26 research outputs found
Dormancy and sprouting in gladiolus
The onset, level and disappearance of dormancy in corms and cormels of summer- flowering gladiolus cultivars were studied in relation to environmental conditions and revaluated as an ecological adaption. The cormels were more deeply dormant than their sister corms, which were most dormant when formed at higher temperatures and in longer photoperiods. The depth of dormancy therefore varied from year to year and from cultivar to cultivar. Dormancy disappeared during dry storage at all temperatures between 6° and 27°C but quickest at 6° or 10°C. These low temperatures were essential to keep cormels out of dormancy. Dormancy was not broken at any single temperature in moist soil; temperatures alternating between 10° and 22° were necessary. Sprouting of the cormels varied with the state of their shell and size. No correlation was found with respiration although CO 2 production of cormels with broken shells was 6-16 times as high as in intact cormels. The different depths of dormancy at planting were maintained throughout a long period in moist soil at 20°C. Plants grown from cormels stored at different temperatures produced the same numbers of corms and cormels, if the plants were the same age and were spaced alike
NOVEL TECHNIQUES TO PREPARE SOLID DISPERSIONS TO IMPROVE SOLUBILITY OF BOSENTAN
ABSTRACT
Objective: Bosentan presents challenges with regard to low and variable oral bioavailability due to its poor aqueous solubility and poor dissolution in gastric fluid. Solid dispersion has been used as the solubility enhancement technique due to its ability to develop suitable system with improved solubility and dissolution rate. Methods: Solid dispersions of bosentan were prepared by using novel techniques like solvent controlled coprecipitation, fusion and nanoprecipitation. Polymers with different ionic characteristics like Eudragit® EPO (cationic), Eudragit® L 100 55 (anionic) and Povidone K 30 (non-ionic) were employed at three different ratios of 1:1, 1:2 and 1:3 to prepare the solid dispersions of weakly basic bosentan. Dissolution study in buffers corresponding to different physiologically relevant pH was performed to understand the effectiveness of the technique and effect of the polymer. Additionally, samples were subjected for X-ray powder diffraction study to understand the nature of the drug in solid state in the solid dispersion systems. Results: It was observed that irrespective of the pH of the dissolution media, the dissolution rate of the solid dispersions of BOS prepared with Eudragit® L 100 55 are higher than that of pure drug and the solid dispersions prepared with the other polymers i.e. Eudragit® EPO and Povidone K 30, which is attributed to the weakly basic nature of bosentan. The diffractograms show decrease in the crystallinity of bosentan in the solid dispersions. Conclusion: The combination of solid dispersion technology with supersaturable systems appears to hold promise for improving dissolution and bioavailability of poorly soluble drugs. The selection of polymers that can inhibit crystallization of the drug in a supersaturated state becomes the key factor for an effective formulation. The present work is an attempt in this direction.
KEYWORDS: Solid Dispersion, Super Saturable systems, Insoluble drugs
Growth of CaF2 buffer on Si using low energy cluster beam deposition technique and study of its properties
International audienc
Growth of CaF2 buffer on Si using low energy cluster beam deposition technique and study of its properties
ADAMTS9-regulated pericellular matrix dynamics governs focal adhesion-dependent smooth muscle differentiation
Focal adhesions anchor cells to extracellular matrix (ECM) and direct assembly of a pre-stressed actin cytoskeleton. They act as a cellular sensor and regulator, linking ECM to the nucleus. Here, we identify proteolytic turnover of the anti-adhesive proteoglycan versican as a requirement for maintenance of smooth muscle cell (SMC) focal adhesions. Using conditional deletion in mice, we show that ADAMTS9, a secreted metalloprotease, is required for myometrial activation during late gestation and for parturition. Through knockdown of ADAMTS9 in uterine SMC, and manipulation of pericellular versican via knockdown or proteolysis, we demonstrate that regulated pericellular matrix dynamics is essential for focal adhesion maintenance. By influencing focal adhesion formation, pericellular versican acts upstream of cytoskeletal assembly and SMC differentiation. Thus, pericellular versican proteolysis by ADAMTS9 balances pro- and anti-adhesive forces to maintain an SMC phenotype, providing a concrete example of the dynamic reciprocity of cells and their ECM
A NOVEL APPROACH FOR IMAGE WATERMARKING USING DCT AND JND TECHNIQUES
Today’s world is digital world. Nowadays, in every field there is enormous use of digital contents. Information handled on internet and multimedia network system is in digital form. The copying of digital content without quality loss is not so difficult. Due to this, there are more chances of copying of such digital information. So, there is great need of prohibiting such illegal copyright of digital media. Digital watermarking is the powerful solution to address this problem. Digital watermarking is the technology in which there is embedding of various types of information in digital content which we have to protect from illegal copying
Synovial chondromatosis: the possible role of FGF 9 and FGF receptor 3 in its pathology
Primary synovial chondromatosis (PSC) is a rare disorder of the synovium typified by cartilaginous nodule formation within the synovial membrane. Fibroblast growth factor receptor 3 (FGFR3) is a recently described specific marker of mesenchymal precartilaginous stem cells. Expression patterns of FGFR3 and its specific ligand, fibroblast growth factor 9 (FGF 9), were evaluated both in situ and in cell cultures. Histologically, cells at the periphery of the cartilage nodules express FGFR3 and PCNA (proliferating cell nuclear antigen). Elevated levels of FGF 9, its specific ligand, have been found in synovial fluids of patients with synovial chondromatosis. Synoviocytes but not chondrocytes from affected patients express FGF9 in culture. This pattern is absent in normal synovium and cartilage. Downregulation of FGF9 may provide a possible nonoperative therapy for PSC