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21.
We investigate the electrodynamic in a Bianchi type I cosmological model. This scenario reveals the possibility that photons, during their traveling, can make quantum interference. This effect is only due to the presence of two different axes of expansion in the cosmic evolution. In other word, it is possible to conclude that a purely metrical - or, equivalently, gravitational - phenomenon gives rise up to a quantum effect that manifests itself in the light propagation.  相似文献   
22.
The special features of cold-adapted lipolytic biocatalysts have made their use possible in several industrial applications. In fact, cold-active enzymes are known to be able to catalyze reactions at low temperatures, avoiding side reactions taking place at higher temperatures and preserving the integrity of products. A lipolytic gene was isolated from the Arctic marine bacterium Rhodococcus sp. AW25M09 and expressed in Escherichia coli as inclusion bodies. The recombinant enzyme (hereafter called RhLip) showed interesting cold-active esterase activity. The refolded purified enzyme displayed optimal activity at 30 °C and was cold-active with retention of 50 % activity at 10 °C. It is worth noting that the optimal pH was 11, and the low relative activity below pH 10 revealed that RhLip was an alkaliphilic esterase. The enzyme was active toward short-chain p-nitrophenyl esters (C2–C6), displaying optimal activity with the butyrate (C4) ester. In addition, the enzyme revealed a good organic solvent and salt tolerance. These features make this an interesting enzyme for exploitation in some industrial applications.  相似文献   
23.
The inclusion properties of a calixarene-based porous material have been studied to investigate the adsorption and the desorption of carbon tetrachloride, chloroform, and water in the zeolite-like structure. Uptake and release processes have been studied both by time-resolved powder X-ray diffraction and by thermogravimetric analysis to obtain structural and kinetic information. The selected guests are able to enter the structure with an increase in the host cell volume and with time-dependent diffusivity coefficients. Chloroform molecules act as a permanent porosity switch promoting a phase transition to non-porous triclinic form.  相似文献   
24.
We present a simple isomorphism between the algebra of one real chiral Fermi field and the algebra of n real chiral Fermi fields. The isomorphism preserves the vacuum state. This is possible by a “change of localization”, and gives rise to new multilocal symmetries generated by the corresponding multilocal current and stress–energy tensor. The result gives a common underlying explanation of several remarkable recent results on the representation of the free Bose field in terms of free Fermi fields (Anguelova, arXiv:1112.3913, 2011; Anguelova, arXiv:1206.4026, 2012), and on the modular theory of the free Fermi algebra in disjoint intervals (Casini and Huerta, Class Quant Grav 26:185005, 2009; Longo et al., Rev Math Phys 22:331–354, 2010)  相似文献   
25.
The chemical co-precipitation process was used to synthesize (in situ) spherical iron-oxide nanoparticle in sulfonated styrene-divinylbenzene polymeric template. X-ray diffraction technique supports the magnetite phase formation with a mean particle diameter of about 19 nm. The analysis of Mössbauer spectra is consistent with two magnetic splitting patterns assigned to A- and B-iron sites of magnetite, with no visible magnetic relaxation effect even at 297 K. Considering the different experimental time window between Mössbauer spectroscopy and DC magnetization, the results obtained from both techniques are in very good agreement. Magnetic data suggest hosting magnetite nanoparticles interacting antiferromagnetically.  相似文献   
26.
In this paper we describe the efficacy of the liposomal-AlClPc (aluminum-chloro-phthalocyanine) formulation in PDT study against Ehrlich tumor cells proliferation in immunocompetent swiss mice tongue. Experiments were conduced in sixteen tumor induced mice that were divided in three control groups: (1) tumor without treatment; (2) tumor with 100 J/cm2 laser (670 nm) irradiation; and (3) tumor with AlClPc peritumoral injection; and a PDT experimental group when tumors received AlClPc injection followed by tumor irradiation. Control groups present similar macroscopically and histological patterns after treatments, while PDT treatment induced 90% of Ehrlich tumor necrosis after 24 h of one single application, showing the efficacy of liposome-AlClPc (aluminum-chloro-phthalocyanine) mediated PDT on the treatment of oral cancer.  相似文献   
27.
Toxoplasma gondii, an obligate intracellular protozoan parasite, infects most species of warm-blooded animals, and in humans it causes toxoplasmosis. Healthy people that become infected rarely present clinical symptoms because the immune system prevents the parasite from causing illness. Congenital toxoplasmosis may result in abortion, hydrocephalus, as well as neurological and ocular disease (most frequently retinochoroiditis) of the newborn. In immunocompromised patients, reactivation of latent disease can cause encephalitis. Cell-mediated immunity to T. gondii antigens involves innate acute inflammatory responses and antigen-specific adaptive immunity. Considering the complexity of the immunological events triggered during toxoplasmosis, systemic and local responses were evaluated by cytokine measurements. Aqueous humour and serum were obtained from non-infected and T. gondii Me-49 strain infected C57BL/6 mice for cytokine quantification. Histopathological analyses were made with eyes enucleated from mice after 30 days of infection. ELISA assays showed an increase of IFN-γ levels both in serum and aqueous humour of infected mice in opposition to a decrease in IL-10 levels. On the other hand, TGF-β was high, whereas IL-12 and TNF-α were present in small levels in both groups. We also detected higher levels of IL-4 and IL-6 in aqueous humour than in serum of infected mice when compared to the control group. MIP-2 presented no significant differences between the two groups. Fas and Fas-L were also present in similar levels in serum of non-infected and infected mice, but both chemokines were increased in the aqueous humour of infected mice. Histopathological analysis of infected mice showed inflammatory infiltrates around blood vessels and alteration of the outer photoreceptor segments, on the external and inner nuclear layer. Parasites were observed in 82% of eyes, inside the blood vessels associated with inflammatory infiltrate. Edema, characterized by the increase of interstitial spaces between the FTR, forming lacunae was also noted. These alterations take the form of projections (retino-vitreal), characteristic of retinochoroiditis. In conclusion, T. gondii infection of C57BL/6 mice revealed that cytokine patterns alone do not assure susceptibility or resistance against infection, thus reinforcing the notion that it is necessary more than cytokine dosage to determine Th1 or Th2 profile in this model.  相似文献   
28.
29.
[Ru(II)L(NH(3))(4)(pz)Ru(II)(bpy)(2)(NO)](PF(6))(5) (L is NH(3), py, or 4-acpy) was prepared with good yields in a straightforward way by mixing an equimolar ratio of cis-[Ru(NO(2))(bpy)(2)(NO)](PF(6))(2), sodium azide (NaN(3)), and trans-[RuL(NH(3))(4)(pz)] (PF(6))(2) in acetone. These binuclear compounds display nu(NO) at ca. 1945 cm(-)(1), indicating that the nitrosyl group exhibits a sufficiently high degree of nitrosonium ion (NO(+)). The electronic spectrum of the [Ru(II)L(NH(3))(4)(pz)Ru(II)(bpy)(2)(NO)](5+) complex in aqueous solution displays the bands in the ultraviolet and visible regions typical of intraligand and metal-to-ligand charge transfers, respectively. Cyclic voltammograms of the binuclear complexes in acetonitrile give evidence of three one-electron redox processes consisting of one oxidation due to the Ru(2+/3+) redox couple and two reductions concerning the nitrosyl ligand. Flash photolysis of the [Ru(II)L(NH(3))(4)(pz)Ru(II)(bpy)(2)(NO)](5+) complex is capable of releasing nitric oxide (NO) upon irradiation at 355 and 532 nm. NO production was detected and quantified by an amperometric technique with a selective electrode (NOmeter). The irradiation at 532 nm leads to NO release as a consequence of a photoinduced electron transfer. All species exhibit similar photochemical behavior, a feature that makes their study extremely important for their future application in the upgrade of photodynamic therapy in living organisms.  相似文献   
30.
The cytotoxicity of two nitroheterocyclic compounds (NHCD), Nitracrine, 1-nitro-9(3-3-dimethylaminopropylamino) acridine and Quinifuryl, 2-(5'-nitro-2'-furanyl) ethenyl-4-[N-[4-(N,N-diethylamino)-1'-methylbutyl] carbamoyl] quinoline, towards two lines of leukaemic cells and a line of non-transformed cells, was measured in comparison, on the dark and under illumination with visible light (350-450 nm). Both drugs showed highly elevated cytotoxicity when illuminated with LC(50) values 7-35 times lower after 1 h illumination compared to 1 h incubation of cells incubation with drug on the dark. Cytotoxicity of Nitracrine toward all cell lines studied exceeded that of Quinifuryl, both on the dark and under illumination, so that approximately 10 times lower concentration of former drug was needed to reach the same toxicity as the latter. General toxic effect was calculated as a direct cell kill and a cell proliferation arrest. The effect >80% for both drugs was achieved after 1 h cell illumination with as low drug concentrations as 0.2 microM for Quinifuryl and 0.02 microM for Nitracrine.  相似文献   
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