Wound healing is a complex process which requires an appropriate environment for quick healing. Recently, biodegradable hydrogel-based wound dressings have been seen to have high potential owing to their biodegradability and hydrated molecular structure. In this work, a novel biodegradable composite of sodium alginate hydrogel with wool needle-punched nonwoven fabric was produced for wound dressing by sol–gel technique. The wool nonwoven was dipped in the sodium alginate-water solution and then soaked in calcium chloride solution which resulted in hydrogel formation. FTIR analysis and SEM images confirm the presence of alginate hydrogel inside the needle-punched wool nonwoven fabric. The wound exudate absorbing capacity of hydrogel based wool nonwoven was increased 30 times as compared to pure wool nonwoven. Moreover, the tensile strength and moisture management properties of hydrogel based nonwoven were also enhanced. The unique combination of alginate hydrogel with biocompatible wool nonwoven fabric provides moist environment and can help in cell proliferation during wound healing process.
Myxobacteria represent a viable source of chemically diverse and biologically active secondary metabolites. The myxochelins are a well-studied family of catecholate-type siderophores produced by various myxobacterial strains. Here, we report the discovery, isolation, and structure elucidation of three new myxochelins N1–N3 from the terrestrial myxobacterium Corallococcus sp. MCy9049, featuring an unusual nicotinic acid moiety. Precursor-directed biosynthesis (PDB) experiments and total synthesis were performed in order to confirm structures, improve access to pure compounds for bioactivity testing, and to devise a biosynthesis proposal. The combined evaluation of metabolome and genome data covering myxobacteria supports the notion that the new myxochelin congeners reported here are in fact frequent side products of the known myxochelin A biosynthetic pathway in myxobacteria. 相似文献
In this paper we show that if G is a group acting on a graph X with inversions such that G has a presentation induced by a fundamental domain for the action of G on X, then X is a tree.
Received: January 3, 2007., Revised: August 10, 2007 and May 3, 2008., Accepted: October 17, 2008. 相似文献
Two silicate minerals talc (Mg3Si4O10(OH)2) and zircon (ZrSiO4) with different crystal lattice structures were subjected to ESR dosimetric studies. Zircon shows anisotropic ESR signals at gxx = 2.0168, gyy = 2.0076 and gzz = 2.0033, which have been identified as a hole-center associated with Y3+ substituted at Zr4+ sites. Other characteristic signals were observed and identified. The ESR signal at g = 2.0033 showed positive response to γ-irradiation at 110 Gy and is suitable for use in dosimetry and dating of natural zircons.Talc (a magnesium sheeted silicate) exhibits ESR derivative spectrum characterized by the presence of Fe3+ at g = 4.28 and the hf-sixtet Mn2+ signals. This is due to the possible substitution of Fe3+ and Mn2+ in the Mg2+ octahedral sites, respectively. The enhancement of the Mn2+ sixtet by γ-irradiation increases the area occupied by the signals that makes it difficult for use with dosimetric applications. 相似文献
The structure of lysozyme-sodium dodecyl sulfate (SDS) complexes in solution is studied using small-angle X-ray scattering (SAXS). The SAXS data cannot be explained by the necklace and bead model for unfolded polypeptide chain interspersed with surfactant micelles. For the protein and surfactant concentrations used in the study, there is only marginal growth of SDS micelles as they complex with the protein. Being a small and rather rigid protein, lysozyme can penetrate the micellar core which is occupied by flexible and disordered paraffin chains and also the shell occupied by the hydrated head groups. A partially embedded swollen micellar model seems appropriate and describes well the scattering data. The SAXS intensity profiles are analyzed by considering the change in the electron scattering length density of the micellar core and shell due to complexation with protein and treating the intermicellar interaction using rescaled mean spherical approximation (RMSA) for charged spheres. 相似文献
Pichia angusta MTCC-225, a catalase-positive yeast that utilizes methanol and lighter hydrocarbons, is the subject of this investigation.
An orthogonal experimental design L16 was used to investigate the effects of methanol, a gas mixture, zero air, temperature, agitation, and salts solution on hydrocarbon
utilizing P. angusta. QUALITEK-4 Software was used for automatic design and analysis of the experimental results. Among the various parameters
tested, agitation contributed the highest influence (56.5%). Zero air, methanol concentration, and gas mixture showed a moderate
influence on the growth of P. angusta. Methanol concentration and gas mixture showed a 10.91 and 10.12% influence, respectively, on yeast growth. Zero air played
an important role, with a 15.19% influence on the utilization of hydrocarbon. 相似文献
A mass sensitive quartz crystal microbalance (QCM) based genosensor has been developed using breast cancer 1 (BRCA1) gene as a model gene. We modified the traditional sandwich assay by conjugating reporter probe DNA (DNA-r) with an assembly of gold nanoparticles leading to an increased mass on the surface, which enhanced the sensitivity to few orders of magnitude. The unique cleavage function of endonuclease is used for achieving the selectivity to complementary DNA over mismatched DNA. With this combination, the sensor exhibited excellent sensitivity with a detection limit of 10 aM BRCA1 gene and it showed good selectivity for even single base mismatch DNA targets. This ultrasensitive and cost-effective DNA detection protocol can be extended to the direct analysis of any non-amplified genomic DNA. 相似文献
The Ti3+ ion in YAlO3 (YAP), Y3Al5O12 (YAG), and Al2O3 crystals occupies distorted octahedral sites relative to the nearest neighbour ligand ions. Such distortions are of even-parity in YAG where the zero-phonon lines in emission occur via magnetic dipole transitions. In contrast, the zero-phonon transitions occur by electric dipole processes in Ti3+:YAP and Ti3+:Al2O3 where there are odd-parity distortions from octahedral symmetry. This paper reports measurements of the zero-phonon lines of Ti3+ ions in YAP, YAG, and Al2O3 at 10 K. The zero-phonon lines of Ti3+:YAP are strongly polarized perpendicular to the tetragonal axis and those of Ti3+:Al2O3 parallel to the trigonal axis. The experimental results are shown to be in accord with a molecular orbital model of the radiative transition according to which the transition intensities derive from odd-parity ligand wavefunctions induced into even-parity ground and excited Ti3+ wavefunctions by odd-parity crystal distortions. 相似文献
A series of new benzimidazole derivatives was synthesized and characterized by IR,1H NMR,13C NMR,MS,and HRMS spectra.All the new compounds were screened for their antimicrobial activities in vitro by a twofold serial dilution technique.The bioactive evaluation showed that 3,5-bis(trifluoromethyl)phenyl benzimidazoles were comparably or even more strongly antibacterial and antifungal than the reference drugs Chloromycin,Norfloxacin,and Fluconazole.The combination of2,4-difluorobenzyl benzimidazole derivative 5l and its hydrochloride 7 respectively with the antibacterials Chloromycin,Norfloxacin,and the antifungal Fluconazole was more sensitive to methicillin-resistant MRSA and Fluconazole-insensitive A.flavus.In addition,the interaction of compound 5l with calf thymus DNA demonstrated that this compound could effectively intercalate into DNA to form a compound 5l-DNA complex that might block DNA replication and thereby exert good antimicrobial activity. 相似文献