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Beckmann rearrangement of three kinds of oximes to lactams on MFI zeolite nanosheets was investigated to elucidate the catalytic reaction sites, silanols.

Mesoporous zeolite-supported Pt3Y catalyst deactivates slowly in propane dehydrogenation, maintaining high propane conversion and propylene selectivity, but the formation of the intermetallic compound requires atomistic migration of yttrium through silanol nests on the zeolite. Compared to the cumbersome generation of silanols via framework demetallation, we report a direct synthesis of mesoporous MFI zeolite possessing silanol nests. The synthesis procedure employed a diammonium-type bromide surfactant [C18H37 N(CH3)2 C6H12 N(CH3)2 C4H9Br2] and a sodium-free silica source. The basicity of the synthesis mixture was adjusted by the addition of readily available N(CH3)4OH, instead of converting the surfactant to hydroxyl form. The presence of silanol nests in the resultant zeolite was confirmed by IR and NMR spectroscopies. When the zeolite was supported with 0.50 wt% Pt and 0.50 wt% Y using nitrate precursors, a remarkably long catalytic lifetime of 20 days was obtained with high propane conversion and propylene selectivity under the reaction condition using neat propane gas at 853 K.

A PtZn alloy nanoparticle catalyst for propane dehydrogenation was synthesized by simple coimpregnation of Pt(NH3)4(NO3)2 with Zn(NO3)2 onto a mesoporous material, which was built with siliceous MF...

Confining Au nanoparticles (NPs) in a restricted space (

Platinum is a much used catalyst that, in petrochemical processes, is often alloyed with other metals to improve catalytic activity, selectivity and longevity1-5. Such catalysts are usually prepared in the form of metallic nanoparticles supported on porous solids, and their production involves reducing metal precursor compounds under a H2 flow at high temperatures6. The method works well when using easily reducible late transition metals, but Pt alloy formation with rare-earth elements through the H2 reduction route is almost impossible owing to the low chemical potential of rare-earth element oxides6. Here we use as support a mesoporous zeolite that has pore walls with surface framework defects (called 'silanol nests') and show that the zeolite enables alloy formation between Pt and rare-earth elements. We find that the silanol nests enable the rare-earth elements to exist as single atomic species with a substantially higher chemical potential compared with that of the bulk oxide, making it possible for them to diffuse onto Pt. High-resolution transmission electron microscopy and hydrogen chemisorption measurements indicate that the resultant bimetallic nanoparticles supported on the mesoporous zeolite are intermetallic compounds, which we find to be stable, highly active and selective catalysts for the propane dehydrogenation reaction. When used with late transition metals, the same preparation strategy produces Pt alloy catalysts that incorporate an unusually large amount of the second metal and, in the case of the PtCo alloy, show high catalytic activity and selectivity in the preferential oxidation of carbon monoxide in H2.

Catalytic cascade reactions are strongly desired as a potential means of combining multistep reactions into a single catalytic reactor. Appropriate catalysts composed of multi-reactive sites to catalyze cascade reactions in a sequential fashion are central to such efforts. Here, we demonstrate a bifunctional zeolite catalyst with close proximity of Bronsted and Lewis acid sites through the synthesis of a mesoporous ZrO2[Al]MFI nanosponge (NS). The unique mesopores of the MFI-NS allow the confinement of zirconium oxide clusters (Lewis acid sites, LA) within the few-unit-cell-thin MFI aluminosilicate zeolite wall (Bronsted acid sites, BA). Such a structure is clearly distinct from the conventional MFI zeolite, where the agglomeration of zirconium oxide clusters onto the external surface area within the crystal bulk is not possible, resulting in segregated BA and LA sites on the internal and external zeolite, respectively. By bringing the BA and LA within ZrO2[Al]MFI-NS 30, we uncovered a more efficient catalytic route for the conversion of furfural (100% within 2 h) to γ-valerolactone (GVL) (83%). This route is only evident when the long molecular diffusion path, in the most extreme case of physically mixed ZrO2-(LA) and Al-zeolites (BA) (45% of GVL yield), is eliminated. Unlike the bifunctional ZrO2–Al-beta (GVL yield of 75%), where the BA concentration is greatly compromised at the expense of LA formation, we also show that the ZrO2[Al]MFI-NS is able to maintain a high density and good stability of both types of acids.

Although low-cost, high-surface-area crystalline aluminosilicate zeolites have been recognized as promising adsorbents for the capture of volatile organic compounds (VOCs), their hydrophilic nature leads to a significant loss of performance owing to the ubiquitous presence of water vapor in the VOC stream. Herein, the aluminosilicate zeolites (i.e., mordenite and nanocrystalline β) are functionalized via a solvothermal post-treatment with methyl iodide as the grafting agent. The methyl groups are primarily attached to the zeolite internal surface via covalent bonding between internal bridging O and -CH3, as evidenced by multiple analysis data. The static isotherms and diffusional studies clearly reveal a remarkable decrease in both the rate of water adsorption and the water affinity due to the attachment of methyl groups to the micropore walls, thus enhancing the water tolerance compared to that of pristine zeolites. In addition, CH3I-functionalized zeolites are investigated as adsorbents for the removal of benzene under dry and humid conditions, and their performance is compared to that of CH3Si(-OCH3)3-functionalized zeolites, wherein the methyl groups have been grafted onto the external surface. The results demonstrate that, although the benzene adsorption capacity under dry conditions is decreased upon internal surface functionalization, the loss of VOC adsorption capacity in the presence of H2O vapor is effectively prevented. By contrast, external surface functionalization is ineffective for preventing the negative effects of moisture upon the benzene adsorption capacity. As a result, CH3I-functionalized zeolites exhibit superior dynamic adsorption performance for benzene at 318 K under humid conditions (relative humidity: 80%), with a saturated adsorption capacity of 64.9 mg g-1. This work provides an easy strategy for tailoring the adsorption properties of aluminosilicate zeolites for adsorption/separation and other advanced applications.

An aluminosilicate beta zeolite with a Si/Al ratio of 12.5 was post-functionalized with aryl diazonium derivatives to yield organic-functionalized zeolites. By grafting with different functional groups, we engineered zeolite micropore walls integrating various moieties, ranging from hydrophobic to hydrophilic and from basic to acidic units, with controllable loading contents. This approach enables the tailored development of various beta zeolites with systematically tuned porosities and functionalities while retaining the zeolite crystallinity. We show that this strategy can be used for the efficient screen for a suitable pore environment for CO2 adsorption under humid conditions. The grafting of benzene onto the zeolite pore walls makes the pore environment hydrophobic, preventing losses of CO2 adsorption capacity by the H2O vapor (CO2 adsorption capacity: 0.130 mmol g−1 without humid vs 0.122 mmol CO2 g−1 with humid). The CO2 uptake was enhanced by introducing various functional groups (e.g., –OH, –NH2, –COOH) able to interact with CO2. Among the modified zeolites, the benzylamine-functionalized beta framework exhibited the highest CO2 uptake of 1.28 mmol g−1 at 10.5 kPa and 20 ℃, which is 48.3% higher than that of the pristine zeolite (0.863 mmol g−1). Furthermore, the benzylamine-functionalized beta zeolite exhibited higher CO2 adsorption than its pristine counterpart under flue gas conditions (composition: 10.5% CO2, 5% H2O, 84.5% N2), which might be attributed to the synergistic effect of the hydrophobic benzene and basic amine moieties in the benzylamine group. The engineering of zeolite micropore walls by post-synthetic functionalization is expected to extend the application of zeolites to challenging adsorption and separation processes.

Hydroisomerization of linear paraffins to branched isomers is an important petrochemical process, which commonly uses a microporous zeolite catalyst supported with Pt metal nanoparticles. Although attempts were made in the past to find an alternative to costly Pt, replacement with low-cost metals was not successful for conventional bulk zeolites, due to the low metal dispersion resulting in poor catalytic performance. Here, we demonstrate that Ni can replace Pt when it is supported on zeolites with uniform mesopores. Ni-supported MFI-, *MRE-, and TON-type zeolites possessing mesopores showed the same or even better catalytic performance in comparison to that of Pt-supported conventional MFI, *MRE, and TON zeolites, respectively. The Ni-supported zeolites exhibited even better branched isomer yields, despite low Ni loading. This result is ascribed to the confinement or sandwiching effect of Ni nanoparticles by the mesopore walls in the zeolites, which stabilizes the highly dispersed Ni nanoparticles.

High loading on a porous support is important for preparing high-performance metal catalysts, but the increased loading often results in a loss of dispersion and limited mass transfer. We approached this problem by supporting a large amount of metal or metal oxide on a hierarchically porous zeolite. The supported catalyst formed an embedded network of nanowires along the zeolite mesopores. Although tightly filled in the mesopores, the catalyst was readily accessible through microporous windows at the encasing mesopore walls. Cobalt, nickel, and TiO2, supported in this manner, exhibited high catalytic performance in Fischer–Tropsch synthesis, benzene hydrogenation, and furfural-to-γ-valerolactone conversion, respectively.

Zeolite solid-acid catalyst can produce p-xylene (PX) via a renewable synthetic route through Diels-Alder cycloaddition and dehydration reactions of bio-derived 2,5-dimethylfuran (DMF) and ethylene (DMF-to-PX). Here, to find a key factor in the physicochemical properties of a zeolite catalyst, we synthesized a series of mesoporous MFI zeolite nanosheets with systematically controlled thickness (2.5 and 7.5 nm) and silica-alumina ratio (Si/Al = 48–340) as well-defined model catalysts for PX production. From the catalytic results using these MFI zeolite nanosheets and conventional MFI zeolites, PX production yield was found to be strongly related to zeolite crystal thickness and concentration of Bronsted acid sites of the MFI zeolite catalysts. The MFI zeolite nanosheet with small thickness provided high PX production due to the presence of Bronsted acid sites on the exterior surface and facile mass transfer of aromatic compounds through mesopores. To verify these catalytic factors and to apply it to commercially available zeolite, a mesoporous MFI zeolite was prepared from a commercial ZSM-5 zeolite via a simple post-treatment process; mesoporous MFI-type zeolites were tested in the DMF-to-PX reaction. This mesoporous MFI zeolite exhibited a superior PX yield (75.8%) with high DMF conversion and PX selectivity compared with those characteristics of pristine MFI zeolite (PX yield = 8.4%).

A cobalt-silica hybrid nanocatalyst bearing small cobalt particles of diameter ~5 nm was prepared through a hydrothermal reaction and hydrogen reduction. The resulting material showed very high CO conversion (>82%) and high hydrocarbon productivity (~1.0 gHC·g−1 cat·h−1) with high activity (~8.5 × 10−5 molCO·g Co −1 ·s−1) in the Fischer–Tropsch synthesis reaction.

Platinum is a much used catalyst that, in petrochemical processes, is often alloyed with other metals to improve catalytic activity, selectivity and longevity

MFI zeolite nanosheets (NS-MFI) with two different thicknesses (2.5 nm and 7.5 nm) and various Si/Al2 ratios (100–700) were prepared and their catalytic activities for propylene production from methanol were investigated. According to analyses of X-ray diffraction patterns as well as scanning electron microscopy, transmission electron microscopy, and N2 adsorption results, all NS-MFI catalysts had a well-developed nanosheet structure with a high specific surface area and a large mesopore volume. In the methanol-to-propylene (MTP) reaction, they showed greater activity and selectivity to propylene and longer lifetimes than commercial ZSM-5. Among these NS-MFI zeolites, thinner NS-MFI had better catalytic activity in MTP reactions than thicker NS-MFI at the same Si/Al2 ratio, and superior catalytic performance for MTP reactions was observed at a Si/Al2 ratio of 500. These results can be attributed to the appropriate acid density and the facile diffusion of molecules in the NS-MFI catalysts.

Post-synthetic Al grafting onto the surface silanols in mesoporous MFI zeolite has been investigated in an attempt to obtain a model catalytic material that possesses strong Bronsted acid sites at mesopore surfaces of the zeolite, but not inside the microporous framework. To this end, a siliceous MFI zeolite with a mesopore/micropore hierarchy was synthesized using a meso-micro dual structure-directing diammonium surfactant. The hierarchically porous zeolite was treated with anhydrous AlCl3 for the formation of Si–O–Al bonding with silanols on the mesopore surfaces. According to solid-state 31P NMR spectroscopy of the surface-adsorbed phosphine oxides and catalytic activity for decalin cracking, the Al-grafting treatment performed in the conventional manner resulted in the formation of weak Bronsted acid sites, similar to Al grafting on SBA-15 mesoporous silica. To obtain strong Bronsted acid sites, we have developed a method of heating the AlCl3-grafted zeolite in a controlled-humidity chamber before calcination. The resultant zeolite was catalytically active for cracking of hydrocarbons requiring strong acid sites, but not for methanol-to-hydrocarbon conversion. The results support that the moisture treatment caused a local reconstruction of the initially grafted Al–O–Si framework portion to a strong Bronsted acid site. In addition, our model catalytic zeolite material unveiled the catalytic activity of Bronsted acid sites at the mesopore surfaces in hierarchically porous zeolite in n-octane cracking. Furthermore, we confirmed that this method was effective for other mesoporous MFI zeolites obtained through a post-synthetic desilication route.

Breast cancer stem cells (BCSCs) are a small subpopulation of breast cancer cells that have been proposed to be a primary cause of failure of therapies, including ionizing radiation (IR). Their embryonic stem-like signature is associated with poor clinical outcome. In the present study, the function of octamer-binding transcription factor 4 (Oct4), an embryonic stem cell factor, in the resistance of BCSCs to IR was investigated. Mammosphere cells exhibited increased expression of stemness-associated genes, including Oct4 and sex‑determining region Y‑box 2 (Sox2), and were more resistant to IR compared with serum-cultured monolayer cells. IR‑resistant MCF7 cells also exhibited significantly increased expression of Oct4. To investigate the possible involvement of Oct4 in IR resistance of breast cancer cells, cells were transfected with Oct4. Ectopic expression of Oct4 increased the clonogenic survival of MCF7 cells following IR, which was reversed by treatment with small interfering RNA (siRNA) targeting Oct4. Oct4 expression decreased phosphorylated histone H2AX (γ-H2AX) focus formation and suppressed IR‑induced premature senescence in these cells. Mammosphere, IR‑resistant and Oct4‑overexpressing MCF7 cells exhibited enhanced phosphorylation of signal transducer and activation of transcription 3 (STAT3) (Tyr705) and inhibitor of nuclear factor κB (NF‑κB), and blockade of these pathways with siRNA against STAT3 and/or specific inhibitors of STAT3 and NF‑κB significantly increased IR‑induced senescence. Secretome analysis revealed that Oct4 upregulated interleukin 24 (IL‑24) expression through STAT3 and NF‑κB signaling, and siRNA against IL‑24 increased IR‑induced senescence, whereas recombinant human IL‑24 suppressed it. The results of the present study indicated that Oct4 confers IR resistance on breast cancer cells by suppressing IR‑induced premature senescence through STAT3- and NF‑κB-mediated IL‑24 production.

Fluorescence recovery after photobleaching (FRAP) is a well-established method commonly used to measure the diffusion of fluorescent solutes and biomolecules in living cells or tissues. Here a fiber-optic-based FRAP (f-FRAP) system was developed, and validated using macromolecules in water and agarose gels of different concentrations. We applied f-FRAP to measure the site-specific diffusion of fluorescein (NaFluo) in peritoneal membranes (PMs) on the liver, cecum, and kidney of a living rat during peritoneal dialysis. Diffusion of fluorescein in PM varied in a time-dependent manner according to the type of organ ( $D_{PM\;on\;Liver}/D_{NaFluo}=0.199{\pm}0.085$ , $D_{PM\;on\;Cecum}/D_{NaFluo}=0.292{\pm}0.151$ , $D_{PM\;on\;Kidney}/D_{NaFluo}=0.218{\pm}0.110$ ). The proposed method allows direct quantitative measurement of the three-dimensional diffusion in local PM in vivo, which was previously inaccessible by peritoneal function test methods such as peritoneal equilibration test (PET) and standardized PM assessment (SPA). f-FRAP is promising for local and dynamic assessments of peritoneal pathophysiology and the mass transport properties of PMs, presumed to be affected by variation of tissue structures over different organs and functional changes of the PM with years of peritoneal dialysis.

We investigated the effects of mesopore generation in a MFI zeolite when used as a catalyst in liquid-phase Friedel–Crafts acylation reactions of bulky aromatic compounds. For this investigation, we obtained an MFI zeolite with nanosponge morphology, following a seed-assisted hydrothermal synthesis route using C22H45–N+(CH3)2–C6H12–N+(CH3)2–C6H13. The zeolite nanosponge exhibited a narrow distribution of mesopore diameters centered at 4 nm, in which the mesopores were built with a disordered network of 2.5-nm thick MFI zeolite layers. This zeolite exhibited high catalytic performance in various acylation reactions, compared with bulk MFI zeolites, beta zeolite and mesoporous materials composed of amorphous aluminosilicates. The high catalytic performance corresponded to the strong Bronsted acid sites existing on the mesopore walls.

A zeolite nanosponge possessing MFI framework type was hydrothermally prepared by a seed-assisted synthesis method using C22H45–N+(CH3)2–C6H12–N+(CH3)2–C6H13 as a structure-directing agent. The nanosponge morphology was composed of a three-dimensional disordered network of MFI nanolayers with 2.5 nm thickness supporting each other. Catalytic performance of the MFI nanosponge was investigated in the Pechmann condensation of bulky reactants (pyrogallol and resorcinol) with ethyl acetoacetate and compared with conventional zeolites MFI, BEA, and USY) and also layered MFI, pillared MFI, and self-pillared MFI. The investigation revealed outstanding catalytic performance of the MFI nanosponge, which can be attributed to the contribution of strong acid sites located on the external surfaces accessible for the reaction of bulky reactants.

A zeolite nanosponge was obtained by a seed-assisted hydrothermal synthesis route using C22H45–N+(CH3)2–C6H12–N+(CH3)2–C6H13 as the structure-directing agent. The zeolite was composed of disordered network of 2.5-nm-thick MFI zeolite nanolayers having a narrow distribution of mesopore diameters centered at 4 nm. The highly mesoporous texture (mesopore volume = 0.5 cm3 g–1) was suitable for supporting cobalt nanoparticles with a narrow distribution of particle diameters centered at 4 nm. The Co/MFI zeolite exhibited high stability of the Co nanoparticles against particle growth, and there was accordingly high catalytic conversion of carbon monoxide to hydrocarbons and long catalytic lifetime in the Fischer–Tropsch synthesis. Furthermore, the Co/MFI catalyst exhibited high selectivity for branched hydrocarbons in the gasoline range (C5–C11), compared to conventional alumina-based catalysts. This high selectivity could be attributed to hydroisomerization in the extremely thin zeolite frameworks that provided...

Skeletal muscle atrophy results from the net loss of muscular proteins and organelles and is caused by pathologic conditions such as nerve injury, immobilization, cancer, and other metabolic diseases. Recently, ubiquitination-mediated degradation of skeletal-muscle-specific transcription factors was shown to be involved in muscle atrophy, although the mechanisms have yet to be defined. Here we report that ret finger protein (RFP), also known as TRIM27, works as an E3 ligase in Pax7-induced degradation of MyoD. Muscle injury induced by sciatic nerve transection up-regulated RFP and RFP physically interacted with both Pax7 and MyoD. RFP and Pax7 synergistically reduced the protein amounts of MyoD but not the mRNA. RFP-induced reduction of MyoD protein was blocked by proteasome inhibitors. The Pax7-induced reduction MyoD was attenuated by RFP siRNA and by MG132, a proteasome inhibitor. RFPΔR, an RFP construct that lacks the RING domain, failed to reduce MyoD amounts. RFP ubiquitinated MyoD, but RFPΔR failed to do so. Forced expression of RFP, but not RFPΔR, enhanced Pax7-induced ubiquitination of MyoD, whereas RFP siRNA blocked the ubiquitination. Sciatic nerve injury-induced muscle atrophy as well the reduction in MyoD was attenuated in RFP knockout mice. Taken together, our results show that RFP works as a novel E3 ligase in the Pax7-mediated degradation of MyoD in response to skeletal muscle atrophy.

Under foreign rule, indigenous collaborators pose a serious challenge that betrays the trust and faith of their compatriots with whom they have long shared experiences. This being the case, the question arises concerning how the occupied define “betrayal” and execute their sense of morality and justice against those considered as switching allegiance from being their fellow nationals to being considered as outsiders. For this analysis, I investigate the practice of the Korean news media under Japanese colonial rule, developing the concept of verbal caricature. I find that the indigenous media create outrageous verbal images of collaborators: (1) sinners, (2) pawns, and (3) criminals. By exploring the media's social justice under political constraint, this project contributes to the accumulation of knowledge on the unique practices of deviance-making, prompting a dialog between the two isolated research realms – social deviance and foreign occupation.

The use of left ventricular assist devices (LVADs) in treating patients with advanced heart failure restores cardiac output resulting in improved perfusion to multiple organ systems with important clinical benefits. Renal pathophysiology during LVAD support remains an evolving, poorly understood, and potentially dynamic problem. Changes in renal function after LVAD placement have been investigated in multiple studies with contradictory results. Renal dysfunction is common prior to LVAD placement, which complicates postoperative clinical outcomes. The purpose of this review is to assess the latest information regarding the effects of LVADs on renal function with regard to hemodynamics, physiology, pathology and clinical issues prior to and after placement of the devices. The review should then aid in identifying patients best suited to benefit from this technology and to refine the therapy to reduce associated risks.

Beta zeolite is known as an efficient catalyst for Friedel–Crafts alkylation. In liquid phase reactions, however, beta zeolite catalyst is often deactivated rapidly. We discovered that the maximum possible catalytic turnovers in benzene alkylation with benzyl alcohol could be increased by six times by using a beta zeolite with a nanosponge-like morphology, in comparison to bulk beta zeolites. The nanomorphic zeolite was obtained using a hydrothermal synthesis method which uses multiammonium surfactants as a meso–micro hierarchical structure-directing agent. The origins of the high catalytic performance were investigated by measuring the catalytic conversions after selectively poisoning acid sites located on external surfaces and in internal micropores selectively. The result indicated that the high catalytic performance was due to the alkylation reactions occurring on external surfaces. External active sites were able to perform the catalytic function even after active sites inside the zeolite micropores were deactivated. Similar results were obtained with other nanomorphic zeolites such as MFI nanosheets, MTW nanosponge and MRE nanosponge.

The first year of life is the most critical time period for structural and functional development of the human brain. Combining longitudinal MR imaging and finite strain theory, this study aimed to provide new insights into normal brain development through a biomechanical framework. Thirty-three normal infants were longitudinally imaged using MRI from 2 weeks to 1 year of age. Voxel-wise Jacobian determinant was estimated to elucidate volumetric changes while Lagrange strains (both normal and shear strains) were measured to reveal directional growth information every 3 months during the first year of life. Directional normal strain maps revealed that, during the first 6 months, the growth pattern of gray matter is anisotropic and spatially inhomogeneous with higher left-right stretch around the temporal lobe and interhemispheric fissure, anterior-posterior stretch in the frontal and occipital lobes, and superior-inferior stretch in right inferior occipital and right inferior temporal gyri. In contrast, anterior lateral ventricles and insula showed an isotropic stretch pattern. Volumetric and directional growth rates were linearly decreased with age for most of the cortical regions. Our results revealed anisotropic and inhomogeneous brain growth patterns of the human brain during the first year of life using longitudinal MRI and a biomechanical framework.

Platinum was supported on MFI-type (ZSM-5) zeolites with various crystal thicknesses ranging from 300 to 2 nm (i.e., from bulk crystal to nanosheet). Two series of Pt/MFI were prepared by the ion exchange of Pt ( NH 3 ) 4 2 + and the impregnation of colloidal Pt nanoparticles. The ion exchange yielded Pt nanoparticles that were supported inside zeolite pores, whereas the impregnation yielded Pt nanoparticles supported exclusively on the external crystal surfaces. The two series of Pt/MFI were used as catalysts for the hydroisomerization of n-heptane to investigate the effects of zeolite crystal thickness and Pt location. This research showed that the product selectivity to branched isomers could be significantly improved by decreasing zeolite crystal thickness to nanosheets. The selectivity improvement was attributed to short diffusion path lengths for branched products to escape before cracking.

The transition of historical actors from forgotten figures to subjects of reproach for their deeds is central to understanding the power of memory movements. In this article, we examine the public recollection of national “traitors” in Korea, focusing on the recent attempt of a South Korean research institute to create a biographical encyclopedia of pro-Japanese collaborators during the Japanese occupation of Korea from 1910 to 1945; the purpose of this enterprise is to establish a “patriotic” history of this period in Korean collective memory. Why and how did such a revisiting of history take place in the first decade of the twenty-first century? To answer this question, we examine not only the historical context that affects national memory but also the efforts of various groups to revive or suppress memory in light of nationalistic ideologies.

Nanomorphic *BEA, MTW, and *MRE zeolites were investigated as catalysts for isopropylation of benzene. From the deactivation pattern of the zeolites, we evaluated the contribution of external and internal active sites. These nanomorphic zeolites exhibited a high activity and long catalytic lifetime. Such catalytic properties can be explained by a large contribution of external sites, which have the advantage of slow deactivation.

Ventricular assist devices (VADs) are used to improve the systemic circulation and to decrease ventricular loading in patients with hemodynamic instability that is refractory to pharmacologic therapies. During an acute critical event, percutaneous devices are preferred because of their rapid deployment, since implantable devices require more extensive procedures. Implantable devices are used for patients with established end-stage heart failure as a bridge to heart transplantation, recovery or destination therapy. This report reviews mechanical principles and clinical studies regarding percutaneous VAD to address their potential renal effects. Since the focus of this study is set on devices that are dedicated to cardiac support only, extracorporeal membrane oxygenation systems are not included.

Introduction: Blood-membrane interaction during hemodialysis develops a secondary protein layer on the dialysis membrane surface, resulting in reduction of hemodialyzer performance. Wall shear stress at the surface of the hollow-fiber membrane is one of the determinant factors able to influence dialysis efficiency. Shaking of hemodialyzer during treatment could increase the wall shear stress of the membrane, which could enhance hemodialyzer performance. Methods: In this study, hemodynamic changes in hollow fibers were analyzed using computational fluid dynamics software for various shaking conditions of hemodialyzer (longitudinal, transverse, rotational motions). Results: Longitudinal motion induced reverse flow, while transverse motion induced symmetric swirling inside the hollow fiber. During rotational motions, nonuniform vortices were developed according to the rotational radius of the hollow fiber. These changes in flow pathlines induced by different shaking profiles increased the relative motion of blood, transmembrane pressure, and wall shear stress on dialysis membrane surfaces. Both longitudinal and transverse shaking profiles showed a linear relationship between shaking velocity (the product of amplitude and frequency) and wall shear stress. Conclusion: Performance of hemodialyzer can be enhanced with simple mechanical shaking motions, and optimal shaking profiles for clinical application can be investigated and predicted with the computational fluid dynamics model proposed in this study.

Extracorporeal organ support in patients with dysfunction of vital organs like the kidney, heart, and liver has proven helpful in bridging the patients to recovery or more definitive therapy. Mechanical ventilation in patients with respiratory failure, although indispensable, has been associated with worsening injury to the lungs, termed ventilator-induced lung injury. Application of lung-protective ventilation strategies are limited by inevitable hypercapnia and hypercapnic acidosis. Various alternative extracorporeal strategies, proposed more than 30 years ago, to combat hypercapnia are now more readily available. In particular, the venovenous approach to effective carbon dioxide removal, which involves minimal invasiveness comparable to renal replacement therapy, appears to be very promising. The clinical applications of these extracorporeal carbon dioxide removal therapies may extend beyond just lung protection in ventilated patients. This article summarizes the rationale, technology and clinical application of various extracorporeal lung assist techniques available for clinical use, and some of the future perspectives in the field.

Recently, new approaches for miniaturization and transportability of medical devices have been developed, paving the way for wearability and the possibility of implantation, for renal replacement therapies. A wearable artificial kidney (WAK) is a medical device that supports renal function during ambulation or social activities out of hospital. With the aim of improving dialysis patients' quality of life, WAK systems have been developed for several decades. However, at present there are a lot of technical issues confronting the attempt to apply WAK systems in clinical practice. This article focuses on technical requirements and potential solutions for WAKs and reviews up-to-date approaches related to dialysis membrane, dialysate regeneration, vascular access, patient-monitoring systems and power sources for WAKs.

The economic crisis of 2008–2010 stimulated an already growing sociological interest in finance. Before the crisis, disintermediation and securitization changed how the U.S. financial system operated, as bank operations shifted from the traditional originate-and-hold model to originate-and-distribute. During the 1980s and 1990s, the overall size and profitability of the financial system grew as deregulation unleashed financial innovation and reorganization. Global shifts toward capital market integration and liberalization created greater global interdependence. Households in the years before the crisis also altered their relationship to the financial system, increasing debt loads and overall exposure to the stock market. Research reveals the importance of politics for many financial market developments, various implications for corporate governance, the continuing significance of social factors within finance, and the role of theoretical and material devices in shaping financial practices. Key directions for future research focus on finance in relation to social inequality, informal sectors, valuation, and social networks.