Microcosm study on cold adaptation and recovery of an exotic mangrove plant, Laguncularia racemosa in China.

Laguncularia racemosa (a white mangrove) is an exotic mangrove species commonly distributed in southern intertidal zones in China since it was introduced for reforestation purposes in 1999. However, the invasiveness of this exotic species and its cold adaptability have rarely been reported. The present work determined the cold resistance level of L. racemosa and its recovery from cold stress, aiming to speculate its potential invasive capability in China. Results showed that the germination of L. racemosa seeds in sand or in simulated sea field models was significantly inhibited by a series of cold treatments, with no germination at 5 °C and decreased in germination at low temperatures (15-25 °C). Low temperature also reduced net photosynthetic rate (A), water use efficiency (WUE), transpiration rate (E), and stomatal conductance (Gs) of the seedlings of L. racemosa. On the other hand, cold stress up-regulated in leaves of malondialdehyde (MDA) and antioxidant activities, including superoxide dismutase (SOD), glutathione reductase (GR), and ascorbate peroxidase (APX). Additionally, these physiological and biochemical indexes of cold-stressed L. racemosa could recover to the original levels if the plants were returned to room temperature with a few exceptions. For instance, the cold exposure duration altered seedlings' physiology, but the photosynthetic related activities could not recover if cold treatment lasted for 120 h. This study suggests that L. racemosa can tolerate low temperatures to some extent, thus settle and even invade the coast of China at high latitudes having cold winter, which poses a challenge to the conservation and management of local mangrove ecosystems.

Notoginsenoside R1 induces DNA damage via PHF6 protein to inhibit cervical carcinoma cell proliferation.

Notoginsenoside R1 (NGR1), a monomer of Traditional Chinese medicine, is from the Panax notoginsenoside complex, and has been reported to inhibit the proliferation of various types of cancer. However the mechanism underlying NGR1­mediated inhibition of cervical carcinoma cell proliferation remains unclear. Therefore, the current study aimed to investigate the antitumor effects of NGR1 on cervical carcinoma cell lines (CaSki and HeLa cells) in vitro. The Cell Counting Kit­8 and soft agar cell colony formation assay results revealed that NGR1 suppressed the viability and the number colonies of CaSki and HeLa cells, respectively. Furthermore, the DAPI staining, flow cytometry and western blotting results revealed that NGR1 induced cervical carcinoma cell apoptosis, cell cycle arrest in the S phase, upregulation of cyclin A2 and CDK2 expression levels, and downregulation of cyclin D1 expression levels. To further investigate the mechanisms of NGR1, DNA­damage­related proteins, including H2A.X variant histone (H2AX), ATR serine/threonine kinase (ATR) and p53, and the nucleolus protein, plant homeodomain finger protein 6 (PHF6) were analyzed. The results indicated that NGR1 triggered the phosphorylation of H2AX and ATR in a dose­ and time­dependent manner, and downregulated the expression level of PHF6 and upregulated the expression level of p53 in a dose­ and time­dependent manner. In conclusion, the findings of the present indicated that NGR1 may inhibit the viability of cervical carcinoma cells and induce cell apoptosis via DNA damage, which may be activated by the downregulation of PHF6 expression levels, and the subsequent triggering of the phosphorylation of H2AX and ATR. In addition, NGR1 may exert an ability to arrest cervical carcinoma cells in the S phase and upregulate the expression levels of cyclin A2 and CDK2. Therefore, NGR1 may serve as a novel chemotherapeutic agent for cervical carcinoma.

[The numerical simulation of the internal flow field inside the pressure generator of a continuous positive airway pressure ventilator].

The problem of noise in ventilator has always been an important topic to study in the development of the ventilator. A great number of data are showing that there are still large gaps of research and application levels in noise control of the ventilator between China and some more advanced foreign countries. In this study, with cooperation of the Shanghai Medical Equipment Limited Liability Company, we used the computational fluid dynamics (CFD), software FLUENT, adopted the standard k-epsilon turbulence model and the SIMPLE algorithm to simulate the inner flow field of the continuous positive airway pressure (CPAP) ventilator's pressure generator. After a detailed analysis, we figured out that there are several deficiencies in this ventilator, like local reflow in volute, uneven velocity distribution and local negative pressure in inlet of the impeller, which easily lead to noise and affect the ventilator's performances. So, it needs to be improved to a certain extent.

[Research on flow characteristics in a non-blade centrifugal blood pump based on CFD technology].

The problem of thrombus and hemolysis in blood pump has always been an important topic to study in the development of the blood pump. Numbers of research results show that it is the complicated flow and the high shear stress of the mechanical movement that result in the thrombus and hemolysis. In this study, with the cooperation of Shanghai Children's Medical Center, we have used computational fluid dynamics (CFD) commercial software FLUENT to compute and analyze the flow characteristics in a non-blade centrifugal blood pump. The results figure out that this pump has a reasonable flow distribution and the shear stress distribution is under the critical broken state of red blood cell; meanwhile, there is less thrombus and hemolysis in this pump. So it is in the foreground for clinical use.