Diagenesis is a key process that affects carbonate reservoir formation and evolution. This paper presents a detailed study of a carbonate shoal reservoir in the Ordovician Majiagou Formation, Ordos ...Basin, China. This reservoir records different diagenetic features that are related to reservoir heterogeneity. Petrographic observations and geochemical data reveal that the two facies present in a single shoal exhibit differences in rock and pore textures, spatial distributions, and reservoir properties. The shoal margins consist of grain dolomite with few intergranular pores and pervasive cement infilling, whereas the shoal core is dominated by crystalline dolomite with abundant intercrystalline pores. These two types of reservoir experienced multi-stage and different diagenetic pathways. The shoal deposits were pervasively dolomitized during the very early diagenesis with the dolomitizing fluid of highly saline seawater due to evaporation. The shoal margins were then cemented due to the inflow of hypersaline seawater and gypsum precipitation during penecontemporaneous to shallow burial, which resulted in significant reservoir degradation. However, this densification and relatively poor reservoir properties of the shoal margins protected the shoal core from cementation and alteration by hypersaline seawater. During deep burial, continued diagenetic modification and recrystallization occurred preferentially in the shoal core as the diagenetic fluid flowed and migrated into the layers with relatively high porosity–permeability. This resulted in intense lithological and porosity transformation within the shoal core. Multiple stages of diagenetic differentiation affected the formation and preservation of dolomite reservoir, which provide new insight into the carbonate reservoir heterogeneity. The results have implications for future oil–gas exploration in high-quality reservoirs developed in old superimposed basins, such as the Ordos Basin and those in a similar geological setting.
•Multistage diagenetic differentiation are identified within shoal facies reservoir.•Facies and diagenetic fluids affected the dolomite reservoir evolution.•Early densification of shoal margin makes for the preservation of shoal core.•Multistage diagenesis and evolution model of high quality reservoir is proposed.
To investigate the association of human chorionic gonadotropin (HCG) level on day 3 of embryo culture with embryo development.
Spent culture media were collected from individually cultured embryos on ...day 3 of in vitro fertilization and embryo transfer (IVF-ET) cycles. HCG concentration in the culture media was measured using an ELISA kit and its association with embryo development was assessed.
In the 163 samples of embryo culture media from 60 patients, HCG was positive in 153 sample (93.8%) with a mean level of 0.85 ± 0.43 mIU/ml. The concentration of hCG in the culture media increased gradually as the number of blastomeres increased (F=2.273, P=0.03), and decreased as the morphological grade of the embryo was lowered (F=3.900, P=0.02).
ELISA is capable of detecting HCG levels in spent culture media of embryos on day 3 of in vitro culture. The concentration of HCG in spent culture media is positively correlated with the status of early embryo development and implantation rate and thus serves as a useful mar
Through the first-principle density-functional theory (DFT) calculations, we have made an exhaustive study of the mechanism of CO oxidation catalyzed by AlCu
n
(
n
= 1–3) clusters on gas phase. It is ...shown that mixing two different metals (Al and Cu) can have beneficial effects on the catalytic activity than monometallic Cu
n
+ 1
(
n
= 1–3) cluster toward the reaction of CO oxidation and the alloyed AlCu3 cluster is proposed as the best effective nanocatalysts.
To understand the development situation of the worldwide public bicycle systems more fully, the comparison research on the representative public bicycle systems at home and abroad is summarized in ...several aspects including operating mode, charging method, technology application, implementation effect, etc. Finally, the experiences and lessons for successful operating of public bicycle system are concluded.
Esophageal squamous cell carcinoma (ESCC) is one of the most common types of cancer in China. Artesunate (ART) is used clinically as an anti-malarial agent and exhibits potent antiproliferative ...activity. In addition, ART has demonstrated remarkable antitumor activity, presenting a novel candidate for cancer chemotherapy. However, its effect on ESCC remains unknown. The present study analyzed the antitumor effects of ART in the KYSE-150 ESCC line by assessing cell proliferation, cell death, cell migration/invasion and the biomechanical properties of ART-treated KYSE-150 cells. ART treatment significantly suppressed the proliferation of KYSE-150 cells in a dose- and time-dependent manner, as assessed by MTT assay. Following treatment with 30 mg/l ART, the cell population in the G0/G1 phase and the level of cell apoptosis significantly increased from 54±1.5 to 68.1±0.3%, and from 4.53±0.58 to 12.45±0.62%, respectively. Furthermore, the cell migration and invasion of KYSE-150 cells treated with 30 mg/l ART was markedly inhibited. The cell membrane and biomechanical properties were investigated using atomic force microscopy, as targets of ART action. ESCC cells treated with 30 mg/l ART exhibited increased adhesive force, increased cytomembrane roughness and reduced elasticity compared with the control group (KYSE-150 cells without ART treatment). The biomechanical properties of KYSE-150 cells treated with 30 mg/l ART were similar to those of the SHEE normal human esophageal epithelial cell line. In conclusion, the present study demonstrated that ART may inhibit cell proliferation and migration in ESCC through changes in the biomechanical properties of the ESCC cells.
A new design of peculiar-shaped β-NaYF
: 20% Yb
/2% Er
hexagonal microcrystal (PSβHM) is proposed and its upconversion (UC) luminescence with adjustable color pattern is studied with near infrared ...excitation. Flower-like green UC luminescence emission pattern from blooming to withering process and intensive directional red emission are achieved by simply adjusting the focal point position of the excitation light. The mechanism that determines the unique UC luminescence phenomena are investigated systematically. The function of the internal light reflection and waveguide effect with annular microcavity is explored based on the structure characteristic of the hexagonal microplate. The current work may have great significant and potential applications in the development of optoelectronic device, color display, directional light and laser emission of microsystem.
Premature fracture of an axle under torsional load occurred after a tracked military tank had experienced field testing for only 80 kilometers. Visual metallographic examinations were performed with ...optical microscope (OM) and scanning electron microscope (SEM). The investigation demonstrates that the premature fracture is caused by metallurgical problems inside the axle where the primary and secondary cracks originate, propagate, and eventually result in final catastrophic rupture through torsional fatigue. The failure mechanism is summarized and improvement of the fatigue lifetime for the axle is recommended.
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