The uterine cervix undergoes changes during pregnancy and labor that transform it from a closed, rigid, collagen dense structure to one that is distensible, has a disorganized collagen matrix, and dilates sufficiently to allow birth. To protect the reproductive tract from exposure to the external environment, the cervix must be rapidly altered to a closed, undistensible structure after birth. Preparturition remodeling is characterized by increased synthesis of hyaluronan, decreased expression of collagen assembly genes and increased distribution of inflammatory cells into the cervical matrix. Postpartum remodeling is characterized by decreased hyaluronan (HA) content, increased expression of genes involved in assembly of mature collagen and inflammation. The focus of this study is to advance our understanding of functions HA plays in this dynamic process through characterization of HA size, structure and binding proteins in the mouse cervix. Changes in size and structure of HA before and after birth were observed as well as cell specific expression of HA binding proteins. CD44 expression is localized to the pericellular matrix surrounding the basal epithelia and on immune cells while inter alpha trypsin inhibitor (IalphaI) and versican are localized to the stromal matrix. Colocalization of HA and IalphaI is most pronounced after birth. Upregulation of the versican degrading protease, ADAMTS1 occurs in the cervix prior to birth. These studies suggest that HA has multiple, cell specific functions in the cervix that may include modulation of tissue structure and integrity, epithelial cell migration and differentiation, and inflammatory responses. 相似文献
Plasmonic nanoparticles are of great importance owing to their highly responsive ‘localized surface plasmon resonance’ (LSPR) behaviour to self-agglomeration/aggregation leading to the development of various nanosensors. Herein, we demonstrated the definite self-assembly of citrate functionalized silver nanoparticles (AgNPs) into a one-dimensional linear chain in presence of charged lead ions (Pb2+), one of the most toxic heavy metal pollutants. We have explored detail mechanism using a variety of spectroscopic tools and electron microscopy. The self-aggregation of AgNPs leads to the generation of new LSPR modes due to coupling of nearby existing modes. The conclusion of our experimental findings is duly supported by our developed numerical modelling based on the quasi-static approximation that the generated new LSPR modes are solely due to formation of chain-like aggregation of AgNPs. We have also monitored the LSPR spectra in the presence of other metal ions; however, only Pb2+ found to give such unique self-assembled geometry may due to its high interaction affinity with citrate. These findings play a key role for citrate functionalised AgNPs to be used as a low cost highly selective and sensitive lead ion sensor for potential application in industrial lead pollution monitoring. We have further varied several sensor parameters such as AgNPs size, concentration, and the allowed reaction time for it to be practically implemented as an efficient lead sensor meeting the Environmental Protection Agency recommendations.
Graphical abstract
The possible sensing mechanism of citrate-functionalized silver nanoparticles towards Pb2?+?followed by unique chain-like aggregation for potential atmospheric and industrial lead pollution monitoring.
The concentration of the juvenile hormone-binding protein (JHB) in hemolymph was determined throughout the last nymphal instar. It was found to be 3.9 μM at the molt to the instar, rising to 13 μM by mid-instar, and dropping to 6.7μM the day before emergence. Endocrine control of its production during the last nymphal instar could not be established. The apparent juvenile hormone esterase (JHF) activity was low at the molt to the last instar, but rose about fivefold by mid-instar, and then modestly declined. On the day of emergence, JHF activity rose to the highest level observed. A four- to fivefold increase in absolute JHF activity was determined during the first half of the last nymphal instar. This increase is not regulated by JH. Removal of the JHB from hemolymph samples by precipitation with a polyclonal specific antibody increased the JHF activity up to 1,000-fold. Thus, changes in the concentrations of JHB can affect the apparent activity of JHE, which is unrelated to the production or degradation of the JHF. 相似文献
The study presents the comparative analyses of endogenous contents of auxin (IAA), cytokinins (CKs), polyamines (PAs), and
phenolic acids (PhAs) in apical and basal parts of elm multiplicated shoots with regard to the organogenic potential. The
shoot-forming capacity was higher in the apical part than in the basal part. However, the timing of root formation was in
the apical type of explant significantly delayed (compared with the organogenic potential of basal part). Significantly higher
contents of free bases, ribosides and ribotides of isopentenyl adenine, zeatin and dihydrozeatin that were found in the apical
segments, might be considered as the most important factor affecting in vitro shoot formation. The content of endogenous free IAA was approximately three times higher in the basal shoot parts than in
the apical parts. The amounts of putrescine and spermidine were higher in the apical part which generally contains less differentiated
tissues than the basal part of shoot. The predominant PhA in both types of explants was caffeic acid, and concentrations of
other PhAs decreased in the following order: p-coumaric, ferulic, sinapic, vanillic, chlorogenic, p-hydroxybenzoic and gallic acids. The contents of all determined PhAs in their free forms and higher contents of glycoside-bound
p-coumaric, ferulic and sinapic acids, precursors for lignin biosynthesis, were found in the basal parts. 相似文献
A bacterial adhesion technique for identification of Fc-receptor bearing cells is based on the ability of Staphylococcus aureus, Cowan 1 strain, to form rosettes with cells previously treated with immune complexes or heat aggregated Ig G. The new technique is distinguished from other Fc-receptor detection methods by its simplicity and ease of detection of both immune complexes and aggregated IgG-binding cells. 相似文献
To develop a better chemotherapeutically potential candidate for lung cancer treatment and cure with repurposed motifs, quinine has been linked with biocompatible CuAAC-inspired regioselective 1,2,3-triazole linker and a series of ten novel 1,2,3-triazolyl-9-quinine conjugates have been developed by utilizing click conjugation of glycosyl ether alkynes with 9-epi-9-azido-9-deoxy-quinine under standard click conditions. In parallel, the docking study indicated that the resulting conjugates have an overall appreciable interaction with ALK-5 macromolecules. Moreover, the mannose-triazolyl conjugate exhibited the highest binding interactions of −7.6 kcal/mol with H-bond interaction with the targeted macromolecular system and indicate the hope for future trials for anti-lung cancer candidates. 相似文献
The change of 11-1, IL-3, CSA concentrations in adherent and nonadherent bone marrow cells condition medium at stress were investigated. The activation of bone marrow hemopoiesis was registered at mice after immobilization stress. The number of CFU-GM increased on 1, 4 and 5 day after stress. Maximum of CSA in adherent and nonadherent cells conditioned medium was observed on day 4, 6 or 2, 5 respectively. The increasing of 11-3 activity in culture of nonadherent bone marrow cells was registered from day 1 and mount to maximum at 4-5 days. The increasing of 11-1 level in culture of adherent bone marrow cells was found at 1 and 4 days. 相似文献