148 research outputs found

    Influence of tidal mixing on bottom circulation in the Caroline Sea

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    Bottom circulation in the abyssal Caroline Sea is an important component of the global meridional overturning circulation. By use of a high-resolution regional ocean model, the influence of tidal mixing processes on bottom water and circulation in the Caroline Sea is investigated. Based on different configurations for diapycnal diffusivities of tidal mixing, three numerical experiments are performed: one completely without tidal mixing, one only with local tidal mixing due to the locally dissipated tidal energy, and one considering tidal mixing processes induced by the total dissipated tidal energy. The results show that tidal mixing processes in the abyssal Caroline Sea could sustain a relatively high horizontal density gradient and hence baroclinic pressure gradient not only across the two deep-water passages connecting to the open ocean, but also within the abyssal West Caroline Basin (WCB) and East Caroline Basin (ECB). Therefore, tidal mixing processes could maintain the large amounts of bottom water inflow, intensify the bottom basin/subbasin-scale horizontal circulation, and drive a more vigorous meridional overturning circulation in the abyssal WCB and ECB. Moreover, simulations of bottom water transport in the experiment with tidal mixing processes are more consistent with previous observations and estimates. These results suggest that tidal mixing processes play a crucial dynamic role in the bottom circulation, and is essential for ocean modelling

    Three-dimensional printing-guided percutaneous transcatheter closure of secundum atrial septal defect with rim deficiency: First-in-human series

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    Background: This study aimed to prospectively evaluate the use of 3-dimensional printing (3DP) for the percutaneous transcatheter closure of a secundum atrial septal defect (ASD) with rim deficiency less than 5 mm.Methods: Patients with ASD were scanned using multi-slice computed tomography to acquire raw data for virtual 3DP reconstruction models. Different ASD occluders were tried on the 3DP models to select the optimal size for intraoperative use. The patients were followed up 1 month postoperatively, and 3DP models were again manufactured to observe the operative effects.Results: From January to April 2016, 6 patients (5 females and 1 male) were recruited. Their average age was 29.5 ± 17.6 years, and the mean ASD size was 13.4 ± 1.3 mm. ASD occlusion succeeded in 5 of 6 cases. There were 1, 2, and 3 cases with 0-mm distance from the defect rim to the aorta, inferior vena cava, and superior vena cava, respectively. ASD occluder sizes were consistent between preoperative simulation and intraoperative placement in 4 cases. One case had occluder size change from 30 mm to 34 mm.Conclusions: A 3DP model presents ASD in a more visible way and allows more direct preoperativesimulation to choose the most appropriate size of occluder, as compared with conventional imaging techniques. This technique is likely to extend the current indications for ASD with an insufficient rim

    Contents and benthic fluxes of nutrients in sediment pore water of Southern Ocean

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    The concentration and profile characters of nutrients in sediment pore water of the South Ocean, sampled during the cruise of CHINARE218 of the austral summer 2001 /02 were determined. The results show that the content of SiO3-Si and NH4-N were much higher than other nutrients. The profile of SiO3-Si was characterized with sharp gradients near the sediment-water interface, profile distribution of silicate show that during the diagenetic reaction of silicate, dissolution was the main part. The organic matter decomposition was occurred under the anaerobic condition. Benthic fluxes of SiO3-Si, NH4-N were from pore water to overlying water, and regeneration of silicate and ammonium were the main part of the nutrient regeneration from the pore water of the study area

    Stirring the Deep, Disentangling the Complexity: Report on the Third Species of Thermochiton (Mollusca: Polyplacophora) From Haima Cold Seeps

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    This study documents a new deep-sea chiton from the Haima cold seeps. Thermochiton xui. nov. is the third species of the genus Thermochiton and the first occurrence of this genus in the South China Sea. This species is identified by its morphological characteristics and the molecular sequence of a Thermochiton species is reported for the first time. The placement of the new species is determined in the phylogenetic tree of Ischnochitonidae by Maximum Likelihood (ML) and Bayesian inference (BI) methods, based on the sequences of the mitochondrial cytochrome c oxidase subunit I (COI), 16S ribosomal DNA (16S), and nuclear 28S ribosomal DNA (28S) gene regions. Bayesian evolutionary analysis with an uncorrelated relaxed clock approach indicated that this new species is estimated to have diverged from its most closely related shallow-water ischnochitonid taxa 5.10–10.07 million years ago in the Late Miocene. A regional ocean general circulation model was used to estimate the potential dispersal ability of the three species of Thermochiton. Because it is highly unlikely for one species to have spread between the northwest and southwest Pacific to the localities in which this genus has been found to date, we propose that ‘stepping-stone’ habitats and/or ‘bridge species’ were involved in the dispersal and evolution of these cold-seep endemic chitons.The ZooBank Life Science Identifier (LSID) for this publication is: urn:lsid:zoobank.org:pub:AD93E4BC-2977-405E-B681-D956C5C66D83. And the ISID for Thermochiton xui sp. nov. is: urn:lsid:zoobank.org:act:0C75D2E3-F30E-4970-9BC2-3363B397720C

    Relationship Between Morning Hypertension and T-Peak to T-End Interval in Patients with Suspected Coronary Heart Disease

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    Objective: To investigate the relationship between morning hypertension (MH) and T-peak to T-end interval (Tp-e interval) in patients with suspected coronary heart disease. Methods: Patients with typical symptoms of coronary heart disease were examined by ambulatory blood monitoring, electrocardiogram, echocardiography, and coronary angiography, and were assigned to two groups on the basis of blood pressure: an MH group and a morning normotension (MN) group. The following data were collected and compared: basic characteristic, Tp-e interval, corrected QT (QTc) interval, echocardiography parameters, and Gensini score of the two groups. Results: Three hundred fifty-eight patients, with a mean age of 64 years (54.1% men), were divided into the MH group ( n =170) and the MN group ( n =188). Tp-e interval (84.52±14.77 ms vs. 65.19±19.03 ms, P<0.001), QTc interval (416.21±29.59 ms vs. 401.70±36.10 ms, P<0.001), left ventricular mass index (121.42±10.97 g/m 2 vs. 105.63±17.10 g/m 2, P<0.001), and Gensini score (72.12±32.90 vs. 39.47±29.32, P<0.001) were significantly increased in the MH group compared with the MN group. Morning systolic blood pressure ( r =0.678, P<0.001), morning diastolic blood pressure ( r =0.404, P<0.001), Gensini score ( r =0.513, P<0.001), and left ventricular mass index ( r =0.646, P<0.001) were correlated with Tp-e interval. Conclusion: Tp-e interval is correlated with morning systolic blood pressure and diastolic blood pressure in patients with coronary heart disease. More research on how the Tp-e interval changes after control of MH is necessary

    Periostin: a promising target of therapeutical intervention for prostate cancer

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    <p>Abstract</p> <p>Background</p> <p>In our recent study, Periostin was up-regulated in prostate cancer(PCa) compared with benign prostate hyperplasia (BPH) by proteomics analysis of prostate biopsies. We investigated the effect of sliencing Periostin by RNA interference (RNAi) on the proliferation and migration of PCa LNCap cell line.</p> <p>Methods</p> <p>All the prostate biopsies from PCa, BPH and BPH with local prostatic intraepithelial neoplasm(PIN) were analyzed by iTRAQ(Isobaric tags for relative and absolute quantification) technology. Western blotting and immunohistochemical staining were used to verify Periostin expression in the tissues of PCa. Periostin expression in different PCa cell lines was determined by immunofluorescence staining, western blotting and reverse transcription PCR(RT-PCR). The LNCap cells with Periostin expression were used for transfecting shRNA-Periostin lentiviral particles. The efficancy of transfecting shRNA lentiviral particles was evaluated by immunofluorescence, western blotting and Real-time PCR. The effect of silencing Periostin expression by RNAi on proliferation of LNCap cells was determined by MTT assay and tumor xenografts. The tissue slices from theses xenografts were analyzed by hematoxylin and eosin(HE) staining. The expression of Periostin in the xenografts was deteminned by Immunohistochemical staining and western blotting. The migration of LNCap cells after silencing Periostin gene expression were analyzed in vitro.</p> <p>Results</p> <p>Periostin as the protein of interest was shown 9.12 fold up-regulation in PCa compared with BPH. The overexpression of Periostin in the stroma of PCa was confirmed by western blotting and immunohistochemical staining. Periostin was only expressed in PCa LNCap cell line. Our results indicated that the transfection ratio was more than 90%. As was expected, both the protein level and mRNA level of Periostin in the stably expressing shRNA-Periostin LNCap cells were significantly reduced. The stably expressing shRNA-Periostin LNCap cells growed slowly in vitro and in vivo. The tissues of xenografts as PCa were verificated by HE staining. Additionally, the weak positive Periostin expressed tumor cells could be seen in the tissues of 6 xenografts from the group of down-regulated Periostin LNCap cells which had a significant decrease of the amount of Periostin compared to the other two group. Furthermore, our results demonstrated that sliencing Periostin could inhibit migration of LNCap cells in vitro.</p> <p>Conclusions</p> <p>Our data indicates that Periostin as an up-regulated protein in PCa may be a promising target of therapeutical intervention for PCa in future.</p

    An integrated chromatin accessibility and transcriptome landscape of human pre-implantation embryos

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    Early human embryonic development involves extensive changes in chromatin structure and transcriptional activity. Here the authors present LiCAT-seq, a method enabling simultaneous profiling of chromatin accessibility and gene expression with ultra-low input of cells and map chromatin accessibility and transcriptome landscapes for human pre-implantation embryos
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