Subjects: Biology >> Botany submitted time 2018-06-12 Cooperative journals: 《广西植物》
Abstract： 该文以广西桂林岩溶石山区的两种典型植被(香椿林和云实灌丛)为例, 利用野外长期定位监测降雨、穿透雨、树干径流、钻孔和表层岩溶水中TOC的变化特征，探讨不同植被林冠层TOC浓度和通量的年变化特征。结果表明:在降雨通过大气-植被-土壤/岩石的过程，TOC浓度变化趋势为：树干径流>穿透雨>钻孔水>泉水>大气降雨；穿透雨和树干流中TOC 浓度的呈现为雨季大旱季小的趋势，钻孔水和泉水的TOC浓度月变化则相对稳定；TOC浓度的增幅不同，穿透雨和树干径流TOC浓度的平均增量和变化幅度比钻孔水和泉水的大；香椿林树干径流TOC 浓度与树干径流量呈负相关关系；TOC月平均通量为:云实穿透雨>香椿穿透雨>降雨>泉水>香椿树干径流>云实树干径流；云实灌丛林下降雨（204.86 kghm-2）的TOC通量是香椿林（153.48 kghm-2）的1.3倍；观测期间,大气降雨输入的TOC通量为63.06kghm-2,表层岩溶泉水输出为48.29kghm-2,TOC输入输出之差为14.77kghm-2,系统TOC为正平衡；降雨进入植被内部后时，植被林冠层作为TOC活库具有增加TOC通量的源作用，而表层岩溶带的土壤/岩石系统作为TOC死库具有吸收、过滤和固定TOC的汇作用。
Subjects: Geosciences >> Geography submitted time 2024-04-29 Cooperative journals: 《干旱区研究》
Abstract： Five typical vegetation types (i.e., coniferous forests, meadow grasslands, alpine shrubs, alpine meadows, and sparse vegetations of limestone flat) along a vertical belt of the Qilian Mountains were selected to explore the spatial elevational patterns of soil carbon, nitrogen, and phosphorus and their stoichiometric ratios. Results showed that: (1) The contents of total carbon (C), nitrogen (N), and phosphorus (P) at the 0~40 cm depth were 15.33~83.46, 1.63~7.76, and 0.37~0.74 mg·kg-1, respectively. Soil C and N decreased gradually with increasing altitudes, following the order coniferous forests > meadow steppes > alpine shrubs > alpine meadows > sparse vegetations of limestone flat. Soil P in alpine scrubs was significantly higher than that in alpine meadows, but the other three vegetations showed no significant difference. (2) The contents of NH+ 4-N, NO- 3-N and available phosphorus at the 0~40 cm depth were 11.01~14.73, 2.78~12.46, and 4.35~13.57 mg·kg-1, respectively. Ammonium was the main inorganic nitrogen form in all vegetation types. The nitrite content decreased gradually with increasing altitude. The content of soil available phosphorus was higher in sparse vegetations of limestone flats. (3) The ratios of soil C:N, C:P, and N:P at the 0~40 cm depth were 9.52~10.11, 29.89~320.24, and 3.18~29.63, respectively. Soil C:N decreased with elevation. Soil C:P and N:P were significantly lower in the soil of sparse vegetations of the limestone flat than in other vegetations, indicating that carbon and nitrogen were the limiting nutrients in the limestone flat. By contrast, the limestone flat was in a phosphorus-rich state. Elevational variations in soil C, N, and P contents and their stoichiometric ratios reflect the joint control of multiple environmental factors, thereby affecting the biochemical processes of soil C, N, and P.
Subjects: Biology >> Biochemistry submitted time 2024-06-18
Abstract： Drug addiction is a serious chronic relapsing brain disease, and methamphetamine dependence has a complex course and is difficult to treat, causing a serious public health burden. In this study, we compared and analyzed the urine proteome of methamphetamine-using patients (patients who stopped using methamphetamine within 24 hours), methamphetamine-withdrawing patients (patients who stopped using drugs for more than 3 months and entered rehabilitation treatment), healthy individuals. The urine proteome of methamphetamine-addicted patients (including patients who were using methamphetamine and methamphetamine-withdrawing patients) was significantly different from that of healthy individuals, and some differential proteins and their enriched biological functions showed that they were associated with addiction or neurotoxicity of methamphetamine and may be potential intervention targets for drug addiction. Patients who withdrew methamphetamine for more than 3 months were still difficult to return to normal levels and may be used to reveal the reasons for the high rate of methamphetamine relapse. In this study, a method of studying addictive drugs from the perspective of urine proteomics was established, which proved that urine proteome can reflect the effects of methamphetamine abuse on the body relatively systematically and comprehensively, and has the potential to provide clues for the study and practice of clinical addictive diseases.
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