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Methyl levulinate was selectively formed from glucose and methanol over a copper modified Beta zeolite bifunctional catalyst at 180 °C under argon atmosphere. The selectivity to methyl levulinate substantially exceeded previously reported in the open literature results. The copper modification was done through an ion-exchange method using a solution of copper nitrate, followed by drying and calcination of the catalyst. Copper modification changed the distribution of acid sites namely, less Brønsted and more Lewis sites were observed with FTIR using pyridine adsorption. Application of the proton form H-Beta-25 gave the methyl levulinate yield of ca. 89%, which could be elevated with the addition of copper, as the apparent selectivity exceeds 99%, assuming that methyl glucosides are eventually transformed to methyl levulinate. The non-acidic Cu/SiO2 catalyst was completely inactive in methyl levulinate formation. Metal modification of Beta zeolite with Sn and Zn did not perform as well as Cu in the formation of methyl levulinate during glucose transformation.

Bimetallic platinum–rhenium catalysts supported on activated carbon were tested for the hydrodeoxygenation (HDO) of isoeugenol at 250 °C and 30 bar of H2 in a batch reactor. The catalysts were characterized by inductively coupled plasma atomic emission spectrometry (ICP-IES), N2 physisorption, electron microscopy (high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), transmission electron microscopy (TEM)), temperature-programmed reduction, X-ray absorption spectroscopy (X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine structure (EXAFS)), and temperature-programmed desorption of ammonia. Bimetallic catalysts containing Pt and Re were much more active than monometallic Pt/C and Re/C. Complete isoeugenol conversion, high propylcyclohexane yield (99%), and a high liquid-phase mass balance (77%) were obtained for the catalyst with the highest Re loading, Pt–Re(1:5)/C. Such high activity is attributed to a synergistic effect between the reduced Pt and the Re-oxide species, as both metal active sites and oxygen vacancies are required for HDO. The apparent activation energy for the HDO of isoeugenol with Pt–Re(1:5)/C was 44 kJ/mol.

Titanium silicates of MWW structures with different Si/Ti ratios were prepared via hydrothermal synthesis using piperidine as the structure directing agent and boric acid as the crystallization agent. All the syntheses resulted in highly crystalline materials independent of the Si/Ti ratio. The observed morphology showed MWW-like well-defined thin hexagonal platelets. The synthesized Ti-MWW materials exhibited higher surface areas and partial meso-porosity compared to the commercial TS-1 catalyst. The coordination of the Ti-species was investigated by UV–vis- and IR-spectroscopy. The MWW titanium silicates were tested for the catalytic performance in the epoxidation of propylene in a laboratory-scale trickle bed reactor to compare their clear different physico-chemical properties with the commercial TS-1. The synthesized Ti-MWW materials showed significantly higher catalytic activities, up to 3.5 times, using acetonitrile as the solvent and enhanced epoxide selectivities partially up to 100% in methanol unlike TS-1. The effect of the Ti content in the MWW and the calcination conditions were investigated in propylene epoxidation, revealing the beneficial effect of a lower calcination temperature and an increased Ti content on the activity. The catalytic results were correlated with the physico-chemical properties of the synthesized materials. Graphical Abstract

The major lactiferous ducts of the human breast branch out and ultimately end at terminal ductal lobular units (TDLUs). These glandular structures are the source of milk upon lactation, and also the most common origin of breast cancer. Despite their functional and clinical importance, the three dimensional (3D) architecture of TDLUs has remained undetermined, largely due to their absence in rodent animal models. By utilizing recent technological advances in optical tissue clearing and microscopy, we imaged the 3D structure of healthy human breast tissue to determine whether general branching patterns or cell type specific niches exist in the TDLU. Our data demonstrate that TDLUs have a consistent shape and their branch parameters are largely comparable between different TDLUs and individuals irrespective of age or parity. Simulation of TDLU branching morphogenesis in 3D by mathematical modelling suggests that evolutionarily conserved mechanisms regulate mammary gland branching in humans and mice, despite their anatomical differences. The data also demonstrate a new level of organization within the TDLU structure identifying a main branch that dominates in bifurcation events and exhibits a more duct-like keratin expression pattern. In all, our data provide the first structural insights into 3D human breast anatomy and branching, and exemplify the power of volumetric imaging in deeper understanding of human breast biology.

Formic acid is one of the key components in green chemistry being involved in energy storage, production of chemical intermediates and fuel components. Therefore the knowledge of its stability is of crucial importance and a systematic study of its decomposition is needed. The kinetics of formic acid decomposition to hydrogen and carbon dioxide was investigated in a laboratory-scale fixed bed reactor at 150–225 °C and atmospheric pressure. Palladium nanoparticles deposited on porous active carbon Sibunit were used as the heterogeneous catalyst. The catalyst was characterized by nitrogen physisorption and high-resolution transmission electron microscopy. The average palladium nanoparticle size was 5–6 nm. The impacts of mass transfer resistance and formic acid dimerization were negligible under the reaction conditions. Prolonged experiments revealed that the catalyst had a good stability. Hydrogen and carbon dioxide were the absolutely dominant reaction products, whereas the amounts of carbon monoxide and water were negligible. The experimental data were described with three kinetic models: first order kinetics, two-step adsorption-reaction model and multistep adsorption-decomposition model of formic acid. The multistep model gave the best description of the data.

In this work, several heterogeneous micro- and mesoporous, acidic catalysts were tested for the selective synthesis of Florol®, an industrial product formed via condensation and rehydration starting from isoprenol and isovaleraldehyde in dimethylcarbonate as a solvent. The results showed that a mildly acidic, microporous H-Beta-300 with SiO2/Al2O3 ratio of 300 was the best catalyst, giving 72% selectivity with 99% conversion at 40 °C when using the molar ratio isoprenol to isovaleraldehyde of 1:5. More acidic zeolites gave slightly lower selectivity, while the lowest selectivity (up to 52%) was obtained with mesoporous catalysts exhibiting mild acidity and no strong Brønsted acid sites. Selectivity to pyranols was nearly constant when changing temperature, while a larger excess of isovaleraldehyde promoted formation of tetrahydropyranol. H-Beta-300 catalyst was successfully after calcination at 400 °C. DFT calculations pointed out on the parallel formation of tetrahydro pyranols and dihydropyrans, which are the corresponding dehydration products., Journal of Catalysis, 405, ISSN:0021-9517, ISSN:1090-2694

Citronellal was converted to menthol in a one-pot approach using H-Beta zeolite-based Ni catalyst in a batch reactor at 80 °C, under 20 bar of total pressure. The effects of H-Beta acidity (H-Beta-25 with the molar ratio SiO2/Al2O3 = 25 and H-Beta-300 with SiO2/Al2O3 = 300) and Ni loading (5, 10 and 15 wt %) on the catalytic performance were investigated. Ni was impregnated on H-Beta support using the evaporation-impregnation method. The physico-chemical properties of the catalysts were characterized by XRD, SEM, TEM, ICP-OES, N2 physisorption, TPR, and pyridine adsorption–desorption FTIR techniques. Activity and selectivity of catalysts were strongly affected by the Brønsted and Lewis acid sites concentration and strength, Ni loading, its particle size and dispersion. A synergetic effect of appropriate acidity and suitable Ni loading in 15 wt.% Ni/H-Beta-25 catalyst led to the best performance giving 36% yield of menthols and 77% stereoselectivity to ( ±)-menthol isomer at 93% citronellal conversion. Moreover, the catalyst was successfully regenerated and reused giving similar activity, selectivity and stereoselectivity to the desired ( ±)-menthol isomer as the fresh one. Graphical Abstract

The three-step reaction of citral to menthol was investigated in an autoclave and a trickle-bed reactor over Ru-MCM-41 catalysts in powder and shaped forms, respectively, with the same composition and controlled metal location. All catalysts were characterized in detail and the results were correlated with catalytic tests. Activity and selectivity were strongly affected by controlling the location of Ru in the powder catalyst applied in the batch experiments. The catalyst with the largest distance between the metal and acid sites, and at the same time, with the highest total acidity, i.e. with Ru deposited exclusively on a binder Bindzil, displayed the highest yield of menthols. In contrast, in the trickle-bed reactor with extrudates the Ru location was of almost no importance which is related to mass transfer. Comparison between batch and continuous experiments also revealed significant differences in the product distribution. The highest yield of the desired menthol of 6% with stereoselectivity of 66% was obtained at a residence time of 12.5 min after 3 h of time-on-stream over egg-shell extrudates with Ru distribution at the outermost layer, deposition of Ru on both H-MCM-41 and the binder Bindzil, and the smallest Ru particle size.

Sugar monomers originating from well-controlled hydrolysis of hemicelluloses appearing in biomass are important platform molecules and they can be further valorized by catalytic hydrogenation, oxid...

Plastics are one of the most widely used polymeric materials. However, they are often undegradable and non-recyclable due to the very stable covalent bonds of macromolecules, causing environmental pollution and health problems. Here, we report that liquid-liquid phase separation (LLPS) could drive the formation of robust, stable, and sustainable plastics using small molecules. The LLPS process could sequester and concentrate solutes, strengthen the non-covalent association between molecules and produce a bulk material whose property was highly related to the encapsulated water amounts. It was a robust plastic with a remarkable Young's modulus of 139.5 MPa when the water content was low while became adhesive and could instantly self-heal with more absorbed water. Finally, responsiveness enabled the material to be highly recyclable. This work allowed us to understand the LLPS at the molecular level and demonstrated that LLPS is a promising approach to exploring eco-friendly supramolecular plastics that are potential substitutes for conventional polymers.

Mesoporous materials are promising catalysts for production of biofuels. Herein, H-MCM-41 catalysts with different concentrations of the silica Bindzil binder (10-50 wt%) were prepared and characterized using pulsed-field gradient (PFG) NMR in the powder form and as extrudates. Effective diffusion coefficients (

Oxidation of a mixture of glucose and arabinose over 1% Au deposited on alumina was investigated in a semi-batch reactor varying pH, temperature and partial pressure of oxygen. Elevation of the latter enhancing the rate induced also losses in selectivity to aldonic acids. A kinetic model representing the catalytic oxidation reactions of arabinose and glucose along with respective isomerization to fructose and ribulose was developed. Calculations based on the model were able to describe experimental data in a reliable way.

Cascade transformations of (±)-citronellal in a continuous mode were investigated over a bifunctional shaped ruthenium catalyst bearing metal clusters of the size 7–13 nm. Four types of Ru/H-MCM-41 extrudates (1.5 × 10 mm) containing 30% of Bindzil-50/80 colloidal silica binder were prepared varying in metal location and metal-to-acid ratio, while the concentration of Bronsted and Lewis acid sites and textural properties of the final extrudates were comparable. Catalytic tests were performed in the trickle-bed reactor under 70 °C, 10 bar of H2, and the initial reactant concentration in cyclohexane 0.086 mol L−1 for the liquid residence time of 12.5 min. As a reactant, isopulegol, citronellol or (±)-citronellal was used. Metal location in extrudates has a significant effect on the catalytic activity and selectivity especially in terms of isopulegol isomers which content correlated with the metal-to-acid site ratio. Stereoselectivity to the desired (±)-menthol was 68–70%. The highest amount of the desired menthol, 32% yield, was obtained over extrudates where Ru was deposited on the catalytic support, i.e. with the shortest distance between the acid and metal sites, the lowest Bronsted acidity, the lowest Bronsted–Lewis acid sites ratio, the highest specific surface area and the narrowest range of the Ru particle size distribution.

Viruses play a major role in modern society and create risks from global pandemics and bioterrorism to challenges in agriculture. Virus infectivity assays and genome copy number determination methods are often used to obtain information on virus preparations used in diagnostics and vaccine development. However, these methods do not provide information on virus particle count. Current methods to measure the number of viral particles are often cumbersome and require highly purified virus preparations and expensive instrumentation. To tackle these problems, we developed a simple and cost-effective time-resolved luminescence-based method for virus particle quantification. This mix-and-measure technique is based on the recognition of the virus particles by an external Eu3+-peptide probe, providing results on virus count in minutes. The method enables the detection of non-enveloped and enveloped viruses, having over tenfold higher detectability for enveloped, dynamic range from 5E6 to 3E10 vp/mL, than non-enveloped viruses. Multiple non-enveloped and enveloped viruses were used to demonstrate the functionality and robustness of the Protein-Probe method. Graphical abstract

Supramolecular polymers self-assembled by small molecules are a type of new material with adaptive and biocompatible properties. However, the mechanical property of these materials is always weak, impeding their applications in practice. Here, we reported that coacervation can be used to explore robust and stable bulk materials without the compromise of responsiveness. The liquid-liquid separation process could sequester and concentrate solutes, which facilitated the non-covalent association of building blocks equipped with multiple binding sites and resulted in bulk materials with versatile properties that were highly related to the encapsulated water amounts. It was a robust plastic with a remarkable Young’s modulus of 139.53  4.74 MPa when the water content was about 5% while became adhesive and could instantly self-heal with more absorbed water. Moreover, the material was reusable and fully recyclable. Our findings suggest that coacervation offers a promising approach to constructing bulk materials using small molecules and new possibilities for the application of supramolecular chemistry.

In the present work, the formulation and performance of the silica-aluminosilicate-based composites were studied for catalytic conversion of sugars to levulinic acid. Tailoring the acidity, surface area and the porosity of the catalysts were the main goal of the work. The acidities of the catalysts were provided by ZSM-5 zeolite and were modulated by microwave assisted solid state ion-exchange with copper. The high surface area and porosity of the catalysts were guaranteed by mesopores silica type HMS. The composites of HMS and CuZSM-5 with different contents of 30, 50, 60 and 70% were synthesized and the morphological and textural features and acidity of the materials were assessed using XRD, EDX, SEM, TEM, N2-physisorption, and FTIR, FTIR with pyridine and NH3-TPD. CuZ(60%)@H composite acted as the best catalyst with production of 45% yield and 30% yield of LA from glucose and cellulose conversion, respectively. High surface area, large pore size and volume of HMS in the best composite structure favored mass transfer of the substrates and products and higher performance of the catalyst especially in cellulose hydrolysis. In addition, tuned and balanced concentration, strength and type of CuZSM-5 acidity in the composite promoted the desired pathway, favored formation of levulinic acid and suppressed humins formation.

The carboxymethylation of cinnamylalcohol with dimethyl carbonate was performed using low-cost catalysts obtained from desulfurization slag. Processing of steel slag performed by different techniques was resulted in a wide range of the catalysts with different morphological and structural properties. Catalytic evaluation of the slag catalysts illustrated diversity of the obtained results strongly dependent on the surface area, crystal morphology and basicity. Catalytic materials demonstrated high variability of the conversion (8–85%) exhibiting similar selectivity to the desired product – cinnamyl methyl carbonate (ca. 80%). A significant impact of ultrasonication on catalytic activity was observed. Comparison of the synthesized samples with commercial basic materials illustrated competitive ability of the slag catalysts. Based on the results of catalytic evaluation and product analysis the reaction network was proposed and verified by thermodynamic analysis. A kinetic model was developed to describe concentration dependencies in carboxymethylation.

Citronellal cyclization was carried out in a continuous mode over H-beta-25 zeolite-based extrudates in a trickle-bed reactor at 35 °C and 10 bar of Ar. The physicochemical properties of zeolitic c...

Continuous cyclization of citronellal over zeolite-based extrudates was performed in a trickle-bed reactor at 35–70 °C and 10 bar of argon. Catalytic results were correlated with the physicochemical properties of the shaped catalyst prepared by extrusion of β or Y zeolites with binders. Rheological tests were used to elucidate the flow properties of a catalytic slurry and relate them with the extrusion performance. This study revealed that application of methylcellulose and bentonite binder modified the textural and acidic properties of the final extrudates. The main product was (−)-isopulegol at all temperatures with selectivity remaining quite constant with time-on-stream. The results illustrated that a binder such as bentonite cannot be considered inert. The mass-transfer limitations observed in extrudates did not significantly influence selectivity to the desired pulegols. This study also showed that a direct transfer of the batch reactor data to industrial continuous operation in citronellal cyclizat...

Hydrodeoxygenation (HDO) of isoeugenol was investigated over several Ni (Ni/SiO2, Ni/graphite) and Co (Co/SBA-15, Co/SiO2, Co/TiO2, Co/Al2O3) catalysts at 200 and 300 °C under 30 bar hydrogen press...

Kinetics of guaiacol hydrodeoxygenation (HDO) was studied using supported MoxC–SBA-15 and as a comparison 5 wt% Pt/C under 30 bar hydrogen at 200 °C and 300 °C. Catalyst characterization was done by a range of physical methods including also determination of the amount of coke and the nature of adsorbed species. Pt/C gave 2-methoxycyclohexanol as the main product, whereas Mo2C–SBA-15 promoted direct deoxygenation exhibiting also strong adsorption of guaiacol on the catalyst surface and formation of oligomers. Thermodynamics of guaiacol HDO was elucidated and the reaction network was proposed based on which kinetic modelling was done. Graphic Abstract: [Figure not available: see fulltext.]

Four different types of shaped catalysts with controlled deposition of platinum and the same composition were prepared by extrusion of beta zeolite agglomerated with bentonite as an aluminosilicate...

Oxychlorination of ethene was conducted in a microreactor (150–375 °C) over a thin layer of CeO2 prepared in the current work with the specific surface area of 80 m2/g and compared with the same reaction in millireactors (250–500 °C). The kinetic analysis revealed influence of the ethene concentration on the apparent activation energy which was different in micro- and millireactors. The previously developed reaction network was completed by including two parallel reactions for formation of ethylchloride and vinylchloride and two consecutive reactions accounting for formation of dichloroethane and vinylchloride via ethyl chloride. The reaction orders with respect to HCl and O2 in the microreactor were comparable with the literature data for millireactors. Kinetic modeling was successfully carried for all reactants by using a steady state model of a packed bed reactor.

Kinetics of the cross aldol condensation of valeraldehyde with cyclopentanone was investigated in a batch reactor under atmospheric pressure at 130 °C using heterogeneous metal modified oxides, such as CeO2–MgO, FeO–MgO, FeO–CaO as well as pristine CaO as catalysts. The catalysts were prepared either by evaporation impregnation or deposition precipitation methods and characterized by XRD, TEM, SEM, nitrogen adsorption, ammonia and CO2 TPD. The results revealed that an optimum amount of strong basic sites gives the highest ratio between cross condensation and self-condensation products of valeraldehyde. The highest yield of the desired product 2-pentylidenecyclopentanone (66%) was obtained with FeO–MgO prepared by the deposition precipitation methods. Cross-condensation of valeraldehyde with cyclopentanone was investigated over heterogeneous Fe–CaO, CeO–MgO, FeO–CaO and CaO catalysts at 130 °C using cyclopentanone as a solvent and reactant. The highest yield of the desired product, 2-pentylidene-cyclopentanone, finding applications as fragrances, flavours and pharmaceuticals, was 66% obtained over FeO–MgO catalyst exhibiting both acid and basic sites.

One-pot menthol synthesis from citronellal in a trickle bed reactor was investigated using Ru/H-beta-300 zeolite extrudates without any binder and Pt- and Ru-extrudates containing 70 wt% H-beta-25 zeolites and 30 wt% bentonite binder using different methods of metal loading on the extrudates. The catalytic results were correlated with the physico-chemical properties of bifunctional zeolite-based extrudates. The conversion of citronellal to menthol was nearly the same for Pt extrudates being independent of catalyst acidity or the metal particle size. Ru extrudates also exhibited similar conversion levels as a function of time-on-stream, except for very mildly acidic Ru/beta-300 extrudates, which gave much lower conversion. Pt extrudates showed better stability with time on stream in comparison with Ru extrudates. The best catalyst giving the highest menthol yield and a low amount of acyclic hydrogenation products was Ru-beta-bentonite extrudates where Ru was located randomly in the mixture of 70% H-beta-25 and 30% bentonite binder. Hydrogenation was more prominent for Pt than for Ru catalysts, most probably due to their higher hydrogenation ability. Stereoselectivity to menthol varied in the trickle bed reactor in the range of 67 to 73%. In a batch reactor for Ru- and Pt-catalysts independent of support acidity, it was in the range of 70–71%. The reuse of Ru/H-beta-300 extrudates was successfully demonstrated.

The present work is focused on the improvement of an effective approach to tailor the acidity of silica alumina composite. SBA-15 was selected based on high surface area, uniform porosity and large mesopores. Modification of SBA-15 was performed to improve both Lewis and Bronsted acidities and hence catalyst activity. Therefore, introduction of alumina as a co-catalyst was carried out to enhance Lewis acid sites through its incorporation into the silica network. Evaporation impregnation method was evaluated for incorporation of aluminium to SBA-15 and materials with different SiO2/Al2O3 ratios were prepared. Acidity and morphological features of the materials were assessed using XRD, EDX, SEM, TEM, N2-physisorption, 27Al MAS-NMR and FTIR with pyridine. Bronsted acidity was attained by the introduction of sulfonic acid groups in the final catalyst via the post-synthesis grafting method. Therefore, the balanced Lewis and Bronsted acidities and proper porosity of modified SBA-15 led to its efficient performance in the conversion of glucose as a biomass-based model component to levulinic acid.

Pulse field gradient NMR technique was used to determine self-diffusivity of heptane and pentadecane at room temperature for microporous catalysts, used both as powders and shaped with a binder extrudates. The results showed that diffusivities increased with increasing specific surface area, micro- and mesopore volume of the studied catalysts. The presence of Bindzil binder together with H-Beta-25 decreased hydrocarbon diffusivities. Self-diffusivities of heptane and pentadecane were smaller for extrudates than for the powder catalysts. The detailed information about mass transfer limitations is needed to further process optimization since effective diffusivity is directly correlated with self-diffusion coefficients. The estimates of the ratio of porosity and tortuosity were also determined. The diffusion measurements with relatively long observation times Δ (20 up to 1000 ms) and catalysts fully immersed in pentadecane revealed that a small portion of sites exhibits very small diffusivities in H-Beta-25-Bindzil extrudates, which is correlated with a low ratio of mesopore to micropore volumes of this material.

Glioblastoma (GB) is the most frequent malignant tumor originating from the central nervous system. Despite breakthroughs in treatment modalities for other cancer types, GB remains largely irremediable due to its high degree of intratumoral heterogeneity, infiltrative growth, and intrinsic resistance towards multiple treatments. These resistant and aggressive sub-populations of GBs including the glioblastoma stem cells (GSCs) can circumvent treatment. GSCs act as a reservoir of cancer-initiating cells; they are a major challenge for successful therapy. We have discovered, as opposed to well-reported anti-cancer drug based therapeutical approach for GB therapy, the role of polyethylenimine (PEI) in inducing selective death of patient-derived GSCs via lysosomal membrane rupturing. Even at very low doses (1 ug/ml), PEI surface-functionalized mesoporous silica nanoparticles (PEI-MSNs), without any additional anti-cancer drug, very potently and selectively killed multiple GSC lines. Very importantly, PEI-MSNs did not affect the survival of well-established GB cells, or other type of cancer cells even at 25x higher doses. Remarkably, any sign of predominant cell death pathways such as apoptosis and autophagy was absent. Instead, as a potential explanation for their GSC selective killing function, we demonstrate that the internalized PEI-MSNs accumulated inside the lysosomes, subsequently causing a rupture of the vulnerable lysosomal membranes, exclusively in GSCs. As a further evaluation, we observed blood-brain-barrier (BBB) permeability of these PEI-MSNs in vitro and in vivo. Taking together the recent indications for the vulnerability of GSCs for lysosomal targeting, and GSC selectivity of the PEI-MSNs described here, the results suggest that PEI-functionalized nanoparticles could have a potential role in the eradication of GSCs.

Correlative light and electron microscopy (CLEM) is revolutionizing how cell samples are studied. CLEM provides a combination of the molecular and ultrastructural information about a cell. For the execution of CLEM experiments, multimodal fiducial landmarks are applied to precisely overlay light and electron microscopy images. Currently applied fiducials such as quantum dots and organic dye-labeled nanoparticles can be irreversibly quenched by electron beam exposure during electron microscopy. Generally, the sample is therefore investigated with a light microscope first and later with an electron microscope. A versatile fiducial landmark should offer to switch back from electron microscopy to light microscopy while preserving its fluorescent properties. Here, we evaluated green fluorescent and electron dense nanodiamonds for the execution of CLEM experiments and precisely correlated light microscopy and electron microscopy images. We demonstrated that green color emitting fluorescent nanodiamonds withstand electron beam exposure, harsh chemical treatments, heavy metal straining, and, importantly, their fluorescent properties remained intact for light microscopy.