377 research outputs found
Saturated Critical Heat Flux in a Multi-Microchannel Heat Sink Fed by a Split Flow System
An extensive experimental campaign has been carried out for the measurement of saturated critical heat flux in a multi-microchannel copper heat sink. The heat sink was formed by 29 parallel channels that were 199 μm wide and 756 μm deep. In order to increase the critical heat flux and reduce the two-phase pressure drop, a split flow system was implemented with one central inlet at the middle of the channels and two outlets at either end. The base critical heat flux was measured using three HFC Refrigerants (R134a, R236fa and R245fa) for mass fluxes ranging from 250 to 1500 kg/m2 s, inlet subcoolings from −25 to −5 K and saturation temperatures from 20 to 50 °C. The parametric effects of mass velocity, saturation temperature and inlet subcooling were investigated. The analysis showed that significantly higher CHF was obtainable with the split flow system (one inlet–two outlets) compared to the single inlet–single outlet system, providing also a much lower pressure drop. Notably several existing predictive methods matched the experimental data quite well and quantitatively predicted the benefit of higher CHF of the split flow
Effects of Compost on Nematode Pratylenchus SP. (Tylenchida: Pratylenchidae) Population in Patchouli
Patchouli is seen as one of the most important export commodities in Indonesia. The presence of parasitic nematode Pratylenchus sp. creates a barrier to plant cultivation. Increasing organic content in soil by applying compost in the plantation is one of approaches in controlling the nematode. This research was mainly aimed to study the effects of compost fertilization on the population growth of nematode Pratylenchus sp. and yields on patchouli. These research used a Completely Randomised Design (CRD) consisting of 12 treatments with three replicates. Selected plant was inoculated with nematodes with the following initial population: 100, 200, 300, 400, and 500 nematodes in soil with and without compost. The plant with no inoculation was used as control. The result of the research confirmed that the addition of compost was capable of suppressing the population of nematode Pratylenchus sp. as much as 58.93 - 67.31% and 40.74 - 59.19% in root and in soil of each treatment, respectively. Compost applied in each treatment positively affected the increasing amount of Patchouli oil yielded, and it could also reduce the loss as much as 18.34 - 43.36%. Trichoderma sp. was found to be dominant in compost in the treatment with its population of 2.1 × 104 propogul/g
Effects of different ACE inhibitor combinations on albuminuria: results of the GUARD study
Clinical practice guidelines recommend blockers of the renin-angiotensin system alone or in combination with other agents to reduce blood pressure and albuminuria in patients with type 2 diabetes. Dihydropyridine calcium channel blockers, however, may lower blood pressure but not albuminuria in these patients. Here we tested the hypothesis that combining an ACE inhibitor with either a thiazide diuretic or a calcium channel blocker will cause similar reductions in blood pressure and albuminuria in hypertensive type 2 diabetics. We conducted a double blind randomized controlled trial on 332 hypertensive, albuminuric type 2 diabetic patients treated with benazepril with either amlodipine or hydrochlorothiazide for 1 year. The trial employed a non-inferiority design. Both combinations significantly reduced the urinary albumin to creatinine ratio and sitting blood pressure of the entire cohort. The percentage of patients progressing to overt proteinuria was similar for both groups. When we examined patients who had only microalbuminuria and hypertension we found that a larger percentage of the diuretic and ACE inhibitor normalized their albuminuria. We conclude that initial treatment using benzaepril with a diuretic resulted in a greater reduction in albuminuria compared to the group of ACE inhibitor and calcium channel blocker. In contrast, blood pressure reduction, particularly the diastolic component, favored the combination with amilodipine. The dissociation between reductions in blood pressure and albuminuria may be related to factors other than blood pressure
In Vivo Mapping of the Choriocapillaris in High myopia: a Widefield Swept Source Optical Coherence Tomography Angiography
To report variation of choriocapillaris (CC) flow in widefield in high in myopic subjects compared with an age-matched normal control group using ultra widefield optical coherence tomography angiography (UW-OCTA). This is a Prospective, cross-sectional study. Thirty high myopia subjects and fifty healthy subjects were enrolled. Healthy and high myopia subjects were imaged with the SS-OCTA system (PLEX Elite 9000, Carl Zeiss Meditec Inc., Dublin, CA, USA). For each eye, five 12 × 12-mm OCTA volume scans were acquired. The en face CC images were then exported to imageJ and a semi-automated algorithm was used for subsequent quantitative analysis. The main outcome was a quantitative analysis of the CC. This analysis was performed in three different regions: (i) peripapillary, (ii) macular, and (iii) periphery. In addition, CC variables were further investigated in distinct fields within these three different regions. Thirty myopic eyes (32 subjects; myopic group) and fifty eyes (50 subjects; control group) without elevated myopia were included in the analysis. Mean ± SD age was 26.9 ± 2.9 years [median: 27 years; range: 20.0–40.0 years]. Mean ± SD axial length was 26.6 ± 0.6 mm [median: 26.2 mm; range: 26.1 to 28.0 mm]. Mean ± SD axial length was 26.6 ± 0.6 mm [median: 26.2 mm; range: 26.1 to 28.0 mm] in the myopic group and 23.9 ± 1.1 mm [median: 23.9 mm; range: 21.8 to 25.9 mm] in the control group. The total signal void area was significantly greater in myopic eyes compared with control group. The peripapillary region exhibited the greatest total signal void area (p < 0.0001 vs macular region, p < 0.0001 vs peripheral region). Within the macular region, the foveal area exhibited a greater total signal void area in comparison with both the parafoveal area (p < 0.0001) and the perifoveal area (p < 0.0001). In conclusion we report quantitative mapping of the choriocapillaris in myopic eyes compared with an age-matched normal control group. The CC perfusion appears to have a wide topographical variation
C-Reactive protein and risk of ESRD: results from the Trial to Reduce Cardiovascular Events With Aranesp Therapy (TREAT)
Background:
To better understand a potential association of elevated C-reactive protein (CRP) level with progression of chronic kidney disease (CKD), we examined the relationship of CRP level with the development of end-stage renal disease (ESRD) in the Trial to Reduce Cardiovascular Events With Aranesp Therapy (TREAT).
Study Design
Post hoc analysis of a randomized controlled trial.
Setting & Participants:
4,038 patients with type 2 diabetes, CKD, and anemia in TREAT.
Predictor:
Baseline serum CRP concentrations.
Outcomes:
The primary outcome was development of ESRD; secondary outcomes included doubling of serum creatinine level, a composite of ESRD/serum creatinine doubling, and a composite of death or ESRD.
Measurements:
We fit unadjusted and adjusted Cox regression models to test the association of baseline CRP level with time to the development of the outcomes of interest.
Results:
Mean age of participants was 67 years, 43% were men, and 64% were white. Approximately half (48%) the patients had CRP levels > 3.0 mg/L; 668 patients developed ESRD, and 1,270 developed the composite outcome of death or ESRD. Compared with patients with baseline CRP levels ≤ 3.0 mg/L, those with moderately/markedly elevated CRP levels (≥6.9 mg/L; 24% of patients) had a higher adjusted risk for ESRD (HR, 1.32; 95% CI, 1.07-1.63) and the composite outcome of death or ESRD (HR, 1.41; 95% CI, 1.21-1.64). Although nonsignificant, similar trends were noted in competing-risk models.
Limitations:
Results may not be generalizable to nondiabetic CKD or diabetic CKD in the absence of anemia.
Conclusions:
Elevated baseline CRP levels are common in type 2 diabetic patients with anemia and CKD and are associated with the future development of ESRD and the composite of death or ESRD
Folding mechanisms steer the amyloid fibril formation propensity of highly homologous proteins
Significant advances in the understanding of the molecular determinants of fibrillogenesis can be expected from comparative studies of the aggregation propensities of proteins with highly homologous structures but different folding pathways. Here, we fully characterize, by means of stopped-flow, T-jump, CD and DSC experiments, the unfolding mechanisms of three highly homologous proteins, zinc binding Ros87 and Ml153-149 and zinc-lacking Ml452-151. The results indicate that the three proteins significantly differ in terms of stability and (un)folding mechanisms. Particularly, Ros87 and Ml153-149 appear to be much more stable to guanidine denaturation and are characterized by folding mechanisms including the presence of an intermediate. On the other hand, metal lacking Ml452-151 folds according to a classic two-state model. Successively, we have monitored the capabilities of Ros87, Ml452-151 and Ml153-149 to form amyloid fibrils under native conditions. Particularly, we show, by CD, fluorescence, DLS, TEM and SEM experiments, that after 168 hours, amyloid formation of Ros87 has started, while Ml153-149 has formed only amorphous aggregates and Ml452-151 is still monomeric in solution. This study shows how metal binding can influence protein folding pathways and thereby control conformational accessibility to aggregation-prone states, which in turn changes aggregation kinetics, shedding light on the role of metal ions in the development of protein deposition diseases
The Risk Quotient of Sulfide Hydrogen Toward Lung Vital Capacity of People Living Around Landfill Area
Waste is one of factors causing air pollution in Palembang City. Volume of waste that should be processed increases every day, while condition of waste management service is still 70% of the total volume. The waste processing is managed by using open dumping system, which affects on the increase of air pollution. One of gases that exist as effect of the process of organic compound decomposition of anaerobic bacteria from garbage is sulfide hydrogen (H2S) pollutant which can promote health disorders, especially respiratory system. This study aimed to analyze correlation between characteristics (age, sex, nutritional status, smoking, and living distance) and the risk quotient of sulfide hydrogen concentration in air ambient to the lung capacity of people around landfillarea. This study used cross-sectional design with the sample of 78 people around landfill area. Data analysis used double logistic regression. Results showed that nutritional status (p value = 0.022, OR = 12.085) and RQ (p value = 0.016; OR = 7.547) significantly related to lung vital capacity of people around landfill area. People around landfill area having worse nutrition and lower RQ than the median were potential to have lung vital capacity disorder. The dominant variable significantly influencing to lung vital capacity of people living around Sukawinatan Landfill is nutritional status
- …