate variables the most important regulators in MX, Northeast China, and QTP, but the in-lake nutrient concentrations were more important in YG and EP (p<0.05). The results from this study show how modern limnic OC sequestration has changed with human disturbance and climate change in China
Targeting Pin1 by inhibitor API-1 regulates microRNA biogenesis and suppresses hepatocellular carcinoma development
No full textHepatocellular carcinoma (HCC) is a leading cause of cancer death worldwide, but there are few effective treatments. Aberrant microRNA (miRNA) biogenesis is correlated with HCC development. We previously demonstrated that peptidyl-prolyl cis-trans isomerase NIMA-interacting 1 (Pin1) participates in miRNA biogenesis and is a potential HCC treatment target. However, how Pin1 modulates miRNA biogenesis remains obscure. Here, we present in vivo evidence that Pin1 overexpression is directly linked to the development of HCC. Administration with the Pin1 inhibitor (API-1), a specific small molecule targeting Pin1 peptidyl-prolyl isomerase domain and inhibiting Pin1 cis-trans isomerizing activity, suppresses in vitro cell proliferation and migration of HCC cells. But API-1-induced Pin1 inhibition is insensitive to HCC cells with low Pin1 expression and/or low exportin-5 (XPO5) phosphorylation. Mechanistically, Pin1 recognizes and isomerizes the phosphorylated serine-proline motif of phosphorylated XPO5 and passivates phosphorylated XPO5. Pin1 inhibition by API-1 maintains the active conformation of phosphorylated XPO5 and restores XPO5-driven precursor miRNA nuclear-to-cytoplasm export, activating anticancer miRNA biogenesis and leading to both in vitro HCC suppression and HCC suppression in xenograft mice. Conclusion: Experimental evidence suggests that Pin1 inhibition by API-1 up-regulates miRNA biogenesis by retaining active XPO5 conformation and suppresses HCC development, revealing the mechanism of Pin1-mediated miRNA biogenesis and unequivocally supporting API-1 as a drug candidate for HCC therapy, especially for Pin1-overexpressing, extracellular signal-regulated kinase-activated HCC. (Hepatology 2018)
Gas-phase intramolecular hydroxyl-amino exchange of protonated arginine and verified by the synthetic intermediate compound
No full textA new fragmentation process was proposed to interpret the characteristic product ion at m/z 130 of protonated arginine. The a-amino group was dissociated from protonated arginine and then combined with the (M + H-NH3) fragment to form an ion-neutral complex which further generated a hydroxyl-amino exchange intermediate compound through an ion-molecule reaction. This intermediate compound was synthesized from argininamide through a diazo reaction, and then the reaction mixture was analyzed using liquid chromatography combined with mass spectrometry (LC-MS). The collision-induced dissociation experiments under the same conditions revealed that this intermediate compound produced the characteristic product ion at m/z 130 as well as protonated arginine, and in addition, density functional theory calculations were performed to confirm simultaneous loss of NH3 and CO from this intermediate to give the m/z 130 ion
Associations between shoot-level water relations and photosynthetic responses to water and light in 12 moss species
No full textIn vascular plants, there is a clear coupling between traits related to water and traits related to carbon economics. For bryophytes this coupling has been little studied but is expected to be strong, because in these poikilohydric plants photosynthesis varies strongly with water availability. We hypothesized that there is a trade-off between water-holding and photosynthetic capacities for mosses, resulting in a limited spectrum of possible trait combinations. At one end of this spectrum, mosses would tend to stay wet and active for long periods but would have slow photosynthetic rates. At the other end, mosses would avoid external water and dry out quicker but would have high photosynthetic capacities. We determined the water relations (water-holding and -retention capacities), photosynthetic water- and light-response curves of shoots of 12 moss species and explored the associations between these traits and their distributions among the studied species. The results partly support our hypotheses, in that the water-holding and water-retention capacities of mosses are positively related to each other and to the value and width of the optimal water-content range for photosynthesis. However, the photosynthetic capacities were specific to taxonomic groups, and the relationships between the water relations and the photosynthetic capacity are weak or inconsistent and depend strongly on the species used for analysis. The positive relationships between water-holding, water-retention and photosynthetic water-use capacities suggest two contrasting adaptations to avoid damage during dehydration: taking more time to 'prepare' or quick photosynthetic adjustment. However, the spectrum we hypothesized cannot be generalized for all mosses and defining a broader spectrum will require the extension of this study to a much larger number of species and including stand-level measurements of water loss and photosynthesis
BAPTA-AM Nanoparticle for the Curing of Acute Kidney Injury Induced by Ischemia/Reperfusion
No full textIschemia-reperfusion (I/R) is a major cause of acute kidney injury (AKI), which is associated with unacceptably high mortality rates in ICU. This research was designed to explore the therapeutic effect of BAPTA-AM (1,2-Bis(2-aminophenoxy)ethane-N, N, N, N-tetraacetic acid tetrakis(acetoxymethyl ester)) nanoparticle (BA-N) on AKI. BA-N was developed by liposome strategy and characterized by standard methods. The rat model was selected and the rats were randomly allocated into four groups: (1) Normal group; (2) Sham-operated group; (3) Model group (I/R+NS); (4) BA-N treatment group (I/R+BA-N). AKI model was established via clipping the bilateral renal artery with a microvascular clamp for 45 min. After reperfusion, serum cystatin C (Cys C), creatinine (Cr), blood urea nitrogen (BUN), lactate dehydrogenase (LDH) and caspase 3 levels were determined for the assessment of renal function. Kidney samples were then collected for the measurement of renal malondialdehyde (MDA) level and superoxide dismutase (SOD) activity. The assays of histological examination, ELISA, immunohistochemistry, western blot, TUNEL and RT-PCR were utilized for the detection of apoptosis. The results demonstrated that AKI model caused a significant decreasing in SOD activity, accompanied by a remarkable increase in Cys C, Cr, BUN, LDH, MDA, caspase 3 and cytochrome c (Cyt C) level, compared to the control group. BA-N (100 mu g/kg i.v.) significantly improved renal function and histopathological appearance, restored MDA level and SOD activity, decreased Bax/Bcl-2 ratio, caspase 3 activity, Cyt C release and TUNEL positive apoptotic cells. Our studies indicated that BA-N plays a renal-protective role, probably through antiapoptotic and antioxidant mechanisms. BA-N may regulate mitochondria pathway via decreasing Bax/Bcl-2 ratio, inhibiting caspase 3 expression and Cyt C release. Overall, BA-N may have potentials as an anti-AKI drug
Maize Yield Response to Nitrogen Rate and Plant Density under Film Mulching
No full textFilm mulching has significantly improved crop productivity in semiarid areas. We hypothesized that plants grown under the film-mulched system (FM) require higher N rates and higher plant densities than the non-mulched system (NM) to optimize grain yield and water use efficiency (WUE). A 2-yr field experiment was conducted at the Changwu experimental station to evaluate the effects of N supply and plant density on grain yield, yield components, evapotranspiration, and WUE in spring maize (Zea mays L.) with and without film mulching. Results showed that FM improved topsoil water content. Mulch practice x N rate and mulch practice x plant density interactions existed for yield and WUE in both years. Regression analysis showed that yield and WUE increased with increasing N rate and plant density for FM. The predicted maximum yield (14.3 and 15.1 Mg ha(-1) in 2013 and 2014, respectively) and WUE (31.3 and 38.4 kg ha(-1) mm(-1) in 2013 and 2014, respectively) for FM were obtained at 280 kg N ha(-1) and 80,000 plants ha(-1). Lower N amounts and lower plant densities were required for NM to obtain the maximum yield and WUE. However, field experiments showed that the N amount of 225 kg ha(-1) in FM increased N use efficiency while yielding > 94% of the maximum. In conclusion, film mulching together with optimum N application rates and plant densities can improve maize production and WUE in semiarid regions