Journal articles on the topic 'Flow lip'
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Srinivasarao, T., P. Lovaraju, and E. Rathakrishnan. "Characteristics of Underexpanded Co-Flow Jets." Applied Mechanics and Materials 575 (June 2014): 507–11. http://dx.doi.org/10.4028/www.scientific.net/amm.575.507.
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The effect of inner nozzle lip thickness on the co-flow jet characteristics has been studied experimentally. Co-flow nozzles with inner nozzle lip thicknesses of 3 mm and 15 mm have been investigated. The thick-lip nozzle promotes mixing better than the thin-lip nozzle, for all the underexpanded operating conditions. The co-flow nozzle with thin-lip is effective in preserving the shock-cells nature, bringing down the longer shock-cell into shorter one and increasing the number of shock-cells compared to that of the co-flow nozzle with thick-lip.
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Kondo, Yuko, Takumi Takahashi, Yasuo Oba, Shingo Kuroda, Eiji Tanaka, and Keiji Moriyama. "Blood Flow Distribution of Repaired Lip in Cleft Lip Patients." Angle Orthodontist 79, no. 6 (November 1, 2009): 1182–87. http://dx.doi.org/10.2319/102908-549r.1.
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Abstract Objective: To investigate the blood flow distribution in the repaired lip of cleft patients using a laser Doppler imager and to evaluate the difference in blood flow of the scar tissue between unilateral cleft lip patients with and without cleft palate. Materials and Methods: Twenty patients with either unilateral cleft lip only (CL group, n = 8) or cleft lip and palate (CLP group, n = 12) were used as subjects. The blood flow of the upper lip was two-dimensionally visualized by a color scale alongside the corresponding photo image of the tissue surface with laser Doppler imaging. The upper lip photo image was divided into five regions: scar, white lip on the cleft side, white lip on the noncleft side, red lip on the cleft side, and red lip on the noncleft side. The average flux score (AFS), which is proportional to blood flow, was analyzed in each region. Results: The AFS for the scar region was significantly (P < .05) lower than in the other four regions. The AFS for the red lip on the cleft side was not significantly different from that for the noncleft side. The white lip revealed a significantly (P < .05) higher score on the cleft side than on the noncleft side. The AFS ratio (AFS in the scar region/AFS in the white lip region) was significantly (P < .01) lower in the CLP group than in the CL group. Conclusions: These results suggest that blood flow distribution in the repaired lip might be affected by the anatomic features of the cleft.
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Zhao, Shen, Xue Yi You, Sheng Jun Liu, Yu Huang, Feng Shi, and Hong Bo Lu. "On the Rigid-Lid Hypothesis Application to the Flow Simulation of Step-Feed A/O Process." Advanced Materials Research 886 (January 2014): 319–22. http://dx.doi.org/10.4028/www.scientific.net/amr.886.319.
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The feasibility of the rigid-lip hypothesis was studied in the flow field simulation of the reaction tank in the step-feed A/O process. Two models were built. One model applied the rigid-lip hypothesis was called as rigid-lid model and the other was called free surface model. The results showed that the velocity distribution of the rigid-lid model is basically consistent with that of the free-surface model. On the vertical monitor sections, the error of the mean velocity between the two models is less than 8%. The results showed that the much less expensive rigid-lid model is applicable to simulate the flow field of reaction tank.
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Hariyono, Rudi, Soedarsono Soedarsono, and Makhfudli Makhfudli. "EFFECT OF COMBINATION PURSED LIP BREATHING AND GUIDED IMAGERY MUSIC ON PEAK EXPIRATORY FLOW PATIENTS WITH CHRONIC OBSTRUCTIVE PULMONARY DISEASE." Jurnal Keperawatan 10, no. 1 (March 24, 2019): 89. http://dx.doi.org/10.22219/jk.v10i1.6353.
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ABSTRACTBackground: Peak expiratory flow influenced by several things, such as anxiety, a psychological factor that is becoming a major comorbidities of COPD and affect the occurrence of exacerbations, increase respiration rate, duration expiratory time, and hyperinflation. This study aimed to determine the effect of combination pursed lip breathing and guided imagery music to increase value of peak expiratory flow in patients with COPD. Methods: The study was quasi-experimental design with pretest posttest with control group approach, respondents of this study is 46 patients with COPD with sampling technique, simple random sampling. Results: Pursed lip breathing increase peak expiratory flow values by the significant of p value = 0.000 (p <0.05). The combination of pursed lip breathing and guided imagery music increase peak expiratory flow values by the significant of p value = 0.000 (p <0.05). COPD patients who received a combination of pursed lip breathing and guided imagery music increased peak expiratory flow value higher than the pursed lip breathing without combination with significant of p value = 0.000 (p <0.05).Conclusion:The combination of pursed lip breathing and guided imagery music proved to have an effect on increasing the value of peak expiratory flow higher than pursed lip breathing without combination.
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Huang, An, and Xueyi Zhang. "Dual-flow Spatio-temporal Separation Network for Lip Reading." Journal of Physics: Conference Series 2400, no. 1 (December 1, 2022): 012028. http://dx.doi.org/10.1088/1742-6596/2400/1/012028.
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Abstract Lip reading is a task of predicting the corresponding language information in a silent video, which has attracted a lot of attention in recent years. Its key is to capture temporal and spatial features from lip motion videos and decode them. In the past, lip reading methods based on deep learning mostly adopt the form of spatio-temporal series connection, which first extracts spatial features, and then carries out global time-domain modeling on this basis. The spatial information extracted by the current approach is insufficient. To get more abundant spatio-temporal video representation and fully integrate the features from different viewpoints, this paper proposes a novel lip motion feature extraction framework, Dual-flow Spatio-temporal Separation Network (DSSN). Specifically, we adopt an end-to-end double tower structure to model the temporal information and spatial information respectively, and carry out feature fusion through collaborative learning. Finally, we evaluate our proposed model on the OuluVS2 lip reading dataset. Experiments show that our method outperforms baseline models.
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Brandner, P. A., and G. J. Walker. "An Experimental Investigation Into the Performance of a Flush Water-Jet Inlet." Journal of Ship Research 51, no. 01 (March 1, 2007): 1–21. http://dx.doi.org/10.5957/jsr.2007.51.1.1.
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An experimental investigation of the flow within a generic flush type water-jet inlet has been carried out to identify the principal flow features and provide a basis for development of computational fluid dynamics (CFD) models. Tests were performed in a cavitation tunnel with the model inlet fitted to the test section ceiling, and effects of thickening the ingested tunnel wall boundary layer were investigated. The model was fitted with a range of instrumentation to investigate the ramp pressure distribution and boundary layer development, lip incidence, and pump face flow properties. Observations of lip and duct cavitation inception and behavior were also made. The results showed the inlet performance to be generally improved with the ingestion of a thicker boundary layer. The thickened boundary layer significantly reduced ramp boundary layer separation and distortion of flow at the notional pump face. However, a greater range of lip incidence occurred with the thickened boundary layer with consequent greater likelihood of lip separation and cavitation occurrence. Ideal lip incidence and pump face flow uniformity occurred at flow parameters significantly different from those for ideal pump face pressure recovery. Large developed cavities on the inlet lip were observed for a range of conditions typical of conventional high-speed vessel operation.
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Teng, Jian, and Hua Cheng Yuan. "Design Methodology and Unsteady Aerodynamic Characteristics of a Rectangular Variable Geometry Hypersonic Inlet." Applied Mechanics and Materials 275-277 (January 2013): 433–41. http://dx.doi.org/10.4028/www.scientific.net/amm.275-277.433.
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Design methodology of a rectangular variable geometry hypersonic inlet whose cowl lip is translatable along flow direction is clarified in current study and recommendation of key design parameters are given. Unsteady Reynolds-averaged Navier-Stokes (uRANS) calculation were carried out to investigate the feasibility and unsteady aerodynamic characteristics of this inlet. Results indicate that by stretching the movable lip of a model inlet upstream, mass flow rate will increases apparently due to the increases of inlet internal duct entrance area. Stretching the movable lip upstream will decrease CR of the model inlet which is favorable for the start or restart of the inlet from an unstarted status. The lip translating process is smooth and will not induce large amplitude flow disturbance within inlet duct. The movable lip is conducive to improve the aeropropulsive performance of the hypersonic inlet in wide flight range
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Marangom, Cristiane, Viviani Souza Peruchi, Marta Assumpção de Andrada e. Silva, Irene Queiroz Marchesan, and Léslie Piccolotto Ferreira. "Association between voice disorder and breathing alteration in children." Revista CEFAC 20, no. 2 (April 2018): 191–200. http://dx.doi.org/10.1590/1982-0216201820217416.
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ABSTRACT Objective: to analyze the association between voice disorder and aspects related to breathing mode in children, according to sex. Methods: 250 children, aged six to nine years, attending a public school in São Paulo city, were selected. The collection consisted of spontaneously audio recorded speech samples. The breathing mode was evaluated for lip resting posture and nasal flow. Three audiologists performed the perceptual evaluation of the voice quality, with the help of GIRBAS scale. The results were associated using the chi-square test (p = 0.05). Results: 50.4% females and 49.6% males. As for the overall grade (G), 12.8% had voice disorder with respect to voice quality. In the breathing mode, 36.8% presented alterations in lip posture and 71.2%, in nasal flow. The associations between voice disorder and gender (p = 0.96), lip posture (p = 0.38) and nasal flow (p = 0.18) and between alterations in the nasal flow and sex (p = 0.449) were not confirmed. The association between lip posture and sex revealed significant differences in favor of males (p = 0.003). Conclusion: there was no statistically significant difference associating voice disorders with breathing mode (lip posture and nasal flow) and gender.
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Salant, Richard F., and Ann H. Rocke. "Hydrodynamic Analysis of the Flow in a Rotary Lip Seal Using Flow Factors." Journal of Tribology 126, no. 1 (January 1, 2004): 156–61. http://dx.doi.org/10.1115/1.1609486.
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The flow field in the lubricating film of a rotary lip seal is analyzed numerically by solving the Reynolds equation with flow factors. The behavior of such a flow field is dominated by the asperities on the lip surface. Since previous analyses treated those asperities deterministically, they required very large computation times. The present approach is much less computationally intensive because the asperities are treated statistically. Since cavitation and asperity orientation play important roles, these are taken into account in the computation of the flow factors. Results of the analysis show how the operating parameters of the seal and the characteristics of the asperities affect such seal characteristics as the pressure distribution in the film, the pumping rate and the load support.
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He, Jinzheng, Zhou Zhao, Yi Ren, Jinglin Liu, Baoxing Huai, and Nicholas Yuan. "Flow-Based Unconstrained Lip to Speech Generation." Proceedings of the AAAI Conference on Artificial Intelligence 36, no. 1 (June 28, 2022): 843–51. http://dx.doi.org/10.1609/aaai.v36i1.19966.
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Unconstrained lip-to-speech aims to generate corresponding speeches based on silent facial videos with no restriction to head pose or vocabulary. It is desirable to generate intelligible and natural speech with a fast speed in unconstrained settings. Currently, to handle the more complicated scenarios, most existing methods adopt the autoregressive architecture, which is optimized with the MSE loss. Although these methods have achieved promising performance, they are prone to bring issues including high inference latency and mel-spectrogram over-smoothness. To tackle these problems, we propose a novel flow-based non-autoregressive lip-to-speech model (GlowLTS) to break autoregressive constraints and achieve faster inference. Concretely, we adopt a flow-based decoder which is optimized by maximizing the likelihood of the training data and is capable of more natural and fast speech generation. Moreover, we devise a condition module to improve the intelligibility of generated speech. We demonstrate the superiority of our proposed method through objective and subjective evaluation on Lip2Wav-Chemistry-Lectures and Lip2Wav-Chess-Analysis datasets. Our demo video can be found at https://glowlts.github.io/.
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Montazerin, N., A. Damangir, and S. Mirian. "A new concept for squirrel-cage fan inlet." Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy 212, no. 5 (August 1, 1998): 343–49. http://dx.doi.org/10.1243/0957650981536916.
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The squirrel-cage fan with a newly introduced outward inlet lip is studied experimentally. Previous research has demonstrated the importance of inlet flow control on the general flow field and vortex generation of such fans. The bell-mouth inlet, which is the common industrial and academic practice, has drawbacks that result in flow separation and turbulence enhancement. The adapted experimental approach is a conceptual study. It is a combination of standard characteristic measurements and detailed laser Doppler anemometry. The measured flow pattern inside the volute demonstrates that the separated flow behind the inlet lip, which for an ordinary inward lip occupies a large part of the rotor blades, disappears. This is promising since removing this separated flow diminishes a major loss-making region in this fan and adds to the effective flow area. It also reduces noise and gives uniform blade loading. The results also show an improvement in performance in comparison with that of a fan with an ordinary inward inlet lip. This modification is industrially feasible with no extra manufacturing cost and therefore can represent a substantial advance over the current practice.
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Fibach, Eitan, and Eugenia Prus. "The Labile Iron Pool in Normal and Pathological Erythroid Cells - Analysis by Flow Cytometry." Blood 106, no. 11 (November 16, 2005): 3597. http://dx.doi.org/10.1182/blood.v106.11.3597.3597.
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Abstract The cellular "labile iron pool" (LIP) is made up of iron ions bound to low affinity ligands varying in composition and quantity under different physiological settings. It is localized primarily, but not exclusively, in the cytosol and, as such, is regarded as the crossroad of cellular iron traffic. The level of the pool is regulated and maintained within a restricted range that meets the cell requirements for iron but prevents excess from developing and triggering cellular damage. The LIP can be quantified due to its ability to bind to cell-permeable chelators, such as calcein-AM. Upon entering viable cells, calcein undergoes hydrolysis by esterases and becomes fluorescent. Its fluorescence is quenched upon binding to cellular LIP, the extent of which is correlated with the amount of LIP. The addition of a non-fluorescent, high affinity chelator, such as salicylaldehyde isonicotinoyl hydrazone (SIH), which removes the iron from the iron-calcein complex, increases the fluorescence emitted by the cells. The difference in the cellular fluorescence before and after incubation with the high affinity chelator reflects the amount of LIP. We adapted this procedure to multi-parameter flow cytometry for measuring LIP in erythroid cells derived from the peripheral blood, bone marrow and primary cultures. The validity of the technique was determined using K562 cells - a human erythroid cell line. Cellular fluorescence increased following incubation with calcein in a concentration- and time-dependent manner. It was further augmented by cell- permeable, high affinity iron chelators such as SIH and Deferiprone (L1), but not by desferrioxamine - an impermeable chelator. Using this method, we showed that pre-incubation of the cells with iron sources such as ferrous ammonium sulfate increased their LIP level. We then studied the LIP content in peripheral blood erythroid cells. Cells were simultaneously stained with calcein and thiazol-orange, a nucleic acid specific dye, which stains reticulocytes according to their RNA content, i.e., degree of maturation. The results indicate that the LIP content decreased (69-fold) with maturation, reaching its lowest level in mature RBC. A comparison of RBC from normal donors (N=5) and patients with β-thalassemia (N=5) indicated higher a (2.4-fold) LIP in the latter. For analysis of bone marrow samples, cells were stained with calcein and fluorochrome-conjugated antibodies to surface antigens (CD45, CD71 and glycophorin A). The results indicated that the LIP content was the highest in basophilic erythroblasts and was reversely correlated with erythroid cell maturation. Finally, we studied erythroid cells in two-phase cultures of peripheral blood-derived erythroid progenitors. Following one week in the absence of erythropoietin, the cells were re-cultured in erythropoietin-supplemented medium. Analysis of the cells on different days of the second phase showed that the LIP content decreased as the cells matured and accumulated hemoglobin. The LIP content could be modulated by changing the culture conditions: increasing by supplementing normal cultures with extra iron (in the form of hollo-transferrin) and decreasing in thalassemic cultures grown in the presence of L1 or SIH. The present findings indicate that the LIP content of erythroid cells is altered under different physiological (e.g., maturation) and pathological (e.g., iron overload, e.g., in thalassemia) conditions. The results also show that flow cytometry, a standard methodology in most hematological labs, could be useful for evaluating the LIP in various diseases and for studying the efficacy of various chelators.
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Selby, G. V. "Passive Control of Three-Dimensional Separated Vortical Flow Associated With Swept Rearward-Facing Steps." Journal of Fluids Engineering 111, no. 1 (March 1, 1989): 99–101. http://dx.doi.org/10.1115/1.3243608.
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Control of the three-dimensional separated-flow region down-stream of a swept, rearward-facing step has been studied with the purpose of reducing the separated-flow region and attendant drag. Results have indicated that geometric modifications in the region downstream of the step where the spanwise vortex is formed has little effect on the extent of the separated flow, while “conical-lip” and “vortex-trough” base modifications lead to a significant reduction in reattachment distances. The “conical-lip” modification involves a step lip with variable radius and the “vortex troughs” are grooves in the surface upstream of the step which produce longitudinal vortices.
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Ma, Shang, Yang Tao, Junqiang Wu, Neng Xiong, and Xingya Da. "Study on aerodynamic characteristics of flying wing knapsack inlet duct." Journal of Physics: Conference Series 2313, no. 1 (July 1, 2022): 012003. http://dx.doi.org/10.1088/1742-6596/2313/1/012003.
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Abstract Based on the extended shape of the existing flying wing standard model with small aspect ratio, this paper studies the flow field characteristics around the model at different angles of attack and the flow field characteristics of the knapsack dual release inlet when the Mach number is equal to 1.8. The pressure coefficient distribution, velocity distribution and eddy characteristics of typical states are illustrated. The results show that the lip of the knapsack inlet has a significant effect on the flow characteristics of the back and abdomen of the model. After passing through the inlet lip and the S-shaped bend in the front section, the internal pressure distribution of the inlet is relatively uniform, there are obvious vortices in the inlet, the core flow near the tail nozzle flows smoothly, and the strong vortices are only near the wall.
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Salant, R. F. "Numerical Analysis of the Flow Field Within Lip Seals Containing Microundulations." Journal of Tribology 114, no. 3 (July 1, 1992): 485–91. http://dx.doi.org/10.1115/1.2920909.
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The flow field within the lubricating film of a rotating shaft lip seal containing microundulations is analyzed numerically. The results demonstrate that the action of the microundulations can prevent leakage through the seal. The effects on leakage rate of shaft speed, undulation amplitude and wavelength, shear deformation of the undulations, flattening of the undulations, and axial lip profile are presented.
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Hoekje, P. L. "Phase relations in the lip reed flow controller." Journal of the Acoustical Society of America 101, no. 5 (May 1997): 3056. http://dx.doi.org/10.1121/1.418709.
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Meyron-Holtz, Esther. "Flow cytometry sets eyes on the iron LIP." Cytometry Part A 73A, no. 6 (2008): 494–95. http://dx.doi.org/10.1002/cyto.a.20538.
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Silnikov, M. V., and M. V. Chernyshov. "Supersonic flow gradients at an overexpanded nozzle lip." Shock Waves 28, no. 4 (November 13, 2017): 765–84. http://dx.doi.org/10.1007/s00193-017-0772-2.
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Sato, Atsushi, Hideyo Hirai, Asumi Yokota, Akihiro Tamura, Tsukimi Shoji, Takahiro Kashiwagi, Masaki Iwasa, Aya Fujishiro, Yasuo Miura, and Taira Maekawa. "C/EBPβ Isoforms Distinctively and Collaboratively Regulate the Behavior of Hematopoietic Stem and Progenitor Cells in Regenerative Conditions." Blood 126, no. 23 (December 3, 2015): 3580. http://dx.doi.org/10.1182/blood.v126.23.3580.3580.
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Abstract CCAAT Enhancer Binding Protein b (C/EBPb) is a leucine zipper type transcription factor. While C/EBPa plays a critical role in maintaining steady-state granulopoiesis, C/EBPb is required for stress-induced granulopoiesis (Hirai et al., 2006). We have been focusing on the functions of C/EBPb in the regulation of hematopoietic stem and progenitor cells (HSPCs) especially under stressed conditions. Last year in this meeting, we have shown that 1) C/EBPb was upregulated at protein level in HSPCs after hematopoietic stresses, 2) C/EBPb was required for initial expansion of HSPCs after transplantation, and 3) C/EBPb promoted exhaustion of HSPCs under repetitive hematopoietic stresses (56th ASH, abstract #67850). Here, we further investigated the significance of C/EBPb in cell cycle regulation of HSPCs and the distinct roles of C/EBPb isoforms in HSPCs during regenerative conditions. To clarify the involvement of C/EBPb in cell cycle regulation of HSPCs, we compared the cell cycle status of wild-type (WT) and Cebpb knockout (KO) HSPCs by intracellular Ki67 staining and short-term BrdU incorporation assay in combination with multi-color flow cytometric analysis. In order to exclude the difference in the bone marrow microenvironment, CD45.2+ WT or Cebpb KO bone marrow (BM) cells were transplanted into lethally irradiated CD45.1+ WT mice. At steady state (12 weeks after the BM transplantation), the cell cycle status of Cebpb KO HSPCs was identical to that of WT HSPCs. Then cell cycle status of HSPCs was assessed at various time points during regeneration after intraperitoneal administration of 5-fluorouracil (5-FU, 150mg/kg). We found that significantly more Cebpb KO HSPCs remained in the G0 phase than WT HSPCs (in LT-HSCs on days 3-10; in MPPs on days 6-12). Significantly less Cebpb KO HSPCs were BrdU+ and were in the S/G2/M phase on day 7. These findings suggest that C/EBPb, in a cell-intrinsic manner, facilitates cell cycle entry, progression and consequent earlier expansion of HSPCs in response to hematopoietic stresses. Next, we investigated the distinct roles of C/EBPb isoforms in regulation of HSPCs. C/EBPb is a unique single exon gene and utilization of three different initiating codons result in three distinct isoforms. Liver-enriched activating protein* (LAP*) and LAP are the longer isoforms containing transactivating domains, DNA binding and dimerization domains, and liver-enriched inhibitory protein (LIP) is the shortest isoform which lacks the transactivating domains. In order to examine the expression pattern of C/EBPb isoforms in vivo in scarce populations of regenerating HSPCs, we developed a novel flow cytometric method to distinguish the cells predominantly expressing shorter isoform (LIP) from the cells expressing both LIP and the longer isoforms (LAP* and LAP) by intracellular double staining. Using this method, we found that predominantly LIP-expressing cells transiently emerged within MPP fraction in the regenerating bone marrow (on days 5-6 after administration of 5-FU, Figure below), while overall C/EBPb expression levels were significantly upregulated in most cells. To examine the roles of respective C/EBPb isoforms in regulation of HSPCs, EML cells, a murine hematopoietic stem cell line, were retrovirally transduced with one of the C/EBPb isoforms and the transduced cells were subjected to further analysis (vectors are kind gifts from Dr Watanabe-Okouchi N and Dr Kurokawa M, Tokyo Univ). LIP-expressing EML cells were more proliferative and actively cycling than EML cells transduced with a control vector, whereas the proliferation of LAP*- or LAP-expressing cells were markedly suppressed. LIP-expressing cells remained undifferentiated status (c-kithigh CD11b-) for more than 2 weeks, while LAP*- or LAP-expressing cells rapidly differentiated into c-kitlow CD11b+ myeloid cells and eventually exhausted within a week. These results indicate LIP plays quite distinct roles from LAP* and LAP in regulation of HSPCs. Collectively, our data suggest that C/EBPb isoforms distinctively and collaboratively regulate HSPCs in regenerative conditions: early transient elevation of LIP contributes to cell cycle activation and rapid expansion of HSPC population, which is in turn converted into supply of mature myeloid cells by more abundant upregulation of LAP* and LAP. Figure 1. Figure 1. Disclosures No relevant conflicts of interest to declare.
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He, Z. W., and S. Y. Zhang. "Lip Separate Flow Blowing and Analysis of Coherence of Inlet." Journal of Engineering for Gas Turbines and Power 108, no. 3 (July 1, 1986): 562–65. http://dx.doi.org/10.1115/1.3239947.
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It is found experimentally that blowing at the lip separation of an inlet obviously reduces the turbulence at the inlet exit, and apparently reduces the intensity of pressure fluctuations caused by the shock-boundary layer interaction downstream of the throat. The coherence between pressure in the interaction region and total pressure at the exit is also reduced. The coherence between the pressure in the lip separation region and total pressure at the exit is 0.32. If, in addition, there is a stronger shock downstream of the throat, the abovementioned coherence is reduced to 0.06.
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Jin, W., R. R. Taghav, and S. Farokhi. "Flow distortion in an S-duct inlet with simulated icing effect and heat transfer." Aeronautical Journal 116, no. 1177 (March 2012): 251–70. http://dx.doi.org/10.1017/s0001924000006825.
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Abstract A diffusing S-duct aircraft intake system is computationally studied for the effects of inlet icing and wall heat transfer on engine face distortion. A Reynolds-Averaged Navier-Stokes (RANS) code with k -ω SST turbulence model is used to simulate the compressible viscous flow in the duct. The glaze ice accretion on the inlet lip is simulated as a fixed protrusion from NASA LEWICE3D code. The shape and size of the ice on the inlet lip are assumed to remain constant even in the case of the heated wall. The case of zero external heat transfer is modeled by the adiabatic wall boundary condition, and constant-wall temperature is used to simulate the heated wall effect. The freestream Mach number of 0·85 and glaze ice condition on the inlet lip produce massive flow separation at the lip and internal shock cell structure in the S-duct. The heated wall creates additional vorticity and thus increases the engine face distortion level. The area-averaged total pressure distortion at the engine face in a freestream Mach number of 0·85 is increased by ~7% in the heated wall case as compared to the adiabatic flow.
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Erçöçen, A. R., S. Yilmaz, and M. Saydam. "Bilateral Superiorly Based Full-Thickness Nasolabial Island Flaps for Closure of Residual Anterior Palatal Fistulas in an Unoperated Elderly Patient." Cleft Palate-Craniofacial Journal 40, no. 1 (January 2003): 91–99. http://dx.doi.org/10.1597/1545-1569_2003_040_0091_bsbftn_2.0.co_2.
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Objective Unoperated bilateral complete cleft lip and palate in an adult or elderly patient is seen rarely, and the existence of unoperated clefts is a result of unfavorable economic and social circumstances. We report an unoperated 65-year-old patient with bilateral complete cleft lip and palate and present our preference for the surgical management. Interventions Repair of the bilateral complete cleft lip and palate was successfully carried out using straight-line closure for the bilateral cleft lip and two-flap pushback palatoplasty with superiorly based lateral port control pharyngeal flap for the wide cleft palate at the first stage, and large residual anterior palatal fistulas were closed using bilateral superiorly based (retrograde flow) full-thickness nasolabial island flaps at the second stage. Conclusions To our knowledge based on a review of the literature, this is the first report of an elderly patient with bilateral complete cleft lip and palate and the first application of bilateral superiorly based (retrograde flow) full-thickness nasolabial island flaps for closure of large residual anterior palatal fistulas or alveolar clefts. The bilateral superiorly based (retrograde flow) full-thickness nasolabial island flap may be a good solution in large anterior palatal defects using unilaterally or bilaterally in a single stage with minimal donor site morbidity, in which there is not enough tissue for local repair or if previous attempts are unsuccessful.
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Bahi, Y., M. El Gadari, and M. Rahmoune. "The Grooved Lip Effect on Reciprocating Hydraulic Rod Seal Performances in Transient Condition: Elastohydrodynamic Lubrication." International Journal of Applied Mechanics and Engineering 25, no. 2 (June 1, 2020): 11–21. http://dx.doi.org/10.2478/ijame-2020-0017.
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AbstractIt is commonly known that the sealing performance of dynamic seals is significantly influenced by the surface finish. To reduce friction effect and leakage ratio, new generations of grooved lip or shaft have emerged, but only two computational models were performed up to now with a textured elastomeric lip: spiral groove in the axial direction or micro-cavities according to the circumferential direction. However, if the numerical results have confirmed the slight effect of the grooved lip on the rotary lip seal performances, it seems relevant to investigate the influence of such grooves on the reciprocating hydraulic rod seal behavior.Thus, the scope of this work is to perform a parametric study of the grooved lip throughout a one-dimensional elastohydrodynamic model by taking into account the elasticity of the lip and the shaft roughness.After confirming the validity of the current model, numerical simulations have been performed and compared with experiments. The effect of lip grooves on the hydraulic rod seal behavior in outstroke and instroke shaft motion has been underlined. Thereby, it is shown that the leakage and the average film thickness are sensible to both the depth and the density of the lip groove. Additionally, a slight effect of the pattern shape is observed on the friction force.
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Brandner, P. A., E. C. Dawson, and G. J. Walker. "An Experimental Investigation into the Influence of Ramp-Mounted Vortex Generators on the Performance of a Flush Waterjet Inlet." Journal of Ship Research 54, no. 03 (September 1, 2010): 209–23. http://dx.doi.org/10.5957/jsr.2010.54.3.209.
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The use of ramp-mounted vortex generators for reduction of pump face flow distortion within a generic flush type waterjet inlet has been investigated experimentally. Tests were performed in a cavitation tunnel with the model inlet fitted to the ceiling of the test section and an upstream boundary layer artificially thickened to 30° of the inlet duct diameter. A group of four delta-shaped vortex generators on the inlet ramp mounted symmetrically about the vertical center plane were tested at six streamwise locations and at two incidences. The vortex generators were oriented each side of the centerplane to produce corotating vortex pairs opposing the effects of the dominant secondary flow within the curved duct. The model inlet was fitted with a range of instrumentation to investigate the ramp pressure distribution, lip incidence, and pump face flow properties. Lip cavitation inception, and vortex generator cavitation inception and occurrence were also investigated. Pump face flow distortion within the bare duct flow, which was dominated by a total pressure/velocity deficit at the top of the disc, was significantly reduced by the addition of the vortex generators. Circumferential distortion improvements were assessed using a distortion parameter, harmonics of the velocity variation, and considerations of rotor blade incidence variation. The vortex generators were found to have little effect on local lip pressures and consequently lip cavitation inception; they also had a negligible effect on the duct pressure recovery. Cavitation occurrence on the vortex generators was found to present potential performance limitations at low cavitation numbers.
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Chumaevsky, Andrey V., Dmitry V. Lychagin, Sergei Yu Tarasov, and Alexandr Melnikov. "Fragmentation, Texturing and Plastic Flow in the Subsurface of Friction-Processed Copper Single Crystal." Advanced Materials Research 872 (December 2013): 30–35. http://dx.doi.org/10.4028/www.scientific.net/amr.872.30.
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Copper single crystals grown according to the Bridgman method and having their axes [] or [11 aligned with the normal load axis were processed by dry sliding. As shown, sliding-induced severe plastic deformation occurred in the subsurface of single crystals and caused formation of a lip by mechanism of texture formation. The SEM structure of this lip was found to be composed of fragments with their shapes dependent on the single crystal orientation with respect to normal load and friction force.
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Witono, Kris, and Akhsanu Takwim. "Pengaruh Variasi Lip Thickness Pada Nozzle Terpancung Dengan Swirl Terhadap Kestabilan Api Difusi Concentric Jet Flow." Jurnal Energi dan Teknologi Manufaktur (JETM) 1, no. 01 (June 29, 2018): 11–15. http://dx.doi.org/10.33795/jetm.v1i01.10.
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One of the factors that affect flame diffusion characteristics is the geometry of fuel nozzles in the installation of the combustion system. The nozzle shape greatly affects the turbulence that occurs between fuel and air. This process causes the formation of flow recirculation zones. This process thus produces homogeneous mixing and obtains near perfect combustion. The recirculation zones are zones arising from breaking the flow rate. So as to cause a vortex and backflow around the tip of the nozzle. It is this feedback which inhibits and simultaneously suppresses the flame so that the flow rate of the fuel mixture and the air is maintained lower or equal to the flame velocity. In this study, lip thickness variations in nozzles were used with swirls with variations of 0, 4, 8, 12, and 16 mm to determine flame stability of concentric jet flow diffusion. Fuel velocity and air are varied to obtain flame stability data. In addition, to support and reinforce the results obtained from this study, direct photograph and shadowgraph methods are used to obtain flow pattern visualization. The result of the research shows that the stability of flame concentric jet flow diffusion has increased along with the decreasing of lip thickness in nozzle. The largest flame stability area is obtained in 4 mm thick lip thickness.
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Durst, F., W. F. Schierholz, and A. M. Wunderlich. "Experimental and Numerical Investigations of Plane Duct Flows With Sudden Contraction." Journal of Fluids Engineering 109, no. 4 (December 1, 1987): 376–83. http://dx.doi.org/10.1115/1.3242676.
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The present paper reports on experimental and numerical studies of laminar, two-dimensional flow through plane ducts with sudden contractions in cross-sectional area. A laser-Doppler anemometer and a flow computational program were complementarity employed to study details of the flow close to the step. The results reveal details of the velocity profile variations in the vicinity of the contraction. Information is also provided on the separated flow region in the front concave corner of the duct and on the separated flow region just downstream of the lip of the step. The dimensions of the front separation region are shown to agree well with existing data. The recirculating flow region just downstream of the lip is much smaller than occasionally assumed. At higher contraction ratios off-axis velocity maxima occur just downstream of the contraction. It is shown that strong elongational flow fields occur. These are concentrated to a very small region close to the step.
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Wierach, Peter, Jan Petersen, and Michael Sinapius. "Design and Experimental Characterization of an Actuation System for Flow Control of an Internally Blown Coanda Flap." Aerospace 7, no. 3 (March 17, 2020): 29. http://dx.doi.org/10.3390/aerospace7030029.
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The focus of the work is on the evaluation, development and integration of a robust actuator system for three-dimensional flow control of a blown Coanda flap to improve the high lift system of commercial aircraft. As part of the research work presented, the system is integrated into a wind tunnel model in order to influence the flow across the entire width of the model. The system developed is based on individual bending transducers that can vary the height of the blowing slot dynamically. The system is divided into 33 segments and is therefore able to implement static and dynamic actuation along the wing-span (3D-actuation). All segments can be controlled independently and thus offer great optimization potential for an effective flow control. Different configurations were developed and evaluated against each other with respect to the demanding requirements (small installation space, frequency range from 5 Hz to 300 Hz, 1 bar pressure, 0.4 mm deflection, 1 m span). The design of the blown flap has been specified in an iterative design process. In the final configuration, all mechanical components are reduced to the bare minimum for weight reduction reasons, in order to meet the dynamic requirements of the wind tunnel model. To characterize the lip segments, a test device has been designed that can be pressurized to generate aerodynamic loads on the lip segments. Finally, 33 lip segments were integrated into a wind tunnel model and tested intensively as part of a measurement campaign. The first aerodynamic results show an increase in lift of up to ∆Ca = 0.57. These aerodynamic gains are achieved at amplitudes that do not require the lip segments to completely close or open the blowing slot, which shows the advantage of the current lip design that enables activation with independently controlled stationary and unsteady components.
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Wang, Yuanyuan, Yining Yang, Yibin Yu, Jinyu Li, Weisan Pan, Xinggang Yang, Zhiran Zhang, Shuang Jiang, Xiaobo Yang, and Xiaobo Wang. "Transferrin Modified Dioscin Loaded PEGylated Liposomes: Characterization and In Vitro Antitumor Effect." Journal of Nanoscience and Nanotechnology 20, no. 3 (March 1, 2020): 1321–31. http://dx.doi.org/10.1166/jnn.2020.16955.
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In this study, a novel transferrin modified liposomal dioscin was prepared by the film dispersion method. The transferrin modified dioscin loaded liposomes (Tf-Lip/Dio) were near-spherical in morphology and had an average particle size of 140.07±1.33 nm, a narrow polydispersity index of <0.2 and a relatively stable zeta potential of -23.7±1.16 mV. The drug entrapment efficiency (EE) and drug loading (DL) of Tf-Lip/Dio were 88.94±1.02% and 4.16±0.05%, respectively. Tf-Lip/Dio exhibited a sustained release characterization of approximately 30% of the total dioscin content after 72 h at 37 °C. Tf-Lip/Dio showed higher cytotoxic efficacy after incubation for 24 h in both HeLa cells and HepG2 cells than in nonmodified liposomes. The enhanced antitumor activity of Tf-Lip/Dio might be due to the increased intracellular uptake, which was corroborated by laser scanning confocal microscopy and flow cytometry. Furthermore, hemolysis experiments preliminarily verified the safety of its intravenous injection. Overall, this study demonstrates Tf-Lip/Dio to be a favorable delivery vehicle for dioscin in future cancer therapy.
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Koken, Mete, Ismail Aydin, and Akis Sahin. "Application of computational fluid dynamics to predict hydrodynamic downpull on high head gates." Engineering Computations 34, no. 4 (June 12, 2017): 1191–203. http://dx.doi.org/10.1108/ec-04-2016-0137.
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Purpose High head gates are commonly used in hydropower plants for flow regulation and emergence closure. Hydrodynamic downpull can be a critical parameter in design of the lifting mechanism. The purpose of this paper is to show that a simplified two-dimensional (2D) computational fluid dynamics solution can be used in the prediction of the downpull force on the gate lip by comparison of computed results to experimentally measured data. Design/methodology/approach In this study, ANSYS FLUENT CFD software was used to obtain 2D numerical solution for the flow field around a generic gate model located in a power intake structure which was previously used in an experimental study. Description of the flow domain, computational grid resolution, requirements on setting appropriate boundary conditions and methodology in describing downpull coefficient are discussed. Total number of 245 simulations for variable gate lip geometry and gate openings were run. The downpull coefficient evaluated from the computed pressure field as function of gate opening and lip angle are compared with the experimental results. Findings The computed downpull coefficient agrees well with the previous experimental results, except one gate with small lip angle where a separation bubble forms along the lip, which is responsible from this deviation. It is observed that three-dimensional (3D) effects are confined to the large gate openings where downpull is minimum or even reversed. Research limitations/implications In large gate openings, three dimensionality of the flow around gate slots plays an important role and departure from 2D solutions become more pronounced. In that case, one might need to perform a 3D solution instead. Practical implications This paper presents a very fast and accurate way to predict downpull force on high head gates in the absence of experimental data. Originality/value An extensive amount of simulations are run within the scope of this study. It is shown that knowing its limitations, 2D numerical models can be used to calculate downpull for a wide range of gate openings without the need of expensive experimental models.
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Sato, Atsushi, Naoka Kamio, Asumi Yokota, Yoshihiro Hayashi, Akihiro Tamura, Yasuo Miura, Taira Maekawa, and Hideyo Hirai. "C/EBPβ isoforms sequentially regulate regenerating mouse hematopoietic stem/progenitor cells." Blood Advances 4, no. 14 (July 27, 2020): 3343–56. http://dx.doi.org/10.1182/bloodadvances.2018022913.
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Abstract The transcription factor CCAAT enhancer-binding protein β (C/EBPβ) is required for stress-induced granulopoiesis at the level of hematopoietic stem/progenitor cells (HSPCs); however, its role and mechanisms of action in HSPCs are unknown. In this study, we assessed the regulation and functions of C/EBPβ in HSPCs, especially under stress conditions. After 5-fluorouracil treatment or bone marrow transplantation, Cebpb−/− HSPCs exhibited impaired cell-cycle activation and myeloid differentiation at the early and late phases of regeneration, respectively, whereas at steady state, Cebpb deficiency did not affect HSPCs. C/EBPβ was upregulated in response to hematopoietic stress, especially in CD150high long term-hematopoietic stem cells (LT-HSCs). Intracellular flow cytometric analysis that detected distinct domains of C/EBPβ revealed that, among the 3 isoforms of C/EBPβ, liver-enriched inhibitory protein (LIP) was upregulated in LT-HSCs prior to liver-enriched activating protein (LAP)/LAP* during regeneration. Early upregulation of LIP promoted cell-cycle entry of LT-HSCs by positively regulating Myc and expanded the HSPCs pool. Subsequent myeloid differentiation of amplified HSPCs was mediated by LAP/LAP*, which were upregulated at a later phase of regeneration. Collectively, our findings show that stress-induced sequential upregulation of C/EBPβ isoforms is critical for fine-tuning the proliferation and differentiation of regenerating HSPCs.
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Shi, Lei, Keqiang Wang, Ding Feng, Hong Zhang, and Peng Wang. "Wellbore trajectory control tool seal system leakage analysis based on steady gap flow." Advances in Mechanical Engineering 12, no. 6 (June 2020): 168781402093046. http://dx.doi.org/10.1177/1687814020930461.
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Lubricant leakage will inevitably occur during the working process of wellbore trajectory control tools. Even including the lubricant compensation system, serious leakage will still cause lacks lubrication of the internal mechanical structure as well as electronic system damaged by external infiltration fluid, especially when it comes to battery sub and other electronic equipment. Seal system leakage prediction method was presented based on the assumption of steady gap flow. It is assumed that there is a constant gap between the lip seal and the rotating shaft, the gap height is determined by oil film thickness, and the length of the gap was determined by the contact analysis using the Mooney–Rivlin constitutive model. The analysis results show that the contact length between the primary seal lip and the rotary shaft is about 0.1 mm under the condition of ensuring the contact between the deputy seal lip and the rotary shaft. The overall lubricant leakage finite element analysis model was established, and the relationship between the internal lubricant pressure of the tool and the total leakage was obtained. The results of analysis indicate that under the internal pressure of 0.03 MPa, the lubricant leakage is approximately 6 mL/h, which was verified by experiments.
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Younis, Mwafaq, Inam Ali Kasem, and Ahmed Y. Mohammed. "Effect of Lip Slope For Side Weir on Flow Characteristics." AL-Rafdain Engineering Journal (AREJ) 18, no. 2 (April 28, 2010): 49–59. http://dx.doi.org/10.33899/rengj.2010.28186.
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Hueser, J. E., L. T. Melfi, G. A. Bird, and F. J. Brock. "Rocket nozzle lip flow by direct simulation Monte Carlo method." Journal of Spacecraft and Rockets 23, no. 4 (July 1986): 363–67. http://dx.doi.org/10.2514/3.25813.
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ROCKE, ANN H., and RICHARD F. SALANT. "Elastohydrodynamic Analysis of a Rotary Lip Seal Using Flow Factors." Tribology Transactions 48, no. 3 (January 2005): 308–16. http://dx.doi.org/10.1080/05698190590965639.
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Yang, An-Shik, Chih-Yung Wen, and Chun-Shiang Tseng. "Analysis of flow field around a ribbed helix lip seal." Tribology International 42, no. 5 (May 2009): 649–56. http://dx.doi.org/10.1016/j.triboint.2008.09.003.
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Sato, Atsushi, Asumi Yokota, Yoshihiro Hayashi, Naoka Kamio, Satoshi Sagai, Taira Maekawa, and Hideyo Hirai. "C/EBPβ Isoforms Regulate Proliferation and Differentiation of Regenerating Hematopoietic Stem/Progenitor Cells." Blood 134, Supplement_1 (November 13, 2019): 3713. http://dx.doi.org/10.1182/blood-2019-128026.
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Under stress or regenerative conditions, HSCs rapidly enter into cell cycle and are reprogrammed toward myeloid-biased hematopoiesis to meet the increasing demand of myeloid cells. We have previously shown that the transcription factor C/EBPβ plays critical roles at the level of HSPCs under stress conditions (Nat Immunol 2006, J Immunol 2012, Leukemia 2013 and Blood Adv 2019). However, underlying molecular mechanisms of action remain largely unknown. In this study, we have investigated the detailed function of C/EBPβ in regulation of HSPCs. We first evaluated the impact of C/EBPβ on the cell cycle status of LT-HSCs. To exclude the cell-extrinsic contribution of C/EBPβ, CD45.2+ BM cells from WT or Cebpb-/- mice were transplanted into lethally irradiated CD45.1+ WT mice, and these "BM-replaced" recipients were subjected to the following experiments. At steady state, the cell cycle statuses and the numbers of HSPCs did not significantly differ between the recipients of WT cells and those of Cebpb-/- cells. Immediately after 5-FU treatment, WT LT-HSCs entered the cell cycle, as revealed by the decreased percentage of cells in G0 phase and the increased percentage of cells in S/G2M phase. All these parameters of cell cycle acceleration were observed prior to the nadir of LT-HSCs induced by 5-FU and were significantly attenuated in Cebpb-/- LT-HSCs. Next, we assessed the numbers of LT-HSCs, KSL cells, and KL cells after 5-FU treatment. Following the nadir, the recovery of LT-HSCs preceded that of KSL and KL cells, suggesting the differentiation of LT-HSCs to KSL and KL cells. In the recipients of Cebpb-/- cells, the recovery of KSL and KL cells was delayed significantly. Collectively, cell cycle acceleration and subsequent differentiation of LT-HSCs under stress conditions were impaired in the absence of Cebpb. The Cebpb is a single exon gene, and three isoforms, namely, LAP*, LAP and LIP which lacks N-terminus, are translated from its unique mRNA. Due to their structural difference, they should have distinct functions. Here, we focused on expression and functions of these isoforms in regenerating HSPCs. To monitor expression of these isoforms in small numbers of HSCs, we devised a novel intracellular double staining method for flow cytometric analysis using two distinct anti-C/EBPβ antibodies. An antibody against the C-terminus of C/EBPβ recognized all three isoforms, while an antibody against the N-terminus of C/EBPβ only recognized LAP* and LAP. Thus, simultaneous staining with both antibodies should enable us to distinguish cells that dominantly expressed LIP (C-term+ N-term-) from those that expressed all three isoforms (C-term+ N-term+). Using this method, we monitored the expression patterns of these isoforms in LT-HSCs after 5-FU treatment. LT-HSCs initially became C-term single positive in response to 5-FU and subsequently changed to C- and N-term double positive, suggesting that LIP was upregulated prior to LAP/LAP* under stress conditions. These results suggest that phase-specific upregulation of LIP and LAP/LAP* is strongly associated with phase-specific functions of C/EBPβ in cell cycle activation and differentiation, respectively. Indeed, when EML cells, a mouse HSC line, were retrovirally transduced with LIP, the transduced cells were more proliferative and actively cycling than those transduced with the control vector, whereas proliferation and cell cycle were markedly suppressed in LAP*- and LAP-expressing EML cells. LIP-expressing cells remained undifferentiated, while LAP*- and LAP-expressing cells rapidly differentiated into CD11b+ myeloid cells and eventually stopped proliferating. In summary, our findings clearly suggest that sequential upregulation of C/EBPβ isoforms is critical for the regulation of HSCs under stress conditions. LIP amplifies the "reservoir" of HSPCs by accelerating the proliferation of HSCs during the early phase of regeneration, while LAP*/LAP induce their myeloid differentiation at a later phase. These findings should facilitate our understanding of the pathophysiology of infection, inflammation, and regenerating hematopoiesis in response to myeloablative chemotherapies or hematopoietic stem cell transplantation, all of which increase the hematopoietic demands. Disclosures Hirai: Kyowa Kirin: Research Funding.
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Dadkhah, S., A. B. Turner, and J. W. Chew. "Performance of Radial Clearance Rim Seals in Upstream and Downstream Rotor–Stator Wheelspaces." Journal of Turbomachinery 114, no. 2 (April 1, 1992): 439–45. http://dx.doi.org/10.1115/1.2929163.
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A new experimental facility for the investigation of rim sealing is described and measurements are presented for two representative radial clearance seals with a nominally axisymmetric external flow. One radial seal has an upward rotor lip and is upstream of the rotor, while the other has an upward stator lip and is downstream of the rotor. Measurements include surface pressures, tangential velocities in the core region of the disk cavity flow, and traverses of gas concentration in the cavity showing the distribution of mainstream ingestion. Tests were conducted at rotational Reynolds numbers up to 3 × 106 with nominal seal clearance to radius ratios in the range 0.002 to 0.01. For the radial seals a differential pressure criterion is found to overestimate the minimum sealing flow. Tangential velocity measurements in the wheelspace are in excellent agreement with other workers’ measurements and with theoretical predictions.
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Kellner, Christopher P., Alexander G. Chartrain, Claire Schwegel, Thomas J. Oxley, Hazem Shoirah, and J. Mocco. "Republished: The bumper technique for advancing a large profile microcatheter." Journal of NeuroInterventional Surgery 9, no. 12 (March 9, 2017): e38-e38. http://dx.doi.org/10.1136/neurintsurg-2016-012872.rep.
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Operators commonly encounter difficulty maneuvering a microcatheter beyond the distal lip of wide neck aneurysms and aneurysms in challenging locations. Few techniques have been described to guide operators in these particular situations. In this case report of a 56-year-old woman with a 16 mm ophthalmic artery aneurysm, the microcatheter continually snagged the distal aneurysm lip, preventing delivery of a flow diverter into the distal parent vessel. In troubleshooting this obstacle, a second microguidewire was introduced alongside the microcatheter and was used to cover the distal lip of the aneurysm to prevent further snagging. The second guidewire successfully deflected the microcatheter into the distal vessel, a technique that we have aptly dubbed the ‘bumper technique’.
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Perini, Federico, Kan Zha, Stephen Busch, Eric Kurtz, Richard C. Peterson, Alok Warey, and Rolf D. Reitz. "Piston geometry effects in a light-duty, swirl-supported diesel engine: Flow structure characterization." International Journal of Engine Research 19, no. 10 (December 5, 2017): 1079–98. http://dx.doi.org/10.1177/1468087417742572.
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This work studied how in-cylinder flow structure is affected in a light-duty, swirl-supported diesel engine when equipped with three different piston geometries: the first two featuring a conventional re-entrant bowl, either with or without valve cut-outs on the piston surface and the third featuring a stepped-lip bowl. Particle image velocimetry experiments were conducted inside an optical engine to measure swirl vortex intensity and structure during the intake and compression strokes. A full computational model of the optical diesel engine was built using the FRESCO code, a recently developed object-oriented parallel computational fluid dynamics platform for engine simulations. The model was first validated against the measured swirl-plane velocity fields, and the simulation convergence for multiple cycles was assessed. Flow topology was studied by addressing bulk flow and turbulence quantities, including swirl structure, squish flux, plus geometric and operating parameters, such as the presence of valve cut-outs on the piston surface, compression ratio and engine speed. The results demonstrated that conventional re-entrant bowls have stronger flow separation at intake, hampering bowl swirl, but higher global swirl than for stepped-lip bowls thanks to a stronger and more axisymmetric squish mechanism and less tilted swirl. Stepped-lip bowls have larger inhomogeneities (tilt and axisymmetry) and higher turbulence levels, but also faster turbulence dissipation toward top dead center. They have weaker squish flux but larger squish inversion momentum as a result of the smaller inertia.
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Evans, J. D. "Re-entrant corner flows of UCM fluids: the initial formation of lip vortices." Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 461, no. 2062 (August 23, 2005): 3169–81. http://dx.doi.org/10.1098/rspa.2005.1491.
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We discuss here a third type of boundary-layer structure that arises in steady planar flows at re-entrant corners for the upper convected Maxwell fluid. This structure extends the class of similarity solutions that are associated with the inviscid flow equations and hold in an outer core region local to the corner. In previous work ( Renardy 1995 J. Non-Newtonian Fluid Mech. 58 , 83–39 ; Evans 2005 Proc. R. Soc. A 461 , 117–142 ), single and double layer structures were used to the match outer core similarity solutions to wall boundary layers in which viscometric behaviour is obtained. Here a second double layer structure is discussed, which completes the range of validity for the core similarity solutions. This structure is fundamentally different to the single layer structure in that it only admits reverse flow solutions at the upstream wall, a situation of practical relevance to describe the initial formation of lip vortices in contraction flows.
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Alam, Mohammad Khursheed, Ahmed Ali Alfawzan, Fatema Akhter, Haytham Jamil Alswairki, and Prabhat Kumar Chaudhari. "Evaluation of Lip Morphology and Nasolabial Angle in Non-Syndromic Cleft Lip and/Palate and Non-Cleft Individuals." Applied Sciences 12, no. 1 (December 30, 2021): 357. http://dx.doi.org/10.3390/app12010357.
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Objective: To investigate the variation between the non-syndromic cleft lip and/or palate (NSCLP) and non-cleft (NC) subjects in relation to the lip morphology (LM) and nasolabial angle (NLA). Materials and Methods: Lateral cephalogram (Late. Ceph.) of 123 individuals (92 NSCLP [29 = bilateral cleft lip and palate (BCLP), 41 = unilateral cleft lip and palate (UCLP), 9 = unilateral cleft lip and alveolus (UCLA), 13 = unilateral cleft lip (UCL)], and 31 NC) who did not undergo any orthodontic treatment were investigated. By WebCeph, an artificial intelligence- (A.I.) driven software, 2 (two) parameters of LM, namely upper lip to E line (LM-1) and lower lip to E line (LM-2), and NLA analysis was carried out for each individual. Multiple tests were carried out for statistical analysis. Results: The mean ± SD observed for LM-1, LM-2, and NLA for NC individuals were 1.56 ± 2.98, 0.49 ± 3.51, and 97.20 ± 16.10, respectively. On the other hand, the mean ± SD of LM-1, LM-2, and NLA for NSCLP individuals were 4.55 ± 4.23, 1.68 ± 2.82, and 82.02 ± 14.66, respectively. No significant variation was observed with respect to gender and side. NSCLP (different types) and NC individuals showed significant disparities in LM-1 and NLA. Conclusion: It can be concluded that parameters of lip morphology such as LM-1, LM-2, and NLA vary among NSCLP and NC individuals.
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Fan, Xiaoqiang, and Yuan Tao. "Investigation of Flow Control for the Hypersonic Inlets via Counter Flow." International Journal of Aerospace Engineering 2015 (2015): 1–8. http://dx.doi.org/10.1155/2015/956317.
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Experimental results show that there exist two flow fields in the hypersonic inlets when the forebody waves interact with the lip boundary, which is similar to the shock reflection ion hysteresis phenomenon. In order to improve the performance of the flow field, counterflow is applied to control the shock reflection configuration in the hypersonic inlets. For better understanding of the internal mechanism, inviscid numerical simulation is conducted. And the results demonstrate that it is feasible to realize the transition between the regular reflection configuration and the Mach reflection ion configuration in the hypersonic inlets. That is because the von Neumann criterion and detached criterion play a dominant role, respectively, in these transitions. In addition, the evolution process of Mach reflection ion in the hypersonic inlets can be divided into three stages: transmission of waves, emergence of Mach stem, and stabilization of flow field.
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Dillmann, Andreas. "Linear potential theory of steady internal supersonic flow with quasi-cylindrical geometry. Part 2. Free jet flow." Journal of Fluid Mechanics 286 (March 10, 1995): 327–57. http://dx.doi.org/10.1017/s0022112095000759.
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By extending the methods of Part 1, the general problem of steady cylindrical supersonic free jet flow is treated in a similar manner to the flow in quasi-cylindrical ducts. It is shown that the presence of a finite pressure jump at the nozzle lip gives rise to a periodic singularity pattern in the flow field. Basic examples of free jet flows are discussed, and for the case of a nearly ideally expanded axisymmetric jet, theoretical Mach—Zehnder interferograms are calculated by analytical integration of the density field. Excellent agreement with experiment proves the validity of linear theory even close to the singularities and far downstream of the nozzle orifice. Furthermore, it is shown that Pack's formula for the wavelength of the shock cell structure is inconsistent; the correct formula is derived and excellent agreement with Emden's empirical fit is found.
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SON, JAE HWAN, CHANG WOO HAN, WON SIK CHOI, KYOO IK NOH, YOUNG SUK KIM, and YOUNG MOON LEE. "EXTRUSION SIMULATION FOR MANUFACTURING STABILIZATION OF EXPANDABLE POLYMER." International Journal of Modern Physics: Conference Series 06 (January 2012): 431–36. http://dx.doi.org/10.1142/s201019451200356x.
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This study investigates pressure and temperature changes in an extrusion die of expandable polymer according to resin flow. Depending on die design each three structural changes of the die neck width and lip height were assumed and the effects were analyzed. It is revealed that the maximum pressure decreases as the inlet width of die neck and outlet height of die lip increase. The mean temperature decreases as the inlet width increase, but it does not change with the outlet height.
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Cho, Hyung Hee, and Jin Ki Ham. "Influence of Injection Type and Feed Arrangement on Flow and Heat Transfer in an Injection Slot." Journal of Turbomachinery 124, no. 1 (February 1, 2001): 132–41. http://dx.doi.org/10.1115/1.1424890.
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An experimental investigation is conducted to improve a slot film cooling system used for the cooling of a gas turbine combustor liner. The tangential slots are constructed of discrete holes with different injection types which are the parallel, vertical, and combined to the slot lip. The investigation is focused on the coolant supply systems of normal, inline, and counter-flow paths to the mainstream flow direction. A naphthalene sublimation technique has been employed to measure the local heat/mass transfer coefficients in a slot wall with various injection types and coolant feeding directions. A numerical simulation is also conducted to help understand the flow patterns inside the slot for different injection types. The velocity distributions at the exit of slot lip for the parallel and vertical injection types are fairly uniform with mild periodical patterns with respect to the injection hole positions. However, the combined injection type increases the nonuniformity of flow distribution with the period equaling twice that of hole-to-hole pitch due to splitting and merging of the ejected flows. The dimensionless temperature distributions at the slot exits differ little with blowing rates, injection types, and secondary flow conditions. In the results of heat/mass transfer measurements, the best cooling performance inside the slot is obtained with the vertical injection type among the three different injection types due to the effects of jet impingement. The lateral distributions of heat/mass transfer coefficients with the inline and counter-flow paths are more uniform than the normal-flow path. The average heat/mass transfer coefficients with the injection holes are about two to five times higher than that of a smooth two-dimensional slot path.
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Yang, Guang, Yi Zhang, M. Elizabeth Ross, and Costantino Iadecola. "Attenuation of activity-induced increases in cerebellar blood flow in mice lacking neuronal nitric oxide synthase." American Journal of Physiology-Heart and Circulatory Physiology 285, no. 1 (July 2003): H298—H304. http://dx.doi.org/10.1152/ajpheart.00043.2003.
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We used mice deficient in neuronal nitric oxide (NO) synthase (nNOS) to specifically investigate the role of neuronal NO in the increase of cerebellar blood flow (BFcrb) produced by neural activation. Crus II, a region of the cerebellar cortex that receives trigeminal sensory afferents, was activated by low-intensity stimulation of the upper lip (5–25 V, 4–16 Hz) in anesthetized mice. BFcrb was recorded in Crus II by using a laser-Doppler flow probe. In wild-type mice, upper lip stimulation increased BFcrb in the Crus II by 28 ± 3% (25 V, 10 Hz, n = 6). The rise in BFcrb was attenuated by 73 ± 3% in nNOS-/- mice ( P < 0.05, n = 6). The increases in BFcrb produced by superfusion of Crus II with glutamate or by systemic administration of harmaline were also attenuated in nNOS-/- mice ( P < 0.05). In contrast, the increases in BFcrb produced by topical superfusion of Crus II with acetylcholine or adenosine and the increase in BFcrb produced by hypercapnia were not affected ( P > 0.05). The field potentials evoked in the Crus II by upper lip stimulation did not differ between wild-type and nNOS-null mice. These data provide the first nonpharmacological evidence that nNOS-derived NO is a critical link between glutamatergic synaptic activity and blood flow in the activated cerebellum.
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AKASAKA, Noriyuki. "Dynamic Model of Polymer Melt Flow in Die Lip with Heaters." Transactions of the Society of Instrument and Control Engineers 30, no. 11 (1994): 1341–50. http://dx.doi.org/10.9746/sicetr1965.30.1341.
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Dagum, Leonardo. "Lip leakage flow simulation for the gravity probe B gas spinup." Journal of Spacecraft and Rockets 31, no. 3 (May 1994): 429–34. http://dx.doi.org/10.2514/3.26456.
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MORIMATSU, Akihisa, Takahiro FUKUSIMA, Makoto KOMURA, Tsuneo AKUTO, Kohro TAKATSUKA, and Masatsugu YOSHIZAWA. "11407 Fluid Flow near the Lip of a Moving Wiper Blade." Proceedings of Conference of Kanto Branch 2007.13 (2007): 359–60. http://dx.doi.org/10.1299/jsmekanto.2007.13.359.
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