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The accumulation and spatial distribution of economically important petroleum in sedimentary basins are primarily controlled by its migration from source rocks through permeable carrier beds to reservoirs. Tracing petroleum migration entails the use of molecular indices established according to sorption capacities of polar molecules in migrating petroleum. However, little is known about molecular sorption capacities in natural migration systems, rendering these indices unreliable. Here, we present a new approach based on a novel concept of relative sorption coefficient for quantitatively assessing sorption capacities of polar molecules during natural petroleum migration. Using this approach, we discovered previously unrecognized "stripping" and "impeding" effects that significantly reduce the sorption capacities of polar compounds. These discoveries provide new insights into the behaviors of polar compounds and can easily explain why traditional molecular indices yield incorrect information about petroleum migration. In light of these new findings, we established new molecular indices for tracing petroleum migration. We demonstrate via case studies that the newly established indices, unlike traditional molecular indices, are reliable and effective in tracing petroleum migration. Our approach can be applied to diverse basins around the world to reveal distribution patterns of petroleum, which would decrease environmental risks of exploration by reducing unsuccessful wells.

From mid-Ordovician ∼470 Myr-old limestone >100 fossil L-chondritic meteorites have been recovered, representing the markedly enhanced flux of meteorites to Earth following the breakup of the L-chondrite parent body. Recently one anomalous meteorite, Österplana 065 (Öst 65), was found in the same beds that yield L chondrites. The cosmic-ray exposure age of Öst 65 shows that it may be a fragment of the impactor that broke up the L-chondrite parent body. Here we show that in a chromium versus oxygen-isotope plot Öst 65 falls outside all fields encompassing the known meteorite types. This may be the first documented example of an 'extinct' meteorite, that is, a meteorite type that does not fall on Earth today because its parent body has been consumed by collisions. The meteorites found on Earth today apparently do not give a full representation of the kind of bodies in the asteroid belt ∼500 Myr ago.

Measurements are presented of the magnesium isotopic composition of chlorophyll-a, extracted from cyanobacteria, relative to the isotopic composition of the culture medium in which the cyanobacteria were grown. Yields of 50-93% chlorophyll-a were achieved from the pigment extracts of Synechococcus elongatus, a unicellular cyanobacteria. This material was then digested using concentrated nitric acid to extract magnesium. Separation was accomplished using columns of cation-exchange resin, which achieved a 103 +/- 10% yield of magnesium from chlorophyll-a. This procedure ensured accurate measurement of the magnesium-isotopic ratios without isobaric interferences using a multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS). We find a slight depletion in the heavier isotopes of magnesium in chlorophyll-a relative to culture medium, early growth phase: Delta Mg-26 = -0.71(+/- 0.35)parts per thousand and Delta Mg-25 = -0.37(+/- 0.18)parts per thousand; late growth phase: Delta Mg-26 = -0.53(+/- 0.20)parts per thousand and Delta Mg-25 = -0.26(+/- 0.11)parts per thousand, due to an apparent mass-dependent fractionation. We suggest that the small fractionation results from chelation during intracellular processes. A likely candidate for this chelation step involves the magnesium-chelatase enzyme, which mediates the insertion of magnesium to the tetrapyrrole ring during chlorophyll-a biosynthesis. Proof of this hypothesis can be tested with biological controls whereby steps in the enzymatic pathways of chlorophyll synthesis are selectively suppressed. (c) 2006 Elsevier Inc. All rights reserved.

Purpose of this study was to screen the active compounds of Zhenwu decoction and their gene targets in the treatment of non-alcoholic fatty liver disease by network pharmacology and cytological validation test. The candidate compounds and related targets of Zhenwu decoction were obtained from traditional Chinese medicine system pharmacology database and PharmMapper. The non-alcoholic fatty liver disease-related genes were obtained from online Mendelian inheritance in man, GeneCards and DisGeNET databases. Molecular docking was carried out to simulate the binding affinities between potential core compounds and key target genes, and the chemical constituents of Zhenwu decoction were analyzed and identified by Ultra-Performance Liquid Chromatography-Quadrupole Time-of-Flight Mass Spectrometry technology. Therapeutic effect and mechanism of Zhenwu decoction on non-alcoholic fatty liver disease were validated using in vitro analysis. The protein-protein interaction network analysis identified the albumin, protein kinase B1, epidermal growth factor receptor, caspase 3 and peroxisome proliferator activated receptor gamma as the key target genes. Gene ontology annotation analysis showed that the Zhenwu decoctionnon- alcoholic fatty liver disease target genes were mainly involved in the response to steroid hormone and lipid catabolic process. The results of the Kyoto encyclopedia of genes and genomes pathway enrichment analysis were mainly related to the Forkhead box O signaling pathway and phosphatidylinositol 3-kinaseprotein kinase B signaling pathway. Paeoniflorgenone had the highest binding affinities for albumin, protein kinase B1, epidermal growth factor receptor, caspase 3 and peroxisome proliferator activated receptor gamma. The in vitro experiment showed that 19.5 mg/ml (p≤0.05) and 39 mg/ml (p≤0.01) of Zhenwu decoction could reduce lipid accumulation. Real-time quantitative polymerase chain reaction analyses revealed that Zhenwu decoction induced down-regulation of epidermal growth factor receptor messenger ribonucleic acid levels and up-regulation of heat shock protein 90 alpha family class a member 1, mitogen-activated protein kinase 1 and phosphatidylinositol 3-kinase messenger ribonucleic acid levels. [ABSTRACT FROM AUTHOR]

Author(s): V. Debaille (corresponding author) [1]; A. D. Brandon [2]; Q. Z. Yin [3]; B. Jacobsen [3] Resolving early silicate differentiation timescales is crucial for understanding the chemical evolution and [...]

The relative influence of insolation, CO2, and ice sheets on the East Asian summer monsoon (EASM) is not well understood especially at regional scale. Here a Gaussian emulator based on simulations with HadCM3 is used to quantitatively assess how astronomical forcing, CO2, and northern hemisphere ice sheets affect the variation of the summer precipitation over the last 800 ky. Our results show that in the EASM domain north of 25°N, the variation of the summer precipitation is dominated by precession, leading to strong 23‐ky cycles, while the ice sheets only modulate the effect of insolation by influencing the land‐sea pressure gradient. In the southern part, ice sheets play a more important role, generating 100‐ky cycles, through influencing the latitude of the Intertropical Convergence Zone and the Hadley cell. Obliquity and CO2 have little effect on the summer precipitation as compared to precession and ice sheets. Plain Language Summary: The East Asian summer monsoon (EASM) is a wind which carries moist air from the Indian and Pacific Oceans to East Asia, and it affects the economy and life of a large population. On astronomical time scale, its variation is controlled by insolation, CO2, and ice sheets. Here we use a Gaussian emulator based on climate simulations to assess how these factors affect the variation of the summer precipitation in East Asia. In the northern part of the EASM domain, the summer precipitation has a strong 23‐ky cycle. It is mainly controlled by precession. The effect of insolation is further modulated by ice sheets by the variations of the land‐sea pressure gradient. In the southern part, ice sheets play a vital role on the summer precipitation via its control on the location of the Intertropical Convergence Zone. Obliquity and CO2 have little effect on the precipitation. Key Points: In northern East Asia, the variation of summer precipitation is dominated by precessionIn southern East Asia, ice volume plays a more important role on the summer precipitation via its control on the location of Intertropical Convergence ZoneThe effects of obliquity and CO2 on summer precipitation are very small compared to precession and ice volume [ABSTRACT FROM AUTHOR]

During Marine Isotope Stage (MIS) 13, an interglacial about 500 000 years ago, the East Asian summer monsoon (EASM) was suggested exceptionally strong by different proxies in China. However, MIS-13 is a weak interglacial in marine oxygen isotope records and has relatively low CO2 and CH4 concentrations compared to other interglacials of the last 800 000 years. In the mean time, the sea surface temperature (SST) reconstructions show that the Western Pacific Warm Pool was relatively warm during MIS-13. Based on climate modeling experiments, this study aims at investigating whether this Warm Pool warming could explain the exceptionally strong EASM occurring during the relatively cool interglacial MIS-13. The individual contributions of insolation and of the Warm Pool SST as well as their synergism are quantified through experiments with the Hadley Centre atmosphere model, HadAM3 and using the factor separation technique. The SST over the Warm Pool region has been increased based on geological reconstructions. Our results show that the pure impact of a strong summer insolation contributes to strengthen significantly the summer precipitation in northern China but only little in southern China. The pure impact of enhanced Warm Pool SST reduces, slightly, the summer precipitation in both northern and southern China. However, the synergism between insolation and enhanced Warm Pool SST contributes to a large increase of summer precipitation in southern China but to a decrease in northern China. Therefore, the ultimate role of enhanced Warm Pool SST reinforces the impact of insolation in southern China but reduces its impact in northern China. We conclude that enhanced SST over the Warm Pool region does help to explain the strong MIS-13 EASM precipitation in southern China as recorded in proxy data, but other explanation is needed for explaining the exceptionally strong EASM in northern China. [ABSTRACT FROM AUTHOR]

We investigate the enrichment of the pre-solar cloud core with short-lived radionuclides, especially 26A1. The homogeneity and the surprisingly small spread in the ratio 26A1/27AI observed in the overwhelming majority of calcium-aluminium-rich inclusions in a vast variety of primitive chondritic meteorites places strong constraints on the formation of the solar system. Freshly synthesized radioactive 26A1 has to be included and well mixed within 20 kyr. After discussing various scenarios including X-winds, asymptotic giant branch stars, and Wolf-Rayet stars, we come to the conclusion that triggering the collapse of a cold cloud core by a nearby supernova (SN) is the most promising scenario. We then narrow down the vast parameter space by considering the pre-explosion survivability of such a clump as well as the cross-section necessary for sufficient enrichment. We employ numerical simulations to address the mixing of the radioactively enriched SN gas with the pre-existing gas and the forced collapse within 20 kyr. We show that a cold clump of 10 Mʘ at a distance of 5 pc can be sufficiently enriched in 26A1 and triggered into collapse fast enough—within 18 kyr after encountering the SN shock—for a range of different metallicities and progenitor masses, even if the enriched material is assumed to be distributed homogeneously in the entire SN bubble. In summary, we envision an environment for the birthplace of the solar system 4.567 Gyr ago similar to the situation of the pillars in M 16 nowadays, where molecular cloud cores adjacent to an H II region will be hit by an SN explosion in the future. We show that the triggered collapse and formation of the solar system as well as the required enrichment with radioactive 26A1 are possible in this scenario. [ABSTRACT FROM AUTHOR]

The global climate system has experienced a series of drastic changes during the Cenozoic. These include the climate transformation in Asia, from a zonal pattern to a monsoon-dominant pattern, the disappearance of subtropical aridity related to a planetary circulation system and the onset of inland deserts in central Asia. Despite of the major advances in the last two decades in characterizing and understanding these climate phenomena, disagreements persist relative to the timing, behaviors and underlying causes. This paper addresses these issues mainly based on two lines of evidence. Firstly, we newly collected the available Cenozoic geological indicators of environment in China to compile the paleoenvironmental maps of ten intervals with a more detailed examination within the Oligocene and Miocene. In confirming the earlier observation that a zonal climate pattern was transformed into a monsoonal one, the new maps within the Miocene indicate that this major change was achieved by the early Miocene, roughly consistent with the onset of loess deposition in China. Although a monsoon-like regime would have existed in the Eocene, it was restricted in the tropical-subtropical regions. The observed latitudinal oscillations of the climate zones during the Paleogene are likely attributable to the imbalanced evolution of polar ice-sheets between the two hemispheres. Secondly, we examine the relevant depositional and soil-forming processes of the Miocene loess-soil sequences to determine the circulation characteristics with special emphasis given to the early Miocene. Continuous eolian deposition in the middle reaches of the Yellow River since the early Miocene firmly indicates the formation of inland deserts, which has been constantly maintained in the past 22 Ma. Inter-section grain-size gradients indicate northerly dust-carrying winds and source location, as is regarded as the main criteria of the Asian winter monsoon system. Meanwhile, the well-developed Luvisols evidence the existence of circulations from the ocean, which brought moisture to northern China. These imply the coexistence of two kinds of circulations, one from the ocean as moisture carrier and another from the inland deserts as dust transporter. The accretionary properties of the early Miocene paleosols, resulted from interactive soil-forming and dust deposition processes, evidence two seasonally alternative circulations, i.e. a monsoonal climate regime. The much stronger development of the early Miocene soils compared to those in the Quaternary loess indicates significantly stronger summer monsoons. These lines of evidence indicate a joint change in circulations and inland aridity by the early Miocene, and suggest a dynamic linkage of them. Our recent numerical experiments reconfirm the potential roles of Tibetan uplift and Paratethys shrinkage in triggering this major climate reorganization, as revealed in peer studies, but yielded more details about their combined scenarios. These two factors would have coacted with the help of South China Sea spreading. Although the realistic effects of each factor remain to be further discriminated, probably through more paleoaltimetrical and tectonic approaches, the Miocene loess record provides a vital insight that tectonics had evolved to a threshold by the early Miocene to cause this major climate reorganization in Asia. [ABSTRACT FROM AUTHOR]

Resolving early silicate differentiation timescales is crucial for understanding the chemical evolution and thermal histories of terrestrial planets. Planetary-scale magma oceans are thought to have formed during early stages of differentiation, but the longevity of such magma oceans is poorly constrained. In Mars, the absence of vigorous convection and plate tectonics has limited the scale of compositional mixing within its interior, thus preserving the early stages of planetary differentiation. The SNC (Shergotty–Nakhla–Chassigny) meteorites from Mars retain ‘memory’ of these events. Here we apply the short-lived 146Sm–142Nd and the long-lived 147Sm–143Nd chronometers to a suite of shergottites to unravel the history of early silicate differentiation in Mars. Our data are best explained by progressive crystallization of a magma ocean with a duration of ∼100 million years after core formation. This prolonged solidification requires the existence of a primitive thick atmosphere on Mars that reduces the cooling rate of the interior. [ABSTRACT FROM AUTHOR]

Deep-sea and ice-core records show a significant reduced amplitude of the ice volume, temperature and greenhouse gases variations before Marine Isotope Stage (MIS) 11, about 400 000 years ago, with less warm (more glaciated) interglacials and less cold glacials. At the same time, the loess in northern China, the sedimentary core in the eastern Tibetan Plateau and the palaeosols in southern China all record an unusually warm and wet climate during MIS-13 (about 500 000 years ago), indicating an extremely strong East Asian summer monsoon. To understand this seeming paradox of a strong East Asian summer monsoon occurring during the cool MIS-13, a three-dimension Earth system Model of Intermediate complexity is used. Modeling results show that this very strong MIS-13 East Asian summer monsoon, identified from the precipitation, horizontal and vertical (omega) wind, and pressure (geopotential) fields, results from the astronomical and ice sheet forcings. North Hemisphere summer at perihelion both at 529 and 506 ka BP leads to an East Asian summer monsoon stronger than during the Pre-Industrial time. In addition, the ice sheets reinforce the East Asian summer monsoon through the propagation of a perturbation wave which is induced mainly by the Eurasian ice sheet and is influenced by the Tibetan Plateau. [ABSTRACT FROM AUTHOR]

The δ18O record in deep-sea sediments show a significant reduced amplitude of the ice volume variations before Marine Isotope Stage 11, about 400 kyr ago, with less warm interglacials and less cold glacials. The deuterium temperature and the greenhouse gases records in the Antarctic ice cores show the same feature. As the reduction in the amplitude of climate and greenhouse gases concentration variations before 400 kyr BP is present in both deep-sea and ice cores, it is tempting to conclude that this is a worldwide phenomenon. This is not necessarily true, at least as far as some of the records, in particular of China, are concerned. The loess in northern China, the sedimentary core in the eastern Tibetan Plateau and the palaeosols in southern China all record an unusually warm and wet climate during Marine Isotope Stage 13, indicating an extremely strong East Asian summer monsoon. During the same interglacial, unusually strong African and Indian monsoon are recorded in the sediments of the equatorial Indian Ocean and of the Mediterranean Sea. Other extreme climate events are also recorded in sediment cores of the equatorial Atlantic, the Pacific, the subtropical South Atlantic Ocean and in the Lake Baikal of Siberia. [ABSTRACT FROM AUTHOR]

Aim: To study the analgesic effect of endomorphin-1 (EM-1)., Methods: The experiment was performed in rats and mice to study the analgesic effect of intraperitoneal (ip) injection of EM-1 with tail stimulation-vocalization test, writhing test, adjuvant arthritis, and neuropathic pain model and to compare it with the analgesic effects produced by intracerebroventricular (icv) and intrathecal (it) administrations., Results: 1) EM-1 raised the pain threshold dose-dependently in tail stimulation-vocalization test in rats and inhibited the writhing responses induced by ip acetic acid in mice. EM-1 also decreased the hyperalgesia in both adjuvant arthritis and neuropathic pain model. 2) The analgesic effect induced by central (icv and it) administration of EM-1 was faster and more powerful than that induced by peripheral (ip) administration. 3) The analgesic effect of EM-1 was reversed by naloxone (opioid receptor antagonist), as well as by cyprodime (mu-opioid receptor selective antagonist). Repeated administrations of EM-1 induced tolerance., Conclusion: EM-1 had a definite analgesic effect and the analgesic effect of EM-1 was mediated by central mu-opioid receptor.