Effects of thermal boundary conditions on natural convection in a square enclosure with an inner circular cylinder differdentially heated from bottom wall

Paper presented to the 10th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Florida, 14-16 July 2014.Two-dimensional numerical simulations are carried out for natural convection in an enclosure with a hot inner cylinder located at the center for four different Rayleigh numbers of 103, 104, 105 and 106. The immersed boundary method (IBM) was used to handle the virtual surface of the inner circular cylinder with a no-slip boundary condition. The Prandtl number Pr was taken to be 0.7 corresponding to that of air. This study focuses on the effect of the temperature variation of bottom wall of the enclosure on thermal and flow structures of natural convection. The results indicate negligible changes in thermal and flow structures based on variations in the size of the local heating zone on the bottom wall at Ra =103 and 104, although there is a small variation in the convection velocity in the enclosure. At Ra = 105, small inner vortices formed in the lower part of the cylinder show significant changes in their size with increases due to increasing the bottom wall temperature. At Ra = 106, the magnitude of convection velocity becomes much larger than that when Ra = 105. As a result, much stronger rising plumes than those for Ra = 105 were formed on the top of the cylinder. And the secondary vortices form and separate above the bottom surface of the cylinder. The generation and dissolution of vortices are dependent mainly on the temperature of bottom wall in the enclosure.dc201

Complications Following Outside-in and Inside-out Transobturator-Tape Procedures with Concomitant Gynecologic Operations

This study was undertaken to compare the complications of outside-in transobturator tape procedures (TOT) and inside-out transobturator tape procedures (TVT-O) with concomitant gynecologic surgery for the treatment of female stress urinary incontinence (SUI). A retrospective review of 206 consecutive patients who underwent either TOT or TVT-O with concomitant gynecologic operations between March 2008 and February 2011 was conducted. The incidence of perioperative complications was compared. For statistical analysis, chi-squared tests were used. There were no reports of intraoperative complications such as vaginal injury or bladder perforation. Postoperative complications were noted in 23 procedures (11.2%). These included 6 cases of urinary retention (2.9%), 2 cases of vulva hematoma (1.0%), 7 cases of urinary tract infection (3.4%), 4 cases of de novo urgency (2.9%), and 4 cases of vaginal erosion (2.9%). There were no significant differences in complication rates between the two groups. Our results suggest that inside-out and outside-in procedures are simple and safe techniques that may have a low rate of complications when used with a concomitant gynecologic operation

Effects of Combined Therapy with Ezetimibe Plus Simvastatin After Drug-Eluting Stent Implantation in a Porcine Coronary Restenosis Model

The aim of this study was to examine the anti-proliferative and anti-inflammatory effects of ezetimibe/simvastatin (E/S) after drug-eluting stent (DES) implantation in a porcine coronary restenosis model. Pigs were randomized into two groups in which the coronary arteries (23 pigs) had DES. Stents were deployed with oversizing (stent/artery ratio 1.3:1) in porcine coronary arteries. Fifteen pigs were taken 10/20 mg of E/S and eight pigs were not taken E/S. Histopathologic analysis was assessed at 28 days after stenting. In neointima, most inflammatory cells were lymphohistiocytes. Lymphohistiocyte count was not different between two groups (337±227 vs. 443±366 cells, P=0.292), but neointima area was significantly smaller (1.00±0.49 mm2 vs. 1.69±0.98 mm2, P=0.021) and percent area stenosis was significantly lower (23.3±10% vs. 39±19%, P=0.007) in E/S group compared with control group. There were no significant differences in fibrin score (1.99±0.79 vs. 1.81±0.88, P=0.49), endothelial score (1.75±0.66 vs. 1.80±0.59, P=0.79), and the percent of endothelium covered lumen (43±21% vs. 45±21%, P=0.84) between E/S group and control group. Combined therapy with ezetimibe and simvastatin inhibits neointimal hyperplasia, but does not inhibit inflammatory infiltration and arterial healing after DES implantation in a porcine coronary restenosis model

Tenofovir disoproxil fumarate monotherapy for nucleos(t)ide analogue-naïve and nucleos(t)ide analogue-experienced chronic hepatitis B patients

Background/AimsThis study investigated the antiviral effects of tenofovir disoproxil fumarate (TDF) monotherapy in nucleos(t)ide analogue (NA)-naive and NA-experienced chronic hepatitis B (CHB) patients.MethodsCHB patients treated with TDF monotherapy (300 mg/day) for ≥12 weeks between December 2012 and July 2014 at a single center were retrospectively enrolled. Clinical, biochemical, and virological parameters were assessed every 12 weeks.ResultsIn total, 136 patients (median age 49 years, 96 males, 94 HBeAg positive, and 51 with liver cirrhosis) were included. Sixty-two patients were nucleos(t)ide (NA)-naïve, and 74 patients had prior NA therapy (NA-exp group), and 31 patients in the NA-exp group had lamivudine (LAM)-resistance (LAM-R group). The baseline serum hepatitis B virus (HBV) DNA level was 4.9±2.3 log IU/mL (mean±SD), and was higher in the NA-naïve group than in the NA-exp and LAM-R groups (5.9±2.0 log IU/mL vs 3.9±2.0 log IU/mL vs 4.2±1.7 log IU/mL, P<0.01). The complete virological response (CVR) rate at week 48 in the NA-naïve group (71.4%) did not differ significantly from those in the NA-exp (71.3%) and LAM-R (66.1%) groups. In multivariate analysis, baseline serum HBV DNA was the only predictive factor for a CVR at week 48 (hazard ratio, 0.809; 95% confidence interval, 0.729-0.898), while the CVR rate did not differ with the NA experience.ConclusionsTDF monotherapy was effective for CHB treatment irrespective of prior NA treatment or LAM resistance. Baseline serum HBV DNA was the independent predictive factor for a CVR

Relation between Anemia and Vulnerable Coronary Plaque Components in Patients with Acute Coronary Syndrome: Virtual Histology-Intravascular Ultrasound Analysis

The aim of the present study was to evaluate the plaque components and the predictors of thin-cap fibroatheroma (TCFA) in anemic patients with acute coronary syndrome using virtual histology-intravascular ultrasound (VH-IVUS). Anemia was defined according to criteria of the World Health Organization, (i.e. , hemoglobin levels < 13 g/dL in men and < 12 g/dL in women) and we compared VH-IVUS findings between anemia group (171 patients, 260 lesions) and non-anemia group (569 patients, 881 lesions). Anemia group had greater % necrotic core (NC) volume (21% ± 9% vs 19% ± 9%, P = 0.001) compared with non-anemia group. Hemoglobin level correlated negatively with absolute NC volume (r = -0.235, P < 0.001) and %NC volume (r = -0.209, P < 0.001). Independent predictors of TCFA by multivariate analysis were diabetes mellitus (odds ratio [OR], 2.213; 95% confidence interval [CI], 1.403-3.612, P = 0.006), high-sensitivity C-reactive protein (OR, 1.143; 95% CI, 1.058-1.304, P = 0.012), microalbuminuria (albumin levels of 30 to 300 mg/g of creatinine) (OR, 2.124; 95% CI, 1.041-3.214, P = 0.018), and anemia (OR: 2.112; 95% CI 1.022-3.208, P = 0.028). VH-IVUS analysis demonstrates that anemia at the time of clinical presentation is associated with vulnerable plaque component in patients with acute coronary syndrome