Stopping microfluidic flow

We present a cross-comparison of three stop-flow configurations--such as low-pressure (LSF), high-pressure open-circuit (OC-HSF), and high-pressure short-circuit (SC-HSF) stop-flow--to rapidly bring a high flow velocity within a microchannel to a standstill. The average velocities inside the microchannels were reduced from > 1 m/s to < 10 um/s within 2s of initiating the stop-flow. The performance of the three stop-flow configurations was assessed by measuring the residual flow velocities within microchannels having three orders-of-magnitude different flow resistances. The LSF configuration outperformed the OC-HSF and SC-HSF configurations within the high flow resistance microchannel, and resulted in a residual velocity of < 10 um/s. The OC-HSF configuration resulted in a residual velocity of < 150 um/s within a low flow resistance microchannel. The SC-HSF configuration resulted in a residual velocity of < 200 um/s across the three orders-of-magnitude different flow resistance microchannels, and < 100 um/s for the low flow resistance channel. We hypothesized that the residual velocity resulted from the compliance in the fluidic circuit, which was further investigated by varying the elasticity of the microchannel walls and the connecting tubing. A numerical model was developed to estimate the expanded volumes of the compliant microchannel and connecting tubings under a pressure gradient and to calculate the distance traveled by the sample fluid. A comparison of the numerically and experimentally obtained traveling distances confirmed our hypothesis that the residual velocities were an outcome of the compliance in the fluidic circuit. Therefore, a configuration where the fluidic circuit compliance was minimal resulted in the least residual velocity

Anthocyanin-rich New Zealand blackcurrant extract enhances whole-body resting fat oxidation in physically active males

Background: New Zealand blackcurrant extract has been shown to enhance exercise-induced fat oxidation during walking and cycling. We examined the effects of 14-day intake of New Zealand blackcurrant extract on the metabolic and physiological responses during supine rest in males. Methods: Healthy physically active males (n=16, age: 24±6 yr, body mass: 78±16 kg, height 178±6 cm, BMI: 24.7±4.1 kg·m-2 (8 normal weight, 7 overweight, 1 obese), body fat: 15±6%) volunteered. Participants were tested at baseline (no supplementation) and after 14-days intake of New Zealand blackcurrant extract in a randomized, crossover design. Two capsules of New Zealand blackcurrant extract (600 mg containing 210 mg of anthocyanins) were consumed every morning with breakfast. The last 2 capsules were taken two hours before the visit with one slice of bread and water 3 hours before the visits. There were no differences for carbohydrate, fat, and protein intake between the visits. Resting expired air was collected for two times for 10 min with Douglas bags and recording of heart rate. Rates of whole-body resting fat and carbohydrate oxidation were calculated. Responses for the 10 min with the lowest minute ventilation were analysed. Results: During supine rest, there was no effect on heart rate (baseline: 61±10, 14-day: 61±10 beats·min-1, P=0.96), minute ventilation (baseline: 8.10±1.43, 14-day: 7.82±0.98 L·min-1, (P=0.38), oxygen uptake (baseline: 0.293±0.060, 14-day: 0.285±0.057 L·min-1, P=0.43), carbon dioxide production (baseline: 0.245±0.051, 14-day: 0.233±0.041 L·min-1, P=0.24) and energy expenditure (baseline: 1.49±0.30, 14-day: 1.44±0.27 kcal·min-1, P=0.33). Lower respiratory exchange ratio (baseline: 0.840±0.045, 14-day: 0.820±0.058, P=0.03), higher fat oxidation (baseline: 0.078±0.031, 14-day: 0.088±0.043 g·min-1, P=0.05), and lower carbohydrate oxidation (baseline: 0.168±0.062, 14-day: 0.134±0.066 g·min-1, P=0.03) were observed with 14-day intake of New Zealand blackcurrant extract during supine rest. Twelve participants (75%) had higher fat oxidation during supine rest with for those an increase of 21±17%. Conclusions: Whole-body fat oxidation during supine rest was enhanced by 14-day intake of New Zealand blackcurrant extract in males. Enhanced whole-body resting fat oxidation may be due to combined effects of an increase in lipolysis, an increase in blood flow, and increased metabolic handling of fatty acids in the muscle. Our observations on resting substrate oxidation in the present study may indicate that New Zealand blackcurrant extract has application for weight management. However, the dosing strategy to maximize whole-body resting fat oxidation with intake of New Zealand blackcurrant extract is not known. Acknowledgements: Supplementation was provided by Health Currancy Ltd (United Kingdom) and CurraNZ Ltd (New Zealand). Financial support for conference attendance was obtained from Blackcurrant New Zealand Inc (New Zealand)

Effects of intermittent and daily intake of anthocyanin-rich New Zealand blackcurrant extract on cardiovascular function during supine rest in healthy males

Background: Intake of polyphenols results in plasma bioavailability of metabolites that can last for days. Studies have mostly employed dosing protocols that examined observations following acute or daily prolonged intake. We examined the effects of intermittent and daily intake of New Zealand blackcurrant (NZBC) extract over a 14-day period on cardiovascular function during supine rest. Methods: Healthy physically active males (n=15, age: 24±6 yr, body mass: 78±16 kg, height 177±7 cm, BMI: 24.7±4.3 kg·m-2 (8 normal weight, 6 overweight, 1 obese), body fat: 15±5%) volunteered. Participants visits included resting measurements at baseline (no supplementation), after 14-day intermittent intake (14-I, i.e. every other day) and 14-day daily intake (14-D) of two NZBC extract capsules (210 mg of anthocyanins for two capsules). Last dose was consumed one hour after breakfast of one slice of bread and water and 2 hours before visiting the laboratory. Cardiovascular measurements were obtained with a beat-to-beat blood pressure monitoring system (Portapres® Model 2, Finapres Medical Systems BV, Enschede, The Netherlands). Expired air was collected for two times for 10 min with Douglas bags and volumes measured. Cardiovascular observations during the 10 min with the lowest minute ventilation were analysed. Result: During supine rest, there was no effect on heart rate and systolic blood pressure. Lower diastolic blood pressure was recorded and similar for intake conditions [baseline: 70±7, 14-I: 64±5 (P<0.01, d= -0.99), 14-D: 63±9 mmHg (P<0.05, d= -0.87)]. Lower mean arterial pressure was recorded and similar for intake conditions [baseline: 87±7, 14-I: 81±6 (P<0.01, d= -0.92), 14-D: 81±9 mmHg (P=0.03, d= -0.74)]. Higher stroke volume was recorded only for 14-day daily intake [baseline: 94.9±13.4, 14-I: 100.0±14.3, 14-D: 103.1±18.1 mL (P=0.01, d=0.51)]. Cardiac output was higher with a trend for change at 14-day intermittent and a change with 14-day daily intake [baseline: 5.68±0.71, 14-I: 6.15±0.90 (P=0.05, d=0.58), 14-D: 6.14±0.88 L·min-1 (P=0.02, d=0.58)]. Total peripheral resistance was reduced and similar for intake conditions (baseline: 15.67±2.85, 14-I: 13.59±2.50 (P<0.01, d= -0.78), 14-D: 13.43±2.61 mmHg·min·L-1 (P<0.01, d= -0.82)]. Conclusions: Beneficial effects of intake of anthocyanin-rich NZBC extract on resting cardiovascular function can be obtained by intermittent (i.e. every other day) intake of 210 mg of anthocyanins. Future work may want to address the effects of longer intermittent intake than the 2-weeks employed in our study. It would also be of interest to examine plasma bioavailability of anthocyanin-derived metabolites with intermittent intake of NZBC extract. Acknowledgements: Supplementation was provided by Health Currancy Ltd (United Kingdom) and CurraNZ Ltd (New Zealand). Financial support for conference attendance was obtained from Blackcurrant New Zealand Inc (New Zealand)

Acute effects of anthocyanin-rich New Zealand blackcurrant extract on cardiovascular function during supine rest in healthy males

Background: Polyphenols in fruits and vegetables provide anti-oxidant, anti-inflammatory and anti-atherosclerotic effects. Reduced risk for cardiovascular disease is likely associated with the effects by polyphenols on blood pressure and arterial stiffness. Studies with 7-day intake of New Zealand blackcurrant extract showed changes during supine rest for cardiovascular parameters. We examined the effects of an acute intake of New Zealand blackcurrant extract on cardiovascular function during supine rest in healthy males. Methods: Healthy physically active males (n=15, age: 24±6 yr, body mass: 78±16 kg, height 177±7 cm, BMI: 24.7±4.3 kg·m-2 (8 normal weight, 6 overweight, 1 obese), body fat: 15±5%) volunteered. Participants visited the laboratory for resting measurements at baseline (no supplementation) and 2 hours after intake of two capsules with New Zealand blackcurrant extract (600 mg containing 210 mg of anthocyanins). Capsules were taken one hour after breakfast of one slice of bread and water and 2 hours before testing. After being seated in a chair for 10 min, participants were asked to lie horizontally on a massage table for resting measurements. Whole body cardiovascular measurements were obtained with a beat-to-beat blood pressure monitoring system (Portapres® Model 2, Finapres Medical Systems BV, Enschede, The Netherlands). Expired air was collected for two times for 10 min with Douglas bags and volume measured. Cardiovascular observations during the 10 min with the lowest minute ventilation were analysed. Results: At supine rest, there was no effect on heart rate, systolic blood pressure, diastolic blood pressure, mean arterial pressure and stroke volume. However, 10 out of 15 participants had lower systolic and diastolic blood pressure values with acute intake of New Zealand blackcurrant extract. There was a trend for cardiac output to be higher by 5% (baseline: 5.68±0.71, NZBC: 5.99±0.98 L·min-1, P=0.09, d=0.36). Total peripheral resistance was reduced by 7% (baseline: 15.67±2.85, NZBC: 14.45±3.04 mmHg·min·L-1, P<0.05, d= -0.41). Conclusions: In previous work, we observed with 7- and 14-day intake of New Zealand blackcurrant extract larger changes in cardiac output and total peripheral resistance than in the present study. Our observations indicate only a moderate effect on cardiovascular function at rest with acute intake. Future studies need to address whether an acute intake of New Zealand blackcurrant extract is effective in people with hypertension or peripheral arterial disease. Acknowledgements: Supplementation was provided by Health Currancy Ltd (United Kingdom) and CurraNZ Ltd (New Zealand). Financial support for conference attendance was obtained from Blackcurrant New Zealand Inc (New Zealand)

Comparison of Methods for Detection of Blastocystis Infection in Routinely Submitted Stool Samples, and also in IBS/IBD Patients in Ankara, Turkey

BACKGROUND: This study compared diagnostic methods for identifying Blastocystis in stool samples, and evaluated the frequency of detection of Blastocystis in patients with irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD). RESULTS AND DISCUSSION: From a set of 105 stool specimens submitted for routine parasitological analysis, 30 were identified as positive for Blastocystis by the culture method. From that group of 30 positives, Lugol's stain, trichrome staining, and an immunofluorescence assay identified 11, 15, and 26 samples as positive respectively. Using culture as a standard, the sensitivity of Lugol's stain was 36.7%, trichrome staining was 50%, and the IFA stain was 86.7%. The specificity of Lugol's stain was 91%, trichrome staining was 100%, and the IFA stain was 97.3%. In the group of 27 IBS and IBD patients, using all methods combined, we detected Blastocystis in 67% (18/27) of the patients. Blastocystis was detected in 33% (2/6) of IBD patients and 76% (16/21) of IBS patients. For comparison, trichrome staining alone, the method most frequently used in many countries, would have only identified Blastocystis infection in 29% (6/21) of the IBS patients. No parasitic co-infections were identified in the IBS/IBD patients. Most Blastocystis-positive IBS/IBD patients were over 36 with an average length of illness of 4.9 years. CONCLUSIONS: Most IBS patients in this study were infected with Blastocystis. IFA staining may be a useful alternative to stool culture, especially if stool specimens have been chemically preserved

Conformal slant submersions

WOS: 000464826500003As a generalization of conformal holomorphic submersions and conformal anti-invariant submersions, we introduce a new conformal submersion from almost Hermitian manifolds onto Riemannian manifolds, namely conformal slant submersions. We give examples and find necessary and sufficient conditions for such maps to be harmonic morphism. We also investigate the geometry of foliations which are arisen from the definition of a conformal submersion and obtain a decomposition theorem on the total space of a conformal slant submersion. Moreover, we find necessary and sufficient conditions of a conformal slant submersion to be totally geodesic.Scientific and Technological Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [114F339]This paper is supported by The Scientific and Technological Council of Turkey (TUBITAK) with number (114F339)

Golden maps between golden Riemannian manifolds and constancy of certain maps(vol 19, pg 333, 2014)

WOS: 00040933960001

CONFORMAL ANTI-INVARIANT RIEMANNIAN MAPS TO KAHLER MANIFOLDS

WOS: 000453448400020We introduce conformal anti-invariant Riemannian maps from Riemannian manifolds to almost Hermitian manifolds and show that they include both anti-invariant submanifolds and anti-invariant Riemannian maps. We give non-trivial examples, investigate the geometry of certain distributions and obtain decomposition theorems for the base manifold. The harmonicity and totally geodesicity of conformal anti-invariant Riemannian maps are also obtained. Moreover, we study weakly umbilical conformal Riemannian maps and obtain a classification theorem for umbilical conformal anti-invariant Riemannian maps.Scientific and Technological Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [114F339]This paper is supported by the Scientific and Technological Council of Turkey (TUBITAK) under project number 114F339