Separation and identification of phenolics and flavonoids from wild Pistacia palaestina extract and its antioxidant activity

An in-vitro evaluation of the antioxidant activities of wild Palestinian Pistacia palaestina extracts was done. In parallel, the total phenolic content (TPC) and the total flavonoids content (TFC) were measured. The antioxidant activities were determined spectrophotometrically by DPPH, FRAP, CUPRAC and the ABTS methods. The phenolic and flavonoid contents were separated and identified using LC-PDA-MS. The P. palaestina extract was found to contain many phenolic and flavonoids that enhance its reducing activity and free radical scavenging ability. Total phenolic content, and total flavonoids contents were found to be 66.5 ± 2.2 mg Gallic acid/g, and 20.3 ± 1.1 mg catechin/g, respectively. Antioxidant activity represented as FRAP, CUPRAC, DPPH and ABTS was found to be 23.5± 1.2 mmol Fe+2/g, 4562 ± 63 μmol Trolox/g, 344 ± 11 μmol/g, 53.1 ± 6.6 μmol/g, respectively. The aim of the study is therefore to employ different antioxidant tests to evaluate the antioxidant activities of crude ethanol leaf extracts of P. palaestina, and to determine its phenolic and flavonoids content

Cinnamon bark water-infusion as an in-vitro inhibitor of β-hematin formation

Malaria remains one of the prominent public health problems that lead to severe morbidity and mortality in many developing countries around the globe. New antimalarial drugs are urgently needed due to the emergence of antimalarial-resistant strains of Plasmodium falciparum. In previous studies, we tested several plants extracts that are capable of inhibiting β-hematin formation, with efficiency similar to chloroquine. In the current study, the effect of cinnamon ethanol and water extracts on inhibiting β- hematin formation was studied. Powdered cinnamon extracts and bark in a stick form were investigated using various extraction methods. A semi-quantitative in vitro method, based on the inhibition of ferriprotoporphyrin IX (FP) bio-crystallization developed by Deharo et al. (2002) was utilized. Water extracts of cinnamon revealed potential activity even at low concentration of infusions, which was manifested by a high capability to inhibit β-hematin formation in vitro

Pure Isolates and Preparative HPLC Fractions or Crude Extract of Inula viscosa: Effect on β-hematin Inhibition in vitro

The antimalarial activity of wild Inula viscosa (I. viscosa) plant leaves was investigated. The efficacy of the whole crude extract versus preparative HPLC fractions versus pure isolates were compared by measuring their effect on β-hematin inhibition in-vitro. The preparative HPLC experiments consisted of reversed phase preparative column (22.2mm x 250mm, 10μm) and linear gradient of water, acetonitrile as the mobile phase. Injection volume was 1000μl and the wavelengths range were from 200-450 nm using photodiode array detector (PDA). While fractions (IV, V and VI) showed antimalarial potential in comparison to chloroquine positive control, the rest of the fractions did not show any significant inhibition to the β-hematin formation. The antimalarial results showed that whole crude exact of the plant works better than the preparative fractions or the pure isolates presumably due to synergistic effect. The chemical identity of some of the pure isolates was explored using UHPLC-ESi-MS. Moreover, I. viscosa extract powder stayed stable over several years, while many other products such as Artemisia annua extract or Artemisin Combined Therapy (ACT) drugs rapidly lost their efficiency under tropical storage conditions.None

Computational study of the dissociation reactions of secondary ozonide

This contribution presents a comprehensive computational study on the reactions of secondary ozonide (SOZ) with ammonia and water molecules. The mechanisms were studied in both a vacuum and the aqueous medium. All the molecular geometries were optimized using the B3LYP functional in conjunction with several basis sets. M06-2X, APFD, and ωB97XD functionals with the full basis set were also used. In addition, single-point energy calculations were performed with the G4MP2 and G3MP2 methods. Five different mechanistic pathways were studied for the reaction of SOZ with ammonia and water molecules. The most plausible mechanism for the reaction of SOZ with ammonia yields HC(O)OH, NH3, and HCHO as products, with ammonia herein acting as a mediator. This pathway is exothermic and exergonic, with an overall barrier height of only 157 kJ mol−1 using the G3MP2 method. All the reaction pathways between SOZ and water molecules are endothermic and endergonic reactions. The most likely reaction pathway for the reaction of SOZ with water involves a water dimer, in which the second water molecule acts as a mediator, with an overall barrier height of only 135 kJ mol−1 using the G3MP2 method. Solvent effects were found to incur a significant reduction in activation energies. When the second H2O molecule acts as a mediator in the reaction of SOZ with water, the barrier height of the rate-determining step state decreases significantly

Collagen-calcium alginate film dressing with therapeutic ultrasound to treat open wound in rats

About 24 healthy female Sprague-Dawley rats weighing between 300-350 g were used in this study over a 20 day period. They were allocated randomly into 4 groups of 6 animals each. After the creation of 2x2 cm open wound, group 1 was control treated with Gentamycin ointment. Groups 2-4 were treated with Therapeutic ultrasound massage, collagen-calcium alginate film and collagen-calcium alginate film with therapeutic ultrasound. On application, the collagen-calcium alginate film with therapeutic ultrasound was well accepted by the animals without any adverse reaction. Mean percentage of wound contraction were significantly better in group 4 (p<0.05). Faster epithelialization was also seen in the collagen-calcium alginate film with therapeutic ultrasound treated group as compared to the other groups. Collagen is a biocompatible protein that does not interfere with the body’s normal immunologic response and can be used in non-healing chronic wounds which require a trigger to stimulate the normal healing process. In extensive wounds when there is lack of autologous tissue, biomaterials like collagen-calcium alginate may be beneficial and can be used

Doc2b Protects β-Cells Against Inflammatory Damage and Enhances Function

Loss of functional β-cell mass is an early feature of type 1 diabetes. To release insulin, β-cells require soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) complexes, as well as SNARE complex regulatory proteins like double C2 domain-containing protein β (Doc2b). We hypothesized that Doc2b deficiency or overabundance may confer susceptibility or protection, respectively, to the functional β-cell mass. Indeed, Doc2b+/- knockout mice show an unusually severe response to multiple-low-dose streptozotocin (MLD-STZ), resulting in more apoptotic β-cells and a smaller β-cell mass. In addition, inducible β-cell-specific Doc2b-overexpressing transgenic (βDoc2b-dTg) mice show improved glucose tolerance and resist MLD-STZ-induced disruption of glucose tolerance, fasting hyperglycemia, β-cell apoptosis, and loss of β-cell mass. Mechanistically, Doc2b enrichment enhances glucose-stimulated insulin secretion (GSIS) and SNARE activation and prevents the appearance of apoptotic markers in response to cytokine stress and thapsigargin. Furthermore, expression of a peptide containing the Doc2b tandem C2A and C2B domains is sufficient to confer the beneficial effects of Doc2b enrichment on GSIS, SNARE activation, and apoptosis. These studies demonstrate that Doc2b enrichment in the β-cell protects against diabetogenic and proapoptotic stress. Furthermore, they identify a Doc2b peptide that confers the beneficial effects of Doc2b and may be a therapeutic candidate for protecting functional β-cell mass

Urinary tract infection and their risk factors association in renal transplant recipients

Background: Urinary tract infection (UTI) remains one of the most common and major complications after renal transplantation. Objective: The study was undertaken to get an insight regarding the bacterial pathogen which is responsible for UTI in post renal transplant patients and their risk factors association. Methods: This was an observational study, conducted in the Department of Microbiology and Immunology Bangabandhu Sheikh Mujib Medical University (BSMMU) from December 2010 to December 2011. Twenty- one renal transplant recipients were evaluated for UTl after surgery up to six weeks. Microscopic examination and culture of urine were performed in every pre-transplant period, 3rd POD, 7th POD, within six weeks and as per patient's clinical condition. UTI was considered when bacterial count wa

Towards building a practical face recognition system

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1997.Includes bibliographical references (p. 56-57).by Wasiuddin A.S.M. Wahid.M.Eng

Feasibility on equivalence ratio measurement via OH*, CH*, and C2* chemiluminescence and study of soot emissions in co-flow non-premixed DME/C1–C2 hydrocarbon flames

The effects of dimethyl ether (DME) addition to methane and ethylene fuels on the combustion characteristics of heat release, soot emissions, and flame temperature were investigated experimentally and numerically in a non-premixed laminar flame configuration. The flame-heat release soot-volume fraction was measured experimentally using CH*, OH*, and C2* chemiluminescence and planar two-color soot pyrometry, respectively. The CH*, OH*, and C2* were used to locate flame-heat release regions as well as to investigate the soot signal’s effect on their measurements. The ratios of the chemiluminescence pairs (OH*/CH* and OH*/C2*) were studied for the feasibility of map local equivalence ratios. Numerical calculations across a full range of DME mixing ratios were performed through 1D laminar flame simulations implemented with a detailed mechanism to provide an indication of the flame structures and profiles of key species including OH*, OH, CH*, CH, CH3, C3H3, C2H2, heat release rate (HRR), and flame temperature. An existing developed soot model was used in a 2D computational study to investigate its validity for modeling soot for DME (oxygenated fuel)/C2H4/N2 flames. Parametric studies have been carried out on some key parameters in the soot model to find optimum values that can be used in future studies. Although soot radiation intensities increased at a small amount (25%vol) of DME addition in the DME/methane flames, the soot pyrometry results showed a reduced soot volume fraction with an increased DME mixture ratio in both DME/methane and DME/ethylene flames studied, agreeing with the key conclusion of 1D numerical results. The flame HRR decreases with the increasing addition of DME to methane and ethylene flames and correlates with the trend of OH* and CH* profiles. The 1D simulation showed a non-monotonic correlation between OH*/CH* ratios and equivalence ratios, implying a limited use of OH*/CH* for the equivalence ratio measurement in non-premixed flames with DME additions