[Research progress of extracellular vesicles in hepatic fibrosis].

Liver fibrosis is a pathophysiological process characterized by abnormal accumulation of connective tissues in the liver caused by chronic liver injuries, in which the activation and migration of hepatic stellate cells (HSCs) play a central role. Extracellular vesicles (EVs) are a class of nanoscale, bilayer lipid enveloped vesicles secreted by almost all cells. EVs are of great interest in liver pathology because they have been found to mediate the communication between cells and regulate cellular microenvironment via horizontal transfer of their cargoes. EVs carry bioactive cargoes including proteins, lipids and RNA molecules, and are involved in the activation of HSCs during liver fibrogenesis.

[Hemodynamic changes in standing-up test of children and adolescents with postural tachycardia syndrome].

OBJECTIVE: To explore the hemodynamic changes in standing-up test of children and adolescents with postural tachycardia syndrome (POTS) and to compare hemodynamic parameters of POTS patients with decreased cardiac index (CI) and those with not-decreased CI. METHODS: A retrospective study was conducted to show the trends of CI, total peripheral vascular resistance index (TPVRI), heart rate and blood pressure in standing-up test of 26 POTS patients and 12 healthy controls, and to compare them between the two groups. The POTS patients were divided into two groups based on CI decreasing or not in standing-up test, namely decreased CI group (14 cases) and not-decreased CI group (12 cases). The trends of the above mentioned hemodynamic parameters in standing-up test were observed and compared between decreased CI group and not-decreased CI group. RESULTS: In standing-up test for all the POTS patients, CI (F=6.936, P=0.001) and systolic blood pressure (F=6.049, P<0.001) both decreased significantly, and heart rate increased obviously (F=113.926, P<0.001). However, TPVRI (F=2.031, P=0.138) and diastolic blood pressure (F=2.018, P=0.113) had no significant changes. For healthy controls, CI (F=3.646, P=0.016), heart rate (F=43.970, P<0.001), systolic blood pressure (F=4.043, P=0.020) and diastolic blood pressure (F=8.627, P<0.001) all increased significantly in standing-up test. TPVRI (F=1.688, P=0.190) did not change obviously. The changing trends of CI (F=6.221, P=0.001), heart rate (F=6.203, P<0.001) and systolic blood pressure (F=7.946, P<0.001) over time were significantly different between the patients and healthy controls, however, no difference was found in TPVRI and diastolic blood pressure (P > 0.05). Among the POTS patients, CI was significantly different between decreased CI group and not-decreased CI group (F=14.723, P<0.001). Systolic blood pressure of the former decreased obviously (F=8.010, P<0.001), but it did not change obviously in the latter (F=0.612, P=0.639). Furthermore, none of the changes of TPVRI, heart rate and diastolic blood pressure in standing-up test were significantly different between the two groups (P > 0.05). Age was an independent factor for decreased CI patients (P=0.013, OR=2.233; 95% CI, 1.183 to 4.216). CONCLUSION: POTS patients experience vital hemodynamic changes in standing-up test, part of them suffering from decreased CI, but others from not-decreased CI. Age is an independent factor for patients suffering from decreased CI.

Vortex-induced morphology on a two-fluid interface and the transitions.

We investigate experimentally the steady flows in a cylinder containing two immiscible liquids, with the primary fluid being driven by the upper boundary rotating at constant speeds. The system exhibits interesting interplays between the flow fields and the morphology of the interface, with evidence showing that the remarkable flattop structure is a consequence of the vortex breakdown discovered decades ago, and that the deformability of the interface also feedbacks positively to the development of the vortices. Monitoring the topological structure of the flow fields defines the base states and transitions behind the morphology, whereas our survey over different aspect ratios also reveals rich phenomena of surface instabilities accompanying these steady states.

Theoretical investigation for the EPR g-factors of the mixed ground state in NaCl: Ag2+ crystals.

In this paper, it is considered that the local structure of the (AgCl6)4- cluster for the NaCl: Ag2+ crystal is of the axially elongational D4h symmetry which possesses the weaker rhombic distortion at <001> lattice site. The mechanism for an admixture of the 2A1g into the ground state 2B1g is taken into account. The electron paramagnetic resonance (EPR) g factors of NaCl: Ag2+ are studied by using the double spin-orbit coupling model and an approximation of a semiempirical molecular orbit. The EPR g factors for the NaCl: Ag2+ crystals are reasonably explained as well as the good agreement between the calculated values and the experimental data is obtained.