Heat Transfer Enhancement Using Al2O3-MWCNT Hybrid-Nanofluid inside a Tube/Shell Heat Exchanger with Different Tube Shapes.

The high demand for compact heat exchangers has led researchers to develop high-quality and energy-efficient heat exchangers at a lower cost than conventional ones. To address this requirement, the present study focuses on improvements to the tube/shell heat exchanger to maximize the efficiency either by altering the tube's geometrical shape and/or by adding nanoparticles in its heat transfer fluid. Water-based Al2O3-MWCNT hybrid nanofluid is utilized here as a heat transfer fluid. The fluid flows at a high temperature and constant velocity, and the tubes are maintained at a low temperature with various shapes of the tube. The involved transport equations are solved numerically by the finite-element-based computing tool. The results are presented using the streamlines, isotherms, entropy generation contours, and Nusselt number profiles for various nanoparticles volume fraction 0.01 ≤ φ ≤ 0.04 and Reynolds numbers 2400 ≤ Re ≤ 2700 for the different shaped tubes of the heat exchanger. The results indicate that the heat exchange rate is a growing function of the increasing nanoparticle concentration and velocity of the heat transfer fluid. The diamond-shaped tubes show a better geometric shape for obtaining the superior heat transfer of the heat exchanger. Heat transfer is further enhanced by using the hybrid nanofluid, and the enhancement goes up to 103.07% with a particle concentration of 2%. The corresponding entropy generation is also minimal with the diamond-shaped tubes. The outcome of the study is very significant in the industrial field and can solve many heat transfer problems.

MHD Flow of a Hybrid Nano-Fluid in a Triangular Enclosure with Zigzags and an Elliptic Obstacle.

The current study uses the multi-physics COMSOL software and the Darcy-Brinkman-Forchheimer model with a porosity of ε = 0.4 to conduct a numerical study on heat transfer by Cu-TiO2/EG hybrid nano-fluid inside a porous annulus between a zigzagged triangle and different cylinders and under the influence of an inclined magnetic field. The effect of numerous factors is detailed, including Rayleigh number (103 ≤ Ra ≤ 106), Hartmann number (0 ≤ Ha ≤ 100), volume percent of the nano-fluid (0.02 ≤ ϕ ≤ 0.08), and the rotating speed of the cylinder (-4000 ≤ w ≤ 4000). Except for the Hartmann number, which decelerates the flow rate, each of these parameters has a positive impact on the thermal transmission rate.

LOOP-MEDIATED ISOTHERMAL AMPLIFICATION (LAMP): SENSITIVE AND RAPID DETECTION OF SCHISTOSOMA HAEMATOBIUM DNA IN URINE SAMPLES OF EGYPTIAN SUSPECTED CASES.

Schistosomiasis haemalobium is a major endemic parasitic disease in many tropical regions including Egypt. Typical infection results in haematuria, dysuria, anaemia, genital as well as urinary tract lesions, with prospect of kidney damage in complicated cases. In addition, deposited eggs in the tissue, eventually leads to squamous cell carcinoma of urinary bladder in chronically infected individuals. Microscopic detection of excreted ova in urine samples remains the gold standard diagnostic method, in spite of its inherited low sensitivity, inconsistent egg excretion and unreliable results in chronic phase of the disease. Moreover due to pre-requisite for skilled personals and pricey equipment, PCR-based technologies are of limited use especially in low-income endemic countries. So emergence of loop-mediated isothermal DNA amplification (LAMP) seemed a promising technique. Our study evaluated application of LAMP technique in detection of S. haematobium DNA in 69 urine samples of suspected patients for urogenital schistosomiasis, versus conventional urine filtration followed by microscopy ova detection method. Specificity of LAMP was tested using other parasites DNA samples that showed no cross reactivity. Furthermore our results of the calculated diagnostic parameters for sensitivity and specificity for LAMP assay were 100%, with 95% CI (88.78%-100%), and 63.16%, with 95% CI (45.99%-78.19%) respectively, moreover Positive likelihood ratio (LR+) 2.7, and Negative likelihood ratio (LR-) 0.0, which display that LAMP technique is an up-to-date simple, sensitive, diagnostic important tool that could be employed in clinical diagnosis in poorly equipped facilities, as well as in surveillance of infectious diseases. As authors knowledge, this is the first national report evaluation of LAMP technique as a promising diagnostic tool for urogenital schistosomiasis.

Schistosome infection aggravates HCV-related liver disease and induces changes in the regulatory T-cell phenotype.

Schistosome infections are renowned for their ability to induce regulatory networks such as regulatory T cells (Treg) that control immune responses against homologous and heterologous antigens such as allergies. However, in the case of co-infections with hepatitis C virus (HCV), schistosomes accentuate disease progression and we hypothesized that expanding schistosome-induced Treg populations change their phenotype and could thereby suppress beneficial anti-HCV responses. We therefore analysed effector T cells and n/iTreg subsets applying the markers Granzyme B (GrzB) and Helios in Egyptian cohorts of HCV mono-infected (HCV), schistosome-co-infected (Sm/HCV) and infection-free individuals. Interestingly, viral load and liver transaminases were significantly elevated in Sm/HCV individuals when compared to HCV patients. Moreover, overall Treg frequencies and Helios(pos) Treg were not elevated in Sm/HCV individuals, but frequencies of GrzB(+) Treg were significantly increased. Simultaneously, GrzB(+) CD8(+) T cells were not suppressed in co-infected individuals. This study demonstrates that in Sm/HCV co-infected cohorts, liver disease is aggravated with enhanced virus replication and Treg do not expand but rather change their phenotype with GrzB possibly being a more reliable marker than Helios for iTreg. Therefore, curing concurrent schistosome disease could be an important prerequisite for successful HCV treatment as co-infected individuals respond poorly to interferon therapy.

Effect of Ramadan fasting on Muslim patients with chronic liver diseases.

The study evaluated the efficacy of fasting in Ramadan on the clinical, laboratory and ultrasonographic parameters of chronic liver disease patients. A total of 202 patients were selected from the departments of Tropical medicine and outpatient clinics of Al-Azhar University hospitals, Cairo, Egypt from the 26th of July till the 30th of September 2010. Patients submitted to complete clinical, laboratory, ultrasonographic and endoscopic evaluation pre, during, and post Ramadan. The fasting group was 103 (51%) and the non-fasting group was 99 (49%) patients. The non-fasting group showed significantly a good adherence to therapy (43.4%) compared to (27.2%) the fasting group (p=0.016). Dyspeptic symptoms was higher in the fasting (53.4%) compared to (38.4%) the non-fasting group (p=0.032). G.I. bleeding during Ramadan was higher in the fasting group (17.5%) compared to non-fasting (14.1%), but the bleeding due to o.v. was significantly higher in the non-fasting group (9.1%) compared to (1%) in the fasting group (p=0.004). Chronic hepatitis in the fasting group showed non significant changes pre, during and post-Ramadan regarding liver function. Fasting cirrhotic group patients child class C was developed to (13%) during and (32.6%) after Ramadan compared to (0%) before (p=0.001).

Comparison of different PCR protocols for the detection and diagnosis of Plasmodium falciparum.

An assessment of differing PCR protocols for the diagnosis of Plasmodium falciparum infection was performed on samples from an area of holoendemic malaria transmission in western Burkina Faso. The PCR protocols had generally high sensitivities (>92%) and specificities (>69%), but the negative predictive values (NPV) were moderate and differed widely among the PCR protocols tested. These PCR protocols that amplified either the P. falciparum pfcrt gene or the small subunit ribosomal DNA were the most reliable diagnostic tools. However, the moderate NPV imply that more than one PCR protocol should be used for diagnosis in holoendemic areas.

Selective use of single-photon emission computed tomography myocardial perfusion imaging in a chest pain center.

Emergency department chest pain centers (CPCs) vary in their approach to patients with chest pain and nonischemic electrocardiograms (ECG). Although single-photon emission computed tomography (SPECT) myocardial perfusion imaging has been evaluated in this setting, both acutely at rest and after stress, we questioned its application in all patients. We prospectively evaluated the utility of selective SPECT imaging in a CPC (i.e., rest SPECT for ongoing pain, stress SPECT if unable to undergo exercise electrocardiography) and its impact on the overall disposition of all emergency department chest pain patients. Over 3 years, 2,601 patients were evaluated in a CPC (2,211 [85%] were sent home, 390 [15%] were hospitalized). Of 390 CPC patients hospitalized, 182 (47%) were diagnosed with coronary artery disease at the time of hospital discharge. Only 28 patients (1.1%) had an acute myocardial infarction. After 3 years, the proportion of all chest pain patients hospitalized and those diagnosed as "rule-out myocardial infarction" decreased from 53% to 41% and 32% to 18% of all chest pain patients, respectively (both p <0.0001). Overall, 906 patients (35%) required SPECT imaging to complete the CPC evaluation. Had SPECT imaging not been performed selectively, and all 906 patients been admitted, 762 (29%) would have been hospitalized unnecessarily based on the final diagnoses. Alternatively, sending all these patients home would have resulted in 144 (6%) inappropriate discharges of patients with coronary artery disease. A CPC protocol using the selective use of SPECT imaging permits the complete evaluation of all patients in the CPC, significantly reduces hospitalizations for chest pain, and restricts hospital admission to more appropriate patients.

Hemodynamic performance of stentless porcine bioprosthesis and mechanical bileaflet prosthesis using dobutamine stress echocardiography.

Currently available aortic valve prostheses have satisfactory hemodynamic performance during rest, but with exercise they possess different responses. The objective was to compare the hemodynamic response of the stentless porcine bioprosthesis (SP) and the mechanical bileaflet prosthesis (MB) at rest and during peak exercise using dobutamine stress echocardiography (DSE). DSE was used to evaluate the effective orifice area index (EOAI), peak and mean pressure gradients at rest and during maximum stress in 15 patients with SP (group T, mean age, 30.9 year) and another 15 patients with MB (group M, mean age, 28.6 year). The increment in pressure gradient (mean/peak) was significantly less in patients with SP than those with MB (P <.01). The EOAI did not change with exercise. At rest, both valve substitutes have satisfactory hemodynamics, but during exercise the stentless porcine bioprosthesis has better hemodynamics because it is less obstructive that justifies its use in young population.

Duodenal perforation following blunt abdominal trauma: case report.

A case of severe duodenal injury in a 20-year-old female due to blunt abdominal trauma secondary to road traffic accident is presented. The difficulty and hence delay in making a diagnosis of duodenal injury is discussed.

Effect of cyclic AMP on fructose utilization, progressive motility and protein synthesis by ram spermatozoa.

Ejaculated washed ram spermatozoa showed consistent increases in the intracellular concentration of cyclic 3', 5'-adenosine monophosphate (cAMP) after incubation for 15 minutes with the phosphodiesterase (PDE)-inhibitors, theophylline and caffeine. In vitro addition of cAMP or PDE-inhibitors to ram semen also stimulated and maintained sperm motility and enhanced the rate of fructose utilization. The same doses of cAMP or theophylline significantly stimulated the rate of protein synthesis by the washed spermatozoa, while the PDE-stimulator, imidazole, inhibited protein synthesis significantly. The stimulatory effect of cAMP on sperm protein synthesis was not affected by cycloheximide, but was abolished by the mitochondrial inhibitor, chloramphenicol. The present results indicate a positive correlation between the intracellular concentration of cAMP and the rates of progressive motility, fructose utilization, and protein synthesis by ram spermatozoa. The results suggest that the effect of cAMP is associated with the synthesis of mitochndrial proteins which may be involved with the observed enhancement of sperm motility and metabolism. The data also indicate that cAMP map act either as a first or a second messenger in mature spermatoza.