Effect of Slip velocity on Blood Flow in Catheterized Tapered Artery

Effect of slip velocity on blood flow through an arterial stenosis which is developed along a tapering wall is studied here. A uniform catheter is inserted in a stenosed tube. Blood is assumed to behave like Newtonian fluid. No slip as well as slip condition is taken in the present paper, at the arterial wall a velocity slip condition is employed and a no slip at the catheter boundary. Analytic expressions are obtained for different flow parameters and their behavior discussed through graphs. For the numerical solution of the problem, which is described by Navier-Stokes equations with appropriate boundary conditions, the Perturbation method is adopted. It is found that due to the introduction of an axial slip velocity and flow rate increases but wall shear stress decreases. The effect of tapering is also seen in the present model

Experimental investigation of performance, emission and combustion characteristics of an indirect injection multi-cylinder CI engine fuelled by blends of de-inking sludge pyrolysis oil with biodiesel

De-inking sludge can be converted into useful forms of energy to provide economic and environmental benefits. In this study, pyrolysis oil produced from de-inking sludge through an intermediate pyrolysis technique was blended with biodiesel derived from waste cooking oil, and tested in a multi-cylinder indirect injection type CI engine. The physical and chemical properties of pyrolysis oil and its blends (20 and 30 vol.%) were measured and compared with those of fossil diesel and pure biodiesel (B100). Full engine power was achieved with both blends, and very little difference in engine performance and emission results were observed between 20% and 30% blends. At full engine load, the brake specific fuel consumption on a volume basis was around 6% higher for the blends when compared to fossil diesel. The brake thermal efficiencies were about 3-6% lower than biodiesel and were similar to fossil diesel. Exhaust gas emissions of the blends contained 4% higher CO2 and 6-12% lower NOx, as compared to fossil diesel. At full load, CO emissions of the blends were decreased by 5-10 times. The cylinder gas pressure diagram showed stable engine operation with the 20% blend, but indicated minor knocking with 30% blend. Peak cylinder pressure of the 30% blend was about 5-6% higher compared to fossil diesel. At full load, the peak burn rate of combustion from the 30% blend was about 26% and 12% higher than fossil diesel and biodiesel respectively. In comparison to fossil diesel the combustion duration was decreased for both blends; for 30% blend at full load, the duration was almost 12% lower. The study concludes that up to 20% blend of de-inking sludge pyrolysis oil with biodiesel can be used in an indirect injection CI engine without adding any ignition additives or surfactants

Biological screening and docking studies of unique hybrids synthesized by conventional versus microwave assisted techniques

Purpose: To carry out the synthesis of various hybrids of 1,2,4-triazole in search of potential therapeutic enzyme inhibitory agents, and carry out docking and bovine serum albumin (BSA) binding studies on docking and bovine serum albumin (BSA) binding studies on the hybrids. Methods: The target compounds were synthesized by following a multistep protocol. Compound 1 was synthesized from 4-methoxybenzenesulfonyl chloride (a) and ethyl isonipecotate (b). Compound 1 was refluxed with hydrazine to synthesize compound 2, which was converted to compound 3 through two consecutive steps. Compound 4 and different amines (5a-5i), were utilized to synthesize an array of electrophiles (6a-6i). A series of 1,2,4-triazole hybrids (7a-7i) were synthesized at room temperature by stirring together 3 and 6a-6i. The final structures of 7a-7i were elucidated through 1H-NMR, 13C-NMR and EI-MS spectroscopy. The BSA binding studies were performed by fluorometric titration. Furthermore, antioxidant and enzyme inhibition activities were determined colorimetrically. Results: Compound 7d was the most active antioxidant agent, compared to butylated hydroxyanisole (BHA), while compounds 7d, 7e, 7f, 7g and 7i proved to be potent urease inhibitors with half-maximal inhibitory concentration (IC50) values of 19.5 ± 0.12, 21.1 ± 0.68, 18.2 ± 0.78, 19.9 ± 0.77 and 17.9 ± 0.10 µM, respectively, compared to thiourea with an IC50 of 24.3 ± 0.24 µM. Compounds 7a, 7b, 7d, and 7e exhibited high butyrylcholinesterase inhibition potential, compared to eserine. Conclusion: The synthesized compounds require studies further as potential therapeutic enzyme inhibitory agents in view of their urease inhibition as well as antioxidant activity

Use of hydrophilic and hydrophobic polymers for the development of controlled release tizanidine matrix tablets

The aim of the present study was to develop tizanidine controlled release matrix. Formulations were designed using central composite method with the help of design expert version 7.0 software. Avicel pH 101 in the range of 14-50% was used as a filler, while HPMC K4M and K100M in the range of 25-55%, Ethylcellulose 10 ST and 10FP in the range of 15 - 45% and Kollidon SR in the range of 25-60% were used as controlled release agents in designing different formulations. Various physical parameters including powder flow for blends and weight variation, thickness, hardness, friability, disintegration time and in-vitro release were tested for tablets. Assay of tablets were also performed as specified in USP 35 NF 32. Physical parameters of both powder blend and compressed tablets such as compressibility index, angle of repose, weight variation, thickness, hardness, friability, disintegration time and assay were evaluated and found to be satisfactory for formulations K4M2, K4M3, K4M9, K100M2, K100M3, K100M9, E10FP2, E10FP9, KSR2, KSR3 & KSR9. In vitro dissolution study was conducted in 900 ml of 0.1N HCl, phosphate buffer pH 4.5 and 6.8 medium using USP Apparatus II. In vitro release profiles indicated that formulations prepared with Ethocel 10 standard were unable to control the release of drug while formulations K4M2, K100M9, E10FP2 & KSR2 having polymer content ranging from 40-55% showed a controlled drug release pattern in the above mentioned medium. Zero-order drug release kinetics was observed for formulations K4M2, K100M9, E10FP2 & KSR2. Similarity test (f2) results for K4M2, E10FP2 & KSR2 were found to be comparable with reference formulation K100M9. Response Surface plots were also prepared for evaluating the effect of independent variable on the responses. Stability study was performed as per ICH guidelines and the calculated shelf life was 24-30 months for formulation K4M2, K100M9 and E10FP2

Agro-morphological characterization of upland rice accessions

The agro-morphological characterization is fundamental in order to provide information for plant breeding programs. The aim of the present study was to characterize 146 accessions of upland rice (Oryza sativa L.), based on qualitative and quantitative agro-morphological descriptors. The experiment was conducted in Recife, state of Pernambuco, Brazil, using a randomized block design with three replicates. Polymorphism was observed among 12 of 14 qualitative characters evaluated, whereas significant differences (p < 0.05) were observed for 11 of the 14 analysed quantitative traits. Genetic variance was higher than environmental variance and the average inheritability coefficients were above 80 % for all characters, which ensures the predominance of the genetic components in the differences observed among accessions. On the cluster analysis for qualitative traits the accessions were classified in two groups with a total of 18 duplicates, whereas for the quantitative traits three groups were obtained with few subgroups. The principal component analysis for quantitative traits showed great dispersion of the accessions. The most divergent group of accessions included the genotypes Mitsukasane, Mie, Tomoe mochi, Ooba kirishima and Nourin mochi 6, which showed a higher number of spicklets per plant. There is high variability among the rice accessions from the germplasm collection studied, which presents great importance for breeding programs or for genetic studies on this species

Global Retinoblastoma Presentation and Analysis by National Income Level

Importance: Early diagnosis of retinoblastoma, the most common intraocular cancer, can save both a child's life and vision. However, anecdotal evidence suggests that many children across the world are diagnosed late. To our knowledge, the clinical presentation of retinoblastoma has never been assessed on a global scale. Objectives: To report the retinoblastoma stage at diagnosis in patients across the world during a single year, to investigate associations between clinical variables and national income level, and to investigate risk factors for advanced disease at diagnosis. Design, Setting, and Participants: A total of 278 retinoblastoma treatment centers were recruited from June 2017 through December 2018 to participate in a cross-sectional analysis of treatment-naive patients with retinoblastoma who were diagnosed in 2017. Main Outcomes and Measures: Age at presentation, proportion of familial history of retinoblastoma, and tumor stage and metastasis. Results: The cohort included 4351 new patients from 153 countries; the median age at diagnosis was 30.5 (interquartile range, 18.3-45.9) months, and 1976 patients (45.4) were female. Most patients (n = 3685 84.7%) were from low-and middle-income countries (LMICs). Globally, the most common indication for referral was leukocoria (n = 2638 62.8%), followed by strabismus (n = 429 10.2%) and proptosis (n = 309 7.4%). Patients from high-income countries (HICs) were diagnosed at a median age of 14.1 months, with 656 of 666 (98.5%) patients having intraocular retinoblastoma and 2 (0.3%) having metastasis. Patients from low-income countries were diagnosed at a median age of 30.5 months, with 256 of 521 (49.1%) having extraocular retinoblastoma and 94 of 498 (18.9%) having metastasis. Lower national income level was associated with older presentation age, higher proportion of locally advanced disease and distant metastasis, and smaller proportion of familial history of retinoblastoma. Advanced disease at diagnosis was more common in LMICs even after adjusting for age (odds ratio for low-income countries vs upper-middle-income countries and HICs, 17.92 95% CI, 12.94-24.80, and for lower-middle-income countries vs upper-middle-income countries and HICs, 5.74 95% CI, 4.30-7.68). Conclusions and Relevance: This study is estimated to have included more than half of all new retinoblastoma cases worldwide in 2017. Children from LMICs, where the main global retinoblastoma burden lies, presented at an older age with more advanced disease and demonstrated a smaller proportion of familial history of retinoblastoma, likely because many do not reach a childbearing age. Given that retinoblastoma is curable, these data are concerning and mandate intervention at national and international levels. Further studies are needed to investigate factors, other than age at presentation, that may be associated with advanced disease in LMICs. © 2020 American Medical Association. All rights reserved