727 research outputs found
Electronic Shore Power Station Based on Matrix-style Frequency Algorithm
AbstractThe current port power supply to foreign ships, there are two ways power-type for owned diesel-powered and frequency conversion unit,In this paper,Proposed electronic shore power station, put forward electronic shore power station's concepts, and gives a whole building program of electronic shore power station based on matrix conversion algorithm, It will change 10kV/50Hz (35Kv/50Hz) input voltage into 440V/60Hz low-voltage, not only eliminating intermediate links, but also simplify the hardware circuit and reduce the production cost and improve the competitiveness of enterprises. Simulation and experimental results show that this program has a built shore power station of high power factor, sinusoidal effective, low distortion, environmental pollution and the advantages,It will be very definite practical significance
A general stability criterion for switched linear systems having stable and unstable subsystems
We report conditions on a switching signal that guarantee that solutions of a
switched linear systems converge asymptotically to zero. These conditions are
apply to continuous, discrete-time and hybrid switched linear systems, both
those having stable subsystems and mixtures of stable and unstable subsystems
7-Piperazinethylchrysin inhibits melanoma cell proliferation by targeting Mek 1/2 kinase activity
Purpose: To investigate the growth-inhibitory effect of 7-piperazinethylchrysin (PEC) on melanoma cell lines.Methods: Cell viability was analyzed by trypan blue exclusion assays and the cell cycle by flow cytometry using ModFit LT software. Specifically, cells were stained with propidium iodide (0.5 mg/mL) supplemented with RNase A (50 mg/mL), and analyzed using flow cytometry and ModFit LT software.Results: In A375 and B16F10 cell cultures, proliferation was reduced to 79 and 72 %, respectively, on treatment with 30 μM PEC. PEC increased the proportion of A375 cells in G1/G0 phase to 71.23 %, versus 42.76 % in untreated cells. In B16F10 and A375 cells, treatment with PEC caused the inhibition of Mek 1/2 kinase activity and suppressed Erk 1/2 phosphorylation. The level of cAMP-response element binding protein was increased by PEC. The expression of microphthalmia-linked transcription factor was also increased by PEC treatment. Marked enhancement was observed in the level of tyrosinase in melanoma cells on treatment with PEC. Analysis of PBG-D expression showed a marked increase in B16F10 and A375 cells on the addition of PEC to cell cultures at 72 h. The level of PBG D expression was increased by 9- and 8.5-fold in B16F10 and A375 cells, respectively, on incubation with 30 μM PEC. The addition of a Mek 1/2 inhibitor (U0126) to the cultures promoted PEC-mediated growth inhibition.Conclusion: PEC inhibited melanoma cell proliferation, apparently by blocking the cell cycle at G0/G1 and downregulating the Ras/Raf/Mek/Erk pathway.Keywords: Tyrosinase, Kinase, Microphthalmia, Phosphorylation, 7-Piperazinethylchrysi
Evaluation of three high abundance protein depletion kits for umbilical cord serum proteomics
<p>Abstract</p> <p>Background</p> <p>High abundance protein depletion is a major challenge in the study of serum/plasma proteomics. Prior to this study, most commercially available kits for depletion of highly abundant proteins had only been tested and evaluated in adult serum/plasma, while the depletion efficiency on umbilical cord serum/plasma had not been clarified. Structural differences between some adult and fetal proteins (such as albumin) make it likely that depletion approaches for adult and umbilical cord serum/plasma will be variable. Therefore, the primary purposes of the present study are to investigate the efficiencies of several commonly-used commercial kits during high abundance protein depletion from umbilical cord serum and to determine which kit yields the most effective and reproducible results for further proteomics research on umbilical cord serum.</p> <p>Results</p> <p>The immunoaffinity based kits (PROTIA-Sigma and 5185-Agilent) displayed higher depletion efficiency than the immobilized dye based kit (PROTBA-Sigma) in umbilical cord serum samples. Both the PROTIA-Sigma and 5185-Agilent kit maintained high depletion efficiency when used three consecutive times. Depletion by the PROTIA-Sigma Kit improved 2DE gel quality by reducing smeared bands produced by the presence of high abundance proteins and increasing the intensity of other protein spots. During image analysis using the identical detection parameters, 411 ± 18 spots were detected in crude serum gels, while 757 ± 43 spots were detected in depleted serum gels. Eight spots unique to depleted serum gels were identified by MALDI- TOF/TOF MS, seven of which were low abundance proteins.</p> <p>Conclusions</p> <p>The immunoaffinity based kits exceeded the immobilized dye based kit in high abundance protein depletion of umbilical cord serum samples and dramatically improved 2DE gel quality for detection of trace biomarkers.</p
Assessment of chemotherapy response in non-Hodgkin lymphoma involving the neck utilizing diffusion kurtosis imaging: a preliminary study
PURPOSE:We aimed to examine the utility of non-Gaussian diffusion kurtosis imaging (DKI) for assessment of chemotherapy response in patients with cervical (neck) non-Hodgkin lymphoma (NHL).METHODS:Patients with cervical NHL underwent 3.0 T magnetic resonance imaging with maximal b value of 2000 s/mm2 at baseline and seven days after chemotherapy onset. Apparent diffusion coefficient (ADC) value and diffusion kurtosis imaging maps for diffusion coefficient (D) and kurtosis (K) were calculated. Based on clinical examination, laboratory screening, and PET/CTs, patients were classified as responders or nonresponders.RESULTS:Twenty-six patients were enrolled. Among them, 24 patients were classified as responders and two as nonresponders. For responders, mean follow-up ADC and D increased significantly compared with baseline (ADC: 0.92±0.11 ×10-3 mm2/s vs. 0.68±0.11 ×10-3 mm2/s; D: 1.47±0.32 ×10-3 mm2/s vs. 0.98±0.21 ×10-3 mm2/s, P < 0.001 for both). Mean follow-up K decreased significantly compared with baseline (1.14±0.10 vs. 1.47±0.19, P < 0.001) for responders. Dratio showed significant positive correlation and high agreement with ADCratio (r = 0.776, P < 0.001). Likewise, Kratio showed significant negative correlation and high agreement with ADCratio (r = -0.658, P < 0.001).CONCLUSION:The new DKI model may serve as a new biomarker for the evaluation of early chemotherapy response in NHL
Sea surface cooling in the Northern South China Sea observed using Chinese sea-wing underwater glider measurements
Vascularization of Nanohydroxyapatite/Collagen/Poly(L-lactic acid) Composites by Implanting Intramuscularly In Vivo
It still remains a major challenge to repair large bone defects in the orthopaedic surgery. In previous studies, a nanohydroxyapatite/collagen/poly(L-lactic acid) (nHAC/PLA) composite, similar to natural bone in both composition and structure, has been prepared. It could repair small sized bone defects, but they were restricted to repair a large defect due to the lack of oxygen and nutrition supply for cell survival without vascularization. The aim of the present study was to investigate whether nHAC/PLA composites could be vascularized in vivo. Composites were implanted intramuscularly in the groins of rabbits for 2, 6, or 10 weeks (n=5×3). After removing, the macroscopic results showed that there were lots of rich blood supply tissues embracing the composites, and the volumes of tissue were increasing as time goes on. In microscopic views, blood vessels and vascular sprouts could be observed, and microvessel density (MVD) of the composites trended to increase over time. It suggested that nHAC/PLA composites could be well vascularized by implanting in vivo. In the future, it would be possible to generate vascular pedicle bone substitutes with nHAC/PLA composites for grafting
Anti-Hepatitis B Virus X Protein in Sera Is One of the Markers of Development of Liver Cirrhosis and Liver Cancer Mediated by HBV
Hepatitis B virus X protein (HBx) plays a crucial role in the development of hepatocellular carcinoma (HCC). However, the significance of circulating antibody to hepatitis B virus X antigen (anti-HBx) in sera remains unclear. In the present study, we examined the titers of anti-HBx (IgG) in the sera from 173 patients with chronic hepatitis B (CHB), 106 liver cirrhosis (LC), and 61 HCC by enzyme-linked immunosorbent assay (ELISA), respectively. Our data showed that the positive rates of anti-HBx were higher in sera of LC (40.6%) and HCC (34.4%) than those of CHB (10.4%), P < .05. In all 40 patients with anti-HBx+ out of 340 patients, 39 (97.5%) were HBsAg/HBeAg/anti-HBc+ and 1 (2.5%) was anti-HBs+ (P < .01), suggesting that anti-HBx in sera is a marker of HBV replication rather than a protective antibody. Thus, our findings reveal that circulating anti-HBx in sera is one of the markers of development of LC and HCC mediated by HBV
Axial Vascularization of Nano-HA/Collagen/PLA Composites by Arteriovenous Bundle
In previous studies, nano-hydroxyapatite/collagen/poly(L-lactic acid) (nHAC/PLA) composites have been prepared and confirmed to repair small sized bone defects. However, they are restricted to repair a large defect without sufficient oxygen and nutrition for cell survival. The result of this study confirmed that nHAC/PLA composites could be axially vascularized by being implanted intramuscularly with arteriovenous (AV) bundle (Group A) in the groins of rabbits. The combination with autologous bone marrow (Group B) could not enhance it the vascularization in early phase (2 weeks, P>0.05), but it could enhance in middle and later phases (6 and 10 weeks, P<0.01). It meant that nHAC/PLA could be prefabricated as a vascularized bone substitute for grafting
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