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11.
Sonodynamic therapy (SDT) is a novel tumor therapy method. We investigated membrane fluidity, activity of the enzymes and membrane morphology in vitro post hematoporphyrin-SDT treatment. Furthermore, the potential mechanisms behind the changes in membrane fluidity and enzymic activity were discussed. Tumor cells were exposed to ultrasound at 1.75 MHz for up to 3 min in the presence and absence of hematoporphyrin. Fluorescence polarization, contents of Malonaldehyde, and levels of free fatty acid were assessed. Activity of enzymes was checked by the plumbic nitrate detection method. For the morphologic study, a scanning electron microscope was used to observe the cellular surface. Ultrasonically induced cell damage increased in the presence of HPD (from 15% to 24%). Compared with ultrasound treatment alone, the fluidity decreased from 5.037 to 3.908, malonaldehyde content and free fatty acid level increased from 0.743 nmol/mL to 0.979 nmol/mL and from 237.180 μmol/L to 730.769 μmol/L, respectively, post ultrasound combined with HPD treatment. Inactivity of adenylate cyclase and guanylate cyclase and significant deformation of the cellular surface were also observed post SDT treatment. Our results suggested that alterations in membrane modality and lipid composition played important roles in SDT-mediated inhibition of tumor growth, even inducing tumor cell death, which might be attributed to a sono-chemical activation mechanism. 相似文献
12.
Dan Xie Huan-Huan Li Yan-Hong Shi Wan-Yue Diao Ru Jiang Prof. Hai-Zhu Sun Prof. Xing-Long Wu Dr. Wenliang Li Dr. Chao-Ying Fan Prof. Jing-Ping Zhang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(4):853-862
The Fe-based transition metal oxides are promising anode candidates for lithium storage considering their high specific capacity, low cost, and environmental compatibility. However, the poor electron/ion conductivity and significant volume stress limit their cycle and rate performances. Furthermore, the phenomena of capacity rise and sudden decay for α-Fe2O3 have appeared in most reports. Here, a uniform micro/nano α-Fe2O3 nanoaggregate conformably enclosed in an ultrathin N-doped carbon network (denoted as M/N-α-Fe2O3@NC) is designed. The M/N porous balls combine the merits of secondary nanoparticles to shorten the Li+ transportation pathways as well as alleviating volume expansion, and primary microballs to stabilize the electrode/electrolyte interface. Furthermore, the ultrathin carbon shell favors fast electron transfer and protects the electrode from electrolyte corrosion. Therefore, the M/N-α-Fe2O3@NC electrode delivers an excellent reversible capacity of 901 mA h g−1 with capacity retention up to 94.0 % after 200 cycles at 0.2 A g−1. Notably, the capacity rise does not happen during cycling. Moreover, the lithium storage mechanism is elucidated by ex situ XRD and HRTEM experiments. It is verified that the reversible phase transformation of α↔γ occurs during the first cycle, whereas only the α-Fe2O3 phase is reversibly transformed during subsequent cycles. This study offers a simple and scalable strategy for the practical application of high-performance Fe2O3 electrodes. 相似文献
13.
Summary The partition of the spin probe TEMPO between the fluid lipid phase of single-walled vesicles of dipalmitoylphosphatidylcholine
and the aqueous bulk solution have been used to investigate the interaction of monovalent ions with polar head of neutral
phospholipids. The study has been performed by electron spin resonance (ESR) spectroscopy in the temperature range of (20÷60)°C
and in the presence of (0÷3) M 1∶1 electrolyte. In the absence of electrolyte the spin probe TEMPO reveals the characteristic
order→disorder DPPC main phase transition atT
m≈37°C, while the pretransition occurs atT
p≈27.5°C. On increasing the ionic strength of the dispersion medium it results for the partition coefficient,P
C, that, at each temperature,P
C(3)>P
C(2)>P
C(1)>P
C(0). Correspondingly, the pretransition disappears and theT
m value downshifts from ≈37°C with 0 M electrolyte to ≈34°C with 3M salt in the order:T
m(3)>T
m(2)>T
m(1)>T
m(0). The results suggest an increase in the net surface charge density of vesicles due to high ionic-strength values. The
alteration of the electric interactions occurring into the polar zone of DPPC bilayer reduces the hindrances which, in turn,
favour the enhancement of TEMPO partitioning in the hydrophobic core of phospholipid bilayers.
The authors of this paper have agreed to not receive the proofs for correction. 相似文献
14.
J. Prost J.-B. Manneville R. Bruinsma 《The European Physical Journal B - Condensed Matter and Complex Systems》1998,1(4):465-480
Membranes in thermal equilibrium are well known to exhibit Brownian motion type shape fluctuations. Membranes containing active
force centers -- such as chemically active membrane proteins -- suffer additional non-equilibrium shape fluctuations due to
the activity of these force centers. We demonstrate, using scaling arguments, that non-equilibrium shape fluctuations are
in general greatly amplified by the presence of a nearby wall or membrane due to the absence of a fluctuation-dissipation
theorem. For adhesive membranes, this fluctuation magnification effect may facilitate the establishment of bonding. For non-adhesive
membranes, fluctuation magnification produces a long-range repulsive pressure which can exceed the well known Helfrich repulsion
due to purely thermal fluctuations.
Received: 1 September 1997 / Accepted: 3 December 1997 相似文献
15.
《Arabian Journal of Chemistry》2022,15(1):103524
MXene, well-identified as Ti3C2TX, belongs to the family of two-dimensional (2D) materials, which have been currently explored in various applications. Very recently, such materials have been pointed out as potential nanomaterials for advanced solute separations when introduced in membranes, such as ion separation, gas separation, nanofiltration, chiral molecular separation, and solvent separation. This latter separation, generally named Pervaporation (PV), is identified as a highly selective technology for water separations. To date, few pieces of research have been released but providing interesting insights into several solvent (including water) separations. Hence, this brief review aims to analyze and discuss the latest advances for utilizing MXenes for PV membranes. Particular emphasis has been devoted to the relevant outcomes in the field, along with the strategies followed by researchers to tailor membranes. Based on the current findings, the perspectives in the field are also stated. 相似文献
16.
Fabien Pascale Klaus Doll Francesco Silvio Gentile Roberto Dovesi 《Journal of computational chemistry》2023,44(2):65-75
The ferromagnetic and antiferromagnetic wave functions of the KMnF3 perovskite have been evaluated quantum-mechanically by using an all electron approach and, for comparison, pseudopotentials on the transition metal and the fluorine ions. It is shown that the different number of α and β electrons in the d shell of Mn perturbs the inner shells, with shifts between the α and β eigenvalues that can be as large as 6 eV for the 3s level, and is far from negligible also for the 2s and 2p states. The valence electrons of F are polarized by the majority spin electrons of Mn, and in turn, spin polarize their 1s electrons. When a pseudopotential is used, such a spin polarization of the core functions of Mn and F can obviously not take place. The importance of such a spin polarization can be appreciated by comparing (i) the spin density at the Mn and F nuclear position, and then the Fermi contact constant, a crucial quantity for the hyperfine coupling, and (ii) the ferromagnetic–antiferromagnetic energy difference, when obtained with an all electron or a pseudopotential scheme, and exploring how the latter varies with pressure. This difference is as large as 50% of the all electron datum, and is mainly due to the rigid treatment of the F ion core. The effect of five different functionals on the core spin polarization is documented. 相似文献
17.
The processes of lactic acid production include two key stages, which are (a) fermentation and (b) product recovery. In this
study, free cell of Bifidobacterium longum was used to produce lactic acid from cheese whey. The produced lactic acid was then separated and purified from the fermentation
broth using combination of nanofiltration and reverse osmosis membranes. Nanofiltration membrane with a molecular weight cutoff
of 100–400 Da was used to separate lactic acid from lactose and cells in the cheese whey fermentation broth in the first step.
The obtained permeate from the above nanofiltration is mainly composed of lactic acid and water, which was then concentrated
with a reverse osmosis membrane in the second step. Among the tested nanofiltration membranes, HL membrane from GE Osmonics
has the highest lactose retention (97 ± 1%). In the reverse osmosis process, the ADF membrane could retain 100% of lactic
acid to obtain permeate with water only. The effect of membrane and pressure on permeate flux and retention of lactose/lactic
acid was also reported in this paper. 相似文献
18.
Bok Lyeon Lee Yoon Hee Lee Il Yoon Jong Hwa Jung Ki-Min Park Shim Sung Lee 《Microchemical Journal》2001,68(2-3)
Extraction and transport behaviors of isomeric oxathia macrocycles (L2, ortho-; L3, meta- and L4, para-isomer) and their structure related open-chain compound (L1) towards Ag(I) picrate have been examined. From the plot of log (DAg(I)/[pic−]) vs. log [L]0 for all of the ionophores were linear with slope near unity, thereby confirming the 1:1:1 complex formations of Ag(I)/ligand/picrate ion to be extracted into the dichloromethane phase. The extractability of an acyclic ionophore was superior to those of the corresponding cyclic ones. In membrane transport experiments, the slow rate of release of Ag(I) from the membrane into the receiving phase seems to be responsible for lower transport efficiency. Upon addition of sodium thiosulfate as a stripping reagent in receiving phase, the efficiency of transport is significantly enhanced in the order of L1 (acyclic)>L2 (ortho-)>L3 (meta-)>L4 (para-) in accordance with those of log Kex values. It is hypothesized that the ion-pair complexation of L1 in extraction step would be more favorable in extraction and transport of Ag(I). Its structure have been confirmed by X-ray diffraction analysis of [Ag(L1)pic], where L1=1,10-bis(mercaptobenzylyl)-4,7-dioxadecane. 相似文献
19.
The selective enhancement of membrane introduction mass spectrometry for non-polar alkanes, alkenes, and aromatic hydrocarbon
compounds by the application of acetonitrile as a chemical ionization reagent was investigated. Acetonitrile Cl is able to
produce specific fragment ions for many of the compounds test and this can be used to identify and quantify the parent neutrals.
This method provided relatively high detection limits of the test compounds. This method could potentially be useful for analytical
applications such as the detection of non-polar hydrocarbons for environmental studies if CH3CN Cl/MIMS is coupled with a preconcentration method. 相似文献
20.
Obermaier C Jankowski V Schmutzler C Bauer J Wildgruber R Infanger M Köhrle J Krause E Weber G Grimm D 《Electrophoresis》2005,26(11):2109-2116
The method of preparing protein mixtures for electrophoretic analysis of membrane-associated cell proteins was improved. By sonication, about one-half of the proteins of thyroid cells were released into the supernatant, while the other half preferentially comprising membrane proteins still remained in cell fragments, which could be sedimented by centrifugation. After sonication, even those proteins which remained in cell fragments, could completely be dissolved by free-flow isoelectric focusing media. They migrated through the free-flow electrophoresis chamber without forming precipitates. Because of these improvements, it was possible to show that the two thyroid cancer cell lines ML-1 and ONCO-DG1 express cytokeratin 8 at similar rates, but cytokeratins 7 and 18 differently. In addition, the presence of inorganic pyrophosphatase, tubulin-beta-5, and tubulin-beta-1 chains in human thyroid cells was proved for the first time. 相似文献