The micro-sized Sb2O3 octahedra can be synthesized on a large scale via a simple PEG-1000 polymer-assisted hydrothermal route (PAHR) in the temperature range of 160-180 °C for 10-14 h. The structures, compositions, and morphologies of the as-synthesized products are derived from X-ray power diffraction pattern, X-ray photoelectron spectra, and field emission scanning electronic microscope. Meanwhile, the optical properties of the micro-sized Sb2O3 octahedra are studied by their photoluminescene spectroscopy and Raman spectrum. Furthermore, the possible growth mechanism of the micro-metered Sb2O3 octahedra is discussed on the basis of a series of supplementary experiments. And it has been found that PEG-1000, sodium tartrate, the reaction temperature, and the reaction time have considerable effects on the final morphology of Sb2O3, while the pH value has an influence on the formation of the Sb2O3 crystals. 相似文献
The authors describe a method for DNA target recognition and signal amplification that is based on the target-induced formation of a three way junction. The subsequent assembly of two DNA probes releases the inhibitory strand and triggers a downstream strand displacement amplification. This causes the formation of a G-rich single sequence that binds to a hemin monomer with its peroxidase-mimicking properties. The resulting peroxidase (POx) activity is quantified by using H2O2 and TMB as the substrate. In the presence of an inhibitor, in contrast, the POx-like activity is strongly reduced. This forms the basis for a highly sensitive DNA assay. It has a 0.8 pM detection limit when operated at a wavelength of 450 nm and was applied to the isothermal determination of target DNA with high selectivity.
Graphical abstract Schematic of the assay: Introduction of target results in the formation of a three way junction. The subsequent assembly of two probes releases the inhibitory strand and triggers a downstream strand displacement amplification, generating amount of G-rich single sequence which causes peroxidase-mimicking activity on binding to a hemin monomer.
The extraction of high‐purity proteins from the washing solution (WS) of rubber particles (also termed latex‐producing organelles) from laticifer cells in rubber tree for proteomic analysis is challenging due to the low concentration of proteins in the WS. Recent studies have revealed that proteins in the WS might play crucial roles in natural rubber biosynthesis. To further examine the involvement of these proteins in natural rubber biosynthesis, we designed an efficiency method to extract high‐purity WS proteins. We improved our current borax and phenol‐based method by adding reextraction steps with phenol (REP) to improve the yield from low protein concentration samples. With this new method, we extracted WS proteins that were suitable for proteomics. Indeed, compared to the original borax and phenol‐based method, the REP method improved both the quality and quantity of isolated proteins. By repeatedly extracting from low protein concentration solutions using the same small amount of phenol, the REP method yielded enough protein of sufficiently high‐quality from starting samples containing less than 0.02 mg of proteins per milliliter. This method was successfully applied to extract the rubber particle proteins from the WS of natural rubber latex samples. The REP‐extracted WS proteins were resolved by 2DE, and 28 proteins were positively identified by MS. This method has the potential to become widely used for the extraction of proteins from low protein concentration solutions for proteomic analysis. 相似文献
Protein extraction from plants like the halophyte Salicornia europaea has been problematic using standard protocols due to high concentrations of salt ions in their cells. We have developed an improved method for protein extraction from S. europaea, which allowed us to remove interfering compounds and salt ions by including the chemicals borax, polyvinylpolypyrrolidone, and phenol. The comparative study of this method with several other protocols using NaCl-treated S. europaea shoots demonstrated that this method gave the best distinction of proteins on 2-DE gels. This protocol had a wide range of applications as high yields and good distinction of 1-DE gels for proteins isolated from twelve other plants were rendered. In addition, we reported results of 2-DE using the recalcitrant tissue of the S. europaea roots. We also demonstrated that this protocol is compatible with proteomic analysis as eight specific proteins generated by this method have been identified by MS. In conclusion, our newly developed protein extraction protocol is expected to have excellent applications in proteomic studies of halophytes. 相似文献
Analytical and Bioanalytical Chemistry - A molecular beacon (MB) is an oligonucleotide hybridization probe with a hairpin-shaped structure that leads to specific and instantaneous nucleic acid... 相似文献
Hydrogen plasma immersion ion implantation (PIII) in conjunction with ion-cut is an efficient and economical technique to synthesize silicon-on-insulator (SOI) substrates. Unlike beam-line ion implantation, the PIII hydrogen profile usually exhibits multiple peaks because of different implanted species, such as H+, H2 +, and H3+. In addition, a certain amount of adsorbed hydrogen exists near the surface and the hydrogen in-depth distribution is broader than that of a beam-line implant also as a result of a low-energy component. For the ion-cut process, the broadened hydrogen profile and surface hydrogen can decrease the efficiency of the blistering process, induce uneven exfoliation, and degrade the interfacial quality of the bonded wafer. Hydrogen can adsorb on the wafer surface during the “off-cycle” of the sample voltage pulse and consequently be driven in by ion mixing or diffusion. In order to reduce surface hydrogen incorporation, the implantation time must be short, and this requires an efficient cooling mechanism on the sample stage because a high ion current is needed to implant a high dose in a short time (less than 5 min). Another mechanism of profile broadening is that the expanding sheath creates low-energy ions during PIII. Our experimental and simulation data disclose that profile broadening is less severe for a shorter sample voltage pulsewidth and that good blistering characteristics can be achieved using a long pulse, in spite of a relatively long implantation time of 1 h 相似文献
Considering the importance of CBB staining in visualizing proteins in 2-DE gels, any improvement in the existing protocols with high sensitivity and good MS compatibility is of significant importance. In this study, we systematically evaluated the effects of different staining parameters on CBB methods by 1-DE and 2-DE, and demonstrated that G-250 was more suitable for visualizing low-abundant proteins as well as generating more spots than R-250, whereas R-250 had a superior capability for quick staining of high-abundant proteins. The staining produced by mixing G-250 and R-250 in different ratios showed similar sensitivity. Compared with acetic acid, phosphoric acid produced more protein spots. Ammonium-based stain demonstrated a superior sensitivity than the aluminum-based one. Based on these findings, a new protocol using CBB G-250, ammonium sulfate and phosphoric acid (GAP) was developed by incorporating the fixation, sensitization and staining procedures together. The comparison of GAP with other methods revealed that GAP generated more protein spots and had wider applications. The identification of 11 proteins demonstrated that GAP was not only compatible with MS but also obviously reduced in vitro protein modification, and thus could be a preferable protocol in the future proteomic analysis. 相似文献