In this paper, we have reported an investigation on the evolution of nitrogen structures in diamond crystals which contain nitrogen donor atoms in the range of 1500 ppm-1600 ppm following an annealing treatment at a h...In this paper, we have reported an investigation on the evolution of nitrogen structures in diamond crystals which contain nitrogen donor atoms in the range of 1500 ppm-1600 ppm following an annealing treatment at a high pressure of about 6.5 GPa and high temperatures of 1920 K-2120 K. The annealing treatment was found to completely transform nitrogen atoms originally arranged in a single substitutional form （C-center）, into a pair form （A-center）, indicated from infrared （IR） spectra. The photoluminescence （PL） spectra revealed that a small fraction of nitrogen atoms remained in C-center form, while some nitrogen atoms in A-center form were further transformed into N3 and H3 center structures. In addition, PL spectra have revealed the existence of two newly observed nitrogen-related structures with zero phonon lines at 611 nm and 711 nm. All these findings above are very helpful in understanding the formation mechanism of natural diamond stones of the Ia-type, which contains nitrogen atoms in an aggregated form.展开更多
Aim: We demonstrated the risk of developing islet autoantibodies-Insulin Autoanti-bodies (IAAs) and Islets cell Autoantibodies (ICAs)-in type-1 diabetic relatives and newly diagnosed type-1 patients compared to non-di...Aim: We demonstrated the risk of developing islet autoantibodies-Insulin Autoanti-bodies (IAAs) and Islets cell Autoantibodies (ICAs)-in type-1 diabetic relatives and newly diagnosed type-1 patients compared to non-diabetic controls. We also aimed to determine the predictive strengths of both autoantibodies in the development of type-1 diabetes mellitus, and which of the two autoantibodies is a better predictive marker of type-1 diabetes mellitus among Nigerian adults. Methodology: A total number of four hundred and fifty five (455) subjects (211 (46%) males, and 244 (54%) females) aged between 35 - 76 years were recruited for the study. IAA and ICA levels were estimated using ELISA reagents from Biomerica Inc. Other parameters such as fasting blood sugar, urine glucose, and urine protein were assessed using standard biochemical techniques. Results: Relatives of type-1 diabetic patients and newly diagnosed type-1 diabetic patients were at greater risk (p < 0.05) of testing positive for more than one autoantibody (ICA and IAA) compared to non-diabetic controls. In addition, IAAs appeared to be better predictors or markers of type-1 diabetes mellitus compared to ICAs. Conclusion: The present study indicated a greater risk of autoim-mune destruction of the insulin producing beta cells of the pancrease of the type-1 relatives and newly diagnosed type-1 patients and suggests the need for periodic re-cruitment of individuals in the general population, siblings and relatives of type-1 diabetic patients for planned intervention trials. In addition, IAAs appeared to be better autoimmune markers of type-1 diabetes compared to ICAs.展开更多
基金Project supported by the Natural Science Foundation of Heilongjiang Province,China(Grant No.E201341)the Open Research Program of Key Lab of Superhard Materials of Mudanjiang Normal College,China(Grant No.201302)
文摘In this paper, we have reported an investigation on the evolution of nitrogen structures in diamond crystals which contain nitrogen donor atoms in the range of 1500 ppm-1600 ppm following an annealing treatment at a high pressure of about 6.5 GPa and high temperatures of 1920 K-2120 K. The annealing treatment was found to completely transform nitrogen atoms originally arranged in a single substitutional form （C-center）, into a pair form （A-center）, indicated from infrared （IR） spectra. The photoluminescence （PL） spectra revealed that a small fraction of nitrogen atoms remained in C-center form, while some nitrogen atoms in A-center form were further transformed into N3 and H3 center structures. In addition, PL spectra have revealed the existence of two newly observed nitrogen-related structures with zero phonon lines at 611 nm and 711 nm. All these findings above are very helpful in understanding the formation mechanism of natural diamond stones of the Ia-type, which contains nitrogen atoms in an aggregated form.
文摘Aim: We demonstrated the risk of developing islet autoantibodies-Insulin Autoanti-bodies (IAAs) and Islets cell Autoantibodies (ICAs)-in type-1 diabetic relatives and newly diagnosed type-1 patients compared to non-diabetic controls. We also aimed to determine the predictive strengths of both autoantibodies in the development of type-1 diabetes mellitus, and which of the two autoantibodies is a better predictive marker of type-1 diabetes mellitus among Nigerian adults. Methodology: A total number of four hundred and fifty five (455) subjects (211 (46%) males, and 244 (54%) females) aged between 35 - 76 years were recruited for the study. IAA and ICA levels were estimated using ELISA reagents from Biomerica Inc. Other parameters such as fasting blood sugar, urine glucose, and urine protein were assessed using standard biochemical techniques. Results: Relatives of type-1 diabetic patients and newly diagnosed type-1 diabetic patients were at greater risk (p < 0.05) of testing positive for more than one autoantibody (ICA and IAA) compared to non-diabetic controls. In addition, IAAs appeared to be better predictors or markers of type-1 diabetes mellitus compared to ICAs. Conclusion: The present study indicated a greater risk of autoim-mune destruction of the insulin producing beta cells of the pancrease of the type-1 relatives and newly diagnosed type-1 patients and suggests the need for periodic re-cruitment of individuals in the general population, siblings and relatives of type-1 diabetic patients for planned intervention trials. In addition, IAAs appeared to be better autoimmune markers of type-1 diabetes compared to ICAs.
