Experimental Investigation Of Thermophysical Properties, Pressure Drop And Heat Transfer Of Non-Newtonian Silica Colloid Flow In Tubes

Thermophysical properties and rheological behavior of silica (SiO2) nanoparticle colloidal suspension with 9.58% volume concentration in water were analyzed. The laminar flow of the fluid through tubes of different diameter was studied to compare its pressure drop and heat transfer performance with those of water. Thermal conductivity of the silica suspension was found to be 0.99% to 3.6% higher than the same property of water when measured from 7°C to 50°C. Within the temperature range, thermal conductivity of the silica suspension and water increased by 9.88% and 11.1% respectively, with increase in temperature. It was observed that the colloidal dispersion of silica behaved as non-Newtonian shear thickening fluid whose viscosity increased with increasing shear rate when temperature was kept constant. Power law model for non-Newtonian fluid could fairly predict the viscosity of the fluid at certain shear rate. While measuring viscosity data with a rotary viscometer at fixed shear rate and temperature, the fluid viscosity showed a change in value with time for first 12-15 second of shear application and then obtained a constant value. Pressure drop analysis showed that the friction factor of the silica suspension and the friction factor of water have no significant difference after a Reynolds number of 750. Before that, silica suspension has higher friction factor than that of water and the highest increase observed was 63%. Conventional correlation to predict the friction factor of single phase fluid can also be used in case of silica colloidal dispersion. As the diameter of the test section got smaller, the increase in the friction factor of silica dispersion enhanced compared to the friction factor of water. There was no eminent difference between the heat transfer performance of silica suspension and water. Correlation that is used for water was found to be suitable for nanoparticle dispersion too. The highest value of Nusselt number for silica suspension and water was 17.54 and 13.42 respectively, when the fluids were circulated through the tube with the biggest diameter

Preventing Vaccine Failure in Poultry Flocks

Poultry sector is very useful for humans in terms of production of food items like meat and eggs. Pakistan has a developing poultry sector and is the second important sector after the textile industry. The poultry sector is encountered with many challenges; among them is the high incidence of disease outbreaks that result in colossal economic losses. The diseases of commercial and rural poultry include Newcastle disease (ND), infectious bursal disease (IBD), fowl pox, Marek’s disease, infectious bronchitis (IB), avian influenza, hydropericardium syndrome, etc. The disease outbreaks have also occurred in vaccinated flocks. Better understanding of the causes of vaccine failure will result in identifying prophylactic measures regarding disease outbreaks in poultry flocks. This chapter overviews the common causes of vaccine failure and further highlights the procedures for successful immunization

Antidiabetic and Hypolipidemic Effects of Aqueous Methanolic Extract of Acacia Nilotica Pods in Alloxan-Induced Diabetic Rabbits

This study was designed to investigate the effect of an aqueous methanol extract of Acacia nilotica pods (Anp) on various biochemical parameters, namely blood glucose levels, total cholesterol, High density lipids (HDLs), triglycerides, Serum Glutamate Oxaloacetate and Pyruvate Transaminase (SGOT, SGPT) and serum creatinine clearance in alloxan-induced diabetic rabbits. Rabbits were divided into three experimental groups: control, diabetic and Anp treated. The Anp treated group was further subdivided into three different groups based on the dose administered. This showed that a dose of 400 mg/kg body weight maximally reduced the blood glucose levels as compared to the diabetic group (p<0.001). This dose also significantly (p<0.05) lowered the plasma total cholesterol, triglyceride and Low-density lipids (LDLs) in treated rabbits as compared to diabetic rabbits. Furthermore, the same dose also significantly increased the plasma HDL levels of the treated group when compared with the diabetic group. Whereas the activity of SGOT and SGPT were decreased significantly (p<0.001). Anp extract in treated diabetic rabbits. Anp treatment showed no significant effect on creatinine clearance. For interest a paper with similar aims, but using water extract of Nigella stiva L. appeared in this journal in 2004, (Merel et at, 31 (1), 49-53)

Effect of Berberis lycium Royle on Lipid Profile in Alloxan Induced Diabetic Rabbits

Berberis lycium Royle (B.l.R) commonly known as Ishkeen (Kashmal and Darbald) is widely used in folk medicines for the treatment of Diabetes mellitus. Experimental diabetes use to alter the lipid profile. The aim of the present study was to evaluate the effects of Berberis lycium root bark on various lipid profiles in alloxan induced diabetic rabbits. Diabetes was induced by single intravenous injection of Alloxan (150 mg/kg).Oral administration of 250mg/kg and 500mg/kg crude powder of Berberis lycium root for four weeks resulted in significant reduction in total cholesterol, triglyceride and low density lipids (LDLs) levels. Berberis lycium treatment increased the levels of high density lipids (HDLs). Furthermore same doses stabilized the weight of diabetic rabbits. Thus our investigation clearly shows that crude powder of Berberis lycium Royle has antihyperlipidemic effect

Down-regulation of UHRF1, associated with re-expression of tumor suppressor genes, is a common feature of natural compounds exhibiting anti-cancer properties

Over-expressed in numerous cancers, Ubiquitin-like containing PHD Ring Finger 1 (UHRF1, also known as ICBP90 or Np95) is characterized by a SRA domain (Set and Ring Associated) which is found only in the UHRF family. UHRF1 constitutes a complex with histone deacetylase 1 (HDAC1) and DNA methyltransferase 1 (DNMT1) via its SRA domain and represses the expression of several tumour suppressor genes (TSGs) including p16INK4A, hMLH1, BRCA1 and RB1. Conversely, UHRF1 is regulated by other TSGs such as p53 and p73. UHRF1 is hypothetically involved in a macro-molecular protein complex called "ECREM" for "Epigenetic Code Replication Machinery". This complex would be able to duplicate the epigenetic code by acting at the DNA replication fork and by activating the right enzymatic activity at the right moment. There are increasing evidence that UHRF1 is the conductor of this replication process by ensuring the crosstalk between DNA methylation and histone modifications via the SRA and Tandem Tudor Domains, respectively. This cross-talk allows cancer cells to maintain the repression of TSGs during cell proliferation. Several studies showed that down-regulation of UHRF1 expression in cancer cells by natural pharmacological active compounds, favors enhanced expression or re-expression of TSGs, suppresses cell growth and induces apoptosis. This suggests that hindering UHRF1 to exert its role in the duplication of the methylation patterns (DNA + histones) is responsible for inducing apoptosis. In this review, we present UHRF1 expression as a target of several natural products and we discuss their underlying molecular mechanisms and benefits for chemoprevention and chemotherapy

Study of the anti-cancer effects of natural polyphenols : key role of reactive oxygen species and tumor suppressor genes

Ce travail de recherche montre que les différentes sources de polyphénols (polyphénols de vin rouge, jus d'aronia melanocarpa, jus de cassis) ont de puissants effets chemothérapeutiques et chemopréventifs sur différentes lignées de culture cellulaires, mais également in vivo sur un modèle de tumorigenèse. Ces polyphénols inhibent la prolifération des cellules cancéreuses (leucémie lymphoblastique aigüe, cellules souches) en induisant un arrêt du cycle cellulaire et l'apoptose. Les effets anti-cancéreux sont dépendants de l' induction du stress oxydatif mettant en jeu les anions superoxydes et le peroxyde d·hydrogène qui à son tour, activent les voies de signalisation conduisant à une surexpression des gènes suppresseurs de tumeurs comme p73 et p53 et ainsi que caspase 3. Celle étude montre également que les polyphénols contrôlent la prolifération des cellules cancéreuses au niveau épigénétique en diminuant l'expression d'UHRF1 (un intégrateur épigénétique de prolifération). Cependant l'effet anticancéreux de ces polyphénols est sélectif et agit sur les cellules cancéreuses et non sur les cellules normales. Le fractionnement de ces sources riches en polyphénols et les études menées en utilisant des composés purs montrent que les effets anticancéreux sont attribués à plusieurs composés différents. Cette étude montre l' identification de cyanidine-3-glucoside et de cyanidine-3-rutinoside comme source de composés anticancéreux actifs.This research work shows that different sources of polyphenols (RWPs, AMJ and blackcurrant) have strong chemotherapeutic and chemopreventive effects on several cancer cells lines (acute lymphoblastic leukemia and cancer stem cells) and also in vivo in a model of tumorigenesis in mouse. These polyphenols inhibit the proliferation of various cancer cells by inducing cell cycle arrest and apoptosis. The anti-cancer effect is dependent on the induction of oxidative stress involving superoxide anions and hydrogen peroxide which, in turn, activate the signaling pathways leading to the re-expression of tumor suppressor genes such as p73 and p53 and executor of apoptosis such as caspase 3. This study also shows that polyphenols control the proliferation of cancer cells at epigenetic level by decreasing the expression of UHRF1 (an epigenetic integrator of proliferation). Moreover, the anticancer effect of these polyphenols is selective towards cancer cells and not in normal cells. Fractionation of these rich sources of polyphenols and studies on the commercially available pure products shows that anti-cancer effects of these polyphenols involve several different compounds. This study leads to the identification of cyaniding-3-O-glucoside and cyaniding-3-O-rutinoside as active anticancer compounds

Study of the anti-cancer effects of natural polyphenols : key role of reactive oxygen species and tumor suppressor genes

Ce travail de recherche montre que les différentes sources de polyphénols (polyphénols de vin rouge, jus d'aronia melanocarpa, jus de cassis) ont de puissants effets chemothérapeutiques et chemopréventifs sur différentes lignées de culture cellulaires, mais également in vivo sur un modèle de tumorigenèse. Ces polyphénols inhibent la prolifération des cellules cancéreuses (leucémie lymphoblastique aigüe, cellules souches) en induisant un arrêt du cycle cellulaire et l'apoptose. Les effets anti-cancéreux sont dépendants de l' induction du stress oxydatif mettant en jeu les anions superoxydes et le peroxyde d·hydrogène qui à son tour, activent les voies de signalisation conduisant à une surexpression des gènes suppresseurs de tumeurs comme p73 et p53 et ainsi que caspase 3. Celle étude montre également que les polyphénols contrôlent la prolifération des cellules cancéreuses au niveau épigénétique en diminuant l'expression d'UHRF1 (un intégrateur épigénétique de prolifération). Cependant l'effet anticancéreux de ces polyphénols est sélectif et agit sur les cellules cancéreuses et non sur les cellules normales. Le fractionnement de ces sources riches en polyphénols et les études menées en utilisant des composés purs montrent que les effets anticancéreux sont attribués à plusieurs composés différents. Cette étude montre l' identification de cyanidine-3-glucoside et de cyanidine-3-rutinoside comme source de composés anticancéreux actifs.This research work shows that different sources of polyphenols (RWPs, AMJ and blackcurrant) have strong chemotherapeutic and chemopreventive effects on several cancer cells lines (acute lymphoblastic leukemia and cancer stem cells) and also in vivo in a model of tumorigenesis in mouse. These polyphenols inhibit the proliferation of various cancer cells by inducing cell cycle arrest and apoptosis. The anti-cancer effect is dependent on the induction of oxidative stress involving superoxide anions and hydrogen peroxide which, in turn, activate the signaling pathways leading to the re-expression of tumor suppressor genes such as p73 and p53 and executor of apoptosis such as caspase 3. This study also shows that polyphenols control the proliferation of cancer cells at epigenetic level by decreasing the expression of UHRF1 (an epigenetic integrator of proliferation). Moreover, the anticancer effect of these polyphenols is selective towards cancer cells and not in normal cells. Fractionation of these rich sources of polyphenols and studies on the commercially available pure products shows that anti-cancer effects of these polyphenols involve several different compounds. This study leads to the identification of cyaniding-3-O-glucoside and cyaniding-3-O-rutinoside as active anticancer compounds