To see the other types of publications on this topic, follow the link: SVGF.
Journal articles on the topic 'SVGF'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'SVGF.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Moshapa, Florah Tshepo, Kirsten Riches-Suman, and Timothy Martin Palmer. "Therapeutic Targeting of the Proinflammatory IL-6-JAK/STAT Signalling Pathways Responsible for Vascular Restenosis in Type 2 Diabetes Mellitus." Cardiology Research and Practice 2019 (January 2, 2019): 1–15. http://dx.doi.org/10.1155/2019/9846312.
Full textAbstract:
Type 2 diabetes mellitus (T2DM) is increasing worldwide, and it is associated with increased risk of coronary artery disease (CAD). For T2DM patients, the main surgical intervention for CAD is autologous saphenous vein grafting. However, T2DM patients have increased risk of saphenous vein graft failure (SVGF). While the mechanisms underlying increased risk of vascular disease in T2DM are not fully understood, hyperglycaemia, insulin resistance, and hyperinsulinaemia have been shown to contribute to microvascular damage, whereas clinical trials have reported limited effects of intensive glycaemic control in the management of macrovascular complications. This suggests that factors other than glucose exposure may be responsible for the macrovascular complications observed in T2DM. SVGF is characterised by neointimal hyperplasia (NIH) arising from endothelial cell (EC) dysfunction and uncontrolled migration and proliferation of vascular smooth muscle cells (SMCs). This is driven in part by proinflammatory cytokines released from the activated ECs and SMCs, particularly interleukin 6 (IL-6). IL-6 stimulation of the Janus kinase (JAK)/signal transducer and activator of transcription 3 (STAT) pathway is a key mechanism through which EC inflammation, SMC migration, and proliferation are controlled and whose activation might therefore be enhanced in patients with T2DM. In this review, we investigate how proinflammatory cytokines, particularly IL-6, contribute to vascular damage resulting in SVGF and how suppression of proinflammatory cytokine responses via targeting the JAK/STAT pathway could be exploited as a potential therapeutic strategy. These include the targeting of suppressor of cytokine signalling (SOCS3), which appears to play a key role in suppressing unwanted vascular inflammation, SMC migration, and proliferation.
2
Yayla, Cagri, Kevser Balci, Ozcan Ozeke, Orhan Maden, Halil Kisacik, Ahmet Temizhan, Sinan Aydogdu, and Mehmet Akboga. "Relationship between Serum Albumin Level and Monocyte-to-High-Density Lipoprotein Cholesterol Ratio with Saphenous Vein Graft Disease in Coronary Bypass." Thoracic and Cardiovascular Surgeon 65, no. 04 (April 25, 2016): 315–21. http://dx.doi.org/10.1055/s-0036-1582260.
Full textAbstract:
Background Previous studies proposed that inflammation, oxidative stress, and impaired endothelial dysfunction have a crucial role in occurrence of saphenous vein graft (SVG) disease (SVGD). The aim of this study was to assess the relationship between monocyte-to-high-density lipoprotein cholesterol (HDL-C) ratio (MHR) and serum albumin (SA) level as readily available inflammatory and oxidative stress markers with the presence of SVGD in patients with a coronary bypass. Methods In this retrospective cross-sectional study, a total of 257 patients (n = 112 SVGD [+] [mean age was 65.3 ± 8.4 years, 75.0% males] and n = 145 SVGD [−] [mean age was 66.5 ± 10.1 years, 74.5% males]) were enrolled. At least one SVG with ≥ 50% stenosis was defined as SVGD. Independent predictors of SVGD were determined by logistic regression analysis. Results White blood cell, neutrophil, monocyte, the age of SVG, and MHR were significantly higher, whereas SA level was significantly lower in patients with SVGD. In regression analysis, neutrophil, age of SVG, SA (odds ratio [OR]: 0.232 [0.156–0.370], p < 0.001), and MHR (OR: 1.122 [1.072–1.174], p < 0.001) remained as independent predictors of SVGD. Moreover, age of SVG showed a significant negative correlation with SA (r = − 0.343, p < 0.001) and a positive correlation with MHR (r = 0.238, p < 0.001). In the receiver-operating characteristic curve analysis, the cutoff value of ≤ 3.75 g/dL for SA has a 73.2% sensitivity and 64.8% specificity and the cutoff value of ≥ 12.1 for MHR has a 71.4% sensitivity and 60.0% specificity for prediction of SVGD. Conclusion Consequently, to the best of our knowledge, this is the first study showing a significant and independent association between SA and MHR with SVGD.
3
Cianfrone, Beth A., and James J. Zhang. "The Impact of Gamer Motives, Consumption, and In-Game Advertising Effectiveness: A Case Study of Football Sport Video Games." International Journal of Sport Communication 6, no. 3 (September 2013): 325–47. http://dx.doi.org/10.1123/ijsc.6.3.325.
Full textAbstract:
Sport video games (SVGs) are a highly consumed media source among 18- to 34-yr-old sport consumers. Many corporations have become advertisers or sponsors of SVGs to reach this consumer segment. This case study examined the systematic relationships among SVG motives, consumption levels, and sponsorship effectiveness. Research participants (N = 213) were SVG gamers who responded to a survey. The proposed hierarchical relationships were tested in a structural model analysis to determine the effectiveness of SVGs. The fit indices showed that the model fit the data well, indicating that, sequentially, SVG motivations influenced game play frequency, awareness of sponsoring brands in SVGs, attitude toward the sponsoring brands, and future purchase intentions of sponsoring products. Researchers and practitioners may consider applying SVG motivational factors to enhance SVG play frequency so as to enhance the awareness of and attitude toward sponsoring brands, which would in turn promote behavioral intentions for consuming the sponsoring brands.
4
Yayla, Cagri, and Kadriye Gayretli Yayla. "C-Reactive Protein to Albumin Ratio in Patients With Saphenous Vein Graft Disease." Angiology 72, no. 8 (March 8, 2021): 770–75. http://dx.doi.org/10.1177/0003319721998863.
Full textAbstract:
Atherosclerosis plays an important role in saphenous vein graft disease (SVGD). Previous studies showed that inflammatory blood cells play an active role in this process. C-reactive protein to albumin ratio (CAR) is considered as a novel predictor for cardiovascular risk and an indicator of inflammation. We aimed to assess the relationship between SVGD and CAR. A total of 711 participants with saphenous vein graft (SVG) were included; 348 patients had SVGD and 363 patients had patent (no stenosis) SVG. C-reactive protein to albumin ratio was higher in patients with SVGD ( P < .001). There was a significant positive correlation between CAR and the age of SVG (r = 0.123; P = .001) and SYNTAX score (r = 0.568; P < .001). Multivariate logistic regression analyses showed that lymphocyte count, CAR, and SYNTAX score were independent predictors of SVGD ( P < .05). C-reactive protein to albumin ratio may be a useful marker after bypass surgery to predict SVGD.
5
Takazawa, Akitoshi, Hiroyuki Nakajima, Atsushi Iguchi, Mimiko Tabata, Kozo Morita, Hiroyuki Koike, Kazuhiko Uwabe, Toshihisa Asakura, and Hiroshi Niinami. "Impacts of Intraoperative Flow on Graft Patency of Sequential and Individual Saphenous Vein Grafts." Innovations: Technology and Techniques in Cardiothoracic and Vascular Surgery 10, no. 2 (March 2015): 85–89. http://dx.doi.org/10.1097/imi.0000000000000140.
Full textAbstract:
Objective We sought to delineate the predictor of saphenous vein graft (SVG) failure and to evaluate the impact of sequential grafting of SVG on graft flow as the significant predictor of patency. Methods Angiograms and clinical records of 439 patients who underwent coronary artery bypass grafting with aortocoronary SVG were reviewed. Of these, 708 distal anastomoses were created by 480 SVGs. Of 349 patients who underwent isolated coronary artery bypass grafting, operation was performed with an off-pump technique in 347 patients (99%). For 90 patients, a combined procedure on cardiopulmonary bypass was performed. A postoperative angiography was performed in 230 SVGs for clinical reasons. Insufficient flow (IF) was defined as a graft flow of 20 mL/min or less, measured by transit-time Doppler flowmetry during operation. Results In 480 SVGs, 44 (9.2%) presented IF, and 24 SVGs presented partial or total occlusion. Six of the nine failed individual SVG had IF, whereas none of the failed sequential SVG was associated with IF. Univariate and multivariate logistic regression analyses demonstrated that IF ( P = 0.002; odds ratio, 6.63) and sequential grafting ( P = 0.004; odds ratio, 2.51) were significantly correlated with a failure of the SVG. The patency rate of sequential SVG to the most distal target was 78/93 (83.9%), which was significantly lower than 9/139 (93.5%) of the individual SVG ( P = 0.02) and 7/113 (93.8%) of the sequential SVG to proximal targets ( P = 0.02). Conclusions When both targets seem to have sufficient demand, avoidance of sequential grafting would be reasonable. Moreover, the important target should be grafted by individual grafting or sequential proximal anastomosis.
6
Willemsen, Laura M., Paul W. A. Janssen, Joyce Peper, Mohamed A. Soliman-Hamad, Albert H. M. van Straten, Patrick Klein, Chris M. Hackeng, et al. "Effect of Adding Ticagrelor to Standard Aspirin on Saphenous Vein Graft Patency in Patients Undergoing Coronary Artery Bypass Grafting (POPular CABG)." Circulation 142, no. 19 (November 10, 2020): 1799–807. http://dx.doi.org/10.1161/circulationaha.120.050749.
Full textAbstract:
Background: Approximately 15% of saphenous vein grafts (SVGs) occlude during the first year after coronary artery bypass graft surgery (CABG) despite aspirin use. The POPular CABG trial (The Effect of Ticagrelor on Saphenous Vein Graft Patency in Patients Undergoing Coronary Artery Bypass Grafting Surgery) investigated whether ticagrelor added to standard aspirin improves SVG patency at 1 year after CABG. Methods: In this investigator-initiated, randomized, double-blind, placebo-controlled, multicenter trial, patients with ≥1 SVGs were randomly assigned (1:1) after CABG to ticagrelor or placebo added to standard aspirin (80 mg or 100 mg). The primary outcome was SVG occlusion at 1 year, assessed with coronary computed tomography angiography, in all patients that had primary outcome imaging available. A generalized estimating equation model was used to perform the primary analysis per SVG. The secondary outcome was 1-year SVG failure, which was a composite of SVG occlusion, SVG revascularization, myocardial infarction in myocardial territory supplied by a SVG, or sudden death. Results: Among 499 randomly assigned patients, the mean age was 67.9±8.3 years, 87.1% were male, the indication for CABG was acute coronary syndrome in 31.3%, and 95.2% of procedures used cardiopulmonary bypass. Primary outcome imaging was available in 220 patients in the ticagrelor group and 223 patients in the placebo group. The SVG occlusion rate in the ticagrelor group was 10.5% (51 of 484 SVGs) versus 9.1% in the placebo group (43 of 470 SVGs), odds ratio, 1.29 [95% CI, 0.73–2.30]; P =0.38. SVG failure occurred in 35 (14.2%) patients in the ticagrelor group versus 29 (11.6%) patients in the placebo group (odds ratio, 1.22 [95% CI, 0.72–2.05]). Conclusions: In this randomized, placebo-controlled trial, the addition of ticagrelor to standard aspirin did not reduce SVG occlusion at 1 year after CABG. Registration: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT02352402.
7
Cianfrone, Beth A., Galen T. Trail, James J. Zhang, and Richard J. Lutz. "Effectiveness of In-Game Advertisements in Sport Video Games: An Experimental Inquiry on Current Gamers." International Journal of Sport Communication 1, no. 2 (June 2008): 195–218. http://dx.doi.org/10.1123/ijsc.1.2.195.
Full textAbstract:
Sport video games (SVGs) are a popular form of sport media and sponsorship, and advertising in SVGs is increasingly common. This study assessed the effectiveness of SVG in-game advertisements in 3 consumption domains: cognitive, affective, and conative. An experimental study was designed with 89 gamers randomly assigned to 1 of 2 conditions: (a) experimental, playing an SVG with advertisements, or (b) control, playing an SVG without advertisements. Consumption background and identification level were incorporated as covariates to ensure group equivalence. Participants responded to a questionnaire measuring brand awareness, brand attitude, and purchase intentions. MANCOVA revealed that after controlling for the effect of covariate variables, the experimental group had a significantly (p < .05) greater mean brand-awareness score than the control group. Mean brand-attitude and purchase-intention scores were not significantly (p > .05) different between groups. The findings indicated that SVG in-game advertising was effective in creating awareness.
8
Karasev, E. V., N. P. Maslova, and T. M. Kodrul. "SVGm – a new tool for measuring linear dimensions with quality characteristics of objects: applications in biology." Palaeobotany 10 (2019): 5–12. http://dx.doi.org/10.31111/palaeobotany/2019.10.5.
Full textAbstract:
The advantages and disadvantages of a number of specialized computer programs for obtaining dimensional characteristics of biological objects by analysis of their digital images are considered in comparative terms. The authorial methodology of using a vector graphics editor Inkscape and a new online service SVGm (Scalable Vector Graphics measurer, https://svgm.cf) is proposed to measure the linear parameters of the objects in the images and to prepare the quantitative characteristics of objects and their different qualitative characteristics for the subsequent statistical analysis. An algorithm for working with Inkscape editor and SVGm online service is described in detail. Object images imported into Inkscape editor are measured using vector elements (lines, rectangles, circles, ellipses, polygons) and saved in the standard SVG format. Properties of vector figures of SVG files are converted by the online service SVGm in the measurement results shown in the table. The potential of the method is shown by the example of morphological measurements of various botanical objects.
9
Garcia, Anastacia M., Jessica C. McPhaul, Genevieve C. Sparagna, Danielle A. Jeffrey, Raleigh Jonscher, Sonali S. Patel, Carmen C. Sucharov, Brian L. Stauffer, Shelley D. Miyamoto, and Kathryn C. Chatfield. "Alteration of cardiolipin biosynthesis and remodeling in single right ventricle congenital heart disease." American Journal of Physiology-Heart and Circulatory Physiology 318, no. 4 (April 1, 2020): H787—H800. http://dx.doi.org/10.1152/ajpheart.00494.2019.
Full textAbstract:
Despite advances in both medical and surgical therapies, individuals with single ventricle heart disease (SV) remain at high risk for the development of heart failure (HF). However, the molecular mechanisms underlying remodeling and eventual HF in patients with SV are poorly characterized. Cardiolipin (CL), an inner mitochondrial membrane phospholipid, is critical for proper mitochondrial function, and abnormalities in CL content and composition are known in various cardiovascular disease etiologies. The purpose of this study was to investigate myocardial CL content and composition in failing and nonfailing single right ventricle (RV) samples compared with normal control RV samples, to assess mRNA expression of CL biosynthetic and remodeling enzymes, and to quantitate relative mitochondrial copy number. A cross-sectional analysis of RV myocardial tissue from 22 failing SV (SVHF), 9 nonfailing SV (SVNF), and 10 biventricular control samples (BVNF) was performed. Expression of enzymes involved in CL biosynthesis and remodeling were analyzed using RT-qPCR and relative mitochondrial DNA copy number determined by qPCR. Normal phase high-pressure liquid chromatography coupled to electrospray ionization mass spectrometry was used to quantitate total and specific CL species. While mitochondrial copy number was not significantly different between groups, total CL content was significantly lower in SVHF myocardium compared with BVNF controls. Despite having lower total CL content however, the relative percentage of the major tetralinoleoyl CL species is preserved in SVHF samples relative to BVNF controls. Correspondingly, expression of enzymes involved in CL biosynthesis and remodeling were upregulated in SVHF samples when compared with both SVNF samples and BVNF controls. NEW & NOTEWORTHY The mechanisms underlying heart failure in the single ventricle (SV) congenital heart disease population are largely unknown. In this study we identify alterations in cardiac cardiolipin metabolism, composition, and content in children with SV heart disease. These findings suggest that cardiolipin could be a novel therapeutic target in this unique population of patients.
10
Liu, Yin, Chang-Ping Li, Yue-Ying Wang, Ya-Nan Dong, Hong-Wei Liu, Jian-Yong Xiao, Ming-Dong Gao, et al. "Prediction of Major Adverse Cardiovascular Events and Slow/No-Reflow by Virtual Histology Imaging After Percutaneous Interventions on Saphenous Vein Grafts." Angiology 71, no. 3 (December 23, 2019): 263–73. http://dx.doi.org/10.1177/0003319719892354.
Full textAbstract:
Saphenous vein grafts disease (SVGD) is a common complication after coronary artery bypass graft (CABG) and usually treated by percutaneous coronary intervention (PCI). In this prospective cohort study, we performed virtual histology-intravascular ultrasound to investigate whether plaque composition and morphological characteristics were associated with post-PCI major adverse cardiac events (MACEs) and slow/no-reflow in patients with SVGD. Patients (n = 90) were studied (76.7% men, mean age 64.9 ± 8.2 years and mean duration of SVG 8.0 ± 3.6 years). There were 77.8% lesions with a plaque burden of at least 70%; 18 MACE incidences accumulated in 14 patients over 12 months post-PCI and slow/no-reflow was observed in 12 patients. On adjusted multivariate analysis, lesion length (hazard ratio [HR] = 1.05; 95% confidence interval [CI]: 1.01-1.08]); age of CABG (HR = 1.51 [95% CI: 1.11-2.05], and absolute necrotic core (NC) area (HR = 8.04 [95% CI: 1.86-34.73]) were independently associated with MACEs. Factors independently associated with slow/no-reflow post-PCI were preprocedure systolic blood pressure (odds ratio [OR] = 0.98; 95% CI: 0.96-0.99) and absolute NC area (OR = 2.47 (95% CI: 1.14-5.36). A cutoff value of absolute NC area at ≥1.1 mm2 may serve as a significant risk predictor for no-reflow after SVG-PCI. Factors associated with MACEs and the slow/no-reflow phenomenon following PCI of the SVG can be used in risk assessment of SVG.
11
Gao, Jing, Hai-Bo Wang, Jian-yong Xiao, Min Ren, Kathleen Heather Reilly, Yu-Ming Li, and Yin Liu. "Association between proprotein convertase subtilisin/kexin type 9 and late saphenous vein graft disease after coronary artery bypass grafting: a cross-sectional study." BMJ Open 8, no. 7 (July 2018): e021951. http://dx.doi.org/10.1136/bmjopen-2018-021951.
Full textAbstract:
ObjectiveThe study aims to explore the association between serum proprotein convertase subtilisin/kexin type 9 (PCSK9) level and saphenous vein grafts disease (SVGD) after coronary artery bypass grafting (CABG).DesignA cross-sectional study.SettingA secondary hospital in Tianjin City, China.ParticipantsA total of 231 participants were included in the study. Inclusion criteria were as follows: age ≥18 years, previous CABG surgery at least 12 months ago, at least one SVG for bypass during CABG, abnormal non-invasive test results or recurrent stable angina pectoris by coronary angiography indications, and willing to participate and sign informed consent. Participants with any of the following were excluded from the study: congenital valvular disease, decompensated heart failure, anaemia defined as a haemoglobin level of <12 g/dL in women or <13 g/dL in men, malignant neoplasms, renal failure, severe hepatic disease, thyroid disease, acute or chronic inflammatory disease and chronic obstructive lung disease.Primary outcome measureSVGD was defined as at least one SVG with significant stenosis (≥50%). Circulating PCSK9 levels were measured using commercial ELISA kits according to the manufacturer’s instructions.ResultsThe mean PCSK9 level in the SVGD group was significantly higher than that in the patent group (275.2±38.6 vs 249.3±37.7, p<0.01). The multivariate logistic regression model revealed a significant association between serum PCSK9 and SVGD (OR 2.08, 95% CI 1.46–2.95) per 1 SD increase in serum PCSK9.ConclusionsThe present study is the first to identify an independent association between PCSK9 and late SVGD after adjustment for established cardiovascular risk factors. A multicentre prospective cohort study with large sample size should be conducted in the future to further research this relationship.
12
Hu, Shao Gang, Da Yong Gao, Shu Han Wang, Lian Zhi Wu, Hong Sheng Li, Jia Yong Chen, and Bo Cai. "Simulation Study on Three-Phase Three-Wire System Low Voltage SVG in PSCAD." Advanced Materials Research 1049-1050 (October 2014): 703–7. http://dx.doi.org/10.4028/www.scientific.net/amr.1049-1050.703.
Full textAbstract:
Among the current 3G SVCs, the one with the highest compensating capacity is the static var generator, which is featured by smooth and continuous bipolar reactive power, quick responding and small loss, and widely applied in petrochemical, metallurgy, wind power and power transmission and distribution, etc, working out power quality problems. As demand for static var compensators in market grows, LV SVG comes to the stage. Compared with HV and MV SVGs, although LV SVG is simple in structure, it has stricter requirements on compensating capacity and stability, which requires R&D to consider more technical details in product design.
13
Nikolaos, Konstantinidis, and Sianos Georgios. "Post-coronary Artery Bypass Grafting – Degenerated Saphenous Vein Graft Intervention, or Native Vessel Coronary Chronic Total Occlusion Recanalisation?" Interventional Cardiology Review 7, no. 1 (2012): 66. http://dx.doi.org/10.15420/icr.2012.7.1.66.
Full textAbstract:
Coronary artery bypass grafting (CABG) has dramatically changed the management of patients with ischaemic heart disease. Saphenous vein grafts (SVGs) are the most common type of grafts used in CABG, but have a progressive occlusion rate reaching 50 % at 10 years post-surgery. Treatment of SVG stenosis with percutaneous coronary intervention (PCI) is limited by the substantial risk of major adverse cardiac events. Moreover, conflicting data exist regarding the efficacy of bare metal and drug-eluting stents in SVG lesions. Success rates for the recanalisation of coronary chronic total occlusions with PCI using modern techniques and materials can be in excess of 90 % if performed by experienced operators. We report on the case of a patient who had previously undergone CABG and presented with multivessel disease and a degenerating SVG in a chronically occluded dominant left circumflex coronary artery. We address the dilemma of whether to revascularise the degenerating SVG graft, or to recanalise the chronically occluded native vessel.
14
Kumar, Ashwani, Dixon Santana, and Leigh Ann Jenkins. "Closure of a Giant Saphenous Vein Graft Aneurysm with Embolization Coil." Cardiology Research and Practice 2009 (2009): 1–3. http://dx.doi.org/10.4061/2009/748272.
Full textAbstract:
Aneurysms of saphenous vein grafts (SVGs) to coronary arteries are rare, usually asymptomatic and found incidentally. We report a case of an 84-year-old female who was found to have 8.1 8.4 cm aneurysm of an SVG to obtuse marginal (OM) artery. The aneurysm was prior to the distal anastamosis but no flow into the OM artery was noted. Cook Tornado Embolization Coils were used successfully to occlude the SVG proximal to the aneurysm. No complications occurred. The use of embolization coils is an effective and safe method for aneurysm occlusion when the anatomy is suitable and especially when patient is high risk for repeat surgical intervention.
15
Temizkan, Veysel, Murat Ugur, Gokhan Arslan, Ibrahim Alp, Erturk Yedekci, Alper Ucak, and Ahmet Turan Yilmaz. "Comparison of Conventional Technique and Ultrasonographic Mapping in Saphenous Vein Harvesting." Heart Surgery Forum 16, no. 5 (November 11, 2013): E248—E251. http://dx.doi.org/10.1532/hsf98.2013134.
Full textAbstract:
Background: Saphenous vein mapping provides accurate identification of the graft diameter, location of the harvest side, and quality of graft and also led to a selective leg skin incision. In this article, we aimed to compare patients who underwent coronary artery bypass graft (CABG) surgery with or without vein mapping.Methods: Patients who underwent CABG surgery with saphenous vein grafts (SVG) between January 2005 and January 2010 in our service were analyzed retrospectively. One hundred seventy-eight 178 SVGs were harvested with classical methods (Group A), and 136 SVGs were harvested after Doppler ultrasonography (USG) mapping (Group B).Results: In Group A, 6.7% of patients needed additional incisions for graft harvesting than planned before CABG surgery due to unsuitable vein grafts. In Group B, SVGs were harvested from left lower extremity in 16 patients, and the saphenous vein was not suitable for grafting in 1 patient due to Doppler examination. In the postoperative period, complications at the incision site were reduced in Group B.Conclusion: Preoperative vein mapping for harvesting SVGs is an effective method in reducing wound site complications, hospital stay, and hospital costs and in increasing patient comfort and satisfaction.
16
Lee, Michael, and Jeremy Kong. "Current State of the Art in Approaches to Saphenous Vein Graft Interventions." Interventional Cardiology Review 12, no. 02 (2017): 85. http://dx.doi.org/10.15420/icr.2017:4:2.
Full textAbstract:
Saphenous vein grafts (SVGs), used during coronary artery bypass graft surgery for severe coronary artery disease, are prone to degeneration and occlusion, leading to poor long-term patency compared with arterial grafts. Interventions used to treat SVG disease are susceptible to high rates of periprocedural MI and no-reflow. To minimise complications seen with these interventions, proper stents, embolic protection devices (EPDs) and pharmacological selection are crucial. Regarding stent selection, evidence has demonstrated superiority of drug-eluting stents over bare-metal stents in SVG intervention. The ACCF/AHA/SCA American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Society for Cardiovascular Angiography and Interventions guidelines recommend the use of EPDs during SVG intervention to decrease the risk of periprocedural MI, distal embolisation and no-reflow. The optimal pharmacological treatment for slow or no-reflow remains unclear, but various vasodilators show promise.
17
Takayama, Tadateru, Naotaka Akutsu, Takafumi Hiro, Toshiyuki Oya, Daisuke Fukamachi, Hironori Haruta, Korehito Iida, et al. "A case of giant saphenous vein graft aneurysm followed serially after coronary artery bypass surgery." Open Medicine 11, no. 1 (January 1, 2016): 155–57. http://dx.doi.org/10.1515/med-2016-0030.
Full textAbstract:
AbstractSaphenous vein graft aneurysm (SVGA) is one of the chronic complications after coronary aorta bypass grafting (CABG) and may be caused by atherosclerosis-like phenomena of the vein graft, weakness around the vein valve, rupturing of the suture of the graft anastomosis, or perioperative graft injury. We describe a case of a large, growing saphenous vein graft aneurysm that was followed serially by chest radiography and computed tomography. Eighteen years after CABG, an SVGA (23 × 24 mm) was incidentally detected. The patient was asymptomatic and was followed conservatively. Four years later, coronary computed tomographic angiography showed that the giant aneurysm had grown to 52.1 by 63.8 mm and revealed a second, smaller aneurysm. Finally, the SVG was ultimately resected without bypass via off-pump surgery. Therefore, this case suggested that aggressive treatment that includes surgical intervention should be considered before the aneurysm becomes larger, even if it is asymptomatic.
18
Genoni, Michele, Dragan Odavic, Helen Loblein, and Omer Dzemali. "Use of the eSVS Mesh: External Vein Support Does Not Negatively Impact Early Graft Patency." Innovations: Technology and Techniques in Cardiothoracic and Vascular Surgery 8, no. 3 (May 2013): 211–14. http://dx.doi.org/10.1097/imi.0b013e3182a326ed.
Full textAbstract:
Objective The aim of this study was to assess early graft patency in eSVS Mesh–covered saphenous vein grafts (SVGs) in patients undergoing coronary artery bypass grafting. Methods In 20 patients meeting criteria for double arterial grafting to the left-sided coronary system and eSVS Mesh–covered SVG to the right-sided coronary system, patency was evaluated intraoperatively by transit time flow measurement and at 5 days postoperatively by computed tomographic angiography. Results Twenty patients underwent 49 arterial and 22 venous grafts (mean, 3.55/patient) using off-pump techniques. All grafts were determined to be patent intraoperatively. On computed tomographic angiography, arterial graft patency was 100%. In one venous anastomosis, the distal limb of a sequential graft was occluded, for an overall patency rate of 95%. Conclusions The eSVS Mesh does not compromise early SVG patency.
19
Demircelik, Bora, Muzaffer Cakmak, Yunus Nazli, Ozgul M. Gurel, Nermin Akkaya, Mustafa Cetin, Zehra Cetin, Yusuf Selcoki, Alparslan Kurtul, and Beyhan Eryonucu. "Adropin: A New Marker for Predicting Late Saphenous Vein Graft Disease after Coronary Artery Bypass Grafting." Clinical & Investigative Medicine 37, no. 5 (October 4, 2014): 338. http://dx.doi.org/10.25011/cim.v37i5.22014.
Full textAbstract:
Purpose: Saphenous vein graft disease (SVGD), defined as an occlusion of 50% or more of the SVG excluding distal anastomotic occlusion, is an important predictor of morbidity after coronary artery bypass grafting (CABG). Late graft occlusion is a serious complication that often limits the use of the saphenous vein as a coronary bypass graft. Late graft occlusion is particularly common in old, degenerated venous grafts with advanced atherosclerotic plaques. Adropin has been implicated in the homeostatic control of metabolism. The purpose of this study was to investigate whether serum adropin levels are associated with late SVGD following CABG. Methods: Thirty-eight patients with SVGD involving at least one graft (occluded group; 14 females, 24 males) and 42 patients with a patent saphenous vein graft (patent group; 15 females, 27 males) were enrolled in this study. Venous blood samples were taken from all of the participants to measure plasma adropin levels using an enzyme-linked immunsorbent assay kit. Results: The mean adropin level was significantly lower in the occluded group than in the patent group (3.2 ± 0.71 vs. 4.9 ± 1.51 ng/mL, p < 0.001). Multivariate regression analysis showed that the adropin level was the independent predictor of late saphenous vein graft occlusion. Conclusions: Adropin levels are lower in patients with late saphenous vein graft occlusion and these reduced adropin levels, together with other factors, may lead to saphenous vein graft occlusion. Larger and prospective studies are needed to determine if adropin plays a role in the pathogenesis of SVGD.
20
Morton, Ryan P., Anne E. Moore, Jason Barber, Farzana Tariq, Kevin Hare, Basavaraj Ghodke, Louis J. Kim, and Laligam N. Sekhar. "Monitoring Flow in Extracranial-Intracranial Bypass Grafts Using Duplex Ultrasonography: A Single-Center Experience in 80 Grafts Over 8 Years." Neurosurgery 74, no. 1 (October 1, 2013): 62–70. http://dx.doi.org/10.1227/neu.0000000000000198.
Full textAbstract:
Abstract BACKGROUND: High-flow extracranial-intracranial (EC-IC) bypass is performed by using radial artery graphs (RAGs) or saphenous vein grafts (SVGs) for various pathologies such as aneurysms, ischemia, and skull-base tumors. Quantifying the acceptable amount of blood flow to maintain proper cerebral perfusion has not been well established, nor have the variables that influence flow been determined. OBJECTIVE: To identify the normative range of blood flow through extracranial-intracranial RAGs and SVGs as measured by duplex ultrasonography. Multiple variables were evaluated to better understand their influence of graft flow. METHODS: All EC-IC grafts performed at Harborview Medical Center from 2005 to 2012 were retrospectively reviewed for this cohort study. Daily extracranial graft duplex ultrasonography with flow volumes and transcranial graft Doppler were examined, as were short- and long-term outcomes. Both ischemic and hyperemic events were evaluated in further detail. RESULTS: Eighty monitorable high-flow EC-IC bypasses were performed over the 8-year period. Sixty-five bypasses were performed by using RAGs and 15 were performed with SVGs. The average flow was 133 mL/min for RAGs and 160 mL/min for SVGs (P = .25). For both RAG and SVG groups, the donor and recipient vessel selected significantly impacted flow. For the RAG group only, preoperative graft diameter, postoperative hematocrit, and postoperative date significantly influenced flow. A 1-week average of >200 mL/min was 100% sensitive to cerebral hyperemia syndrome. CONCLUSION: This study establishes the normative range of duplex ultrasonographic flow after high-flow EC-IC bypass, as well the usefulness and practicality of such monitoring as a surrogate to flow in the postoperative period.
21
Tseng, Yuan-Hsi, Chih-Chen Kao, Chien-Chao Lin, Chien-Wei Chen, Ming-Shian Lu, Chu-Hsueh Lu, and Yao-Kuang Huang. "Do the Paths of Sequential Vein Grafts Influence the Outcomes of Coronary Artery Bypass Surgeries?" Heart Surgery Forum 23, no. 1 (January 23, 2020): E001—E006. http://dx.doi.org/10.1532/hsf.2729.
Full textAbstract:
Background: The use of a sequential vein graft (SVG) in coronary artery bypass grafting (CABG) in multi-vessel coronary disease is common. This study aimed to investigate the influence of the paths of SVGs on the outcomes of CABG.
Methods: From January 2011 to June 2017, 126 patients underwent elective isolated CABG. If the path of the SVG was from the aorta to the right coronary artery (RCA)/ posterior descending artery (PDA) to the left circumflex artery (LCX)/obtuse marginal artery (OM), the patients were included in Group R. If the path was from the aorta to the LCX/OM to the RCA/PDA, the patients were included in Group L. The in-hospital and follow-up outcomes were analyzed.
Results: Group R had 69 patients, and Group L had 57 patients. Univariate analysis showed that Group L had a higher number of grafts (P < .001) and less aortic cross-clamping time (P < .001) and total bypass time (P = .001). Otherwise, Group L had 14 patients (19.3%), who received first diagonal branch (D1) bypass grafting, while Group R had none (P < .001). In the multivariate analysis, in- hospital mortality from heart failure, postoperative acute kidney injury, medium-term mortality, and readmission for cardiac incidents were not associated with the SVG path.
Conclusion: The SVG path from the aorta to the LCX/OM to the RCA/PDA facilitated the additional D1 bypass grafting, but the outcomes for this approach were not significantly different from those for the other path.
22
Krotin, Mirjana, Miljko Ristic, Marija Zdravkovic, Danica Popovic-Lisulov, Jovica Saponjski, and Svetomir Putnik. "Large saphenous venous graft aneurysm mimicking atypical mediastinal mass." Vojnosanitetski pregled 66, no. 11 (2009): 920–23. http://dx.doi.org/10.2298/vsp0911920k.
Full textAbstract:
Background. Saphenous venous graft (SVG) aneurysm is a very rare but potentially fatal complication of the coronary artery bypass surgery. Case report. We reported a case of 72-year-old man admitted to hospital because of atypical chest pain related to body motions in horizontal position, especially to the left side. Pain was followed by dispnea, palpitations, fatigue, cough, yellow sputum expectorations, as well as elevated temperature. He had had coronary artery bypass grafting (CABG) surgery with saphenous vein grafts (SVGs) to the left anterior descending artery (LAD) and right coronary artery (RCA) 27 years earlier. Chest X-ray revealed a poor-defined shadow in the region of the right atrium. A transthoracic echocardiogram revealed an atypical tumorous mediastinal mass near the right atrium and right ventricle that seemed partially calcified on transesophaeal echocardiography (TEE). CT scan confirmed an atypical mediastinal mass in contact with the right ventricle that might be a right ventricle aneurysm, pericardial cyst or SVG aneurysm. Coronary angiography was performed subsequently and it revealed a big saphenous venous graft aneurysm originating from the previous venous graft to the RCA. The aneurysm was resected and a new bypass graft was placed. Histopathology confirmed a true aneurysm of the venous graft. Conclusion. Although SVG aneurysm is a very rare complication of CABG surgery, patients presenting with atypical hilar or mediastinal mass following CABG should always be evaluated firstly for existence of this cardiosurgical complication.
23
Baker, Thomas A., Kevin K. Byon, Beth A. Cianfrone, and John Grady. "Conceptualizing and Measuring the Use of Student-Athlete Likeness in EA’s NCAA Football." Journal of Sport Management 28, no. 3 (May 2014): 281–94. http://dx.doi.org/10.1123/jsm.2012-0257.
Full textAbstract:
The purpose of the study was twofold: a) to conceptualize and measure student-athlete “likeness” in theNCAA Footballsport video games (SVGs) and b) to examine the impact of use of likeness on SVG consumption (i.e., purchase intention and word-of-mouth). Data (N= 621) were collected fromNCAA FootballSVGs users with experience in purchasing and playing the game. Descriptive statistics,ttest, factor analysis, and hierarchical regression analyses showed that student-athlete likeness featured inNCAA FootballSVGs were well perceived by gamers. The results indicated that dimensions of the student-athlete likeness were empirically supported in that the factors (i.e., identity value and identity use) were found to be positively related to purchase intention and word-of-mouth. Results were discussed with regards to theoretical and practical implications for sport managers in the legal and consumer behavior perspective.
24
Gu, Jinlin, Mingchao Zhu, Lihua Cao, Ang Li, Wenrui Wang, and Zhenbang Xu. "Improved Uncalibrated Visual Servo Strategy for Hyper-Redundant Manipulators in On-Orbit Automatic Assembly." Applied Sciences 10, no. 19 (October 5, 2020): 6968. http://dx.doi.org/10.3390/app10196968.
Full textAbstract:
Aiming at on-orbit automatic assembly, an improved uncalibrated visual servo strategy for hyper-redundant manipulators based on projective homography is proposed. This strategy uses an improved homography-based task function with lower dimensions while maintaining its robustness to image defects and noise. This not only improves the real-time performance but also makes the joint space of hyper-redundant manipulator redundant to the homography-based task function. Considering that the kinematic parameters of the manipulator are easily changed in a space environment, the total Jacobian between the task function and manipulator joints is estimated online and used to construct a controller to directly control the manipulator joints without a kinematics model. When designing the controller, the above-mentioned redundancy is exploited to solve the problem of the over-limiting of the joint angles of the manipulator. The KF-SVSF method, which combines the optimality of the Kalman filter (KF) and the robustness of the smooth variable structure filter (SVSF), is introduced to the field of uncalibrated visual servos for the first time to perform the online estimation of the total Jacobian. In addition, the singular value filtering (SVF) method is adopted for the first time to avoid the interference caused by the unstable condition number of the estimated total Jacobian. Finally, simulations and experiments verify the superiority of this strategy in terms of its real-time performance and precision.
25
Gao, Jing, Yin Liu, and Yu-Ming Li. "Review of risk factors, treatment, and prevention of saphenous vein graft disease after coronary artery bypass grafting." Journal of International Medical Research 46, no. 12 (September 4, 2018): 4907–19. http://dx.doi.org/10.1177/0300060518792445.
Full textAbstract:
Saphenous vein graft disease (SVGD) is a type of vascular disease that may develop after coronary artery bypass grafting (CABG). SVGD seriously affects the short-term and long-term effects of CABG and increases the incidence of major adverse cardiovascular events. It is very important to identify patients at greatest risk and carry out prevention and treatment measures to determine the risk factors for SVGD. Many factors contribute to SVGD when the vein is grafted into an arterial environment, such as surgery-related factors, smoking, diabetes mellitus, hyperlipidemia, and others. In this review, we discuss the risk factors for SVGD, current surgical and pharmacologic therapies with which to manage SVGD, and the prevention of SVGD.
26
Gaudino, Mario, Faisal G. Bakaeen, Umberto Benedetto, Antonino Di Franco, Stephen Fremes, David Glineur, Leonard N. Girardi, et al. "Arterial Grafts for Coronary Bypass." Circulation 140, no. 15 (October 8, 2019): 1273–84. http://dx.doi.org/10.1161/circulationaha.119.041096.
Full textAbstract:
Observational and randomized evidence shows that arterial grafts have better patency rates than saphenous vein grafts (SVGs) in coronary artery bypass grafting. Observational studies suggest that the use of multiple arterial grafts is associated with longer postoperative survival, but this must be interpreted in the context of treatment allocation bias and hidden confounders intrinsic to the study designs. Recently, a pooled analysis of 6 randomized trials comparing the radial artery with the SVG as the second conduit and the largest randomized trial comparing the use of single and bilateral internal thoracic arteries have provided apparently divergent results about a clinical benefit with the use of >1 arterial conduit. However, both analyses have methodological limitations that may have influenced their results. At present, it is unclear whether the well-documented increased patency rate of arterial grafts translates into clinical benefits in the majority of patients undergoing coronary artery bypass grafting. A large randomized trial testing the arterial grafts hypothesis (ROMA [Randomized Comparison of the Clinical Outcome of Single Versus Multiple Arterial Grafts]) is underway and will report the results in a few years.
27
Rinfret, Stéphane, and Rustem Dautov. "When SVGs “Had Enough”." JACC: Cardiovascular Interventions 13, no. 4 (February 2020): 527–29. http://dx.doi.org/10.1016/j.jcin.2019.11.030.
Full text
28
Bandiera, Elisabetta, Roberta Franceschini, Claudia Specchia, Eliana Bignotti, Chiara Trevisiol, Massimo Gion, Sergio Pecorelli, Alessandro Davide Santin, and Antonella Ravaggi. "Prognostic Significance of Vascular Endothelial Growth Factor Serum Determination in Women with Ovarian Cancer." ISRN Obstetrics and Gynecology 2012 (June 26, 2012): 1–11. http://dx.doi.org/10.5402/2012/245756.
Full textAbstract:
Introduction. We performed a review of the literature to elucidate the potential prognostic significance of serum vascular endothelial growth factor (sVEGF) levels in ovarian cancer. Methods. Eligible studies in English and Italian were identified in MEDLINE/PubMed from VEGF discovery to October 2011. All studies evaluating: (i) sVEGF levels before any surgical and chemotherapeutic treatment; (ii) the association between sVEGF levels and the established prognostic variables; (iii) the value of sVEGF levels in predicting patients’ outcomes, were selected for this review. Results. The search resulted in 758 titles. Nine studies met the inclusion criteria. A statistically significant association between the level of sVEGF and FIGO stage, tumour grade, residual tumour size, lymph node involvement, and presence of ascites was found in at least one study. sVEGF, in comparison with the established prognostic factors, appears to be the best prognostic marker for overall survival, since it stands out as an independent prognostic factor in most of the studies considered. Moreover, sVEGF levels were shown to be independent prognostic factors by 2 out of the 3 studies that considered DFS as an end point. Conclusion. High levels of sVEGF identify a subgroup of patients with higher risk of death and/or recurrence. These patients should be eligible for individually tailored therapeutic interventions.
29
Wang, Shu, Saeid Habibi, and Richard Burton. "A COMPARATIVE STUDY OF A SMOOTH VARIABLE STRUCTURE FILTER AND THE EXTENDED KALMAN FILTER." Transactions of the Canadian Society for Mechanical Engineering 32, no. 3-4 (September 2008): 353–70. http://dx.doi.org/10.1139/tcsme-2008-0023.
Full textAbstract:
A new method of filtering strategy, referred to as the Smooth Variable Structure Filter (SVSF) is applied to the problem of state estimation on a class of nonlinear system. The SVSF is revised to reach the better estimation resolution. A comparative study is presented in which the Extended Kalman Filter (EKF) is applied to the same nonlinear system model. The estimation convergence and accuracy of the SVSF and EKF are comparable. The robustness of the SVSF to parameter variations is established through simulation results. This study is important because it allows the new SVSF to be critically compared to a standard technique such as the EKF.
30
Suwoyo, Heru, Yingzhong Tian, Wenbing Wang, Long Li, Andi Adriansyah, Fengfeng Xi, and Guangjie Yuan. "ADAPTIVE DEVELOPMENT OF SVSF FOR A FEATURE-BASED SLAM ALGORITHM USING MAXIMUM LIKELIHOOD ESTIMATION AND EXPECTATION MAXIMIZATION." IIUM Engineering Journal 22, no. 1 (January 4, 2021): 269–86. http://dx.doi.org/10.31436/iiumej.v22i1.1403.
Full textAbstract:
ABSTRACT: The smooth variable structure filter (SVSF) has been considered as the robust estimator. Like other filters, the SVSF needs an accurate system model and known noise statistics to approximate the posterior state. Unfortunately, the system cannot be accurately modeled, and the noise statistic is unknown in the real application. For these reasons, the performance of SVSF might be decreased or even led to divergence. Therefore, the enhancement of SVSF is required. This paper presents an Adaptive SVSF. Initially, SVSF is smoothed. To provide the ability to estimate the noise statistic, ASVSF is then derived based on maximum likelihood estimation (MLE) and expectation-maximization (EM). Additionally, the unbiased noise statistic is also approached. However, its covariance is complicatedly formulated. It might cause a negative definite symmetric matrix. Therefore, it is tuned based on the innovation covariance estimator (ICE). The ASVSF is designed to solve the online problem of Simultaneous Localization and Mapping (SLAM). Henceforth, it is termed as the ASVSF-SLAM algorithm. The proposed algorithm showed better accuracy and stability compared to the conventional algorithm in terms of root mean square error (RMSE) for both Estimated Path Coordinate (EPC) and Estimated Map Coordinate (EMC). ABSTRAK: Penapis struktur bolehubah lembut (SVSF) telah dianggap sebagai penganggar teguh. Seperti penapis lain, SVSF memerlukan model sistem yang tepat dan statistik hingar yang diketahui bagi menganggar keadaan posterior. Malangnya, sistem tidak dapat dimodelkan dengan tepat dan statistik hingar tidak diketahui dalam aplikasi sebenar. Atas sebab-sebab ini, prestasi SVSF mungkin berkurangan, bahkan berbeza. Oleh itu, memperbaharui SVSF adalah perlu. Kajian ini adalah mengenai SVSF Mudah Suai. Pada awalnya, SVSF dilembutkan. Bagi menyediakan keupayaan anggaran statistik hinggar, ASVSF dihasilkan terlebih dahulu berdasarkan anggaran kemungkinan maksimum (MLE) dan maksimum-harapan (EM). Tambahan, statistik hinggar yang tidak berat sebelah juga dibuat. Walau bagaimanapun, rumusan formula kovarians ini adalah kompleks. Ini mungkin menyebabkan matriks simetri menjadi negatif. Oleh itu, ia diselaraskan berdasarkan penganggar kovarians inovasi (ICE). ASVSF dibina bagi menyelesaikan masalah dalam talian Penempatan dan Pemetaan Serentak (SLAM) dalam talian. Oleh itu, ia disebut sebagai algoritma ASVSF-SLAM. Algoritma yang dicadangkan ini menunjukkan ketepatan dan kestabilan yang lebih baik berbanding algoritma konvensional dari segi ralat punca min kuasa dua (RMSE) bagi kedua-dua Koordinat Anggaran Laluan (EPC) dan Anggaran Koordinat Peta (EMC).
31
Al-Shabi, Mohammad, and Saeid Habibi. "Iterative Smooth Variable Structure Filter for Parameter Estimation." ISRN Signal Processing 2011 (June 26, 2011): 1–18. http://dx.doi.org/10.5402/2011/725108.
Full textAbstract:
The smooth variable structure filter (SVSF) is a recently proposed predictor-corrector filter for state and parameter estimation. The SVSF is based on the sliding mode control concept. It defines a hyperplane in terms of the state trajectory and then applies a discontinuous corrective action that forces the estimate to go back and forth across that hyperplane. The SVSF is robust and stable to modeling uncertainties making it suitable for fault detection application. The discontinuous action of the SVSF results in a chattering effect that can be used to correct modeling errors and uncertainties in conjunction with adaptive strategies. In this paper, the SVSF is complemented with a novel parameter estimation technique referred to as the iterative bi-section/shooting method (IBSS). This combined strategy is used for estimating model parameters and states for systems in which only the model structure is known. This combination improves the performance of the SVSF in terms of rate of convergence, robustness, and stability. The benefits of the proposed estimation method are demonstrated by its application to an electrohydrostatic actuator.
32
Chen, Yu, Luping Xu, Bo Yan, and Cong Li. "A Novel Smooth Variable Structure Smoother for Robust Estimation." Sensors 20, no. 6 (March 23, 2020): 1781. http://dx.doi.org/10.3390/s20061781.
Full textAbstract:
The smooth variable structure filter (SVSF) is a new-type filter based on the sliding-mode concepts and has good stability and robustness in overcoming the modeling uncertainties and errors. However, SVSF is insufficient to suppress Gaussian noise. A novel smooth variable structure smoother (SVSS) based on SVSF is presented here, which mainly focuses on this drawback and improves the SVSF estimation accuracy of the system. The estimation of the linear Gaussian system state based on SVSS is divided into two steps: Firstly, the SVSF state estimate and covariance are computed during the forward pass in time. Then, the smoothed state estimate is computed during the backward pass by using the innovation of the measured values and covariance estimate matrix. According to the simulation results with respect to the maneuvering target tracking, SVSS has a better performance compared with another smoother based on SVSF and the Kalman smoother in different tracking scenarios. Therefore, the SVSS proposed in this paper could be widely applied in the field of state estimation in dynamic system.
33
Wang, Haoran, Hitomi Anzai, Youjun Liu, Aike Qiao, Jinsheng Xie, and Makoto Ohta. "A Hemodynamic-Based Evaluation of Applying Different Types of Coronary Artery Bypass Grafts to Coronary Artery Aneurysms." Complexity 2020 (June 10, 2020): 1–10. http://dx.doi.org/10.1155/2020/9359340.
Full textAbstract:
Coronary artery bypass grafts (CABGs), including saphenous vein grafts (SVGs) or left internal mammary artery (LIMA) grafts, are recently applied to treat coronary artery aneurysm (CAA). Surgical outcomes are considered to be related to surgical strategies (types of the bypass graft and whether CAA ligated or not) and the size of the CAA (usually characterized by diameter). However, the understanding of the relationship between the surgical outcomes and the abovementioned factors is limited. Previous studies related to CABG treatments have shown hemodynamic studies could help evaluate surgical outcomes through graft mass flow rate, wall shear stress (WSS), and oscillatory shear index (OSI). It is believed that the hemodynamic study of applying CABGs to CAA, which is not studied yet, could help us understand the different CABG surgeries. The aim of the study was to evaluate the hemodynamic differences among different surgical methods. To do this, eight three-dimensional models were constructed, representing application of SVGs and LIMA grafts to CAAs (whether ligated or not) with diameters two, three, and five times the normal diameter, to perform computational fluid dynamics (CFD) simulation. The lumped-parameter model (LPM) was coupled to the boundary of the 3D models which increase the complexity of the simulation, but it can ensure the stability of the simulation boundary conditions. The results show that SVG (no matter whether ligated or not) hemodynamic characteristics are positive, with an average high graft mass flow rate of 70 ml/min, an average WSS of 0.479 Pa, and a low OSI of 0.001. LIMA with CAA ligation has the same characteristics with higher WSS (average 1.701 Pa). The hemodynamic characteristics of LIMA without CAA ligation are negative, including high reverse mass flow rate and high OSI (0.367). The results indicate that the surgical outcomes of LIMA with CAA ligation are likely to be the best among these models. The surgical outcomes of LIMA without CAA ligation seem to be undesirable due to the high reverse mass flow and high OSI. The CAA diameter may not have a significant effect on surgical outcomes.
34
Batyrova, Anna S., E. M. Vasilyeva, M. I. Bakanov, and A. N. Surkov. "CHANGES OF ANGIOGENIC FACTORS AND MARKERS OF ENDOTHELIAL DYSFUNCTION IN CHILDREN AND ADOLESCENTS OF WILSON-KONOVALOV DISEASE." Medical Journal of the Russian Federation 24, no. 6 (December 15, 2018): 295–98. http://dx.doi.org/10.18821/0869-2106-2018-24-6-295-298.
Full textAbstract:
Although angiogenesis is an integral part of tumor progression, it has also been observed in different inflammatory, fibrotic, and ischemic diseases. Angiogenesis is a multifactorial process and its changes bring essential information about the status of complex pathology. Aim: evaluate the role of angiogenesis and endothelial dysfunction factors in Wilson-Konovalov disease (WKD) in children and adolescents. Methods: 19 children and adolescents with WKD were included in the study. VEGF-A, angiotensin (ANG), soluble receptors of VEGF-A (sVEGF-R1 и sVEGF-R2) and trombomodulin have been investigated in serum by enzyme immunoassay using special kits (BCM Diagnostics, USA). Other endothelial dysfunction markers as von Willebrand factor (vWf) was determined in blood plasma by immunoturbidimetry (Siemens, Germany), plasminogen (PLG) was investigated due to extended coagulation. Results: it was founded marked decreasing of VEGF-A and increasing concentration of sVEGF-R1, sVEGF-R2 in blood plasma of WKD children and adolescence by comparison of reference group. ANG did not change. Comparing the ratio of levels VEGF-A+ANG/sVEGF-R1+sVEGF-R2 (in children with WKD 16,7±1,9 and in reference group 23,0±1,6, р
35
Hariri, Nasir, Hector Gutierrez, John Rakoczy, Richard Howard, and Ivan Bertaska. "Performance Characterization of the Smartphone Video Guidance Sensor as Vision-Based Positioning System." Sensors 20, no. 18 (September 16, 2020): 5299. http://dx.doi.org/10.3390/s20185299.
Full textAbstract:
The Smartphone Video Guidance Sensor (SVGS) is a vision-based sensor that computes the six-state position and orientation vector of a target relative to a coordinate system attached to a smartphone. This paper presents accuracy-characterization measurements of the Smartphone Video Guidance Sensor (SVGS) to assess its performance as a position and attitude estimator, evaluating its accuracy in linear and angular motion for different velocities and various types of targets based on the mean and standard deviation errors between SVGS estimates and known motion profiles, in both linear and angular motions. The study also examines the effects of target velocity and sampling rate on the overall performance of SVGS and provides an overall assessment of SVGS’ performance as a position/attitude estimator. While the error metrics are dependent on range and camera resolution, the results of this paper can be scaled to other operational conditions by scaling the blob size in pixels (the light markers identified in the images) relative to the total resolution (number of pixels) of the image. The error statistics of SVGS enable its incorporation (by synthesis of a Kalman estimator) in advanced motion-control systems for navigation and guidance.
36
Pihan, Morgane, Stephen Keddie, Shirley D'Sa, Andrew J. Church, Kwee L. Yong, Mary M. Reilly, and Michael P. Lunn. "Raised VEGF." Neurology - Neuroimmunology Neuroinflammation 5, no. 5 (August 15, 2018): e486. http://dx.doi.org/10.1212/nxi.0000000000000486.
Full textAbstract:
ObjectiveTo investigate the sensitivity and the specificity of serum vascular endothelial growth factor (sVEGF) for the diagnosis of polyneuropathy, organomegaly, endocrinopathy, M-protein, and skin changes (POEMS) syndrome in patients with a neuropathy (NP) and to identify confounding causes of raised vascular endothelial growth factor (VEGF) in this context to improve accuracy.MethodsWe studied the specificity and sensitivity of sVEGF for the diagnosis of POEMS syndrome in a cohort of 195 consecutive patients with an NP in serum samples from June 2009 to November 2013, including 27 untreated patients with POEMS syndrome. We then studied VEGF in other neuropathies and analyzed causes of elevated VEGF in a multiple logistic regression analysis in a larger cohort of 236 patients including 168 with a non-POEMS NP and 68 without NP.ResultsThe sensitivity of elevated sVEGF for the diagnosis of POEMS was 100%. Its specificity was 91% in patients with an NP and 92% in patients with an NP and a paraproteinemia. sVEGF was much higher in POEMS before treatment. sVEGF was not significantly elevated in any non-POEMS NP or hematologic disease group. Multiple logistic regression showed that anemia with low iron was a significant predictor for elevated sVEGF and that chronic obstructive pulmonary disease (COPD) and obstructive sleep apnoea-hypopnoea syndrome were significant predictors for very elevated sVEGF.InterpretationWe confirmed the high sensitivity and specificity of an elevated VEGF for the diagnosis of POEMS. However, VEGF testing should be repeated, particularly after acute illnesses. Raised sVEGF should be interpreted with caution unless anemias with low iron, sleep apnea, COPD, cancers, vasculitis, and chronic inflammatory diseases are excluded.Classification of evidenceThis study provides class IV evidence that elevated sVEGF levels accurately identifies patients with POEMS syndrome.
37
Stojimirovic, Biljana, Natasa Jovanovic, Jasna Trbojevic-Stankovic, Slobodan Krstic, Dejan Nesic, and Snezana Zunic-Bozinovski. "Levels of vascular endothelial growth factor during first six months of peritoneal dialysis." Srpski arhiv za celokupno lekarstvo 143, no. 9-10 (2015): 578–83. http://dx.doi.org/10.2298/sarh1510578s.
Full textAbstract:
Introduction. Chronic peritoneal dialysis (PD) up-regulates vascular endothelial growth factor (VEGF) synthesis and VEGF is found in drained dialysate (dd). Objective. Aims of this prospective study were to evaluate serum (s) and ddVEGF concentration during the first six months of PD, relationships between these concentrations and demographic and biochemical parameters, presence of diabetes, peritonitis, and the use of medications. Methods. The study included 20 patients, with the mean age of 62.9?12.69, 11 of whom were affected by diabetes mellitus. Fasting venous blood samples were taken at the beginning and after six months of PD, in tri-potassium ethylenediaminetetraacetic acid (K3EDTA) vacutainer. Results. After six months of PD, sVEGF concentrations increased significantly, without significant change in ddVEGF. Concentrations of sVEGF at the beginning of chronic PD treatment directly significantly correlated with serum fibrinogen, and after six months with fibrinogen and glycemia. In patients receiving erythropoiesis-stimulating agent (ESA), levels of sVEGF and ddVEGF were lower at baseline, while after six months of PD ddVEGF increased. In patients not receiving ESA, sVEGF increased more prominently, while ddVEGF decreased. The changes were not statistically significant. Patients receiving angiotensinconverting- enzyme inhibitor (ACEi) had sVEGF and ddVEGF levels insignificantly lower than those not using ACEi, however sVEGF significantly increased during six months of PD. After six months of PD, ddVEGF was significantly higher compared to those not using ACEi. Treatment with statins did not significantly influence levels of sVEGF and ddVEGF during the follow-up. Concentrations of sVEGF were continually lower than those of ddVEGF and increased more, while concentrations of ddVEGF were higher in patients using statins. Conclusion. Serum and drained dialysate concentrations of VEGF in PD patients were connected with poorer metabolic profile, while the role of inflammation and treatment agents should be studied further.
38
Dai, Huan Yao, Xue Song Wang, and Yong Zhen Li. "Spatial Virtual Polarization Filter Design for Radar Sensor." Advanced Materials Research 239-242 (May 2011): 768–72. http://dx.doi.org/10.4028/www.scientific.net/amr.239-242.768.
Full textAbstract:
As interferences are introduced from main-lobe direction which results in tar-get signal are masked by interference, traditional adaptive beam-forming can not suppress main-lobe interferences effectively. Polarization filtering is a main method to suppress the interference in radar and other sensor systems. Based on the spatial polarization characteristic (SPC) of antenna, a spatial virtual polarization filter (SVPF) is proposed by constructing polarization decomposition and polarization estimation of the received signal. A generalized construction method of SVPF is provided, the performance of the SVPF is given, and simulation results of the interference suppressing are illustrated. It is indicated that the proposed filter is a valid filtering technique for interference canceling. SVPF made single polarized radar own polarization information processing ability which improved radar working performance.
39
Čerba, Otakar. "SVG v kartografii." Geoinformatics FCE CTU 1 (December 17, 2006): 112–22. http://dx.doi.org/10.14311/gi.1.12.
Full textAbstract:
V červenci 2005 se ve španělském městě A Coruña konala dvacátá druhá Mezinárodní kartografická konference. Ve svém příspěvku definoval předseda Komise pro mapy a internet Mezinárodní kartografické asociace (Commission on Maps and the Internet, International Cartographic Association / Association Cartographique Internationale) Prof. Michael P. Peterson čtyři základní směry, kterými by se měl ubírat výzkum v oblasti digitální kartografie v prostředí internetu:<br />Internet Map Use,Internet Map Delivery,Internet Multimedia Mapping,Internet Mobile Mapping.<br />Cílem tohoto příspěvku je ukázat SVG (Scalable Vector Graphics) jako pravoplatného člena rodiny technologií pro tvorbu digitálních map, konkrétně pro tzv. Internet Mapping. Jednotlivé části se věnují představení SVG, možnostem využívání SVG v současné kartografii s přihlédnutím k bodům z výše uvedeného seznamu, přednostem a nedostatkům současné verze SVG a také různého aplikakčního software. Článek také obsahuje výčet možností tvorby map ve formátu SVG, včetně jejich stručného zhodnocení.
40
Liu, Huaping, Yong Qin, Ruoyu Wang, Dongfei Zhang, and Bingxiao Lu. "The Performance of the Self-Supplying Vortex Generator Jets on a High-Speed Compressor Cascade." International Journal of Turbo & Jet-Engines 36, no. 1 (March 26, 2019): 113–25. http://dx.doi.org/10.1515/tjj-2016-0056.
Full textAbstract:
Abstract The self-supplying vortex generator jet (SVGJ) is introduced to the separation control of a high-speed compressor cascade with an inlet Mach number of 0.67. A parametric investigation concerning the jet location and the injection angle is conducted numerically. The effect mechanisms of SVGJ on the cascade performance are analyzed in detail. The potentials of SVGJ at off-design points are also discussed. The vortex generated by the jet utilizing the pressure difference between the pressure surface and suction surface could enhance the fluid exchange between the boundary layer and the mainstream, thus weakening the flow separation and reducing the flow loss effectively. With a hole of diameter 0.5 mm and a jet-to-inflow mass flow ratio less than 0.3‰, the maximum loss reductions are 5.2 % at the design point and 8.0 % at the off-design point, validating the high efficiency of SVGJ. In this work, the optimum performance is obtained by the SVGJ located at xj/B=40 %, h/H=15 % with a skew angle of β=60°.
41
Ouanani, Mouloud, Boualem Tiliouine, and Malek Hammoutene. "Effect of spatial variability of ground motion on non-linear dynamic behavior of cable stayed bridges." MATEC Web of Conferences 149 (2018): 02044. http://dx.doi.org/10.1051/matecconf/201814902044.
Full textAbstract:
This present paper summarizes the main results of incoherence of Spatial Variability of Ground Motion (SVGM) component on the non-linear dynamic behavior of a Mila cable stayed bridge. The Hindy and Novack coherence model is developed for the present study in order to examine the SVGM on bridge responses, Nonlinear bridge responses are investigated in terms of transverse displacements and bending moments along the superstructure and substructure of the study bridge, as well as temporal variations of rotational ductility demands at the bridge piers ends under the incoherence SVGM component. The results are systematically compared with those obtained assuming uniform ground motion. As a general trend, it may be concluded that incoherence component of SVGM should be considered for the earthquake response assessments of cable-stayed bridges.
42
Tiryaki, Kemal Tunc, Steven Cohen, Polen Kocak, Serli Canikyan Turkay, and Sierra Hewett. "In-Vitro Comparative Examination of the Effect of Stromal Vascular Fraction Isolated by Mechanical and Enzymatic Methods on Wound Healing." Aesthetic Surgery Journal 40, no. 11 (June 8, 2020): 1232–40. http://dx.doi.org/10.1093/asj/sjaa154.
Full textAbstract:
Abstract Background Enzymatic digestion has been the gold standard for stromal vascular fraction (SVF) isolation but remains expensive and raises practical and legal concerns. Mechanical SVF isolation methods have been known to produce lower cell yields, but may potentially produce a more robust product by preserving the extracellular matrix niche. Objectives The aim of this study was to compare mechanically dissociated SVF (M-SVF) and enzymatically digested SVF (E-SVF) in terms of wound-healing efficacy. Methods Lipoaspirate was partitioned into 2 equal groups and processed by either mechanical or enzymatic isolation methods. After SVF isolation, cell counts and viabilities were determined by flow cytometry and cell proliferation rates were measured by the WST-1 test. A wound-healing scratch assay test, which is commonly used to model in-vitro wound healing, was performed with both cell cocktails. Collagen type 1 (Col1A) gene expression level, which is known for its role in wound healing, was also measured for both groups. Results As predicted, E-SVF isolated more cells (mean [standard deviation], 1.74 [3.63] × 106/mL, n = 10, P = 0.015) than M-SVF (0.94 [1.69] × 106/mL, n = 10, P = 0.015), but no significant difference was observed in cell viability. However, M-SVF expressed over 2-fold higher levels of stem cell surface markers and a 10% higher proliferation rate compared with E-SVF. In addition, the migration rate and level of Col1A gene expression of M-SVF were found to be significantly higher than those of E-SVF. Conclusions Although the cell yield of M-SVF was less than that of E-SVF, M-SVF appears to have superior wound-healing properties.
43
Frantsiyants, E. M., I. V. Kaplieva, and L. K. Trepitaki. "Levels of growth factors in the lungs affected by cancer with preventive effect of 1,3-diethylbenzimidazolium triiodide in the experiment." Research and Practical Medicine Journal 7, no. 4 (December 22, 2020): 27–35. http://dx.doi.org/10.17709/2409-2231-2020-7-4-3.
Full textAbstract:
Purpose of the study. Analyzing the dynamics of VEGF-А, TGF-β and their receptors in the lung tissues in rats with antitumor effect of 1,3-diethylbenzimidazolium triiodide (Stellanin).Material and methods. The study included white outbred rats weighing 180–220 g. The main group included males (n=27) and females (n=27) with sarcoma 45 (s45) inoculated into the subclavian vein but not developed in the lungs (2×106 cells in 0.5 ml of saline) due to the subsequent intragastric administration of Stellanin (0.4 mg/kg once a day) according to an intermittent scheme: administration for 5 days and a break for 2 days. The control group included males (n=14) and females (n=14) without treatment with growing s45 in the lungs. Intact groups included 5 males and 5 females. After 4, 5 and 8 weeks of the experiment animals were decapitated, and levels of VEGF-A, sVEGF-R1, sVEGF-R2, TGF-β and sTGFβR2 were measured in 10% lung homogenates by ELISA (CUSABIO BIOTECH Co., Ltd., China).Results. Lung tissues of intact females showed 1.4 times (p<0.05) lower VEGF-А and 3.3 times higher sVEGF-R1, compared to males. The development of tumors in all control rats was accompanied by the VEGF-А increase (by 1.6–3.0 times) and the TGF-β reduction (by 3 times). The dynamics of both VEGF receptors differed in males and females. The levels of sVEGF-R1 in males increased by 1.5 times (p<0.05), while in females it decreased by 1.8 times (p<0.05), and as a result, the levels became similar in all animals. The levels of sVEGF-R2 in males decreased by 2 times, and in females it increased by 1.4 times (p<0.05), so the sVEGF-R2 content in females became 2.4 times higher than in males. In two-thirds of rats, Stellanin prevented s45 development in the lungs due to inhibition of VEGF-A growth by more than 2.0 times and an increase in concentrations of sVEGF-R1 by 10.0 times and TGF-β by 6.0 times, together with normalization of sVEGF-R2 and sTGFβR2.Conclusions. Stellanin prevents the development of malignant process in the lungs by inhibiting neoangiogenesis (deficiency of VEGF-A and excess of sVEGF-R1) and suppressing the proliferation of malignant cells (TGF-β growth).
44
Magalon, Jérémy, Mélanie Velier, Stéphanie Simoncini, Pauline François, Baptiste Bertrand, Aurélie Daumas, Audrey Benyamine, et al. "Molecular profile and proangiogenic activity of the adipose-derived stromal vascular fraction used as an autologous innovative medicinal product in patients with systemic sclerosis." Annals of the Rheumatic Diseases 78, no. 3 (January 5, 2019): 391–98. http://dx.doi.org/10.1136/annrheumdis-2018-214218.
Full textAbstract:
ObjectiveThe autologous stromal vascular fraction (SVF) from adipose tissue is an alternative to cultured adipose-derived stem cells for use in regenerative medicine and represents a promising therapy for vasculopathy and hand disability in systemic sclerosis (SSc). However, the bioactivity of autologous SVF is not documented in this disease context. This study aimed to compare the molecular and functional profiles of the SVF-based medicinal product obtained from SSc and healthy subjects.MethodsGood manufacturing practice (GMP)-grade SVF from 24 patients with SSc and 12 healthy donors (HD) was analysed by flow cytometry to compare the distribution of the CD45− and CD45+ haematopoietic cell subsets. The ability of SVF to form a vascular network was assessed using Matrigel in vivo assay. The transcriptomic and secretory profiles of the SSc-SVF were assessed by RNA sequencing and multiplex analysis, respectively, and were compared with the HD-SVF.ResultsThe distribution of the leucocyte, endothelial, stromal, pericyte and transitional cell subsets was similar for SSc-SVF and HD-SVF. SSc-SVF retained its vasculogenic capacity, but the density of neovessels formed in SVF-loaded Matrigel implanted in nude mice was slightly decreased compared with HD-SVF. SSc-SVF displayed a differential molecular signature reflecting deregulation of angiogenesis, endothelial activation and fibrosis.ConclusionsOur study provides the first evidence that SSc does not compromise the vascular repair capacity of SVF, supporting its use as an innovative autologous biotherapy. The characterisation of the specific SSc-SVF molecular profile provides new perspectives for delineating markers of the potency of SVF and its targets for the treatment of SSc.
45
Kandasamy, Yogavijayan, Leo Hartley, and Donna Rudd. "Vascular Endothelial Growth Factor-A Levels in Term Neonates." Journal of Child Science 07, no. 01 (January 2017): e151-e154. http://dx.doi.org/10.1055/s-0037-1612596.
Full textAbstract:
AbstractVascular endothelial growth factor-A (VEGF-A) plays an integral role in physiological and pathophysiological angiogenesis and has increasingly been implicated in the development of retinopathy of prematurity (ROP) in preterm infants. Application of intravitreal anti-VEGF is frequently used to treat ROP with little consideration given to the role of VEGF-A in neonatal growth and development. Previous studies have demonstrated systemic anti-VEGF persistence, reduced peripheral VEGF levels following treatment, and possible diagnostic and prognostic uses for VEGF-A determination. This study seeks to determine a normal range for serum VEGF-A (sVEGF-A) in healthy, term infants. The sVEGF-A levels were obtained from 32 neonates born at term infants (16 males and 16 females) using an enzyme-linked immunosorbent assay. No significant correlations were found between sVEGF-A levels and time of sample collection, birth weight, or gender. The median sVEGF-A level was 976 (394–1635) pg/mL (95% confidence interval for median: 496–1,318 pg/mL). This preliminary study determines a normal range for the sVEGF-A level in healthy, term neonates. This normal range will provide a tool to assist in the diagnosis, prognosis, and monitoring of treatment of infants with ROP.
46
Xie, Shaofeng, Yiming Zhang, and Hui Wang. "A Novel Co-Phase Power Supply System for Electrified Railway Based on V Type Connection Traction Transformer." Energies 14, no. 4 (February 23, 2021): 1214. http://dx.doi.org/10.3390/en14041214.
Full textAbstract:
Power quality and neutral section are two technical problems that hinder the development of electrified railway to high-speed and heavy railway. The co-phase power supply technology is one of the best ways to solve these two technical problems. At present, a V type connection traction transformer is widely used in a power frequency single-phase AC traction power supply system, especially in high-speed railway. In this paper, a new type of co-phase power supply system for electrified railway based on V type connection traction transformer is proposed. One single-phase winding in the V type connection traction transformer is used as main power supply channel, and three ports are used as compensation ports. Neutral section is no longer set with traction substation, and the train is continuously powered through. The independent single-phase Static Var Generators (SVGs) are used to compensate the three-phase imbalance caused by single-phase traction load. When necessary, the power factor can be improved at the same time. The principle, structure, control strategy, and capacity configuration of the technical scheme are analyzed in this paper, and the effectiveness of the scheme is verified by using the measured data of electrified railway. The advantage of this scheme lies in the universal applicability of the V type connection traction transformer, and the flexibility of the SVG device.
47
Sharun, Khan, Abhijit M. Pawde, Rohit Kumar, E. Kalaiselvan, Prakash Kinjavdekar, Kuldeep Dhama, and Amar Pal. "Standardization and characterization of adipose-derived stromal vascular fraction from New Zealand white rabbits for bone tissue engineering." Veterinary World 14, no. 2 (February 25, 2021): 508–14. http://dx.doi.org/10.14202/vetworld.2021.508-514.
Full textAbstract:
Background and Aim: Adipose tissue-derived stromal vascular fraction (SVF) contains a heterogeneous cell population comprising multipotent adipose-derived stem cells. Regenerative therapy using adipose-derived SVF has broad applications in bone tissue engineering due to the superior osteogenic potential of SVF. This study was designed to standardize and characterize adipose-derived SVF obtained from New Zealand white rabbits for bone tissue engineering and other potential applications. Materials and Methods: Ten skeletally mature and clinically healthy adult New Zealand white rabbits were used in this study. The SVF was prepared using surgically resected interscapular adipose tissue following enzymatic digestion with 0.1% collagenase type I solution. The SVF pellet obtained after the final centrifugation step was suspended in a 0.5 mL control solution to obtain ready-to-use adipose-derived SVF. The freshly prepared SVF was characterized based on the total SVF cell count and cell yield per gram of adipose tissue. The SVF cells were enumerated using a hemocytometer. Results: Interscapular adipose tissue depots are ideal for preparing autologous adipose-derived SVF due to the ease of access. The interscapular adipose-derived SVF prepared by enzymatic digestion had an average cell yield of 3.15±0.09×106 cells/g adipose tissue. Freshly prepared SVF had a total cell count of 3.15±0.09×104 cells/μL. Conclusion: The enzymatic digestion of adipose tissue using 0.1% collagenase resulted in better cell yield per gram than methods previously reported in rabbits. The use of adipose-derived SVF can preclude the requirement for an additional culture period. In addition, it may also reduce the risk of extensive cell contamination, which makes it a safe and cost-effective strategy for bone tissue engineering applications.
48
Shi, Xin Chun, Wei Zhang, and Pei Ran Liu. "Study on SVG Simulation with the Voltage and Current Dual Closed-Loop PWM Control Strategy." Advanced Materials Research 732-733 (August 2013): 1265–70. http://dx.doi.org/10.4028/www.scientific.net/amr.732-733.1265.
Full textAbstract:
This paper first introduced the SVG main circuit and the basic principles of SVG, then finished SVG modeling in dq coordinate process. Then an SVG direct current control method was proposed as well. Considering stability requirement to the DC side voltage, the paper designed voltage and current dual closed-loop PWM control system. Finally, SVG system was simulated using the Matlab/simulink. Results show that SVG has a good dynamic performance, verifying the correctness and validity of the dual closed-loop control.
49
Nishio, Shoko, and Fumiko Ito. "Application of Method for Calculating Sky View Factor Using Google Street View: Relation Between Sky View Factor and Physical Elements in Urban Space." Proceedings of the ICA 2 (July 10, 2019): 1–8. http://dx.doi.org/10.5194/ica-proc-2-92-2019.
Full textAbstract:
<p><strong>Abstract.</strong> We applied a computation method of calculating the sky view factor (SVF) using Google Street View to Shibuya area, Tokyo, for the purpose of examining the relation between the SVF/SVF change and physical elements. The distribution of the SVF calculated by the above method was visualized, and the statistical process showed the tendency of a high SVF in quasi-residential districts and roadsides of high-graded trunk roads. The difference in the SVF change was small at 10-m intervals. The SVF change tended to be more apparent near an intersection and at different elevations.</p>
50
LeBlanc, Amanda J., Jeremy S. Touroo, James B. Hoying, and Stuart K. Williams. "Adipose stromal vascular fraction cell construct sustains coronary microvascular function after acute myocardial infarction." American Journal of Physiology-Heart and Circulatory Physiology 302, no. 4 (February 15, 2012): H973—H982. http://dx.doi.org/10.1152/ajpheart.00735.2011.
Full textAbstract:
A three-dimensional tissue construct was created using adipose-derived stromal vascular fraction (SVF) cells and evaluated as a microvascular protection treatment in a myocardial infarction (MI) model. This study evaluated coronary blood flow (BF) and global left ventricular function after MI with and without the SVF construct. Fischer-344 rats were separated into four groups: sham operation (sham), MI, MI Vicryl patch (no cells), and MI SVF construct (MI SVF). SVF cells were labeled with green fluorescent protein (GFP). Immediately postinfarct, constructs were implanted onto the epicardium at the site of ischemia. Four weeks postsurgery, the coronary BF reserve was significantly decreased by 67% in the MI group and 75% in the MI Vicryl group compared with the sham group. The coronary BF reserve of the sham and MI SVF groups in the area at risk was not significantly different (sham group: 83 ± 22% and MI SVF group: 57 ± 22%). Griffonia simplicifolia I and GFP-positive SVF immunostaining revealed engrafted SVF cells around microvessels in the infarct region 4 wk postimplant. Overall heart function, specifically ejection fraction, was significantly greater in MI SVF hearts compared with MI and MI Vicryl hearts (MI SVF: 66 ± 4%, MI: 37 ± 8%, and MI Vicryl: 29 ± 6%). In conclusion, adipose-derived SVF cells can be used to construct a novel therapeutic modality for treating microvascular instability and ischemia through implantation on the epicardial surface of the heart. The SVF construct implanted immediately after MI not only maintains heart function but also sustains microvascular perfusion and function in the infarct area by sustaining the coronary BF reserve.