Hundredfold productivity of genome analysis by introduction of microtemperature-gradient gel electrophoresis

Genome profiling, which employs temperature-gradient gel electrophoresis (TGGE) for DNA analysis, has recently been developed in identifying species by genotype. However, the performance of this technology like the general applications of TGGE was, though highly informative, limited in its ability due to methodological reasons. This study demonstrates that minimization of the gel for TGGE, to around one-tenth of its conventional size (approximately 2 cm), can be successfully introduced, resulting in a hundredfold higher performance (total evaluation of time, cost, and degree of parallel operations) than that of the conventional. Reproducibility was evaluated from the measures of the pattern similarity scores (PaSS) between band patterns (genome profiles) obtained with the conventional TGGE, and that with micro-TGGE (microTGGE) developed here, after extracting a set of featuring points from genome profiles. Size minimization, which leads to the reduction of the amount of samples required (cost-saving), is another great advantage, enhancing the employment of multicolor fluorescence technology. Since the further development of microbe-related fields such as epidemiology and microbial ecology inevitably require knowledge based on the identification of a great number of species and strains, microbe-related fields will receive the most optimal benefits from the technological improvements attained here.     

Solution-processed electrochemical synthesis of ZnFe2O4 photoanode for photoelectrochemical water splitting

Journal of Solid State Electrochemistry - Herein, we report the synthesis of ZnO nanorod films onto FTO (fluorine-doped tin oxide) substrates using the solution-processed electrodeposition method....     

Crystallizable Polyphenylacetylene-Preparation and Solution Properties

The molecular weight distribution (MWD) of crystallizable polyphenylacetylene prepared near room temperature in the presence of ferric acetylacetonate and triethylaluminum was determined through use of fractions characterized by vapor pressure osmometry and gel permeation chromatography (GPC). The number- and weight-average molecular weights (M _n and M _w) are both less than the molecular weight corresponding to the maximum of the weight distribution function, which lacks a high molecular weight tail. M _wandM _n is less than is consistent with models allowing for chain termination characteristic of vinyl polymers. GPC elution volumes are much less than those characteristic of polystyrene of similar molecular weight, and the Mark-Houwink exponent is high (2.4 for M _v 4800 to 6800). These data indicate more rodlike behavior than for polystyrene of equivalent molecular weight. The MWD and other data suggest intramolecular chain termination, possibly associated with the molecule's tendency to form paramagnetic defect states.     

Development of a validated high-performance thin-layer chromatography method for the standardization of an Ayurvedic formulation using berberine and ursolic acid

Giloy Tulsi tablet is an Ayurvedic preparation containing Tinospora cordifolia (Giloy) and Ocimum sanctum (Tulsi) and it is recommended for boosting the body’s immune response. This research work is about the marker-based standardization of this Ayurvedic preparation using high-performance thin-layer chromatography method. Standardization is based on the determination and quantification of the phytoconstituents berberine and ursolic acid present in Giloy Tulsi tablets. Separation was performed on pre-coated silica gel 60 F₂₅₄ plate as the stationary phase, with chloroform‒acetone‒formic acid (6:3.5:0.5, V/V) as the mobile phase. Identification and quantification were conducted densitometrically at 330 nm. The developed method resulted in good quality peak shape and enabled high-quality resolution of biomarkers. The R_F value for berberine (0.46 ± 0.02) and for ursolic acid (0.68 ± 0.02) in both reference standard and formulation were found to be comparable. The method was validated for specificity, linearity, limit of detection, limit of quantification, intra-day and inter-day precisions, accuracy, and robustness. The limit of detection values were 91 and 153 ng/band for berberine and ursolic acid, respectively. The limit of quantification values were 175 and 465 ng/band for berberine and ursolic acid, respectively. Regression analysis of the calibration data revealed a good linear relationship between peak area response and concentration in the range 200‒1000 ng/band for berberine (r² = 0.995) and 500‒2500 ng/band for ursolic acid (r² = 0.9968). The accuracy of the method, determined by measurement of recovery at three different levels, was in the range 98‒102% for both markers. These results are indication of reliability, reproducibility, accuracy, and precision of the method.

     

Identification of HPr kinase/phosphorylase inhibitors: novel antimicrobials against resistant Enterococcus faecalis

Journal of Computer-Aided Molecular Design - Enterococcus faecalis, a gram-positive bacterium, is among the most common nosocomial pathogens due to its limited susceptibility to antibiotics and its...     

β-Cyclodextrin-based chiral nanocomposite for thin-layer chromatographic detection of enantiomers of fluoxetine

Enantioselective analysis or separation is very essential for improved therapeutic effects of drugs as the pure enantiomeric drug formulations display potential benefits over racemates. In this work, we carried out (i) the synthesis of a nanocomposite of β-cyclodextrin and 3D graphene (G/β-CD NC), and (ii) its application for the detection of fluoxetine enantiomers [(RS)-FLX)] using a thin-layer chromatographic method. The synthesized nanocomposite was introduced into silica gel slurry while preparation of thin-layer plates. The separation conditions were optimized by altering pH, temperature, and mobile phase composition. The method is simple and easy to be optimized, and it can therefore be exploited to assess and monitor routine work of enantiomeric purity of drug enantiomers. The average precision (as measured by RSD) was in the region of 1.35‒1.65% for the enantiomers of (RS)-FLX. The measured limit of detection and limit of quantification for (RS)-FLX enantiomers were 1.8 and 5.4 mg mL^‒1, respectively.

     

Micromechanical Properties of Microstructured Elastomeric Hydrogels

Local, micromechanical environment is known to influence cellular function in heterogeneous hydrogels, and knowledge gained in micromechanics will facilitate the improved design of biomaterials for tissue regeneration. In this study, a system comprising microstructured resilin‐like polypeptide (RLP)–poly(ethylene glycol) (PEG) hydrogels is utilized. The micromechanical properties of RLP‐PEG hydrogels are evaluated with oscillatory shear rheometry, compression dynamic mechanic analysis, small‐strain microindentation, and large‐strain indentation and puncture over a range of different deformation length scales. The measured elastic moduli are consistent with volume averaging models, indicating that volume fraction, not domain size, plays a dominant role in determining the low strain mechanical response. Large‐strain indentation under a confocal microscope enables the visualization of the microstructured hydrogel micromechanical deformation, emphasizing the translation, rotation, and deformation of RLP‐rich domains. The fracture initiation energy results demonstrate that failure of the composite hydrogels is controlled by the RLP‐rich phase, and their independence with domain size suggested that failure initiation is controlled by multiple domains within the strained volume. This approach and findings provide new quantitative insight into the micromechanical response of soft hydrogel composites and highlight the opportunities in employing these methods to understand the physical origins of mechanical properties of soft synthetic and biological materials.     

The method of lines applied to nonlinear nonlocal functional differential equations

This paper discusses nonlinear functional differential equation in a real reflexive Banach space with nonlocal history condition. By using the method of lines, the existence and uniqueness of a strong solution are established. Finally, some applications of the abstract results are presented.     

Principal eigenvector field segmentation for reproducible diffusion tensor tractography of white matter structures

The study was aimed to test the feasibility of utilizing an algorithmically determinable stable fiber mass (SFM) map obtained by an unsupervised principal eigenvector field segmentation (PEVFS) for automatic delineation of 18 white matter (WM) tracts: (1) corpus callosum (CC), (2) tapetum (TP), (3) inferior longitudinal fasciculus (ILF), (4) uncinate fasciculus (UNC), (5) inferior fronto-occipital fasciculus (IFO), (6) optic pathways (OP), (7) superior longitudinal fasciculus (SLF), (8) arcuate fasciculus (AF), (9) fornix (FX), (10) cingulum (CG), (11) anterior thalamic radiation (ATR), (12) superior thalamic radiation (STR), (13) posterior thalamic radiation (PTR), (14) corticospinal/corticopontine tract (CST/CPT), (15) medial lemniscus (ML), (16) superior cerebellar peduncle (SCP), (17) middle cerebellar peduncle (MCP) and (18) inferior cerebellar peduncle (ICP). Diffusion tensor imaging (DTI)-derived fractional anisotropy (FA) and the principal eigenvector field have been used to create the SFM consisting of a collection of linear voxel structures which are grouped together by color-coding them into seven natural classes to provide PEVFS signature segments which greatly facilitate the selection of regions of interest (ROIs) for fiber tractography using just a single mouse click, as compared with a manual drawing of ROIs in the classical approach. All the 18 fiber bundles have been successfully reconstructed, in all the subjects, using the single ROIs provided by the SFM approach, with their reproducibility characterized by the fact that the ROI selection is user independent. The essentially automatic PEVFS method is robust, efficient and compares favorably with the classical ROI methods for diffusion tensor tractography (DTT).     

Quantitative Analysis of Flavonoids in Annona squamosa Leaf Extracts and Its Pellet Formulation by Validated High-Performance Thin-Layer Chromatographic Technique

JPC – Journal of Planar Chromatography – Modern TLC - Annona squamosa, commonly known as custard apple, possesses various medicinal properties such as antimicrobial, insecticidal,...