Mechanochemically Enhanced Synthesis Of Isomorphously Substituted Kaolinites

A mechanochemical method for the rapid, bulk synthesis of kaolinite has been developed. Metal hydroxides and silicic acid are mechanically ground and hydrothermally treated for as little as a day at 250 °C to produce X-ray pure crystalline materials. This approach has been expanded to allow the synthesis of kaolinites with a portion of the aluminum sites isomorphously substituted with other trivalent metals. The synthetic parameters, such as length of mechanical and hydrothermal treatment, were studied. Products were analyzed by powder X-ray diffraction, attenuated total reflectance infrared spectrometry, scanning electron microscopy, and transmission electron microscopy. The samples exhibited strong order along the c axis and less order along the a and b axes. Trivalent transition and rare earth metals were used to replace aluminum in the structure. These metals included Cr, La, Ce, Pr, Nd, Eu, Gd, Ho, and Er. Cerium (III) substituted kaolinite was successfully synthesized utilizing air-free conditions. This approach allows bulk quantities of substituted kaolinites to be prepared in a relatively short amount of time and offers a new route to synthesize pure and substituted kaolinites that may have novel catalytic properties. © 2011 Elsevier B.V

Mechanochemically enhanced synthesis of isomorphously substituted kaolinites

A mechanochemical method for the rapid bulk synthesis of kaolinte has been developed. Metalhydroxides and silicic acid are mechanically ground and hydrothermally treated for as little as a day at 250C to produce X-ray pure crystalline materials. This approach has been expanced to allow the synthesis of kaolinites with a portion of the aluminium sites isomorphously substituted with other trivalent metals. The synthetic parameters, such as length of mechanical and hydrothermal treatment, were studied. Products were analyzed by powder X=ray diffraction, attenuated total reflectance infrared spectrometry, scanning electron microscopy, and transmission electron microscopy. The samples exhibited strong order along the c axis and less order along the a and b axes. Trivalent transition and rare earth metals were used to replace aluminum in the structure. These metals included Cr, La, Ce, Pr, Nd, Eu Gd, Ho, and Er. Cerium (III) substituted kaolinite was sucessfully synthesized using air-free conditions. This approach allows bulk quantities of substituted kaolinites to be prepared in a relatively short amount of time and offers a new route to synthesize pure and substituted kaolinites that may have novel catalytic properties

Total Colonic Hirschsprung\u27s Disease: The Hypermotility and Skin Rash Protocol

© 2020 American Medical Association. All rights reserved. Introduction Total colonic Hirschsprung\u27s disease (TCHD) presents a postoperative challenge due to multiple stools and perineal rash. We propose a protocol developed by pediatric surgeons and ostomy nurses to help prevent and treat hypermotility and severe perineal rash, especially in younger children who are not toilet trained. Materials and Methods We retrospectively reviewed our TCHD patients\u27 charts from 2014 to 2017. All patients received a prescribed protocol for the treatment of hypermotility and perineal rash. We describe patients who underwent their pull through before and after the age of urine toilet training, and assessed the number of bowel movements, the perineal skin status, and growth. Results We treated 25 patients. Out of 25, 9 patients received a straight ileoanal pull through before the age of 18 months. Nine of 25 patients presented for a second opinion and had redo pull through. The remaining seven presented for bowel management after having a pull through at another institution. All these were treated following the hypermotility protocol. In total, 19 of 25 patients were not toilet trained. The mean number of bowel movements in all groups was 4 (3-5). All had a resolution of perineal rash and liquid stools after 3 months. Eleven of the 25 patients presented with failure to thrive. Two older patients experienced severe proctalgia requiring replacement of the ileostomy. Conclusion TCHD patients who underwent definitive pull through had nine high incidence of multiple stool, perineal rash, and low growth. With the implementation of bowel management care to slow the stools and a perineal skin protocol to treat the skin, we believe that these symptoms can be minimized even in patients who are not toilet trained. Since the implementation of this protocol, we have changed our practice to perform the pull through in such patients between the age of 6 and 18 months