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BACKGROUND In order to quickly identify and screen high pressure and high temperature (HPHT) grown synthetic diamonds, a lot of research about their luminescent and spectral characteristics has been done. However, the comparative analysis is lacking, and less attention is paid to electrical and magnetic properties. OBJECTIVES To summarize the spectral characteristics and investigate the electrical and magnetic properties of HPHT synthetic diamonds systematically. METHODS Conventional gemological observation, high precision spectroscopy and electrical conductivity and magnetism testing were used for comparative analysis of 49 colorless and yellow samples. RESULTS The residual metal catalysts, including iron, cobalt, and nickel, caused the ferromagnetism of diamonds. All of the HPHT synthetic diamond samples could be attracted by the magnetic bar with magnetic intensity up to 12000Gs. The colorless samples were type Ⅱa+Ⅱb diamonds. The presence of boron led to its good conductivity, and the conductivity increased with increased boron content. The yellow samples were Ib+IaA type diamonds, and about one-third of the single nitrogen was converted into A aggregate. The synthetic diamond had undergone high temperature annealing treatment after growth. The ubiquitous presence of boron, and the presence of nitrogen mainly as single atoms and A aggregates led to the characteristic infrared spectra of HPHT synthetic diamonds. HPHT synthetic diamonds often contained crystal lattice defects caused by impurity elements such as nitrogen, nickel and silicon, which led to characteristic photoluminescence spectra. Colorless samples showed strong blue-green fluorescence and phosphorescence, whereas yellow samples had green fluorescence, with obvious cube-octahedron patterns. CONCLUSIONS Spectral and luminescent characteristics are still an important basis for screening and identification of HPHT synthetic diamonds. HPHT synthetic diamonds under the current growth technology also have obvious differences from natural diamonds in both conductivity and magnetism, which can be used as an auxiliary basis for rapid identification.

BACKGROUND As the world's largest producer of synthetic diamonds, China accounts for more than 90% of the world's total production, of which high pressure-high temperature (HPHT) synthetic diamonds are dominant. Previous scholars have conducted many studies on analytical methods and property analysis of HPHT synthetic diamonds. However, the research on the pickling process after the growth of HPHT synthetic diamonds and the internal and external micro-structures after pickling is still insufficient. OBJECTIVES To characterize 118 synthetic diamonds produced in China by high temperature and high pressure method. METHODS The HPHT synthetic diamonds were observed by laser scanning confocal microscopy (LSCM) and ultra-depth-of-field 3D microscopy, and the dark inclusions in these micro-structures were qualitatively analyzed by laser Raman spectroscopy. RESULTS Three structure types were found. Step-like growth structures with certain angles revealed the crystallographic characteristics of HPHT synthetic diamond poly-crystals. Near-parallel linear scratches reflected the contact relationship between diamond grains in the growth chamber. The 'rope-tied' structures reflected the growth rate of HPHT synthetic diamonds. CONCLUSIONS The micromorphology of these diamond surfaces reflects the growth conditions and environment of HPHT synthetic diamond gradient high temperature and continuous high pressure, which is of significance for the identification of HPHT synthetic diamonds.

Abstract Background Triglyceride/HDL cholesterol ratio (TG/HDL-C) is considered as a risk factor for cardiovascular events. Genetic components were important in controlling the variation in western countries. But the mode of inheritance and family aggregation patterns were still unknown among Asian-Pacific countries. This study, based on families recruited from community and hospital, is aimed to investigate the mode of inheritance, heritability and shared environmental factors in controlling TG/HDL-C. Results Two populations, one from community-based families (n = 988, 894 parent-offspring and 453 sibling pairs) and the other from hospital-based families (n = 1313, 76 parent-offspring and 52 sibling pairs) were sampled. The population in hospital-based families had higher mean age values than community-based families (54.7 vs. 34.0). Logarithmic transformed TG/ HDL-C values, after adjusted by age, gender and body mass index, were for genetic analyses. Significant parent-offspring and sibling correlations were also found in both samples. The parent-offspring correlation coefficient was higher in the hospital-based families than in the community-based families. Genetic heritability was higher in community-based families (0.338 ± 0.114, p = 0.002), but the common shared environmental factor was higher in hospital-based families (0.203 ± 0.042, p < 0.001). Commingling analyses showed that more than one-component distribution models were the best-fit models to explain the variance in both populations. Complex segregation analysis by regressive models revealed that in both samples the best-fit model of TG/HDL-C was the model of environmental effects plus familial correlation, in which significant parent-offspring and sibling correlations were demonstrated. Models of major gene effects were rejected in both samples. Conclusion Variations of TG/HDL-C in the normal ranges were likely to be influenced by multiple factors, including environmental and genetic components. Higher genetic factors were proved in younger community-based families than in older hospital-based families.

Surgical post-operative adhesions can lead to serious clinical complications. Barrier agent is the broad usage for the prevention of post-operative adhesions. This study aimed to evaluate the reducing adhesion efficacy of non-animal hyaluronic acid (HA) hydrogel in pigs undergoing conventional laparotomy pelvic surgery. HA hydrogel was applied to eighteen female pigs who underwent conventional laparotomy. The adhesion degrees and histopathology were evaluated in bilateral uterine horns as well as peritoneal sidewall excision. In the present study, all animals survived and had no complications after the surgery. The histopathological observations were demonstrated that HA obviously improved laparotomy pelvic surgery-induced adhesion in peritoneal sidewall and uterine horn. The anastomotic healing score of injury + HA group was significantly lower than the injury alone group. We conclude HA hydrogel can attenuate the post-operative adhesions in porcine. [ABSTRACT FROM AUTHOR]