From colloidal dispersions of zeolite monolayers to effective solid catalysts in transformations of bulky organic molecules : role of freeze-drying and dialysis

We investigated the properties and catalytic activity of zeolites with MWW topology obtained by unprecedented liquid exfoliation of the MCM-56 zeolite into solutions of monolayers and isolation/reassembly of the dispersed layers by various methods, with optional purification by dialysis or ammonium exchange. The layers were recovered by flocculation with alcohol or ammonium nitrate and freeze-drying. Flocculation alone, even with ammonium nitrate, did not ensure removal of residual sodium cations resulting in catalysts with low activity. Dialysis of the solutions with dispersed monolayers proved to be efficient in removing sodium cations and preserving microporosity. The monolayers were also isolated as solids by freeze-drying. The highest BET area and pore volume obtained with the freeze-dried sample confirmed lyophilization efficiency in preserving layer structure. The applied test reaction, Friedel–Crafts alkylation of mesitylene, showed high benzyl alcohol conversion due to increased concentration of accessible acid centers caused by the presence of secondary mesoporosity. The applied treatments did not change the acid strength of the external acid sites, which are the most important ones for converting bulky organic molecules. Zeolite acidity was not degraded in the course of exfoliation into monolayers, showing the potential of such colloid dispersions for the formation of active catalysts

Exogenous lipoid pneumonia (oil granulomas of the lung)

The authors observed three cases of exogenous lipid pneumonia clinically suspected of lung carcinoma. Histological examination of material after thoracotomy gave the possibility of correct diagnosis. The lesions in lungs were characteristic granulomas around lipid material and with surrounding advanced fibrosis

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Przezskórna embolizacja tętnicy nerkowej (PRAE, percutaneous renal artery embolisation) jest zabiegiem wykonywanym od ponad 40 lat [1] obarczonym niskim odsetkiem powikłań [2]. Trzeba jednak pamiętać, iż przy sporej atrakcyjności tego zabiegu dla chorego, niestety, nie ma dowodów potwierdzających korzystny wpływ PRAE na rokowanie odległe u chorych z rakiem nerki

The structure-catalytic activity relationship for the transient layered zeolite MCM-56 with MWW topology

Zeolite MCM-56 is a high alumina, monolayered form of the commercially useful framework MWW but it is a transient product during crystallization, so many factors influence its state and quality. This work examines properties of a series of MCM-56 and MCM-49 samples synthesized for different times using Aerosil, Ultrasil and Ludox as silica sources, hexamethyleneimine as the structure directing agent and additionally aniline as structure promoting agent. It was found that the most important parameter, governing the catalytic activity in the test reaction of Friedel-Crafts alkylation of mesitylene with benzyl alcohol, was availability of the Brønsted acid centers located at the external surfaces of the crystals. The key role in correlating physical characteristic with activity was played by infrared spectroscopy as it enabled the study of many properties of the tested materials, starting from the total concentration of acid centers, and their type (Brønsted or Lewis acids) through the concentration of centers available for the reagent molecules, to investigating the correlation of acidity with the degree of zeolite crystallinity

Alzheimer's disease - the role of nurses in patient care

Alzheimer's disease is the most common degenerative disorder of the brain resulting in dementia. It occurs most frequently among the elderly. This article presents the causes, effects and manner of developing the disease. Described above are the most important aspects of patient care. Particular attention was paid to the adaptation of housing, communication, rehabilitation, diet, forms of support for the patient and caregivers. Due to the nature of care they were also presented specific problems in health and the role of nurses has been determined