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The current methods for detecting myelin changes in ischemic stroke are indirect and cannot accurately reflect their status. This study aimed to develop a novel fluorescent-magnetic resonance dual-modal molecular imaging probe for direct imaging of myelin. Compounds 7a and 7b were synthesized by linking the MeDAS group and Gadolinium (III) 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetate. Compound 7a was selected for characterization and further study. Cell uptake, cytotoxicity, and magnetic resonance imaging scans were performed on cells. In vitro experiments on frozen brain sections from 7-day-old, 8-week-old, and ischemic stroke rats were compared with commercially available Luxol Fast Blue staining. After HPLC and MR scanning, brain tissue was soaked in 7a and scanned using T 1 WI and T 1 maps sequences. Spectrophotometer results showed that compounds 7a and 7b had fluorescent properties. MR scans indicated that the compounds had contrast agent properties. Cells could uptake 7a and exhibited high signals in imaging scans. Compound 7a brain tissue staining showed more fluorescence in myelin-rich regions and identified injury sites in ischemic stroke rats. MR scanning of brain sections provided clear myelin contrast. A novel fluorescent-magnetic resonance dual-modal molecular imaging probe for direct imaging of myelin was successfully developed and tested in rats with ischemic stroke. These findings provide new insights for the clinical diagnosis of demyelinating diseases. • Compounds 7a and 7b have fluorescent properties from spectrophotometer results. • Compounds 7a and 7b have MRI contrast agent properties. • Our novel dual-mode probes effectively visualized the rat infarction model. • Our study may provide new ideas for diagnosing demyelinating diseases. [ABSTRACT FROM AUTHOR]

[Display omitted] Demyelination exists in many neurological diseases of nervous system, such as stroke. Currently, magnetic resonance imaging (MRI) has been the main tool for diagnosing and monitoring the myelin related diseases. However, the conventional MRI unable to distinguish demyelinating lesions from other inflammatory lesions. To address this problem, we have designed and prepared a myelin specific magnetic resonance contrast agent, Gd-DTDAS, which was based myelin specific moiety MeDAS g g MeDAS: (E)-4-(4-aminostyryl)- N -methylaniline. and Gd-DTPA h h Gd-DTPA: gadopentetate acid.. In this work, we verified the specificity and sensitivity of Gd-DTDAS to myelin. Moreover, we investigated the specific binding ability of Gd-DTDAS to myelin sheath in the MCAO mice i i MCAO: middle cerebral artery occlusion. models. The in vivo imaging results showed that Gd-DTDAS can bind to the undamaged myelin sheath in the BBB disruption areas, and in turn reduce the relaxation time. The fluorescence images also showed significant fluorescence in the brain right infarct area of the MCAO model mice with administration of Gd-DTDAS. The above results confirmed that Gd-DTDAS could be preferentially distributed in areas with high myelination and can detect focally induced demyelination. [ABSTRACT FROM AUTHOR]

The Triassic Chang 7 shale in the Ordos Basin with considerable total organic carbon content (TOC) has been considered as an ideal target for in-situ conversion process (ICP) in China. However, the compositional kinetics for oil and gas generation from the Chang 7 organic matter during heating remain unclear, causing difficulty in the resource evaluation of shale oil and the temperature optimization in future ICP. In this study, the non-isothermal pyrolysis of two Chang 7 kerogens at 2 and 20 ºC/h were conducted to investigate the potential of individual components of products as well as their evolution kinetics. By using a comprehensive two-dimensional gas chromatography (GC×GC), the yields of individual components (including C 1–5 , C 6–14 saturates, C 6–14 aromatics, C 15+ saturates, C 15+ aromatics and NSOs) in pyrolysis products were measured. The maximum yields of oils and C 1–5 from ZK-2 kerogen with hydrogen index (HI) of 471 mg/g TOC were 421.5 and 240.5 mg/g TOC, much higher than those from ZK-1 with HI of 332 mg/g TOC. Relatively, the temperature for giving maximum yield of C 6–14 is significantly higher than those of C 15+ and heteroatomic compounds (NSOs), which were decomposed to re-generate light hydrocarbons in the closed system. It showed that activation energies (Ea) for the generation and cracking of C 6–14 and C 2–5 were distributed in broader ranges compared with NSOs and C 15+ components by kinetic fits. Meanwhile, the mass conversions of oil and gas from the Chang 7 kerogen in ICP at 0.5–10 ºC/d were obtained. The temperatures giving maximum HC yield in ICP were predicted to be 330–368 ºC. The oil and gas generation potentials of the Chang 7 shale in the Ordos Basin giving maximum HC yields were estimated as 542 × 108 t and 89.4 × 108 m3, respectively. Finally, it is elucidated that heated temperatures of about 20 ºC higher than those giving maximum oil yield result in GOR higher than 200 m3/m3. These findings are beneficial for the economic production of shale oil in ICP. • Yields of individual pyrolysis products from the Chang 7 kerogens were determined. • Compositional kinetic models for the evolution of nine components were addressed. • T giving maximum HC yield in ICP at 0.5–10 ºC/d are 330–368 ºC. • ICP at T of 20 ºC higher than those giving maximum oil yield will result in GOR > 200 m3/m3. [ABSTRACT FROM AUTHOR]

In recent years, petroleum exploration has extended from shallow to deep reservoirs in the globle petroliferous basins. In contrast to conventional carbonate reservoirs, the fractures and hydrotherm related karst reservoirs could mainly be developed in deep strata along the tectonic deformation and fault zone. The seismic imaging and tectonic analysis have been combined to identify the scale and features of the deep fault system in the Tarim Basin, NW China. It was found that the tectonic collision and movement generated a prevalent strike-slip fault system, which was conjugated and extended from paleo-uplift to the inside of the Manjar Sag (source kitchen) in the Tarim Basin. The micrograph of cores and images of well logging demonstrated that deep reservoirs are dominated by porosities, fractures, and hydrothermal minerals (e.g., fluorite, pyroxenite). Burial dissolution and thermohydrology along strike-slip fault have greatly contributed to the formation of deep carbonate reservoirs, meanwhile controled the accumulation and hydrocarbon properties in the deep carbonates reservoirs of Tarim Basin. The analysis of adamantane, dibenzothiophene, and carbon isotopes indicated that oil-cracking, thermochemical sulfate reduction (TSR), and gas-washing fractionation could be the main factors to control the sequential accumulation of various hydrocarbons around Manjar Sag. The formation and hydrocarbon accumulation of the deep carbonate reservoirs along this strike-slip fault system could provide important details regarding deep petroleum geological processes from both scientific and practical aspects. These findings could be applied to future studies and the exploration of deep potential marine reserves worldwide. • δ13C 18~19 2,3,6-TMAI ranged −19.81‰ ~ −21.25‰ in North China Mesoproterozoic. • Distribution of Green Sulphur Bacteria exhibited dynamic variations of oceanic redox. • Contributions of GSB to the Xiamaling sedimentary organic matter were limited. [ABSTRACT FROM AUTHOR]