Transport behavior and efflux of Rg1 in rat pulmonary epithelial cells

The aim of this study was to investigate whether ginsenoside Rg1 could be transported into rat pulmonary epithelial cells and its transport behavior and efflux through the cells. A high-performance liquid chromatography coupled with 2487 UV-vis detector at 203 nm was applied. The mobile phase was 0.05% phosphate-acetonitrile (75:25, v/v). Cells were incubated with Rg1 (100 microg/mL) for a specific time, then lysed and sonicated in methanol to extract intracellular Rg1. Cells incubated with Rg1 and verapamil or KCN were processed by the same method. A 20 microL aliquot of sample was injected into the HPLC system to determine Rg1 concentration. The results showed that Rg1 could be transported into the epithelial cells with peak concentration of 1.28 microg/10(5) cells at 0.5 h. Metabolic inhibitor KCN and P-glycoprotein inhibitor verapamil could increase Rg1 concentration within the cells, indicating that efflux of Rg1 was energy-dependent and P-gp was likely to be involved. This is the first time that the transport behavior and efflux of Rg1 through rat pulmonary epithelial cells has been demonstrated. The phenomenon that Rg1 concentration in the cells decreased whereas that in the medium remained high indicated that a more effective means of drug administration should be found.     

Resonance Raman spectroscopy of red blood cells using near-infrared laser excitation

Resonance Raman spectra of oxygenated and deoxygenated functional erythrocytes recorded using 785 nm laser excitation are presented. The high-quality spectra show a mixture of enhanced A_1g, A_2g, B_1g, B_2g, E_u and vinyl modes. The high sensitivity of the Raman system enabled spectra from four oxygenation and deoxygenation cycles to be recorded with only 18 mW of power at the sample over a 60-minute period. This low power prevented photo-/thermal degradation and negated protein denaturation leading to heme aggregation. The large database consisting of 210 spectra from the four cycles was analyzed with principal components analysis (PCA). The PC1 loadings plot provided exquisite detail on bands associated with the oxygenated and deoxygenated states. The enhancement of a band at 567 cm⁻¹, observed in the spectra of oxygenated cells and the corresponding PC1 loadings plot, was assigned to the Fe–O₂ stretching mode, while a band appearing at 419 cm⁻¹ was assigned to the Fe–O–O bending mode based on previous studies. For deoxygenated cells, the enhancement of B_1g modes at 785 nm excitation is consistent with vibronic coupling between band III and the Soret transition. In the case of oxygenated cells, the enhancement of iron-axial out-of-plane modes and non-totally symmetric modes is consistent with enhancement into the y,z-polarized transition centered at 785 nm. The enhancement of non-totally symmetric B_1g modes in oxygenated cells suggests vibronic coupling between band IV and the Soret band. This study provides new insights into the vibrational dynamics, electronic structure and resonant enhancement of heme moieties within functional erythrocytes at near-IR excitation wavelengths. Part of this work was first presented at SPEC 2006, Shedding New Light on Disease: Optical Diagnosis for the New Millennium, held at Heidelberg, Germany, on 20–24 May 2006.     

Efficient modification on PLLA by ozone treatment for biomedical applications

RGDS (Arg-Gly-Asp-Ser) is immobilized on poly(L-lactic acid) (PLLA) with ozone oxidation and the addition of an intermediate reactant, acryl succinimide (ASI) to promote the grafting efficiency. A DPPH (2,2-di(4-tert-octylphenyl)-1-picrylhydrazyl) assay has revealed that the peroxide concentration can be controlled by adjusting the ozone treatment time. The immobilization of ASI is verified by elemental analysis. The peptide concentrations are in the effective order, as shown by means of high performance liquid chromatography (HPLC), and the grafting efficiency is proven to be relatively high compared with the previous studies. The culture of rat osteosarcoma 17/2.8 (ROS), osteoblastic-like cells, demonstrates that the grafting of RGDS can enhance the attachment and osteogenesis of ROS cells on PLLA. With the addition of ASI, the cultured ROS cells express normal function in proliferation and mineralization. From in vivo experiments, ASI immobilized on the surface is shown to be biocompatible. These results lead to the conclusion that the ozone treatment with the intermediate reactant ASI is an efficient, biocompatible, and easily controllable procedure to modify PLLA. Furthermore, the immobilization of RGDS in significant amounts following the ozone oxidation could further promote the biocompatibility and the osteoinduction of PLLA.     

Donor/conductor/acceptor triads spatially organized on the micrometer-length scale: an alternative approach to photovoltaic cells

We have used porous anodised Al(2)O(3) membranes as inert matrix for constructing and organizing spatially ternary donor/conductor/acceptor (DCA) systems exhibiting photovoltaic cell activity on the micrometric-length scale. These DCA triads were built stepwise by first growing a conducting polymer inside the membrane pores, thus forming nanorods that completely fill the internal pore space of the membrane. Then, an electron donor and an electron acceptor were adsorbed one on each side of the membrane, so that they were separated by a distance equal to the membrane thickness (ca. 60 microm), but electronically connected through the conductive polymer. When this device was placed between two electrodes and irradiated with visible light, electrons jumped from the donor molecule, crossed the membrane from side to side through the conductive polymer (a journey of about 60 microm!) until they finally reach the acceptor molecule. In so doing, an electric voltage was generated between the two electrodes, capable of maintaining an electric current flow from the membrane to an external circuit. Our DCA device constitutes the proof of a novel concept of photovoltaic cells, since it is based on the spatial organization at the micrometric scale of complementary, but not covalently linked, electron-donor and electron-acceptor organic species. Thus, our cell is based in translating photoinduced electron transfer between donors and acceptors, which is known to occur at the molecular nanometric scale, to the micrometric range in a spatially organised system. In addition our cell does not need the use of liquid electrolytes in order to operate, which is one of the main drawbacks in dye-sensitised solar cells.     

Pressure and temperature variation of the depolarized light scattering spectra of the fragile glass-former liquid salol

The pressure and temperature dependences of the depolarized light scattering spectra of salol have been measured at isobaric condition P = 1 bar for T between 328 and 393 K, and at isothermal condition T = 343 K for P between 1 and 625 bar, i.e. outside the metastable liquid region. The experimental results for both the α- and β-relaxations can be well described by the Mode Coupling Theory. The independence of the power-law parameters a, and consequently b and γ, from the thermodynamic variables T and P is demonstrated.The critical temperature T _c at 1 bar and the critical pressure P _c at T = 343 K have been determined from the normal liquid state. Received 2 May 2000     

交流示波极谱法中if～E曲线的研究(Ⅰ)——求取if～E曲线的仪器装置

本文报道求取i_f～E曲线的一种双电解池差分装置。通过扣除交流示波极谱法总电流中双电层充电电流i_c,测量法拉第电流对工作电极电位的曲线(即i_t～E曲线),可提高灵敏度。     

Solar Neutrino Problem in Seesaw Model

A specific texture for the Dirac and Majorana mass matrices in the seesaw model leading to a pair of almost degenerate neutrinos is discussed. This texture can be obtained by imposing a global U(1) symmetry. This model could solve the solar neutrino problem through the MSW mechanism and offer the hot component of the dark matter of the universe which requires Σm_vi = 7 eV.     

DOPANT EFFECTS OF SQUARYLIUM CYANINE DYES ON FUNCTIONAL DEVICES

本文初步研究了方酸菁染料在功能器件中的应用,并探讨了相关机理。我们用方酸菁掺杂8羟基喹啉铝发光层,获得了红光有机电致发光器件;用掺杂方酸菁的联吡啶钌作光敏剂修饰TiO₂纳晶薄膜电极,有效地弥补了联吡啶钌在600nm以上红光区采光能力的不足,从而大大提高了光电化学太阳电池的总体光电转换效率。     

Sage,Salvia officinalis L., Constituents,Hepatoprotective Activity,and Cytotoxicity Evaluations of the Essential Oils Obtained from Fresh and Differently Timed Dried Herbs: A Comparative Analysis

Sage, Salvia officinalis L., is used worldwide as an aromatic herb for culinary purposes as well as a traditional medicinal agent for various ailments. Current investigations exhibited the effects of extended dryings of the herb on the yields, composition, oil quality, and hepatoprotective as well as anti-cancer biological activities of the hydrodistillation-obtained essential oils from the aerial parts of the plant. The essential oils’ yields, compositions, and biological activities levels of the fresh and differently timed and room-temperature dried herbs differed significantly. The lowest yields of the essential oil were obtained from the fresh herbs (FH, 631 mg, 0.16%), while the highest yield was obtained from the two-week dried herbs (2WDH, 1102 mg, 0.28%). A notable decrease in monoterpenes, with increment in the sesquiterpene constituents, was observed for the FH-based essential oil as compared to all the other batches of the essential oils obtained from the different-timed dried herbs. Additionally, characteristic chemotypic constituents of sage, i.e., α-pinene, camphene, β-pinene, myrcene, 1, 8-cineole, α-thujone, and camphor, were present in significantly higher proportions in all the dried herbs’ essential oils as compared to the FH-based essential oil. The in vivo hepatoprotective activity demonstrated significant reductions in the levels of AST, ALT, and ALP, as well as a significant increase in the total protein (p < 0.05) contents level, as compared to the acetaminophen (AAP) administered experimental group of rats. A significant reduction (p < 0.05) in the ALT level was demonstrated by the 4WDH-based essential oil in comparison to the FH-based essential oil. The levels of creatinine, cholesterol, and triglycerides were reduced (p < 0.05) in the pre-treated rats by the essential oil batches, with non-significant differences found among them as a result of the herbs dryings based oils. A notable increase in the viability of the cells, and total antioxidant capacity (TAOxC) levels, together with the reduction in malondialdehyde (MDA) levels were observed by the essential oils obtained from all the batches as compared with the AAP-treated cell-lines, HepG-2, HeLa, and MCF-7, that indicated the in vitro hepatoprotective effects of the sage essential oils. However, significant improvements in the in vivo and in vitro hepatoprotective activities with the 4WDH-based oil, as compared to all other essential oil-batches and silymarin standard demonstrated the beneficial effects of the drying protocol for the herb for its medicinal purposes.     

Design,Synthesis, Biological Evaluation and In Silico Study of Benzyloxybenzaldehyde Derivatives as Selective ALDH1A3 Inhibitors

Aldehyde dehydrogenase 1A3 (ALDH1A3) has recently gained attention from researchers in the cancer field. Several studies have reported ALDH1A3 overexpression in different cancer types, which has been found to correlate with poor treatment recovery. Therefore, finding selective inhibitors against ALDH1A3 could result in new treatment options for cancer treatment. In this study, ALDH1A3-selective candidates were designed based on the physiological substrate resemblance, synthesized and investigated for ALDH1A1, ALDH1A3 and ALDH3A1 selectivity and cytotoxicity using ALDH-positive A549 and ALDH-negative H1299 cells. Two compounds (ABMM-15 and ABMM-16), with a benzyloxybenzaldehyde scaffold, were found to be the most potent and selective inhibitors for ALDH1A3, with IC₅₀ values of 0.23 and 1.29 µM, respectively. The results also show no significant cytotoxicity for ABMM-15 and ABMM-16 on either cell line. However, a few other candidates (ABMM-6, ABMM-24, ABMM-32) showed considerable cytotoxicity on H1299 cells, when compared to A549 cells, with IC₅₀ values of 14.0, 13.7 and 13.0 µM, respectively. The computational study supported the experimental results and suggested a good binding for ABMM-15 and ABMM-16 to the ALDH1A3 isoform. From the obtained results, it can be concluded that benzyloxybenzaldehyde might be considered a promising scaffold for further drug discovery aimed at exploiting ALDH1A3 for therapeutic intervention.