基于网络药理学-分子对接探索大黄牡丹汤治疗大肠癌的作用机制

目的：利用网络药理学-分子对接技术探索经方大黄牡丹汤治疗大肠癌的作用机制。方法：通过TCMSP、TCMID数据库获得大黄牡丹汤药物成分,通过PubChem、Swisstarget prediction数据库获得药物成分对应靶点,分析GSE113513芯片获得差异基因,随即获取大黄牡丹汤与大肠癌的共同靶点。利用R、Cytoscape、Autodock软件进行PPI、GO、KEGG、分子对接等分析。结果：获得大黄牡丹汤靶点561个,大肠癌差异基因1227个,共同靶点71个。共同靶点的通路富集分析显示主要与PPAR、p53等信号通路相关,Reactome机制分析显示大黄牡丹汤治疗大肠癌主要通过影响信号转导、免疫系统、疾病等产生作用,分子对接结果显示大肠癌核心靶点与大黄牡丹汤主要成分亲和力较好,能够有效自由结合。结论：经方大黄牡丹汤可通过多层次、多途径、多靶点发挥对大肠癌的治疗作用。     

南海神狐海域沉积物自生黄铁矿和石膏S同位素特征及对甲烷渗漏强度的示踪

The northern slope of the South China Sea is a gas-hydrate-bearing region related to a high deposition rate of organic-rich sediments co-occurring with intense methanogenesis in subseafloor environments.Anaerobic oxidation of methane(AOM) coupled with bacterial sulfate reduction results in the precipitation of solid phase minerals in seepage sediment,including pyrite and gypsum.Abundant aggregates of pyrites and gypsums are observed between the depth of 667 and 850 cm below the seafloor(cmbsf) in the entire core sediment of HS328 from the northern South China Sea.Most pyrites are tubes consisting of framboidal cores and outer crusts.Gypsum aggregates occur as rosettes and spheroids consisting of plates.Some of them grow over pyrite,indicating that gypsum precipitation postdates pyrite formation.The sulfur isotopic values(δ~(34) S) of pyrite vary greatly(from –46.6‰ to –12.3‰ V-CDT) and increase with depth.Thus,the pyrite in the shallow sediments resulted from organoclastic sulfate reduction(OSR) and is influenced by AOM with depth.The relative high abundance and δ~(34) S values of pyrite in sediments at depths from 580 to 810 cmbsf indicate that this interval is the location of a paleo-sulfate methane transition zone(SMTZ).The sulfur isotopic composition of gypsum(from–25‰ to –20.7‰) is much lower than that of the seawater sulfate,indicating the existence of a 34 S-depletion source of sulfur species that most likely are products of the oxidation of pyrites formed in OSR.Pyrite oxidation is controlled by ambient electron acceptors such as MnO_2,iron(Ⅲ) and oxygen driven by the SMTZ location shift to great depths.The δ~(34) S values of gypsum at greater depth are lower than those of the associated pyrite,revealing downward diffusion of 34 S-depleted sulfate from the mixture of oxidation of pyrite derived by OSR and the seawater sulfate.These sulfates also lead to an increase of calcium ions from the dissolution of calcium carbonate mineral,which will be favor to the formation of gypsum.Overall,the mineralogy and sulfur isotopic composition of the pyrite and gypsum suggest variable redox conditions caused by reduced seepage intensities,and the pyrite and gypsum can be a recorder of the intensity evolution of methane seepage.     

波浪作用下单桩基础周围海床液化机制研究

建立波浪作用下单桩周围三维海床动力响应模型,考虑自重影响下的海床长时间固结过程。采用已有物理模型试验数据对模型进行验证,证实其具有较好的适用性。模拟波浪作用下单桩周围三维海床液化区域,通过定量分析超孔隙水压力和土体初始有效应力的变化,讨论单桩插入深度对海床液化的影响机制。研究表明,单桩插入深度发生变化时,土体初始有效应力对海床液化的影响要大于超孔隙水压力,且影响程度随着插入深度的增加而逐渐增大。     

南海北部冷泉区深水珊瑚的发现及其特征

冷水珊瑚也称为深水珊瑚, 在生物多样性、生态资源和科研价值等方面具有重要意义。文章对采自南海北部冷泉区的冷水珊瑚骨骼碎屑进行测定, 鉴定出冷水珊瑚2个种(Crispatotrochus sp.1和Crispatotrochus sp.2), 以及4个属[Balanophyllia (Balanophyllia)、Balanophyllia (Eupsammia)、Lochmaeotrochus和Enallopsammia]。测定的冷水珊瑚的δ¹³C为-7.36‰~-1.15‰, δ¹⁸O为-1.38‰~3.67‰, 与全球冷水珊瑚碳氧同位素组成相似, 但明显不同于南海暖水珊瑚、冷泉碳酸盐岩及低温热液成因碳酸盐岩的碳氧同位素组成。     

Calibration and use of continuous heat-type automated seepage meters for submarine groundwater discharge measurements

Submarine groundwater discharge (SGD) assessments were conducted both in the laboratory and at a field site in the northeastern Gulf of Mexico, using a continuous heat-type automated seepage meter (seepmeter). The functioning of the seepmeter is based on measurements of a temperature gradient in the water between downstream and upstream positions in its flow pipe. The device has the potential of providing long-term, high-resolution measurements of SGD. Using a simple inexpensive laboratory set-up, we have shown that connecting an extension cable to the seepmeter has a negligible effect on its measuring capability. Similarly, the observed influence of very low temperature (≤3 °C) on seepmeter measurements can be accounted for by conducting calibrations at such temperatures prior to field deployments. Compared to manual volumetric measurements, calibration experiments showed that at higher water flow rates (>28 cm day⁻¹ or cm³ cm⁻² day⁻¹) an analog flowmeter overestimated flow rates by ≥7%. This was apparently due to flow resistance, turbulence and formation of air bubbles in the seepmeter water flow tubes. Salinity had no significant effect on the performance of the seepmeter. Calibration results from fresh water and sea water showed close agreement at a 95% confidence level significance between the data sets from the two media (R² = 0.98). Comparatively, the seepmeter SGD measurements provided data that are comparable to manually-operated seepage meters, the radon geochemical tracer approach, and an electromagnetic (EM) seepage meter.     

Probability of Sediment Incipient Motion Under Complex Flows

Presented in this paper is a mathematical model to calculate the probability of the sediment incipient motion,in which the effects of the fluctuating pressure and the seepage are considered.The instantaneous bed shear velocity and the pressure gradient on the bed downstream of the backward-facing step flow are obtained according to the PIV measurements.It is found that the instantaneous pressure gradient on the bed obeys normal distribution.The probability of the sediment incipient motion on the bed downstream of the backward-facing step flow is given by the mathematical model.The predicted results agree well with the experiment in the region downstream of the reattachment point while a large discrepancy between the theory and experiment is seen in the region near the reattachment point.The possible reasons for this discrepancy are discussed.     

广东博贺澙湖潮滩的冲淤变化及其动力作用分析

基于遥感技术,对反映17 a来博贺澙湖的5景遥感影像定量反演潮滩水边线,在此基础上推算澙湖潮滩的沉积与冲刷速率,同时对引起潮滩变化的动力作用进行探讨,结果表明博贺澙湖的潮滩以淤展为主,其中处于开敞地段的澙湖潮滩出现冲刷,遮蔽岸段的澙湖潮滩淤积,控制澙湖潮滩变化的主要因子是包括圈围潮滩成盐田、虾池以及鱼塘等的人类活动.     

燕山水库的主要环境工程地质问题

本文在简要介绍燕山水库工程地质环境的基础上,分析论述了可能产生的环境工程地质问题。指出水库淹没及浸没、水库诱发地震、坝基渗透变形及膨胀土体稳定问题是该水库的主要环境工程地质问题,并提出了进一步研究的途径。     

Ancient and modern cold-climate aeolian sand deposition: A review

Although partly active aeolian sand sheets and dunes cover large areas in the zones of (dis)continuous permafrost, little precise information is available about the influence of cold-climate conditions on modern aeolian processes. This means that palaeoenvironmental reconstructions in the stabilised, mainly Late Pleistocene dune fields and cover sand regions in the ‘sand belts’ of the European Lowlands and the Northern Great Plains of the USA and Canada, are necessarily still based on ancient evidence. Cold-climate wind deposits are typically derived from areas of abundant sediment supply like unvegetated flood plains, glacial outwash plains, till plains and lake shores. The common parabolic and transverse dune forms resemble those observed in temperate regions. Although a variety of periglacial features has been identified in Late Pleistocene dune and cover sands none of them indicate that permafrost is crucial to aeolian activity. Specific structures in aeolian strata permit tentative interpretation of the moisture content of depositional sand surfaces, the nature of annual sedimentation cycles and the processes by which strata were deposited and/or contorted. But surprisingly little is known about the role of vegetation in the process of sand accumulation. Dunes are most informative with respect to reconstructions of past wind regimes, which offer important data for verification of palaeoclimatic simulations.     

The effect of pore water pressure on tunnel face stability

The kinematic approach in combination with numerical simulation is used to examine the effect of pore water pressure on tunnel face stability. Pore water pressure distribution obtained by numerical calculations using FLAC^3D is used to interpolate the pore water pressure on a 3D rotational collapse mechanism. Comparisons are made to check the present approach against other solutions, showing that the present approach improves the existing upper bound solutions. Results obtained indicate that critical effective face pressure increases with water table elevation. Several normalized charts are also presented for quick evaluation of tunnel face stability. At the end of the paper, the influence of anisotropic permeability on tunnel face stability is also discussed, showing that the isotropic model leads to an overestimation of the necessary tunnel face pressure for anisotropic soils. Copyright © 2016 John Wiley & Sons, Ltd.