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1.
High Energy Chemistry - In this work, the effect of γ-irradiation on the adhesion properties of FP9120 diazoquinone–novolac photoresist films deposited on single-crystal silicon wafers... 相似文献
2.
One of the most promising strategies to treat cancer is the use of therapeutic antibodies that disrupt cell–cell adhesion mediated by dysregulated cadherins. The principal site where cell–cell adhesion occurs encompasses Trp2 found at the N-terminal region of the protein. Herein, we employed the naturally exposed highly conserved peptide Asp1-Trp2-Val3-Ile4-Pro5-Pro6-Ile7, as epitope to prepare molecularly imprinted polymer nanoparticles (MIP-NPs) to recognize cadherins. Since MIP-NPs target the site responsible for adhesion, they were more potent than commercially available therapeutic antibodies for inhibiting cell–cell adhesion in cell aggregation assays, and for completely disrupting three-dimensional tumor spheroids as well as inhibiting invasion of HeLa cells. These biocompatible supramolecular anti-adhesives may potentially be used as immunotherapeutic or sensitizing agents to enhance antitumor effects of chemotherapy. 相似文献
3.
Ar:O 2 low pressure plasma (Ar:O 2 LPP) surface treatment is proposed for increasing the surface energy and improve the adhesion of wood-polyethylene composite. The treatment time was varied between 20 and 90 s and the configuration of the shelves inside the plasma chamber ( direct and secondary downstream) was also changed. Ar:O 2 LPP treatment during 30–40 s created new surface carbon–oxygen groups, increased the surface energy, mainly its polar component, reduced roughness and caused ablation of wood-polyethylene composite, irrespective of the configuration of the shelves inside the plasma chamber. The increase of the treatment time above 40 s did not cause additional surface modifications. Adhesion of the wood-polyethylene composite was noticeably increased when was treated with Ar:O 2 LPP. The surface modifications of Ar:O 2 LPP treated wood-polyethylene composite were partially lost during 24 h after treatment. 相似文献
4.
The macromolecular structures on nitinol surfaces were prepared by ECR microwave cold-plasma of tetraglyme conditions. The surface chemistry was characterized by high resolution ESCA. The results showed that the modified nitinol surfaces were built up mainly of-CH2-CH2-O-linkages and were particularly effective in preventing platelet adhesion. 相似文献
5.
Introduction Migrationandrecruitmentofleukocytesfromblood toinflammatorylesionsitesaresequentiallyregulated byadhesionmoleculesandtheirreceptors[1].These lectinfamilyplaysamajorroleininitiatingattachement ofneutrophilstotheactivatedendothelium.P selectin,… 相似文献
6.
IntroductionA characteristic tripeptide sequence Arg-Gly-Asp(RGD) that is found within fibronectin and other rela-ted adhesion molecules in extracellular matrices(ECM)has received considerable attention from researcherssince it was proved to be a recognit… 相似文献
7.
Adhesion properties of physically crosslinked hydrogels consisting of partially hydrated poly(sodium acrylate) (PSA) and poly(acrylic acid) (PAA) were investigated. The adhesion force and separation energy between the gels in swollen states were measured using a simple tack-evaluation technique by a point contact. As a result, the adhesion properties were significantly affected by the PSA/PAA ratio, which resulted from the fact that the physical and chemical properties of gels were changed through the replacement of PSA by PAA at gelation. The measurements of attenuated total reflectance Fourier transform infrared spectroscopy and the dynamic shear viscoelasticity suggested that the number of nonionized carboxyl groups increased and the stiffness increased with increasing the PAA ratio, respectively. In order to understand the adhesion properties further, the apparent contact area was evaluated by a stamp experiment using vermilion ink. The relationships between the adhesion properties and the physical and chemical features of gels are discussed in terms of the surface molecular interaction, the elastic and viscous properties of the bulk, and the apparent and true contact areas of the present system. From these results, the factors that determine the adhesion curve and the uniqueness and advantages of the present evaluation method are clarified. 相似文献
8.
Electrochemical reductive dissolution of Li–Mn–O and Li–Fe–Mn–O spinels and Li + extraction/insertion in these oxides were performed using voltammetry of microparticles. Both electrochemical reactions are
sensitive to the Fe/(Fe+Mn) ratio, specific surface area, Li content in tetrahedral positions, and Mn valence, and can be
used for electrochemical analysis of the homogeneity of the elemental and phase composition of synthetic samples. The peak
potential ( E
P) of the reductive dissolution of the Li–Mn–O spinel is directly proportional to the logarithm of the specific surface area. E
P of Li–Fe–Mn–O spinels is mainly controlled by the Fe/(Fe+Mn) ratio. Li + insertion/extraction can be performed with Mn-rich Li–Fe–Mn–O spinels in aqueous solution under an ambient atmosphere and
it is sensitive to the regularity of the spinel structure, in particularly to the amount of Li in tetrahedral positions and
the Mn valence.
Electronic Publication 相似文献
9.
Bubble points of the HCl–water–isopropanol and the HCl–water–isopropanol–benzene systems and liquid–liquid equilibria (LLE) of the HCl–water–benzene and the HCl–water– isopropanol–benzene systems were measured at 25–85°C and 30–70°C, respectively. The electrolyte nonrandom two-liquid model proposed by Chen et al. [C.-C. Chen, H.I. Britt, J.F. Boston, L.B. Evans, AIChE J. 28 (1982) 588–596] can satisfactorily correlate bubble points and liquid–liquid equilibria of the present mixed-solvent electrolyte systems over the entire range of temperature and concentrations using only binary adjustable parameters. 相似文献
10.
Fundamentally different behavior of Ba–Bi–O (Ba : Bi = 11 : 4, 1 : 1, 2: 3, and 1 : 5 mol/mol) and K nBa mBi m+nO y ( m = n = 1, 2,...; exhibiting superconducting properties with Tc = 28–32 K) oxides and BaO 2 in hydrolysis reactions has been revealed by means of potentiometry and chemical analysis. Products of the oxides treatment with water do not contain H 2O 2, evidencing the absence of peroxide ions in their structure. The perovskite-type barium-bismuth(III) oxides are completely hydrolyzed into Ba(OH) 2 and Bi 2O 3 at room temperature. 相似文献
11.
Cooling a melt of a Bi–Sr–Ca–Cu–O system (Bi:Sr:Ca:Cu = 4:3:3:4 or 2:2:2:4) from 1000°C-1050°C yielded crystals of a new red-colored nonsuperconducting phase, accompanying the superconducting 2212 and 2201 phases. Based on the EPR spectra, it was concluded that copper is univalent in this compound. The new phase has a composition Bi 2.2Sr 1.6Ca 1.3Cu 2O x. The X-ray diffraction pattern has been indexed, and the unit cell parameters of the phase have been determined: space group P2/m, a = 12.93, b = 4.55, c = 10.94 ; = 102.72°. 相似文献
12.
The high nitrogen compound 3,6-bis(1H-1,2,3,4-tetrazol-5-yl-amino)-1,2,4,5-tetrazine and the high energy density material hexanitrohexaazaisowurtzitane (HNIW), were used as substitute of hexogen (RDX) in the composite modified double base (CMDB) propellant formulations, the propellant samples were prepared, the thermal behaviors, nonisothermal reaction kinetics, and thermal safety were carried out, and the eight important parameters were calculated and obtained as the self-accelerating decomposition temperature ( T SADT), thermal ignition temperature ( T TIT), critical temperatures of thermal explosion ( T b), critical temperature of hot-spot initiation ( T cr,hot-spot), characteristic drop height of impact sensitivity ( H 50), critical thermal explosion ambient temperature ( T acr), safety degree ( S d), and thermal explosion probability ( P TE). It shows that the content of HNIW has a large effect on the decomposition reaction mechanism of the CMDB propellant, when the content of HNIW is 10 %, the decomposition reaction are controlled by the random nucleation and subsequent growth ( n = l), and the reaction mechanism obeys Mampel law; but when the content of HNIW is 20 %, the decomposition reaction are controlled by the chemical reaction ( n = 1/4). The mechanism can not be changed by the catalysts, and they just make the apparent activation energy change slightly. For the sample, from BC01 to BC04, the values of T SADT and T TIT making an upward tendency, show the resistivity to heat: BC04 > BC03 > BC02 > BC01; the values of T acr and S d, BC01 are the maximum and BC02 are the minimum, show the heat sensitivity: BC01 > BC03 > BC04 > BC02. For the same radius, the thermal safety of the sphere sample is greater than that of the infinite cylinder one. 相似文献
13.
T– x diagrams of polythermal GeAs–SnAs, GeAs–Sn 4As 3 sections of the Sn–As–Ge system and Sn 4P 3–Sn 4As 3 section of the Sn–As–P system were constructed using the results of X-ray powder diffraction and differential thermal analyses. It was found that the section GeAs–Sn 4As 3 is not quasi-binary due to realization of four-phase peritectic transformation L + SnAs ? GeAs + Sn 4As 3 at the temperature of 834 K. The quasi-binary section GeAs–SnAs represents a phase diagram of the eutectic type with the following coordinates of eutectic reaction: temperature of the eutectic point is 840 K, and composition is 20 mol% GeAs. In the Sn–As–P system, the existence of the solid-solution range indicated as (Sn 4As 3) x (Sn 4P 3) 1?x was defined. The polythermal section Sn 4P 3–Sn 4As 3 is not quasi-binary due to the fact that in the composition range with a high content of tin arsenide discussed section intersects the peritectic part of the three-phase volume (L + SnAs + α) of the ternary diagram. 相似文献
14.
CuAl layered double hydroxide (CuAl-LDH) was synthesized by co-precipitation. Sodium phenyl phosphate (SPP) and sodium dodecyl sulfate (SDS) are used to modify CuAl-LDH for preparing CuAl-(SPP)LDH and CuAl-(SDS)LDH, which were incorporated into epoxy resin (EP) to obtain EP/CuAl-(SPP)LDH and EP/CuAl-(SPP)LDH nanocomposites. The results indicate that SPP and SDS are intercalated into the interlayers of CuAl-LDH, and CuAl-(SPP)LDH has larger layer spacing than CuAl-(SDS)LDH. The thermal stability and flame-retardant performances of EP/CuAl-(SPP)LDH nanocomposites were better than those of EP/CuAl-(SDS)LDH composites. Compared with those of EP/4CuAl-(SDS)LDH nanocomposites, the peak heat release rate (PHRR) of EP/4CuAl-(SPP)LDH nanocomposites is reduced 25.8% and 55.6%, and peak smoke production rate (PSPR) value of EP/4CuAl-(SPP)LDH nanocomposites is reduced 27.6% and 46.2%, value of EP/4CuAl-(SPP)LDH nanocomposites is reduced 27.6% and 46.2%, respectively. The improved flame retardancy and smoke suppression performances of EP/CuAl-(SPP)LDH nanocomposites were attributed to the combination of copper compounds and SPP, promoting the formation of swollen, continuous and compact char layers on the surface of EP nanocomposites during combustion, eventually restraining the decomposition of EP nanocomposites. 相似文献
15.
The study explored the compatibility between the main product of Portland cement hydration and the main product of the alkali
activation of fly ash: C–S–H and N–A–S–H gels, respectively. Both gels were synthesized with laboratory reagents at different
pH values. Blends of the two were synthesized as well, using the sol–gel procedure. All the gels were characterized with Fourier
transform IR spectroscopy (FTIR). The gels synthesized with this procedure were shown to precipitate together with a silica-rich
gel. In addition, the pH level was found to play a determinant role in both C–S–H and N–A–S–H gel synthesis. The C–S–H gel
is the major phase formed at pH > 11 and N–A–S–H gel for pH > 12. The results relating to the joint synthesis of the two (C–S–H
and N–A–S–H) gels were not conclusive. Technique used for the characterization failed to differentiate between them in the
blended material.
相似文献
16.
Two complex lanthanide(III) transition metal(II) tellurium(IV) oxyhalides, Cu 3Yb 2(TeO 3) 4Cl 4 and Cu 3Yb 3(TeO 3) 4Cl 6 have been synthesized and the crystal structures were determined by single-crystal X-ray diffraction. Both compounds are layered with only weak connections in between the layers. The layers are made up of [YbO 8], [TeO 3] and [CuO xCl y] polyhedra. In both compounds the strong Lewis acid cations Yb 3+ and Te 4+ only form bonds to oxygen while Cu 2+ form bonds to both oxygen and chlorine. This leads the Cl ? ions to be expelled from the bonding volumes of the crystal structures and protrude from the layers. Magnetic susceptibility measurements were performed on a powder sample of Cu 3Yb 2(TeO 3) 4Cl 4. The Curie–Weiss law found at low temperatures indicates a Curie–Weiss temperature of ca. ?5(1) K. However, indication for long-range magnetic ordering could not be observed down to 1.87 K. The two new phases are to the best of our knowledge the first containing all three of Cu, Yb and Te. 相似文献
17.
Rod-shaped amorphous bulk Ni–Cr–Mo-22 at.%Ta-14 at.%Nb–P alloys resistant to concentrated hydrochloric acids were prepared
by copper-mold casting. Alloys of amorphous single phase and mixture of nanocrystalline phases in the amorphous matrix were
all spontaneously passive in 6 and 12 M HCl and were immune to corrosion in 6 M HCl, although the corrosion weight loss was
detected for heterogeneous alloys in 12 M HCl. Spontaneous passivation is due to presence of stable air-formed films in which
chromium was particularly concentrated in addition to enrichment of tantalum and niobium. The angle resolved X-ray photoelectron
spectroscopy revealed that chromium and molybdenum are rich in the inner part of the film. The major molybdenum species is
in the tetravalent state, although penta- and hexavalent state molybdenum is also included. The high corrosion resistance
was interpreted in terms of the high stability of the outer triple oxyhydroxide, Cr 1−x−yTa xNb yO z(OH) 3+2x+2y−2z, and the effective diffusion barrier of the inner Mo 4+ and Cr 3+ oxide layer.
Contribution to the Fall Meeting of the European Materials Research Society, Symposium D: 9th International Symposium on Electrochemical/Chemical
Reactivity of Metastable Materials, Warsaw, 17th-21st September, 2007. 相似文献
18.
IntroductionMetastasis is the leading cause of the death ofcancer patients.It represents a complex and multi-stepprocess including the detachment of tumor cells from aprimary cancer,the invasion into the surrounding tis-sue,the entry into the circulatory system,the reinva-sion,and the proliferation at a distant secondarysite[1,2].A wide variety of stimuli are known to be as-sociated with the metastasis of tumor cells,which in-clude cytokines,hormones,growth factors,and extra-cellular matrix pr… 相似文献
19.
The tripeptide,Arg-Gly-Asp(RGD)motif is an integrin-recognition site found in adhesive proteins present in extracellular matrices(ECM)and in the blood.HCT-8 cells were treated with cellular adhesion tripeptide RGD at various concentrations.MTT assay was performed to examine the growth and proliferation of HCT-8 cells after treatment with RGD for 48 h.Haematoxylin and Eosin(HE)staining and electromicroscope were used to observe the morphology of apoptotic cells.Survivin and flow cytometry were also used to analyze the HCT-8 apoptosis.Cellular adhesion tripeptide RGD significantly inhibits the growth and proliferation of HCT-8 cells in a dose-dependent manner and induces apoptosis of HCT-8.These results indicate that cellular adhesion tripeptide RGD inhibits the growth and proli-feration of tumor HCT-8 cell,probably by the aid of inducing apoptosis of HCT-8 cell. 相似文献
20.
Systematic investigation of sol–gel process in the Y–Ba–Cu–O acetate–tartrate system was performed using IR spectroscopy. Different values of synthesis parameters (temperature and duration of inorganic polymerization reactions, evaporation temperature and evaporation time during gelation) were used, and significant influence in some cases on superconducting characteristics of the oxide ceramics of composition YBa 2Cu 4O 8 was observed. Characterization by IR spectroscopy and thermogravimetric analysis, revealed the difference of local homogeneity in the precursor gels prepared under different evaporation regimes during gelation process. In addition, the explanation of the possible hydrolysis and condensation reactions in the sol state has been suggested. 相似文献
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