Retorting is a frequently used method for producing shale oil from oil shale. During retorting, heat is usually supplied to the retort by heat-carrier gas of high temperature, such as 700 °C, until retorting ends. In this work, a low-energyinput retorting process using low-temperature carrier gas but without marked loss in oil yield was achieved by a self-heating effect, that is, spontaneously increasing retorting temperature in the absence of external heat provision. The self-heating retorting process starts by preheating oil shale from room temperature to 300 °C by external heating under N 2 and then switching N 2 to air of 150 °C. When N 2 is replaced by air, the self-heating effect starts. Subsequently, the temperature of raw oil shale can increase spontaneously to complete the retorting, so that an external heat supply is no longer required. While using only N 2 or only air as the carrier gas throughout the whole retorting process cannot produce such a good effect. In this N 2 -air sequence retorting process, because an external heat supply is needed only to preheat the raw oil shale to 300 °C (i.e., the required energy input and external-heating terminal temperature are low), the retorting process is significantly simplified. The present work provides a promising starting point for the further development of not only ex situ (aboveground) but also in situ (underground) retorting for the production of shale oil.

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MicroRNAs are small noncoding RNAs involved in various biological processes. We characterized the expression of miR-344-3p during mouse embryonic development. At E9.5-E10.5 and E15.5, in situ hybridization detected strong miR-344-3p signal in the central nervous system, including the cerebral cortex, hindbrain, cerebellum, thalamus, hindbrain, medulla oblongata, spinal cord, and dorsal root ganglia. Further, qRT-PCR analysis identified miR-344-3p expression at E15.5, with expression stably maintained in the brain from E12.5 to E18.5 before decreasing to relatively low levels postnatally. We also analyzed miR-344-3p expression using immunofluorescence in situ hybridization at E18.5 and within the adult brain. miR-344-3p signal was mainly detected in cortical regions surrounding the ventricular system, choroid plexus, glomerular layer of the olfactory bulb, and granular cell layer of the cerebellar cortex. Altogether, our results indicate miR-344-3p may play an important role in morphogenesis, nervous system development in the brain.

A process using plentiful and inexpensive caustic calcined magnesia (CCM; main component is MgO) to prepare lamellar MH of high purity is described. The process begins with the reaction of MgO in CCM with NH4NO3 at ∼100 °C to produce ammonia gas and Mg(NO3)2 solution and the subsequent filtration of Mg(NO3)2 solution to remove impurities (e.g., SiO2). Then, the obtained ammonia is introduced into the Mg(NO3)2 solution to produce MH precipitate and NH4NO3. After the MH precipitate is separated by filtration, the filtrate containing NH4NO3 is returned to the initial step. The overall reaction of this process is the hydration of MgO to MH. Therefore, this process is called the apparent-hydration method. This apparent-hydration method overcomes the disadvantages of the true hydration method, such as the inability to remove impurities. A crucial finding is that, because of the presence of trace SO4 2– in the obtained Mg(NO3)2 solution, a MH product with a narrow particle size distribution cannot be produced. After removal of the SO4 2– with Ba(NO3)2, lamellar MH with a narrow particle size distribution can be synthesized at 120 °C in one step. This work provides a promising route to the use of CCM to prepare MH.

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