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Acute ischemic stroke treatment faces an unresolved obstacle as capillary reperfusion remains insufficient after thrombolysis and thrombectomy causing neuronal damage and poor prognosis. Hypoxia-induced capillary constriction is mediated by actomyosin contraction in precapillary smooth muscle cells (SMCs) therefore smooth muscle myosin-2 could be an ideal target with potentially high impact on reperfusion of capillaries. Methods: The myosin-2 inhibitor para-aminoblebbistatin (AmBleb) was tested on isolated human and rat arterioles to assess the effect of AmBleb on vasodilatation. Transient middle cerebral artery occlusion (MCAO) was performed on 38 male Wistar rats followed by local administration of AmBleb into the ischemic brain area. Development of brain edema and changes in cerebrovascular blood flow were assessed using MRI and SPECT. We also tested the neurological deficit scores and locomotor asymmetry of the animals for 3 weeks after the MCAO operation. Results: Our results demonstrate that AmBleb could achieve full relaxation of isolated cerebral arterioles. In living animals AmBleb recovered cerebral blood flow in 32 out of the 65 affected functional brain areas in MCAO operated rats, whereas only 8 out of the 67 affected areas were recovered in the control animals. Animals treated with AmBleb also showed significantly improved general and focal deficit scores in neurological functional tests and showed significantly ameliorated locomotor asymmetry. Conclusion: Direct inhibition of smooth muscle myosin by AmBleb in pre-capillary SMCs significantly contribute to the improvement of cerebral blood reperfusion and brain functions suggesting that smooth muscle myosin inhibition may have promising potential in stroke therapies as a follow-up treatment of physical or chemical removal of the occluding thrombus. Published version

Complement component 1q subcomponent binding protein (C1qbp) is a multifunctional protein involved in immune response, energy homeostasis of cells as a plasma membrane receptor, and a nuclear, cytoplasmic or mitochondrial protein. Recent reports suggested its neuronal function, too, possibly in axon maintenance, synaptic function, and neuroplasticity. Therefore, we addressed to identify C1qbp in the rat brain using in situ hybridization histochemistry and immunolabelling at light and electron microscopic level. C1qbp has a topographical distribution in the brain established by the same pattern of C1qbp mRNA-expressing and protein-containing neurons with the highest abundance in the cerebral cortex, anterodorsal thalamic nucleus, hypothalamic paraventricular (PVN) and arcuate nuclei, spinal trigeminal nucleus. Double labelling of C1qbp with the neuronal marker NeuN, with the astrocyte marker S100, and the microglia marker Iba1 demonstrated the presence of C1qbp in neurons but not in glial cells in the normal brain, while C1qbp appeared in microglia following their activation induced by focal ischemic lesion. Only restricted neurons expressed C1qbp, for example, in the PVN, magnocellular neurons selectively contained C1qbp. Further double labelling by using the mitochondria marker Idh3a antibody suggested the mitochondrial localization of C1qbp in the brain, confirmed by correlated light and electron microscopy at 3 different brain regions. Post-embedding immunoelectron microscopy also suggested uneven C1qbp content of mitochondria in different brain areas but also heterogeneity within single neurons. These data suggest a specific function of C1qbp in the brain related to mitochondria, such as the regulation of local energy supply in neuronal cells.

Phase-pure [Al]BEA and [Al,B]BEA zeolites, prepared by solid-state recrystallization of synthetic aluminum-containing magadiites and conventionally synthesized [B]BEA, were tested, after ion exchange with nickel, as bifunctional catalysts for hydroconversion of n-heptane. The reducibility of nickel ions incorporated into BEA zeolites by ion exchange was investigated by temperature-programmed reduction (TPR). The acidity of the samples was characterized with strong (pyridine (Py) and ammonia (NH 3 )) and weak (nitrogen) bases. The adsorbed bases were studied by transmission FT-IR (Py), diffuse reflectance infrared Fourier-transform (DRIFT) spectroscopy (N 2 ), and temperature-programmed ammonia evolution (TPAE, NH 3 ). Over Ni/H-[B]BEA the reactants were completely converted via fast hydrogenolysis, whereas this reaction pathway plays only a negligible role in the hydroconversion over Ni/H-[Al]BEA and Ni/H-[Al,B]BEA zeolites. Boron-containing BEA zeolites were less active catalysts than the boron-free catalyst in the principal unimolecular hydroconversion reactions. However, incorporation of boron into the framework of BEA zeolite results in a considerable selectivity shift toward isomerization. Results suggest that the acid strength of bridged hydroxyls, probed with weak (N 2 ) and strong basis (pyridine), was found to be similar in the boron-free and boron-containing BEA samples. The decrease in the isomerization rate and the increase of the apparent activation energy upon incorporation of boron may be attributed to the decrease in the heat of n-heptane adsorption.

Transforming growth factors-beta1 (TGF-beta1), -2, and -3 form a small group of related proteins involved in the regulation of proliferation, differentiation, and survival of various cell types. Recently, TGF-betas were also demonstrated to be neuroprotective. In the present study, we investigated their distribution in the rat brain as well as their expression following middle cerebral artery occlusion. Probes were produced for all types of TGF-betas, and in situ hybridization was performed. We demonstrated high TGF-beta1 expression in cerebral cortex, hippocampus, central amygdaloid nucleus, medial preoptic area, hypothalamic paraventricular nucleus, substantia nigra, brainstem reticular formation and motoneurons, and area postrema. In contrast, TGF-beta2 was abundantly expressed in deep cortical layers, dentate gyrus, midline thalamic nuclei, posterior hypothalamic area and mamillary body, superior olive, areas of monoaminergic neurons, spinal trigeminal nucleus, dorsal vagal complex, cerebellum, and choroid plexus, and a high level of TGF-beta3 mRNA was found in cerebral cortex, hippocampus, basal amygdaloid nuclei, lateral septal nucleus, several thalamic nuclei, arcuate and supramamillary nuclei, superior colliculus, superior olive, brainstem reticular formation and motoneurons, area postrema, and inferior olive. Focal brain ischemia induced TGF-betas with markedly different expression patterns. TGF-beta1 was induced in the penumbral region of cortex and striatum, whereas TGF-beta2 and -beta3 were induced in different layers of the ipsilateral cortex. The expression of the subtypes of TGF-betas in different brain regions suggests that they are involved in the regulation of different neurons and bind to different latent TGF-beta binding proteins. Furthermore, they might have subtype-specific functions following ischemic attack.

Aluminum-free MCM-22 type ferrisilicate, [Fe]MCM-22 (Si/Fe = 19.2) and, for comparison, MCM-22 aluminosilicate, [Al]MCM-22 (Si/Al = 13.1), were synthesized. The materials and their precursors were characterized by X-ray diffractometry (XRD), thermogravimetry (TG), transmission and diffuse reflectance Fourier-transform infrared spectroscopy (FT-IR and DRIFTS), temperature-programmed ammonia evolution (TPAE), in situ Mossbauer spectroscopy and temperature-programmed reduction with hydrogen (H2-TPR). The presence of Fe3+ T atoms (FeFW) were indicated by the appearance of a νOH IR-band at 3634 cm−1. The red shift of the νOH band, induced by the H-bonding of bridged hydroxyls and N2, was smaller for the [Fe]MCM-22 (64 cm−1) than for the [Al]MCM-22 (86 cm−1). The smaller shift evidences sites of weaker intrinsic acid strength. The rate and temperature of the TG-release of hexamethyleneimine template showed relation with the acidity of the sample. The amount of Fe3+ species, present in highly distorted tetrahedral coordination state, was in good correspondence with the concentration of the Bronsted acid sites. After reduction with H2 or CO, Fe2+ appeared in a novel coordination state. Results suggest that these Fe2+ species are bound to the framework via oxygen atoms. Reducibility of the framework iron is related to the high concentration of hydroxyl nests generated in both the wide (12-MR) and the narrow (10-MR) channels of [Fe]MCM-22 during the synthesis and/or template removal.

Micro/mesoporous aluminosilicate composites were prepared applying a two-step hydrothermal synthesis procedure. In the first step a zeolitic component, i.e., the precursor of zeolite MCM-22 was synthesized and its swollen and partially delaminated derivatives were prepared. In the second step mesoporous MCM-41 silicate was synthesized in a slurry of the above MCM-22 type precursor from additional silicate source and using hexadecyltrimethylammonium bromide (CTMABr) template. The structure, morphology and the acidic properties of the obtained composite materials were characterized by X-ray diffraction, infrared spectroscopy, N 2 adsorption isotherms, and electron microscopy (SEM and TEM). The results suggest that the composite materials were built from nanosize, randomly orientated stacks of thin layers of MCM-22 type zeolite and of mesoporous silicate MCM-41 material. The catalytic activity of the composite material was compared to that of the zeolite MCM-22 in the hydroconversion of heptane.

A method for the preparation of phase-pure [Al]-BEA and [Al,B]-BEA zeolites based on solid-state recrystallization of synthetic aluminum-containing magadiites is presented. For comparison [B]-BEA was prepared by conventional hydrothermal synthesis. From X-ray diffraction (XRD) measurements conclusions could be drawn in respect to kinetics and mechanism of the recrystallization process. Coordination state and resistance to hydrolysis of framework boron species in as-synthesized and ion-exchanged BEA varieties were investigated by 11B MAS NMR spectroscopy. The acidity of the samples was studied by temperature-programmed ammonia elimination (TPAE) from the NH4-forms and by IR spectroscopy using pyridine as probe molecule. An effect of framework boron on the acid strength of bridged hydroxyls associated with framework aluminum could not be evidenced. Nevertheless, incorporated boron gives rise to weak acid sites which are involved in ion-exchange processes. The number of strong Bronsted sites can be controlled by the aluminum content of the layer silicate.

Siting of iron and its ability to take part in the Fe3+ ↔ Fe2+ redox process are correlated in certain micro-and mesoporous ferrisilicates as deduced from changes in coordination and oxidation states of iron followed from in situ Mossbauer spectroscopy. The three-dimensional crystalline character stabilizes the Fe3+ state in microporous framework sites, whereas the mentioned reversible redox process proceeds more easily on extra-framework sites in microporous systems, as well as on iron located in the pore walls of the mesoporous ferrisilicates. Correlations with catalytic properties are also mentioned in certain instances.

Iron was incorporated into microporous MFI analogue (ZSM-5, Si/Fe ∼ 200 and FER, Si/Fe = 16) and mesoporous MCM-41 hosts of different preparations (Si/Fe ∼ 100 and 20, respectively). Samples were characterized by in situ Mossbauer spectroscopy under various conditions. Framework (FW) and extra-framework (EFW) sites can be distinguished in relation with strict three-dimensional (3D) crystallinity of the structure. In addition, in the microporous ZSM-5 system occurrence of Fe 4+ oxidation state is hypothesized and reversible Fe 4+ ↔ Fe 3+ transformation is presumed for a minor portion of iron. Spectra of Fe-FER are interpreted in terms of dynamic formation and decomposition of Fe FW –O–Fe EFW dinuclear centres. In the mesoporous systems, the partly amorphous character of the pore wall is correlated with the redox behaviour and coordination of incorporated iron; larger portion of iron may take part in Fe 3+ ↔ Fe 2+ reversible processes and Fe 2+ may be stabilized in distorted coordination (not appearing in microporous structures).

The effect of introduction of Lewis acid sites on the reactions of toluene transformation and catalysts coking has been studied over parent (Si/Al = 2.5) and dealuminated (Si/Al = 3.7) Y zeolites modified with Lewis connected InO+ cationic acid sites. The catalysts with prevalent amount of Bronsted acid sites (less than 40% of protons exchanged by InO+) possess the typical for the proton directed reaction of methyl transfer upon toluene disproportionation long period of activation, the longer the higher the concentration of bridging protons. In contrast, at predominant Lewis sites concentration, the activation period disappear, an enhanced initial activity is observed, followed by deactivation on the expense of a rapid process of accumulation of strongly held reaction products and intermediates. Their further condensation leads to catalysts aging, the faster the higher the concentration of electron acceptor Lewis acid sites. A relation has been found between the initially accelerated processes of alkyl transfer and the reinforced formation of carbonaceous deposits over the In-modified catalysts.

Transition metal containing spherical MCM-41 silicates were prepared and characterized by transmission electron microscopy (TEM), XRD, BET, TPR and IR spectroscopy. Incorporation of aluminum, iron, cobalt, copper ions into the wall of the pores has been established. These ions were almost completely built in into the silicate framework from the synthesis gel. With increasing iron content the ordering of pores decreased, the hydrogen uptake increased, the acidity gained. Only one electron transfer took place (Fe3+ → Fe2+) during the reduction of Fe-MCM-41 samples up to 923 K, which means that iron is stabilized in the mesoporous structure and probably linked with framework via oxygen ions. For cobalt ion containing samples practically no reduction was observed, however, significant Lewis acidity was detected. The copper containing samples behaved different. Two electron transfers took place upon hydrogen treatment proving the reduction of Cu2+ ions to metallic copper, however, a part of the metallic species can be reversible reoxidized to cationic form. The Cu-MCM-41 samples showed also Lewis acidic character. Both Bronsted and Lewis acidic sites could only be observed by IR spectroscopy when aluminum or iron was incorporated into MCM-41. The Fe-MCM-41 samples showed significant catalytic activity in the acid catalyzed alkylation of toluene with benzyl chloride at 333 K.

A solid-state ion-exchange method is described that introduces vanadium into zeolites BZSM-5, BBeta and their deboronated by washing forms at 773 K in hydrogen. Two types of vanadium species (vanadium ions in cationic position and VO 2+ complex in a silanol nest) are identified when the amount of V 2 O 5 is equivalent to the framework boron. The vanadium-loaded samples have been characterised by the methods of IR-KBr, FTIR and UV-Vis spectroscopies; temperature-programmed reduction/oxidation cycles (TPR/TPO).

Dealuminated in solid-state Y zeolite-modified with InO+ by the method of reductive solid-state ion exchange (RSSIE) followed by oxidation have been studied in the reactions of toluene and ethyl benzene disproportionation. The role of the as-created electron acceptor Lewis sites has been investigated in the above Broensted-mediated catalytic reactions. These cationic centers of well-defined chemical nature are stabilized in desired amount without formation of mesopores in the zeolite in contrast to the Al-connected Lewis sites created upon hydrothermal treatment of Y zeolites. Thus, by eliminating the structural factor, an examination of the effect of the Lewis acidity on the catalytic performance has been undertaken. Contribution of the InO+ cationic sites to the enhanced alkyl transfer, dealkylation and catalysts aging upon toluene and ethyl benzene conversion is suggested. It is assumed that they initiate themselves, or by the enhancement of the strength of the neighboring protons, a strong hydride abstraction resulting in highly accelerated formation of diphenylalkane reaction intermediates. This effect is more strongly pronounced with the increasing amount of incorporated indium. The changes in the inner volume of the zeolite caused by the presence of InO+ cationic species can be considered negligible with respect to the catalytic behavior, compared to the effect of the acidity modification.

The catalytic performance of MCM-22 modified with Cs to different extents by Solid-State Ion Exchange has been investigated in toluene disproportionation. It was suggested that protons on the external surface were preferentially replaced by Cs cations. It was observed that the Cs modifications did not provide improved p-xylene selectivity at conversions close to that of the H-form. The remaining unaffected proton sites in the 10 MR channels are considered as responsible for secondary xylene isomerization proceeding upon toluene disproportionation.

Bronsted acidity of faujasite (FAU) type zeolites, such as, H-Y, dealuminated H-Y, and ultra-stabilized H-Y (USY) was studied by DRIFT spectroscopy using N 2 adsorption at 298 K and at pressures ranging from 1 to 9 bar for probing of the acidic sorption sites. Both the α- and β-cage hydroxyl-groups were found to establish H-bonds with N 2 . Dealumination by (NH 4 ) 2 [SiF 6 ] or ultra-stabilization increased the accessibility of the β-cage protons. The Δ ν OH red shift, induced by the adsorption, was used as a measure of the intrinsic acid strength of the OH-groups. Samples, free of extra-framework aluminum (EFAl) species, had about the same Bronsted acid strength regardless of their Al content. In the EFAl-containing USY sample a fraction of the hydroxyl groups showed enhanced Bronsted acidity.

Cu-AlTS-1 catalyst was prepared by solid state ion exchange and studied in the NO and N2O decomposition. Oscillation was observed in a wide range of experimental conditions during the decomposition of N2O. At full N2O conversion, oscillations were observed only in the O2 and NO concentrations the latter being out of phase with respect to O2 and being originated from the decomposition of an excess oxygen containing nitrito–nitrato-like surface complex. Traces of NO extinguished the oscillations and increased the N2O conversion if it was below 100%. The NO also plays a key role in the feed back and synchronisation.

The effects of the introduced Lewis acid sites of different kind (InO+ or AlO+) and the variation of InO+ concentration on the catalytic behavior of dealuminated in solid-state HY zeolites in the reaction of cumene–toluene transalkylation have been studied. The catalysts, indium modified HY(3.7) and ultra stable zeolite USY(3.4), containing essentially equivalent amounts of framework aluminum and Lewis acid sites (InO+ and AlO+, respectively), have been compared to the initial HY(3.7), not containing any extra-framework aluminum (EFAl). Strictly controlled conditions were used for the formation of Lewis acid sites: through reductive solid-state ion exchange (RSSIE) for InO+ or by steaming in the case of AlO+. The ratio between the Lewis and Broensted acid sites was varied by progressive replacement of the protons by InO+ cations in HY(5.6) zeolite. The zeolites modified by monovalent (InO+ and AlO+) have, as a result, an enhanced catalytic activity in comparison with HY(3.7). This effect is mainly due to intense side reactions of dealkylation, oligomerization, cracking and re-alkylation at the expense of the cymenes formation. The data for the distribution of the reaction products suggest a highly preferred mechanism of dealkylation/alkylation with the increase of the Lewis/Broensted acid site ratio. The presence of cation-connected Lewis acid sites is supposed to be responsible for the fast samples’ deactivation.

Mixtures of NH4Na-Y zeolite and crystalline (NH4)2[SiF6] (applied in molar amounts corresponding to 0.38% of the framework aluminium) were subjected in covered but not hermetically closed dishes to heat treatment at temperatures below the decomposition point of the complex salt and subsequently washed with water or buffer solution. This process was twice repeated without any further intermediate treatment. The products were characterized by XRD, IR spectroscopy, without and with pyridine as probe molecule, 29Si MAS NMR spectroscopy, ammonia TPE (thermal deammoniation) and wet chemical analysis. They proved to be highly crystalline with generally low concentrations of lattice defects (vacancies) due to desilication and/or non-substitutive dealumination. The products obtained after two subsequent dealumination steps exhibited X-ray crystallinities of 88–93% at dealumination degrees up to 70%. After the third successive dealumination step the X-ray crystallinity was found to amount to 80–88% and the dealumination degree to about 80%. With increasing dealumination degree the thermal and hydrothermal stability of the structure as well as the resistance of HF and LF bridging hydroxyls to thermal dehydroxylation gradually increased and the LF hydroxyls became accessible to pyridine.

Solid-state reactions in ground mixtures of NH4-Y zeolite and crystalline (NH4)2[SiF6] at temperatures below the decomposition point of the complex compound were investigated. The reaction products were characterized by chemical analysis, IR and MAS NMR spectroscopy, XRD and thermal analysis. Isomorphous substitution of silicon for framework aluminium proceeded when the escape of gaseous products (NH3) from the reaction system was prevented or retarded by use of appropriate reaction vessels. Thus-performed dealumination of Y zeolite resulted in a considerable increase of both acid strength and thermal stability of bridging hydroxyls (Bronsted acid sites). Product inhibition manifested itself at application of more than about 25 (NH4)2[SiF6] per unit cell. Secondary processes (desilication and non-substitutive dealumination of the zeolitic framework), induced by the reaction product (NH4)3[AlF6] and adsorbed water, were found to proceed to a minor degree. They result in the formation of non-acidic silanol groups. Evidently, these undesired reactions can be effectively suppressed by (partial) dehydration of the zeolitic component of the reaction mixture. Another irreversible reaction route involving the release of ammonia and formation of NH4[AlF4] and NH4HF2 was found to be dominant in open systems. Thus-obtained products exhibited low crystallinity, less acidic and thermally highly unstable bridging hydroxyl groups, Lewis acid sites (cationic aluminium species) and acidic silanol groups.

The catalytic properties of H-ferrierite zeolites, prepared by hydrothermal and dry-state synthesis, were compared in the skeletal isomerization of 1-butene. The activity was found to be strongly influenced by the presence of extra-framework Al (EFAl) species in the zeolite micropores and by the carbonaceous deposit formed during the reaction. The dynamics of mass transport in the zeolite crystallites were studied by the frequency-response (FR) method using acetylene, propane, n - and i -butane as probe molecules. The selectivity of n -butene conversion showed correlation with the dynamics of the n -butane sorption process. Either the diffusion or the sorption was the rate-controlling slowest step of n -butane mass transport, depending on the amount and the distribution of the EFAl species in the sample. In the catalyst sample, free of EFAl, the transport was found to be controlled by the rate of sorption. At an EFAl content of about 0.5–1.0 EFAl/unit cell the diffusion resistance of the micropores governed the n -butane transport rate.

Cu-ZSM-5 and Cu-AlTS-1 catalysts were prepared by solid state ion exchange and studied in DeNOx reactions. A NO3 type surface complex was found to be an active intermediate in the decomposition of NO and N2O. Copper was oxidized to Cu2+ in the decomposition reactions. Oscillations at full N2O conversion were observed in the gas phase O2 concentration, without any change in the N2 concentration. The oscillation was synchronized by gas phase NO formed from the NO3 complex. The same complex seems to be an active intermediate also in NO selective catalytic reduction (SCR) by methane, whereas carbonaceous deposits play a role in NO SCR by propane. TPD reveals that only 10–20% of the total copper in the zeolites participates in the catalytic cycles.

The catalytic conversion of cyclohexane over H-ZSM-5 in hydrogen or nitrogen and in hydrogen atmosphere over a series of H-zeolites loaded with platinum was studied using a flow-through microreactor/GC on-line system at pressures of 13 bar. The distribution of the products formed via hydrodecyclization was found to depend definitely on whether or not dimerization of primarily formed hexyl-carbenium ions is sterically hindered in the zeolitic pore system. Reaction routes are suggested which involve, as an essential step, the hydrogenation of intermediate carbenium ions, formed either primarily by reactant adsorption or cracking, by spill-over hydrogen activated on the metallic catalyst component. The basically different product distribution obtained by decyclization of cyclohexane in nitrogen atmosphere or over monofunctional H-ZSM-5 is attributed to disproportionation of primarily formed hexyl-carbenium ions and subsequent hydrogen transfer reactions which results in a broad spectrum of paraffins and aromatics in the effluent and in carbon-rich deposits on the catalyst surface causing fast catalyst deactivation. This process does not manifest itself in bifunctional catalysis due to the much faster hydrogenation and, hence, elimination of carbenium ions by hydrogenation.

Redox properties of substituted iron in low-iron content Fe-MFI (Si/Fe≈200) and Fe-MCM-41 (Si/Fe=137) samples were compared by in situ Mossbauer spectroscopy (in vacuum, H2, CO, N2O, at 300 K

Mesoporous Fe-MCM41 samples (Si/Fe = 25) were synthesized and characterized under evacuation and reducing/oxidizing treatments by in situ FTIR and Mossbauer spectroscopies. Both Fe(II) and Fe(III) located in low coordination states in top layers of pore walls exhibit Lewis acidity and may participate in Fe(III) ↔ Fe(II) processes at low temperatures (570 K). Furthermore, Fe(III) ↔ Fe(II) cycles can be achieved and repeated with participation of the full amount of iron at higher temperatures (670 K). The accompanying formation of oxygen vacancies and restoration of the structure in the reverse process does not result in extended damages; the MCM41 structure retains its stability under the conditions applied.

Purpose Our experiments aimed at exploring potential neurorestorative mechanisms of selegiline, a compound routinely used in the treatment of Parkinson's disease and previously shown to improve the functional recovery of stroke patients. Methods Selegiline was administered continuously via osmotic mini-pumps between 48 and 216 hours following middle cerebral artery occlusion (MCAO) in rats. Twenty-four hours before sacrifice, the animals underwent magnetic resonance imaging (MRI). After decapitation, the peri-infarct region was dissected to perform a TAQMAN array gene expression study, and brains were fixed for immunolabeling. Results In addition to the previously known induction of anti-apoptosis genes, selegiline significantly increased the mRNA level of Notch 1 receptor and its ligand Jagged 1. Immunohistochemistry demonstrated elevated Notch 1 and Jagged 1 immunoreactivities in the peri-infarct region. Double labeling with glial markers revealed that both Notch 1 and Jagged 1 were expressed in astrocytes but not in microglia. MRI examination indicated significantly reduced edema in selegiline-treated rats compared to control MCAO rats, and increased capillary network density was found in the peri-infarct region of the selegiline-treated animals. Conclusion Our results suggest that selegiline treatment enhances Notch-Jagged signaling in astrocytes, reduces peri-lesional edema and potentially helps preserve the capillary network following focal ischemia.

The activity and selectivity of skeletal isomerization of 1-butene and disproportionation of ethylbenzene on H-ferrierite catalysts prepared by dry state recrystallization of magadiite and conventional hydrothermal synthesis from an alkaline SiO2/Al2O3 gel are compared. The isobutene yields of the samples were found to be similar even though the ferrierite crystals had quite different morphologies. Significant differences were observed in the isobutene selectivities which can be correlated with processes occurring inside the crystals. Ammonia, acetylene, methane and propane sorption and intracrystalline diffusion rate-spectra are reported using the frequency-response technique. The sorption properties of the acid sites and the diffusional resistances of the morphologically different ferrierite crystals are compared. It was found that by the dry state synthesis the quality of the ferrierite framework was similar to that obtained by the conventional hydrothermal synthesis. The channels of ferrierite recrystallized from magadiite, however, seem to have fewer barriers and, thus, show better kinetic properties, e.g., faster diffusion of propane and higher selectivity to the formation of isobutene.

Three variants of solid-state ion exchange were studied. Iron exchange was found to proceed in the first case, in theFeCl2+NH4ZSM-5→ FeZSM-5 + NH4Cl↑ process, even at low exchange capacity (Si/Al = 25).The second, Fe2O3 (hematite) + HZ direct reaction does not result in any noticeable interaction for eitherZ = Y or ZSM-5. This process can significantly be promoted by introducing CCl4 vapor via forming chlorine-containingmobile species. However, the structure of the Y zeolite largely collapses during this treatment, whereas the crystalline state of ZSM-5is preserved.

Mesoporous Fe-MCM-41 samples with different framework iron contents were tested as catalysts in CO oxidation and characterized by TPR,Mossbauer and FTIR spectroscopies after heat treatment in high vacuum and reductive or oxidative atmospheres. In samples with Si/Fe ratiosof 20 and 12 all of the iron was found to be reducible with H2, but only a part of Fe(III) species could be reduced to Fe(II) in materialswith lower iron content. In neither of the materials could Fe(III) be fully converted with CO to the divalent oxidation state. A significant part ofiron can be reversibly reduced and reoxidized in successive redox cycles. Large Fe-O clusters could not be detected.

NO decomposition and selective catalytic reduction (SCR) of NO by propane in oxygen were compared over Cu-ZSM-5 with various Si/Al ratios and extent of exchange. It was established that the turnover frequency (TOF) values referred to copper ions species characterized by NO desorption, are independent of the Si/Al ratio and the extent of exchange. The presence of propane and oxygen accelerates N 2 formation and higher conversion can be reached at lower temperature. TPD experiments indicate that the Cu 2+ (O)(NO)(NO 2 ) surface complex, which is formed as an intermediate in the decomposition of NO, is not the active pathway in SCR. In SCR of NO by propane in the presence of oxygen, the first step is Cu(I) to Cu(II) conversion by oxygen. NO 2 formation is facilitated by Cu(II) species, which react with propane forming a nitrito–propane compound. Its result in N 2 formation at a lower temperature than what is required for decomposition of NO.

Conditions that facilitate high Ps formation and interactions that modify the o-Ps lifetime were investigated by positron annihilation techniques in silicalite-1 and various Y-zeolites. Long lifetimes, up to 135 ns, and o-Ps fractions as high as 40% were found. The influence of heat treatment (in the range of 90–520 K), capillary condensation of N 2 (0.085 MPa) and correlation with water removal was examined in Y-zeolites and in silicalite-1, respectively. The latter matrix was also studied in the presence of liquids. In various samples unexpected features were found (peculiar changes in the 2γ/3γ ratio, inversion in the trend of lifetime variations, disappearance of specific components, etc.), denoting the complexity of the processes governing the fate of e + and Ps.

High-silica ferrierites (Si/Al=12–35) were prepared by solid-state recrystallization of aluminum-containing kanemite varieties intercalated with piperidine as template. A thermal pretreatment of the kanemite/template mixture at about 360 K prior to recrystallization at 413–433 K was found to be an essential step of the preparation process. Water-soluble sodium silicate(s) formed as the by-product of recrystallization could be easily removed by washing. It was found that the maximum yield of ferrierite increases with decreasing sodium content of the silica/alumina source (e.g., 90% at 1 mmol Na g−1). The recrystallization kinetics was studied varying the temperature and sodium content of the starting material. With decreasing aluminum content of the starting material and, hence, of the ferrierites obtained, both the accessibility of the zeolitic pore space to pyridine and the concentration of lattice defects increased significantly. This effect is discussed in terms of diffusion restrictions due to extra-framework aluminum species and pore enlargement associated with lattice vacancies.

A redox reaction was found to proceed between metallic zinc and zeolitic lattice protons when ground mixtures of zinc dust ( 4 ,Na–Y zeolite, mordenite or varieties of these zeolites prepared by steaming or acid leaching were heated in a vacuum or an inert atmosphere to temperatures above 250°C. This process results in the evolution of molecular hydrogen and in the formation of Zn 2+ cations occupying, as evidenced by XRD and FTIR spectroscopy, lattice cation sites in the zeolite structure. The reported redox reaction can be regarded as the solid-state analogue of the dissolution of metals in aqueous solutions of acids. In the case of NH 4 ,Na–Y with zinc admixed in an amount equivalent to the ammonium content, the amount of the evolved hydrogen was found to be equivalent to the amount of Bronsted acid sites in the zeolitic component. The hydrogen release proceeded, depending on the type and modification of the applied zeolite, in different temperature ranges. Possibilities of developing a highly sensitive method for the quantification and distinction of hydroxyl groups in zeolites on the basis of the reported reaction are discussed.

A new method for the synthesis of high-silica ferrierite (Si/Al=15–18) by recrystallization of aluminium-containing magadiite varieties in air-dry state and aqueous suspension with piperidine as template is reported. Details on removal and thermal stability of the template occluded during the synthesis (four molecules per unit cell) are given. Properties (e.g. thermal and hydrothermal stability, acidity) of ferrierites prepared by the dry synthesis technique are presented and compositional and morphological characteristics of the products are compared with those of ferrierite conventionally prepared from alkaline SiO2/Al2O3 gel in aqueous medium.

Magadiite varieties isomorphically substituted with aluminum and their aluminosilicic acid derivatives retaining the framework topology of magadiite are recrystallized, after incorporation by ion exchange of four TPA and TBA ions, to MFI- and MEL-type zeolites, respectively. The recrystallization degree and the size and shape of the zeolite crystallites formed can be controlled by the amount of template applied. Partial recrystallization results in products which promise to be advantageously applicable as catalysts because of the small crystallite size of the zeolitic component.

Cu, H-ZSM-5 (Cu/H=1.5) prepared by solid-state ion exchange with excess CuCl proved to be, after reduction with CO at 500°C, highly active in NO decomposition even at reaction temperatures below 300°C, while reduction with hydrogen resulted in a catalyst which was much less active below 450°C but highly active at about 500°C. These phenomena are interpreted in terms of the role of Cu+ lattice cations and Bronsted acid sites involved in the mechanism of the catalytic reaction.

In ground mixtures of In2O3 and NH4Y, incorporation of In+ cations into the zeolitic phase occurs upon thermal treatment by partial reductive solid-state ion exchange associated with oxidation of ammonium ions or released ammonia to N2 and NH2OH. Cationic InO+ species, created in zeolites by reductive solid-state ion exchange of In2O3/NH4-zeolite mixtures in hydrogen atmosphere and subsequent oxidation of the In+ lattice cations by oxygen, do not undergo autoreduction up to 970 K. Reductive solid-state ion exchange easily proceeds in carbon monoxide atmosphere at temperatures between 620 and 770 K. The significance of these observations for the use of indium-containing zeolites as catalysts is discussed.

Transforming growth factor-βs (TGF-β1-3) are cytokines that regulate the proliferation, differentiation, and survival of various cell types. The present study describes the induction of TGF-β1-3 in the rat after focal ischemia at 3 h, 24 h, 72 h and 1 month after transient (1 h) or permanent (24 h) middle cerebral artery occlusion (MCAO) using in situ hybridization histochemistry and quantitative analysis. Double labeling with different markers was used to identify the localization of TGF-β mRNA relative to the penumbra and glial scar, and the types of cells expressing TGF-βs. TGF-β1 expression increased 3 h after MCAO in the penumbra and was further elevated 24 h after MCAO. TGF-β1 was present mostly in microglial cells but also in some astrocytes. By 72 h and 1 month after the occlusion, TGF-β1 mRNA-expressing cells also appeared in microglia within the ischemic core and in the glial scar. In contrast, TGF-β2 mRNA level was increased in neurons but not in astrocytes or microglial cells in layers II, III, and V of the ipsilateral cerebral cortex 24 h after MCAO. TGF-β3 was not induced in cells around the penumbra. Its expression increased in only a few cells in layer II of the cerebral cortex 24 h after MCAO. The levels of TGF-β2 and -β3 decreased at subsequent time points. Permanent MCAO further elevated the levels of all 3 subtypes of TGF-βs suggesting that reperfusion is not a major factor in their induction. TGF-β1 did not co-localize with either Fos or ATF-3, while the co-localization of TGF-β2 with Fos but not with ATF-3 suggests that cortical spreading depolarization, but not damage to neural processes, might be the mechanism of induction for TGF-β2. The results imply that endogenous TGF-βs are induced by different mechanisms following an ischemic attack in the brain suggesting that they are involved in distinct spatially and temporally regulated inflammatory and neuroprotective processes.