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Aim: To evaluate an assay to detect minimum bactericidal concentration (MBC) in Mycobacterium tuberculosis, using as single model rifampicin, isoniazid, levofloxacin (LVX) and linezolid (LNZ) and in combination. Material & methods: MBCs were carried out directly from resazurin microtiter assay plate and 3D checkerboard in M. tuberculosis H37Rv and five resistant clinical isolates. Results: The proposed MBC assay showed similar values to those determined by MGIT™, used as control. LVX and LNZ's MBC values were close to their MIC values. LNZ or LVX combined with isoniazid and rifampicin showed MBC value reduced in 63.7% of the assays. Conclusion: The proposed assay to determine MBCs of drugs can be applied to the study of new compounds with anti- M. tuberculosis activity to detect their bactericidal effect and also in laboratory routine for clinical dose adjustment of drugs according to the patient's profile.

Smith-Magenis syndrome (SMS) is a complex genetic disorder characterized by developmental delay, behavioural problems and circadian rhythm dysregulation. About 90% of SMS cases are due to a 17p11.2 deletion containing retinoic acid induced1 (RAI1) gene, 10% are due to heterozygous mutations affecting RAI1 coding region. Little is known about RAI1 role.

Purpose: Gastrointestinal dysfunction and failure (GID and GIF) in critically ill patients are a common, relevant, and underestimated complications in ICU patients. The aims of this study were (1) to determine plasmatic levels of citrulline, glutamine, and arginine as markers of GID/GIF in critically ill patients with or without GID/GIF with or without multiple organ failure (MOF) and (2) to assess the role of intra-abdominal hypertension in these patient groups. Materials and Methods: This is a 1-year, monocentric (Italian hospital), prospective observational study. Inclusion criteria were adult patients with GID/GIF, with or without MOF. The GIF score was daily evaluated in 39 critically ill patients. Amino acids were measured at the time of GID or GIF. Results: We enrolled 39 patients. Nine patients developed GID and 7 GIF; 6 of patients with GID/GIF developed MOF. Citrulline was lower ( P < .001) in patients with GID/GIF (11.3 [4.4] µmol/L), compared to patients without GID/GIF (22.4 [6.8] µmol/L); likewise, glutamine was lower in patients with GID/GIF, whereas arginine was nonstatistically different between the 2 groups. Intra-abdominal pressure was higher in patients affected by MOF (13.0 [2.2] mm Hg) than in patients with GIF/GID without MOF (9.6 [2.6] mm Hg) and compared to patients without GID/GIF (7.2 [2.1] mm Hg). Conclusions: Both GID and GIF in critically ill patients are associated with low levels of citrulline and glutamine, which could be considered as markers of small bowel dysfunction. The higher the GIF score, the lower the citrulline levels. Patients affected by MOF had higher levels of intra-abdominal pressure.

Increased plasma levels of free fatty acids, including palmitic acid (PA), cause insulin resistance in endothelium characterized by a decreased synthesis of insulin-mediated vasodilator nitric oxide (NO), and by an increased production of the vasoconstrictor protein, endothelin-1. Several in vitro and in vivo studies suggest that anthocyanins, natural phenols commonly present in food and vegetables from Mediterranean Diet, exert significant cardiovascular health-promoting activities. These effects are possibly mediated by a positive regulation of the transcription factor Nrf2 and activation of cellular antioxidant and cytoprotective genes. The present study examined, at a molecular level, the effects of cyanidin-3-O-glucoside (C3G), a widely distributed anthocyanin, on PA-induced endothelial dysfunction and insulin resistance in human umbilical vein endothelial cells (HUVECs). Our results indicate that C3G pretreatment effectively reverses the effects of PA on PI3K/Akt axis, and restores eNOS expression and NO release, altered by PA. We observed that these effects were exerted by changes on the phosphorylation of IRS-1 on specific serine and tyrosine residues modulated by PA through the modulation of JNK and IKK activity. Furthermore, silencing Nrf2 transcripts demonstrated that the protective effects of C3G are directly related to the activation of Nrf2.

Hyperglycemia contributes to dysregulate endothelial function associated with diabetes, leading to initiation and propagation of vascular complications and dysfunction. Caffeic acid (CA), a dietary hydroxycinnamic acid abundant in coffee, has been reported to exert antidiabetic effects in rat models. Herein, we investigated the molecular effects of physiological concentrations of CA (10 nM) against endothelial dysfunction induced by high glucose (HG) in human endothelial cells (HUVECs). HUVECs were exposed to HG 25 mM, to mimic diabetic condition, in presence of CA. Intracellular redox status (reduced glutathione, superoxide dismutase (SOD) and total antioxidant activity levels), and NF-κB pathway were examined. We also evaluated the involvement of NF-E2-related factor 2 (Nrf2)/electrophile responsive element (EpRE) pathway. Our data show that CA inhibits HG-induced nuclear translocation of NF-κB and the downstream expression of endothelial adhesion molecule 1 and restores antioxidant levels by upregulating Nrf2/EpRE pathway. Our data suggest that CA can suppress several aspects of HG-induced endothelial dysfunction through the modulation of intracellular redox status controlled by the transcription factor Nrf2. These findings highlight that low physiological concentration of CA achievable specifically upon food consumption are able to prevent endothelial dysfunction associated with inflammation and oxidative stress induced by high concentration of glucose. © 2016 BioFactors, 43(1):54-62, 2017.

BACKGROUND Myo-inositol is a natural molecule with important therapeutic applications and an impaired oral absorption may result in a reduced clinical effect. Aim of this study was to determine if the combined oral administration of α-lactalbumin and myo-inositol in healthy subjects, could increase the plasma level of myo-inositol administered alone. In vitro studies on human differentiated intestinal Caco-2 cells were also conducted to identify the mechanisms involved in myo-inositol absorption. OBJECTIVE The in vivo study was conducted on healthy volunteers in two phases. Subjects received a single oral myo-inositol dose. After 7 days washout, the same subjects were administered a single dose of myo-inositol and α-lactalbumin. Cmax, Tmax and AUC for myo-inositol in plasma were calculated from samples collected at different times. Transepithelial myo-inositol passage, with or without addition of digested α-lactalbumin, was measured in vitro in differentiated Caco-2 cells and compared to transepithelial electrical resistance and phenol red passage. RESULTS The bioavailability of myo-inositol was modified by the concomitant administration of α- lactalbumin. Although peak concentration of myo-inositol at 180 min (Tmax) was similar for both treatments, administration of α-lactalbumin with myo-inositol in a single dose, significantly increased the plasma concentrations of myo-inositol compared to when administered alone. In vitro, myo-inositol absorption in Caco-2 cells was improved in the presence of digested α-lactalbumin, and this change was associated with an increase in tight junction permeability. CONCLUSION Better myo-inositol absorption when orally administered with α-lactalbumin can be beneficial in non-responder patients. Preliminary in vitro findings suggest that peptides deriving from α- lactalbumin digestion may modulate tight junction permeability allowing increased absorption of myoinositol.

An integrated biomass-to-mixed alcohol process was demonstrated at the pilot scale, including indirect gasification, tar and hydrocarbon reforming, gas conditioning, and gas to liquids operations. Additional bench-scale experiments were conducted to gather insights into reforming and fuel synthesis operations under more extensive conditions. Data from these experiments were combined with tools and knowledge owned by industrial partners—Rentech and The Dow Chemical Company—to validate a conceptual commercial-scale cellulosic ethanol refinery. Results suggest that both reforming and mixed alcohol processes are scalable and economical, with a modeled mature plant ethanol production cost of $0.54/L ($0.82/L of gasoline equivalent). Sustainability metrics for the conversion process are also presented.

This Article is focused on the study of the effect of oxygenate impurities like esters and acids in the mixed methanol and ethanol feed stream on the conversion of methanol and ethanol to light ole...

Potassium promoted molybdenum sulfide catalysts are well-known for the conversion of synthesis gas (H2 and CO) to higher alcohols, primarily ethanol and propanol. Basic supports composed of mixed MgAl based oxides from decomposed hydrotalcites are known to yield enhanced higher alcohol selectivities compared to bulk or carbon supported molybdenum sulfide catalysts. In this study, the role of the metal oxide support and the active as well as precursor molybdenum phases on higher alcohol productivity and selectivity are probed. At fixed loadings of potassium (3 wt%) and molybdenum (5 wt%), supported molybdenum sulfide (MoS2) and molybdenum carbide (Mo2C) catalysts are prepared on mixed MgAl oxide, α-alumina, and magnesium oxide supports and evaluated in higher alcohol synthesis. At low conversions, the catalytic results suggest that basic supports provide similar effects as the alkali promoter, helping to produce lower methanol (MeOH) selectivities and higher C2+OH selectivities while shifting overall selectivity from hydrocarbons towards alcohols. Under similar conditions, it is also shown that Mo2C compositions produce more hydrocarbons than MoS2 catalysts, suggesting that higher potassium loadings are needed to fully eliminate acidity in molybdenum carbide phases. Conversion of the Mo2C phase to a MoS2 phase in situ, followed by catalytic testing in syngas hydrogenation shows that similar catalytic selectivities are obtained at similar CO conversions for catalysts with similar overall molybdenum and potassium loadings, regardless of the molybdenum phase in the precatalyst (MoO3 vs. Mo2C). The highest C2+ alcohol selectivities and productivities among the catalysts tested here are obtained on presulfided MoO3 catalysts on both α-alumina and magnesium oxide supports.

The influence of Co addition on the activity and selectivity of Rb-promoted Mo2C/α-Al2O3 catalysts in CO hydrogenation was explored. The reaction was performed in a fixed-bed reactor system operating at 573 K, 30 bar, and CO/H2 ratio of 1. Addition of Co enhanced the production rates of hydrocarbons and higher alcohols over Rb-promoted Mo2C/α-Al2O3 by about 60 % without significantly increasing the production rate of methanol, thus shifting the alcohol selectivity toward larger molecules. The addition of Co also lessened the negative impact of CO conversion on oxygenate selectivity over Rb-promoted Mo2C/α-Al2O3. Results from X-ray absorption spectroscopy revealed that highly dispersed Co and Mo domains remained more reduced in the bimetallic carbide samples than the corresponding monometallic samples.

Molybdenum disulfide promoted with alkali metals is one of the most studied catalysts for the conversion of synthesis gas to alcohols. In this work, MoS2 was promoted by adding potassium precursors by physical mixing (PM) and incipient wetness impregnation (IWI) and tested in a small scale reactor. The catalysts prepared by impregnation showed poorer performance compared to the sample prepared by physical mixing of K2CO3 and MoS2. The catalysts were characterized by means of X-ray diffraction, TGA–MS, SEM–EDS, TEM and XPS. The characterization results obtained by SEM–EDS and XRD analyses do not show major differences between the catalysts studied here. In contrast, the TGA results indicated that physical mixing leads to catalysts that lose sulfur at temperatures above 330 °C and TEM images showed that randomly oriented small MoS2 crystallites are obtained from PM preparation while IWI preparation gave long MoS2 crystallites.

A series of MoS2 catalysts supported on Mg/Al hydrotalcite-derived mixed-metal oxide (MMO) supports promoted with K2CO3 is used for alcohol synthesis via CO hydrogenation. Alcohol selectivities are found to vary greatly when the Mo is loaded on the support at 5 wt % compared with 15 wt % Mo samples, all with a Mo/K atomic ratio of 1:1. The most striking difference between the catalysts is the comparatively low methanol and high C3+ alcohol selectivities and productivities achieved with the 5% Mo catalyst. This catalyst also produces more ethane than the 15% Mo catalyst, which is shown to be associated with ethanol dehydration and hydrogenation over residual acid sites on this catalyst with lower K content. A series of catalysts with common composition (5% Mo and 3% K supported on MMO) prepared in different manners all yield similar catalytic selectivities, thus showing that selectivity is predominately controlled by the MMO-to-Mo ratio rather than the synthesis method. When the Mo loading is the same, cat...

Molybdenum carbide nanoclusters supported on alumina were promoted by Rb2CO3 and tested for higher alcohol synthesis from syngas. At 573 K and 30 bar syngas (H2/CO = 1), the promoted catalyst demonstrated 63% selectivity to alcohols (on a CO2-free basis), with hydrocarbons and ethers as side products. In contrast, the alcohol selectivity of an unpromoted Mo2C/Al2O3 catalyst was very low. DRIFTS of adsorbed CO on Mo2C/Al2O3 revealed a significant red shift in the CO band with added Rb promoter, which correlated to a decrease in hydrocarbon production rate and therefore an increase in alcohol selectivity. A quantum chemical description of CO adsorbed on a model Mo2C surface identified several possible binding modes of the CO. Both reactivity studies and DRIFTS of adsorbed CO demonstrated that mobility of the Rb promoter was enhanced in the presence of water vapor, which facilitates dispersion of Rb across the catalyst surface and effectively neutralizes acid sites that are deleterious to alcohol selectivity.

Partial charges in dense materials can be either derived from spectroscopic experiments or computed by quantum chemistry calculations. X-ray absorption near-edge spectroscopy (XANES) energies measured for several Mo-containing materials were correlated with charges computed by two density functional theory (DFT)-based charge assignment methods, namely, the Bader and density derived electrostatic and chemical (DDEC) methods. Our results indicated that DDEC charges correlate better with XANES energies than Bader charges and that both of these methods give far better results than using formal oxidation states. We show that the linear relation between DDEC charges and XANES energies can be used in characterizing the degree of reduction in supported catalyst samples.

Chronic intestinal inflammatory disorders, such as Inflammatory Bowel Diseases (IBDs), are characterized by excessive release of proinflammatory mediators, intestinal barrier dysfunction and excessive activation of NF-kB cascade. Previous studies shown that TNF-α plays a central role in intestinal inflammation of IBDs and supported beneficial effects of flavonoids against chronic inflammatory diseases. In this study, we employed an in vitro model of acute intestinal inflammation using intestinal Caco-2 cells exposed to TNF-α. The protective effects of cyanidin-3-glucoside (C3G), an anthocyanin widely distributed in mediterranean diet, were then evaluated. Caco-2 cells exposure to TNF-α activated NF-kB proinflammatory pathway and induced IL6 and COX-2 expression. Cells pretreatment for 24h with C3G (20-40μM) prevented TNF-α-induced changes, and improved intracellular redox status. Our results demonstrated that C3G, also without any kind of stimulus, increased the translocation of the transcription factor Nrf2 into the nucleus so activating antioxidant and detoxifying genes. In conclusion, C3G exhibited protective effects through the inhibition of NF-kB signalling in Caco-2 cells and these beneficial effects appear to be due to its ability to activate cellular protective responses modulated by Nrf2. These data suggest that anthocyanins could contribute, as complementary or preventive approaches, to the management of chronic inflammatory diseases.

Acetaminophen (N-acetyl-p-aminophenol, APAP) overdosage can produce fatal centrilobular hepatic necrosis in humans. The present study attempted to investigate the protective effect of an anthocyanin-rich extract from bilberries and blackcurrants (AE) against APAP-induced acute hepatic damage in rats. Treatment with AE normalised blood activities of glutamate oxaloacetate and glutamate pyruvate transaminase and prevented APAP-induced plasmatic and tissutal alterations in biomarkers of oxidative stress, probably due to various bioproperties of the components of the extract.

Unpromoted and Rb-promoted Mo2C nanoparticles (∼1 nm in size) were synthesized on α-alumina and used for CO hydrogenation. The reaction was performed in a fixed-bed reactor system operating at 573 K and 30 bar with a gas flow rate of 24,000 cm3 gMo–1 h–1 and H2/CO ratio of 1:1. Unpromoted Mo2C functioned as a Fischer–Tropsch catalyst producing mostly hydrocarbons at the standard conditions. Passivation of freshly synthesized Mo2C nanoparticles in 1% O2 prior to CO hydrogenation decreased the Fischer–Tropsch activity of the catalyst by about 40% compared with a nonpassivated sample. Addition of Rb promoter to Mo2C shifted the selectivity of the catalyst by inhibiting the formation of hydrocarbons while preserving the formation of alcohols. The presence of Rb with Mo2C also reduced substantially the sensitivity of the catalyst to passivation by 1% O2 compared with unpromoted Mo2C. The partial oxidation of the Mo2C nanoparticles by passivation and partial reduction by syngas was confirmed by Mo K edge X-ray ...

Background The standard of care in patients with glioblastoma (GBM) relies on surgical resection, radiation therapy (RT), and temozolomide. Steroids are required in almost all patients to reduce peritumoral edema, but are associated with numerous side effects. Vascular endothelial growth factor (VEGF) is a key driver of peritumoral edema and angiogenesis in human GBM. Recently, angiotensin-II inhibitors were reported to reduce VEGF secretion and tumor growth in some animal models. Methods To investigate whether angiotensin-II inhibitors might have a similar effect in humans and before undertaking a prospective study, we retrospectively investigated a series of 87 consecutive, newly diagnosed GBM patients, treated in a single center. Amongst these patients, 29 (33%) were already treated before RT for high blood pressure (HBP), 18 of them (21%) with an angiotensin-II inhibitor. In all patients, performance status, surgical procedures, and steroid dosages were documented. Results Patients treated with angiotensin-II inhibitors, but not other antihypertensive drugs, required half of the steroids of the other patients during radiotherapy (P = 0.005 in multivariate analysis, considering other antihypertensive treatments, surgical resection, and performance status). This effect of angiotensin-II inhibitors was also significant at the beginning of radiotherapy (P = 0.03 in multivariate analysis). Treatment with angiotensin-II inhibitors had no effect on survival (16.2 vs. 17.9 months for the treated and the non-treated group, respectively, P = 0.77). Conclusion Angiotensin-II inhibitors might display significant steroid-sparing effects in brain tumor patients. Given the morbidity associated with steroids, this finding might have important practical consequences in these patients and warrants a randomized study.

A Mg/Al mixed metal oxide material (MMO) is introduced as a support for K2CO3 promoted MoS2 in CO hydrogenation reactions at 310 °C and 1,500 psig. The catalyst is shown to be more selective for C2–C4 linear alcohols (substantially so for C3–C4 linear alcohols) than for methanol and offers good alcohol to hydrocarbon selectivity. Methanol selectivity of the MMO supported catalyst deviates greatly from the Anderson–Shultz–Flory distribution.

The influence of organic supports on the polymerization behavior of post-metallocene catalysts is studied and compared with similarly supported titanium and zirconium metallocenes. The effects of the immobilization, activation, and polymerization process were studied by videomicroscopy, laser confocalfluorescencemicroscopy, SEM, and TEM. A model for the polymerization process for a catalyst supported onlatex particles was developed from the results obtained. Organic supports based on latex particles are easily adjustable for different catalysts due to the versatile functionalization of the surfaces and can be applied to different types of olefin polymerization catalysts. They can be considered as an alternative to SiO2 or MgCl2 supports.

Videomicroscopy as a tool for investigating olefin gas phase co-polymerization is presented in this paper. This technique enables the simultaneous detection of the individual growth of a large number of catalyst particles. The focus is to study the kinetic behaviour of different types of Ziegler- and metallocene catalysts and to demonstrate that videomicroscopy can help to assign a given catalyst system to the appropriate model. Further, the density problem, the estimation of activation energies of single grains, the particle volume enlargement of amorphous copolymers and the comonomer effect are adressed.

Video microscopy as a tool for investigating olefin gas phase copolymerization is presented for the first time in this paper. The central theme of this work is the study of the comonomer effect shown by an unbridged metallocene catalyst supported on silica. By using video microscopy, it is possible to observe the increase in catalytic activity in terms of particle growth as well as monomer consumption. The observation that a more pronounced induction period in the particle growth profile is shown with increasing propylene concentration led us to investigate the copolymers obtained at different polymerization times using 13 C NMR analysis and single particle energy dispersive X-ray (EDX mapping). This allowed us to adapt the polymer growth and particle expansion model to the copolymerization. Besides physical causes for the comonomer effect, we wanted to determine whether the catalyst structure plays an important role in the comonomer effect. To this end we investigated two metallocenes bearing the same long bridging unit but differing in the ligand bound to the zirconium center. One metallocene bears a cyclopentadienyl ring, while the other bears an indenyl group. From a close analysis of the 13 C NMR, it is clear that both catalysts insert ethylene more easily then propylene, probably due to the long bridging unit that results in a narrower aperture angle of the ligand. In addition to this, the indenyl ligand does not allow the formation of propylene blocks even at high propylene concentration.

In this paper, a mathematical model describing olefin polymerization with metallocene catalysts is presented. It is an improvement of a previous model, the “particle growth model” (PGM) proposed by, among others, one of the authors of the present work and derives from the so-called “multigrane model” (MGM). The main differences between this work and others is a more sophisticated approach to fragmentation with respect to the MGM. Additionally, there is a more specific modeling for the unfragmented core with respect to the PGM. The numerical results obtained by the model are compared with experimental data. The results of this work allow to extend the PGM to catalysts with lower activity. The importance of those catalysts depends on the fact that high activity catalysts could bring, in some cases, too poor polymer morphology.

Free fatty acids (FFA), commonly elevated in diabetes and obesity, have been shown to impair endothelial functions and cause oxidative stress, inflammation, and insulin resistance. Anthocyanins represent one of the most important and interesting classes of flavonoids and seem to play a role in preventing cardiovascular diseases. Herein, we investigated the in vitro protective effects of cyanidin-3-O-glucoside (C3G) on cell signaling pathways in human umbilical vein endothelial cells (HUVECs) exposed to palmitic acid (PA), the most prevalent saturated FFA in circulation. Our data reported a significant augmentation of free radicals and oxidative stress in HUVECs exposed to PA for 3h, while C3G pretreatment improved intracellular redox status altered by FFA. Moreover, C3G significantly inhibited NF-κB proinflammatory pathway and adhesion molecules induced by PA, and these effects were attributed to the activation of Nrf2/EpRE pathway. In fact, C3G induced Nrf2 nuclear localization and activation of cellular antioxidant and cytoprotective genes at baseline and after PA exposure in endothelial cells. Our data confirm the hypothesis that natural Nrf2 inducers, such as C3G, might be a potential therapeutic strategy to protect vascular system against various stressors preventing several pathological conditions.

This paper describes experimental results obtained in a fixed bed reactor using a CoMoS based catalyst. The aim of this work was to produce alcohols from CO2 and H2. Conclusions from this work include: · CO2 and H2 can be used as a feed for the CoMoS catalyst to produce alcohols. · Overall, a H2/CO2 ratio of 3 (or higher) seems favorable for reaching significant conversion levels of H2 and CO2. · A relatively small temperature increase does not significantly affect the conversion, probably due to a thermodynamic equilibrium constraint. · Low temperature is better for a good alcohol / alkane ratio. Mainly methanol and ethanol are produced and relatively little propanol. Although the concept was proven, a process where CO2 and H2 are converted into alcohols/olefins is economically viable only if hydrogen can be obtained in a cost effective manner.

It is demonstrated that modern optical methods allow for a very fast study of the behaviour of supported metallocene catalysts. By videomicroscopy several polymeric supports functionalised with cyclopentadiene units or poly(ethylene oxide) and poly(propylene oxide) chains and loaded with a metallocene were simultaneously studied. In this example it is shown that this method allows for a direct comparison of different catalysts under identical conditions in a single experiment. In addition by this experiment more detailed information on the behaviour of the supports can be obtained by studying the growth kinetics of single grains. As a second tool, laser scanning confocal fluorescence microscopy (LSCFM) was applied. Using dye-labelled supports LSCFM can be used as a very rapid tool to study the fragmentation of supports. This is demonstrated by 3D images showing the distribution of different support fragments in the polyethylene product particles. Introduction For industrial applications of metallocenes, immobilisation of the catalyst is necessary to allow for perfect product control, especially of particle size, density and form of the polyolefin particles. Therefore, many different supports for immobilisation have been investigated. Mainly they are based on inorganic materials but also organic supports have received increasing attention [1-16]. It had been shown that supports have to fulfil several requirements as to control the polymerisation process and to obtain products with a desirable morphology. The carrier has quantitatively to immobilise the metallocene to avoid leaching and reactor fouling during the polymerisation process. Typically the supports have to be particles with an average size of 50 100 μm (final particles); however, they should be able to fragment during the polymerisation into nm-sized particles (primary particles). So far the total course of olefin polymerisation and fragmentation of the supported catalyst as a part of this process have been studied by a) Buchi reactor kinetic [17-21]: measuring the monomer consumption gives information about the course of the instationary polymerisation rate with time, reaction orders and activation energy. 1 Unauthenticated Download Date | 6/27/17 8:01 PM b) Bulk polymerisation kinetics in liquid monomer: measuring the polymer formation by means of a heat flow calorimeter leads again to the instationary polymerisation rate, reaction orders and activation energy [22-24]. c) Electron microscopic kinetics: electron microtome sections (scanning electron microscopy and transmission electron microscopy) of the polymerising particles give information about polymer growth, particle fragmentation and particle expansion [22,17]. The results from these investigations led to mathematical models of the total polymerisation process as, e.g., the polymeric flow model, the multi-grain model, and the polymer growth and particle expanding model [25,26]. In this paper we introduce videomicroscopy and laser scanning confocal optical microscopy (LSCFM) as two new optical methods for determining the particle expansion kinetics and particle fragmentation. Videomicroscopy allows the simultaneous observation of many polymerizing particles in situ [27,28]. LSCFM originally used in biology and life sciences to study cells for directly investigating the distribution of a fluorescence-tagged biologically active structure [29] allows studying the fragmentation process. By incorporation of a fluorescent dye into the supports the distribution of the fragments of the support can be measured in the growing and expanding particles within a few minutes. Results and discussion Synthesis of the organic supports To show the applicability of videomicroscopy as a tool to compare different catalysts at the same time, three organic supports as carriers for a metallocene catalyst (Me2Si(2MeBenzInd)2ZrCl2) were prepared. Polystyrene (PS) [14] or nano-sized latex particles [13] with poly(ethylene oxide) (PEO) chains on their surfaces were used as carriers for the metallocene catalyst. Due to the nucleophilic character of the ether groups, the methylaluminoxane (MAO) activated metallocene complexes are immobilised by non-covalent interactions [12,13]. Especially, nano-sized (100 150 nm) latex particles have been proposed as suitable supports for metallocenes as they fragment completely within the final product during the polymerisation reaction, as shown by transmission electron microscopy and fluorescence microscopy [13,30]. The support for catalyst K-1 (Scheme 1) consists of a linear PS chain functionalised with PEO for immobilizing the active metallocene catalyst and with cyclopentadiene (CP) for allowing reversible network formation by a Diels-Alder reaction [31]. This support was proven to be a suitable carrier for metallocene catalysts in olefin polymerisation as it shows good activity in the ethylene polymerisation and PE particles with high bulk densities were obtained. The support for catalyst K-2 (Scheme 2) was also functionalised with PEO chains and CP units; however, this support consists of latex particles prepared by emulsion polymerisation [14]. In the cases of K-2 the support is aggregated not only by DielsAlder reactions between different cyclopentadienyl units but also non-covalently due to the interaction of the polar surfaces of the particles with MAO. As a third example, latex particles (Scheme 3) surface-functionalised only with PEO were applied as supports to obtain catalyst K-3. In this approach, PS-PEO block copolymers were used as surfactants in the emulsion polymerisation process [13]. 2 Unauthenticated Download Date | 6/27/17 8:01 PM The latex particles (primary particles) are only physically aggregated by polar interactions of the ether groups of the surfactant with MAO.

Stem cells isolated from the central nervous system of both embryonic and adult mice can generate neurons and glia through the activation of different patterns of differentiation in dependence of exposure to appropriate epigenetic signals. On the other hand, environmental conditions might affect the proliferation, migration, and differentiation of these cells. We report here, for the first time, that inorganic mercury affects the proliferative and differentiative capacity of adult neuronal stem cells (ANSCs). Actually, inorganic mercury increases apoptosis in ASNC. Furthermore, in stem cell-derived astrocytes, high levels of the 70 kDa heat shock protein (HSP-70) occur, while the levels of GTP-beta-tubulin activity dramatically decrease. Interestingly, when induced to differentiate, inorganic mercury modifies morphological proprieties of astrocytes, while the neuron population is reduced. These results demonstrate that inorganic mercury produces toxicity in the ANSC-derived neuronal population and affects the biological properties of the glial-derived population.

CoMoSx/K catalysts used for the synthesis of higher alcohols from syngas are usually prepared using costly ammonium tetrathiomolybdate. In an attempt to identify inexpensive and more readily available molybdenum precursors with improved performance, catalysts were prepared starting from crystalline MoS2 activated by ball-milling. This communication reports the catalytic performance of these catalysts in the hydrogenation of CO for the synthesis of higher alcohols along with catalyst characterization results.