The sensitive capillary electrophoretic‐LIF method for simultaneous determination of curcuminoids in turmeric by enhancing fluorescence intensities of molecules upon inclusion into (2‐hydroxypropyl)‐β‐cyclodextrin

Curcuminoids have received great attention in the past decades due to their health benefit properties. The aim of this study is to develop a very simple, rapid, and sensitive capillary zone electrophoresis technique coupled with a laser induced fluorescence detector (LIF) for the simultaneous determination of three major curcuminoids of turmeric, namely, curcumin, demethoxy curcumin (DMC), and bisdemethoxy curcumin (BDMC). Background electrolyte was selected as borate at pH 9.6 and (2‐hydroxypropyl)‐β‐cyclodextrin (2‐HP‐β‐CD) was added to prevent rapid alkali degradation of curcuminoids in buffer and to increase fluorescence intensities of molecules. With the addition of 2‐HP‐β‐CD to the separation electrolyte, the fluorescence signal intensities of curcuminoids were enhanced considerably by 30, 40, and 54 fold for curcumin, DMC, and BDMC, respectively. The three curcuminoids of turmeric were fully separated and quantified in less than 4.5 min. The repeatability of the peak areas of curcuminoids for intra‐day and inter‐day experiments was in the satisfactory range of 2.26 and 2.55%, respectively. The LOD and LOQ values for the developed method were equal to or less than 0.081 and 0.270 μg/mL, respectively, for all curcuminoids. The developed method was successfully applied to find curcuminoids amount in turmeric samples and herbal supplements.     

Development of surface chemistry for surface plasmon resonance based sensors for the detection of proteins and DNA molecules

The immobilisation of biological recognition elements onto a sensor chip surface is a crucial step for the construction of biosensors. While some of the optical biosensors utilise silicon dioxide as the sensor surface, most of the biosensor surfaces are coated with metals for transduction of the signal. Biological recognition elements such as proteins can be adsorbed spontaneously on metal or silicon dioxide substrates but this may denature the molecule and can result in either activity reduction or loss. Self assembled monolayers (SAMs) provide an effective method to protect the biological recognition elements from the sensor surface, thereby providing ligand immobilisation that enables the repeated binding and regeneration cycles to be performed without losing the immobilised ligand, as well as additionally helping to minimise non-specific adsorption. Therefore, in this study different surface chemistries were constructed on SPR sensor chips to investigate protein and DNA immobilisation on Au surfaces. A cysteamine surface and 1%, 10% and 100% mercaptoundecanoic acid (MUDA) coatings with or without dendrimer modification were utilised to construct the various sensor surfaces used in this investigation. A higher response was obtained for NeutrAvidin immobilisation on dendrimer modified surfaces compared to MUDA and cysteamine layers, however, protein or DNA capture responses on the immobilised NeutrAvidin did not show a similar higher response when dendrimer modified surfaces were used.     

Undifferentiated (embryonal) sarcoma of the liver (USL): MRI findings including dynamic gadolinium enhancement

We report the MR appearance of undifferentiated (embryonal) sarcoma of the liver (USL) in a 13-year-old female who presented with a 1-year history of intermittent abdominal pain, weight loss, and fatigue. The tumor was a large, solitary, well-defined focal mass lesion with multiple cystic spaces, septations, and substantial central necrosis.     

Hepatic nodules in liver transplantation candidates: MR imaging and underlying hepatic disease

OBJECTIVE: To assess by MR imaging the frequency of hepatic nodules in patients waiting on the liver transplant list and to determine whether certain underlying hepatic diseases were more often associated with the development of such hepatic nodules. MATERIAL AND METHODS: We reviewed the MR and clinical records in all patients seen by the liver transplant service at our center since its inception in January 1998 until September 2002. A total of 371 patients (207 men and 164 women, age range 18-68 years, mean 45 years) were included in the study. The presence of hepatic nodules, size, number and underlying hepatic diseases were determined in all patients. Magnetic resonance imaging was performed on a 1.5-T MR imager using T1-weighted, T2-weighted and multi-phase gadolinium-enhanced sequences. Odds ratio (OR) and 95% confidence intervals (CIs) were computed to evaluate the association between the underlying hepatic disease and the development of hepatic nodule. RESULTS: Among 371 liver transplantation candidates, the most common underlying hepatic disease was hepatitis C virus (HCV) infection, either alone (n=93; 25%) or associated with other hepatic diseases (n=40; 10.8%). Of all patients, 33 (8.9%) had regenerative nodules (RNs), 40 (10.7%) dysplastic nodules (DNs) and 57 (15.3%) hepatocellular carcinomas (HCCs). Hepatocellular carcinoma was observed in 35.3% of patients with HCV infection and alcohol abuse combined, 24.5% with cryptogenic cirrhosis, 25% with hemochromatosis and 19% with alcohol abuse. Patients who had either DNs or HCC were 2.5 times more likely to have either alcohol abuse or HCV, alone or combined, as the substrate of their liver disease (OR 2.54, 95% CI 1.56-4.13). Our data suggest a supra-additive interaction between HCV infection and ethanol in their association with MR imaging detected lesions. CONCLUSION: Patients with cryptogenic cirrhosis, alcohol abuse, HCV infection (alone or combined) and hemochromatosis had the greatest likelihood of having HCC, with the combination of HCV infection and alcohol abuse having the highest of all.     

Energy absorption buildup factors of some potential bioactive compounds in the energy region 0.015–15 MeV

Kinetic energy released per unit mass relative to air and energy absorption buildup factors has been calculated for some potential bioactive compounds in the energy region of 0.015–15?MeV. The bioactive compounds of 1-aryl-3-dibenzylamino-propane-1-on hydrochloride type Mannich bases were used in this work. Aryl part was changed as C₆H₅ (1), 4-CH₃C₆H₄ (2), C₄H₃S-2-yl (3), 4-FC₆H₄ (4), 4-BrC₆H₄ (5), 4-ClC₆H₄ (6), and 4-NO₂C₆H₄ (7). The energy absorption buildup factors have been calculated for penetration depth of 40 mean free paths. It is observed that kinetic energy released per unit mass relative to air depends on the photon energy and chemical content of compounds. The compounds with least mean atomic number possess the maximum value of energy absorption buildup factors. Also, the energy absorption buildup factors are found the highest in intermediate energy, whereas the lowest in low as well as high energies.     

Highly Efficient Method Towards In Situ Immobilization of Invertase Using Cryogelation

A novel method was developed for the immobilization of Saccharomyces cerevisiae invertase within supermacroporous polyacrylamide cryogel and was used to produce invert sugar. First, the cross-linking of invertase with soluble polyglutaraldehyde (PGA) was carried out prior to immobilization in order to increase the bulkiness of invertase and thus preventing the leakage of the cross-linked enzyme after immobilization by entrapment. And then, in situ immobilization of PGA cross-linked invertase within cryogel synthesis was achieved by free radical polymerization in semi-frozen state. The method resulted in 100 % immobilization and 74 % activity yields. The immobilized invertase retained all the initial activity for 30 days and 30 batch reactions. Immobilization had no effect on optimum temperature and it was 60 °C for both free and immobilized enzyme. However, optimum pH was affected upon immobilization. Optimum pH values for free and immobilized enzyme were 4.5 and 5.0, respectively. The immobilized enzyme was more stable than the free enzyme at high pH and temperatures. The kinetic parameters for free and immobilized invertase were also determined. The newly developed method is simple yet effective and could be used for the immobilization of some other enzymes and microorganisms.     

Preparation and characterization of a novel diatomite-based composite and investigation of its adsorption properties for uranyl ions

Journal of Radioanalytical and Nuclear Chemistry - The thiol-functional hydrotalcite (Mg/Al-LDO-SH) composite materials were prepared and characterized by EDS, SEM, FT-IR and XRD. The variables...     

Pyrolysis of tobacco factory waste biomass

Journal of Thermal Analysis and Calorimetry - Tobacco waste is one of the main industrial agricultural wastes. In this study, potential of pyrolysis process for valorization of this type of biomass...     

Simultaneous birefringence,small‐ and wide‐angle X‐ray scattering to detect precursors and characterize morphology development during flow‐induced crystallization of polymers

An experimental configuration that combines the powerful capabilities of a short‐term shearing apparatus with simultaneous optical and X‐ray scattering techniques is demonstrated, connecting the earliest events that occur during shear‐induced crystallization of a polymer melt with the subsequent kinetics and morphology development. Oriented precursors are at the heart of the great effects that flow can produce on polymer crystallization (strongly enhanced kinetics and formation of highly oriented crystallites), and their creation is highly dependent on material properties and the level of stress applied. The sensitivity of rheo‐optics enables the detection of these dilute shear‐induced precursors as they form during flow, before X‐ray techniques are able to reveal them. Then, as crystallization occurs from these precursors, X‐ray scattering allows detailed quantification of the characteristics and kinetics of growth of the crystallites nucleated by the flow‐induced precursors. This simultaneous combination of techniques allows unambiguous correlation between the early events that occur during shear and the evolution of crystallization after flow has stopped, eliminating uncertainties that result from the extreme sensitivity of flow‐induced crystallization to small changes in the imposed stress and the material. Experimental data on a bimodal blend of isotactic polypropylenes are presented.