Liquid–liquid two-phase mass transfer characteristics in a rotating helical microchannel

In this work,the mass transfer characteristics of two immiscible fluids were investigated in a rotating helical microchannel with hydraulic diameter of 932μm.Aqueous phosphoric acid solution and 80%tri-n-butyl phosphate(TBP)in kerosene were selected for the investigation of mass transfer performance in quartz glass/high density polyethylene(HDPE)microchannel.High dispersion between the two immiscible fluids can be obtained in the microchannel due to the intensifying action of centrifugal force,and the majority of the droplets with average diameter of 20–100μm were produced in the microchannel.The flow rate and rotation speed were found to have great effects on the extraction efficiency and average residence time.The empirical correlation of average residence time based on experimental data was developed by theoretical analysis and data fitting method,and a mathematical model of the mass transfer coefficient in dispersed phase was proposed.

Visual study on the characteristics of liquid and droplet in a novel rotor-stator reactor

Rotor–stator reactor(RSR), an efficient mass transfer enhancer, has been applied in many fields. However,the hydrodynamic characteristics of liquid flow in RSR are still a mystery despite they are fundamental for the mass transfer performance and processing capacity. In view of the above, this paper studies the liquid–liquid flow and liquid holdup in RSR under various conditions with a high-speed camera. The paper firstly demonstrates two flow patterns and liquid holdup patterns that we obtained from our experiment and then presents in succession a flow pattern and a liquid holdup criterion for the transition of film flow to filament flow and complete filling to incomplete filling. It is found that experimental parameters, including rotor–stator distance, rotational speed and volume flow rate exert great influence on the average droplet diameter and size distribution. Besides, by comparison and contrast, we also find that the experimental values match well with our previous predicted calculations of the average diameter, and the relation between the average diameter and the mean energy dissipation rate.

Gas-liquid-liquid extraction in a novel rotating microchannel extractor

In this work,a novel rotating microchannel extractor(RME)is designed and further used for the extraction of chromium(Ⅲ)from water.Unexpectedly,the micro-extraction had the same effect as carrying out 2.9-stage cross-flow extractions.Various factors,including the gas intake methods,gas intake quantity(Qg),distance between inner rotor and outer wall(D),rotational inner rotor speed(R)and volumetric flow rate(Qa,Qo),were selected to investigate their effect on the extraction efficiency(η)thoroughly.The relation map ofηwith Weaand We(o-g)for RME provides a comprehension for the gas–liquid–liquid extraction process in this RME system.

基于互相关的仿真算法(CCSIM)的页岩数字岩心重构

页岩储层具有低孔、低渗,矿物组分复杂及各向异性突出等特点,其基础的岩石物理研究实验很难进行,而数字岩心模型可为页岩的岩石物理实验数值模拟奠定基础。针对页岩储层的特殊性质,利用二维扫描电镜图像,选用基于互相关的仿真算法(CCSIM),实现了岩石数字岩心模型的重构。该方法计算效率较高,重构结果与原始二维切片形态具有良好的一致性,再现了页岩组分的长距离连通性,验证了CCSIM用于下一步页岩多尺度三维模型构建的可行性。

Study on an improved rotating microchannel separator in the intensification for demulsification and separation process

An improved rotating microchannel(IRM) separator was further explored in the intensification for demulsification and separation process. Oil-in-water(O/W) emulsion system of 2-ethylhexyl phosphoric acid-2-ethylhexyl ester(P507)–water without emulsifier was employed to evaluate the performance of the new equipment. In this experiment, the influence on demulsification separation process was explored by changing the geometrical structure and channel height of the microchannel and combining the liquid–liquid two-phase flow pattern, and the correlation general graph between demulsification efficiency and dimensionless parameters was established. The total demulsification effect of the IRM and the separation capacity of the clear organic phase recovered from demulsification are significantly improved. In addition, the liquid–liquid two-phase flow pattern of the clear organic phase after demulsification and the remaining emulsion in the IRM are observed and recorded by high-speed photography. The separation ability of organic phase from the upper outlet can be significantly improved when the total demulsification rate of IRM is up to 90%. There are 3 types and 6 kinds of flow patterns observed. The results demonstrated that the suitable demulsification performance is obtained when the liquid–liquid two-phase inside the IRM is in a parallel pattern. Finally, the relation map between total demulsification efficiency and the universal flow is drawn, which provides a basis for the accurate control of the IRM device.

Evolutionary trajectory of TRPM2 channel activation by adenosine diphosphate ribose and calcium

Ion channel activation upon ligand gating triggers a myriad of biological events and,therefore,evolution of ligand gating mechanism is of fundamental importance.TRPM2,a typical ancient ion channel,is activated by adenosine diphosphate ribose(ADPR)and calcium and its activation has evolved from a simple mode in invertebrates to a more complex one in vertebrates,but the evolutionary process is still unknown.Molecular evolutionary analysis of TRPM2s from more than 280 different animal species has revealed that,the C-terminal NUDT9-H domain has evolved from an enzyme to a ligand binding site for activation,while the N-terminal MHR domain maintains a conserved ligand binding site.Calcium gating pattern has also evolved,from one Ca^(2+)-binding site as in sea anemones to three sites as in human.Importantly,we identified a new group represented by olTRPM2,which has a novel gating mode and fills the missing link of the channel gating evolution.We conclude that the TRPM2 ligand binding or activation mode evolved through at least three identifiable stages in the past billion years from simple to complicated and coordinated.Such findings benefit the evolutionary investigations of other channels and proteins.

Crystal modification of rifapentine using different solvents

Rifapentine crystals with different habits were prepared by recrystallization from selected solvents,such as methanol,ethanol,chloroform,and acetic acid.Scanning electron microscopy,X-ray powder diffractometry,infrared spectrometry,and differential scanning calorimetry were used to investigate the physicochemical characteristics of the prepared crystals.The comparative dissolution behaviors of the newly developed crystals and of rifapentine without being treated were also studied.Results show that the newly developed crystals were different from each other with respect to physical properties but were identical chemically.Needle-shaped crystals were obtained from methanol,ethanol,and chloroform solvents,and the block-shaped crystals were obtained from acetic acid solvent.X-ray diffraction spectra and differential scanning calorimetry investigation on those developed crystals clearly indicate that rifapentine has different crystal structure modification.When the crystal was obtained from acetic acid,the change of crystal habit was originated from the crystal structure modification.The dissolution rate of newly developed crystals was found to be higher than that of rifapentine without being treated.However,the modified crystal obtained from acetic acid shows the lower dissolution rate than crystals obtained from other solvents.

Serine 707 of APPL1 is Critical for the Synaptic NMDA Receptor-Mediated Akt Phosphorylation Signaling Pathway

Accumulating evidence indicates that the synaptic activation of N-methyl-o-aspartate receptors （NMDARs） has a neuroprotective effect on neurons. Our previous study demonstrated that APPL1 （adaptor protein containing pleckstrin homology domain, phosphotyrosine- binding domain, and leucine zipper motif） mediates the synaptic activity-dependent activation of PI3K-Akt signaling via coupling this pathway with NMDAR-PSD95 （postsynaptic density protein 95） complexes. However, the molecular mechanism underlying this process is still unknown. In the present study, we investigated the inter- action of APPL1 with PSD95 using co-immunocyto- chemical staining and western blotting. We found that the PDZ2 domain of PSD95 is a binding partner of APPL1. Furthermore, we identified serine 707 of APPL1, a pre- dicted phosphorylation site within the PDZ-binding motif at the C-terminus, as critical for the binding of APPL1 to PSD95, as well as for activation of the Akt signaling pathway during synaptic activity. This suggests that serine 707 of APPL1 is a potential phosphorylation site and may be involved in regulating the neuroprotective Akt signaling pathway that depends on synaptic NMDAR activity.

cFos-ANAB:A cFos-based Web Tool for Exploring Activated Neurons and Associated Behaviors

cFos is one of the most widely-studied genes in the field of neuroscience.Currently,there is no systematic database focusing on cFos in neuroscience.We developed a curated database-cFos-ANAB-a cFos-based web tool for exploring activated neurons and associated behaviors in rats and mice,comprising 398 brain nuclei and sub-nuclei,and five associated behaviors:pain,fear,feeding,aggression,and sexual behavior.Direct relationships among behaviors and nuclei(even cell types)under specific stimulating conditions were constructed based on cFos expression profiles extracted from original publications.Moreover,overlapping nuclei and sub-nuclei with potentially complex functions among different associated behaviors were emphasized,leading to results serving as important clues to the development of valid hypotheses for exploring as yet unknown circuits.Using the analysis function of cFos-ANAB,multi-layered pictures of networks and their relationships can quickly be explored depending on users’purposes.These features provide a useful tool and good reference for early exploration in neuroscience.The cFos-ANAB database is available at www.cfos-db.net.