scholarly journals Understanding the Salt-Dependent Outcome of Glycine Polymorphic Nucleation

Pharmaceutics ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 262
Author(s):  
Guangjun Han ◽  
Pui Shan Chow ◽  
Reginald B. H. Tan

The salt-dependent polymorphs of glycine crystals formed from bulk solutions have been a longstanding riddle. In this study, in order to shed fresh light, we studied the effects of seven common salts on primary nucleation of the metastable α-glycine and the stable γ-glycine. Our nucleation experiments and in-depth data analyses enabled us to reveal that (NH4)2SO4, NaCl and KNO3, in general, promote γ-glycine primary nucleation very significantly while simultaneously inhibiting α-glycine primary nucleation, thereby explaining why these three salts induce γ-glycine readily. In comparison, Ca(NO3)2 and MgSO4 also promote γ-glycine and inhibit α-glycine primary nucleation but not sufficiently to induce γ-glycine. More interestingly, Na2SO4 and K2SO4 promote not only γ-glycine but also α-glycine primary nucleation, which is unexpected and presents a rare case where a single additive promotes the nucleation of both polymorphs. As a result, the promoting effects of Na2SO4 and K2SO4 on γ-glycine do not enable γ-glycine nucleation to be more competitive than α-glycine nucleation, with γ-glycine failing to appear. These observations help us to better understand salt-governed glycine polymorphic selectivity.

Author(s):  
S. K. Peng ◽  
M.A. Egy ◽  
J. K. Singh ◽  
M.B. Bishop

Electron microscopy and energy dispersive x-ray microanalysis (EDXA) are found to be very useful tools for identification of etiologic agents in pneumoconiosis or interstitial pulmonary disorders. Pulmonary interstitial fibrosis and granulomatosis are frequently associated with occupational and environmental pollution. Numerous reports of pneumoconiosis in various occupations such as coal and gold miners are presented in the literature. However, there is no known documented case of pulmonary changes in workers in the sandpaper industry. This study reports a rare case of pulmonary granulomatosis containing deposits from abrasives of sandpaper diagnosed by using EDXA.


2015 ◽  
Vol 21 ◽  
pp. 143
Author(s):  
Elizabeth Sanchez Rangel ◽  
Maria Moscoso Cordero ◽  
Vinuta Mohan ◽  
Tasneem Zahra

2015 ◽  
Vol 21 ◽  
pp. 6
Author(s):  
Roy Guinto ◽  
Michele Ledoux ◽  
Alicia Williams ◽  
Anthony Mark

2016 ◽  
Vol 22 ◽  
pp. 176-177
Author(s):  
Sudhamshi Toom ◽  
Elizabeth Sedlis Singer

2016 ◽  
Vol 22 ◽  
pp. 278
Author(s):  
Anne Bacal ◽  
Nour Batarseh ◽  
Erin Drever ◽  
Tahira Yasmeen

2006 ◽  
Vol 12 ◽  
pp. 96-97
Author(s):  
Mihaela Cosma ◽  
Daniel L. Hurley

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