Dual-channel compressed ultrafast photography for Z-pinch dynamic imaging.

The compressed ultrafast photography (CUP) can capture non-repetitive time-evolving events at 7 × 1013 fps, which is anticipated to find a diverse range of applications in physics, biomedical imaging, and materials science. The feasibility of diagnosing ultrafast phenomenon of Z-pinch by using the CUP has been analyzed in this article. Specifically, a dual-channel CUP design has been adopted for acquiring high quality reconstructed images and the strategies of identical masks, uncorrelated masks, and complementary masks have been compared. Furthermore, the image of the first channel was rotated by 90° to balance the spatial resolution between the sweep direction and the non-sweep direction. Both five synthetic videos and two simulated Z-pinch videos were chosen as the ground truth to validate this approach. The average peak signal to noise ratio of the reconstruction results is 50.55 dB for the self-emission visible light video and 32.53 dB for the laser shadowgraph video with unrelated masks (rotated channel 1). The simulation results show that the time-space-evolving process of plasma distribution can be well retold, and the phenomenon of plasma instability can be accurately diagnosed by the dual-channel CUP with unrelated masks (rotated channel 1). This study may promote the practical applications of the CUP in the field of accelerator physics.

Effect of miR-223 on thrombophlebitis rats through regulating Toll-like receptor signaling pathway.

OBJECTIVE: To explore the effect of the micro ribonucleic acid (miR)-223 on the thrombophlebitis rats by regulating the Toll-like receptor (TLR) signaling pathway. MATERIALS AND METHODS: The rat model of thrombophlebitis was established, and miR-223 was silenced or overexpressed through lentiviral transfection. The rats were divided into miR-223 inhibitors group (Inhibitors group), miR-223 mimics group (Mimics group), and normal group (Control group). The transfection efficiency of miR-223 in venous tissues was detected via Reverse Transcription-Polymerase Chain Reaction (RT-PCR), the hemorheological indexes plasma viscosity (PV) and hematocrit (HCT) were observed, and the content of the serum inflammatory factors interleukin-6 (IL-6) and tumor necrosis factor-ß (TNF-ß) were detected via enzyme-linked immunosorbent assay (ELISA). Moreover, the fibrinolytic indexes plasminogen activator inhibitor (PAI) and the tissue-type plasminogen activator (t-PA) were detected, the morphological changes in the venous tissues were observed via hematoxylin-eosin (HE) staining, and the gene and protein expressions of the TLR signaling pathway were detected via RT-PCR and Western blotting. RESULTS: The expression of miR-223 was significantly increased in the Mimics group (p<0.05) and significantly decreased in the Inhibitors group (p<0.05). The high-shear and low-shear whole blood viscosity and HCT in the Inhibitors group were significantly higher than those in the Mimics group (p<0.05). The levels of serum IL-6, IL-1ß, and TNF-ß in the Inhibitors group were remarkably higher than those in the Mimics group (p<0.05). The Inhibitors group had a remarkably lower level of t-PA (p<0.05) and a remarkably higher level of PAI than the Mimics group (p<0.05). Besides, the inferior vena cava wall shed and disappeared due to complete necrosis in the Inhibitors group. In the Mimics group, the vascular lumen was slightly expanded, and the vascular wall had intact contour. It was found in the gene detection that the mRNA levels of TLR2, myeloid differential protein-88 (MyD88) and c-Jun N-terminal kinase (JNK) were evidently increased in the Inhibitors group, and the significant increases in the protein levels of TLR2 and MyD88 were also observed in the protein detection. CONCLUSIONS: The overexpression of miR-223 can inhibit the TLR signaling pathway, thereby promoting the recovery of thrombophlebitis rats.

MDM2 but not MDM4 promotes retinoblastoma cell proliferation through p53-independent regulation of MYCN translation.

Retinoblastomas can arise from cone photoreceptor precursors in response to the loss of pRB function. Cone precursor-specific circuitry cooperates with pRB loss to initiate this process and subsequently contributes to the malignancy. Intrinsic high-level MDM2 expression is a key component of the cone precursor circuitry and is thought to inactivate p53-mediated tumor surveillance, which could otherwise be induced in response to pRB loss. However, the MDM2-related MDM4 has also been proposed to abrogate p53-mediated tumor surveillance in the absence of detectable MDM2 in retinoblastoma cells, bringing into question the importance of high-level MDM2 versus MDM4 expression. Here we report that high-level MDM2 but not MDM4 has a consistent critical role in retinoblastoma cell proliferation in vitro, as well as in orthotopic xenografts. Reduction of either MDM2 or MDM4 weakly induced p53, yet reduction of MDM2 but not MDM4 severely impaired proliferation and survival through a p53-independent mechanism. Specifically, MDM2 upregulated the mRNA expression and translation of another component of the cone circuitry, MYCN, in retinoblastoma cells. Moreover, MYCN was essential to retinoblastoma cell growth and tumor formation, and ectopic MYCN partially reversed the effects of MDM2 depletion, indicating that MYCN is an important MDM2 target. These findings indicate that high-level MDM2 expression is needed in order to perform a critical p53-independent function and may obviate the need for genomic alterations to the p53 pathway during retinoblastoma tumorigenesis.

Rabbit nucleus pulposus cells facilitate differentiation of adipose-derived stem cells into nucleus pulposus-like cells.

OBJECTIVE: To investigate the feasibility of inducing adipose-derived stem cells (ADSCs) to nucleus pulposus cells (NPCs). MATERIALS AND METHODS: ADSCs were isolated from rabbit while NPCs were isolated from an allogeneic rabbit. NPCs were co-cultured with the 3rd generation ADSCs in co-cultured system. Only NPCs were cultured in single culturing group. Through the collagen type II collagen immunohistochemistry, we observed NPCs and then identify NPC. Proteoglycan messenger RNA (mRNA) and collagen type II mRNA level were measured by real-time polymerase chain reaction. RESULTS: In two group cells, collagen type II collagen were detected by immunohistochemistry. The amount of proteoglycan mRNA and collagen type II mRNA was both significantly higher in co-cultured group than in single cultured group. CONCLUSIONS: In some condition, ADSCs have the potency to differentiate toward nucleus pulposus-like cells. ADSCs are better seed cells for tissue engineering of artificial nucleus pulposus.

Hypoxia-inducible factor 1alpha cDNA cloning and its mRNA and protein tissue specific expression in domestic yak (Bos grunniens) from Qinghai-Tibetan plateau.

Adaptation to hypoxia is regulated by hypoxia-inducible factor 1 (HIF-1), a heterodimeric transcription factor consisting of an oxygen-regulated alpha-subunit and a constitutively expressed beta-subunit. How animals living on Qinghai-Tibetan plateau adapt to the extreme hypoxia environment is known indistinctly. In this study, the Qinghai yak, which has been living at 3000-5000 m altitude for at least two millions of years, was selected as the model of high hypoxia-tolerant adaptation species. The HIF-1alpha ORFs (open reading frames) encoding for two isoforms of HIF-1alpha have been cloned from the brain of the domestic yak. Its expression of HIF-1alpha was analyzed at both mRNA and protein levels in various tissues. Both its HIF-1alpha mRNA and protein are tissue specific expression. Its HIF-1alpha protein's high expression in the brain, lung, and kidney showed us that HIF-1alpha protein may play an important role in the adaptation to hypoxia environment.

Leptin cDNA cloning and its mRNA expression in plateau pikas (Ochotona curzoniae) from different altitudes on Qinghai-Tibet Plateau.

Leptin, an adipocyte-derived hormone, plays an important role in body energy homeostasis. Plateau pika (Ochotona curzoniae), an endemic and keystone species living only at 3000-5000 m above sea level on Qinghai-Tibet Plateau, is a typically high hypoxia and low temperature tolerant mammal with high resting metabolic rate (RMR), non-shivering thermogenesis (NST), and high ratio of oxygen utilization to cope with harsh plateau environment. To explore the molecular mechanism of ecological acclimation in plateau pika, we first cloned pika leptin cDNA and compared its mRNA expression in different altitudes (3200 and 3900 m) using real-time RT-PCR (Taqman probe) technology. The full-length pika leptin cDNA was 3015 with 504 bp open-reading frame encoding the precursor peptide of 167 amino acids including 21 residues of signal peptide. Pika leptin was 70-72% homologous to that of other species and was of similarly structural characteristics with other species. The pika-specific genetic diversity in leptin sequence occurred at twenty sites. With the increase in altitude, there were larger fat store and high level of ob gene expression in plateau pika. Our results indicated that leptin is sensitive to cold and hypoxia plateau environment and may play one of important roles in pika's ecological adaptation to harsh plateau environment.