Mongolian spots(MS) are congenital birthmarks seen most commonly over the lumbosacral area. They are bluish-green to black in color and oval to irregular in shape. They are most commonly found in individuals of Africa...Mongolian spots(MS) are congenital birthmarks seen most commonly over the lumbosacral area. They are bluish-green to black in color and oval to irregular in shape. They are most commonly found in individuals of African or Asian ethnic background. Although these lesions resolve by one to two years of age, widespread, extrasacral and dark colored MS sometimes persist into adulthood. Aberrant MS over occiput, temple, mandibular area, shoulders and limbs may be confused with other dermal melanocytoses and bruises secondary to child abuse, thus necessitating documentation at birth. Although traditionally believed to be benign in nature, they have now been shown to co-exist with inborn errors of metabolism, most commonly GM1 gangliosidosis and mucopolysaccharidosis type Ⅰ(Hurler's disease), followed by mucopolysaccharidosis type Ⅱ(Hunter's syndrome), mucolipidosis, Niemann-Pick disease and mannosidosis. They have also been seen to co-exist with various vascular or other pigmented birthmarks like café-au-lait macules. Co-existing Mongolian spots and vascular birthmarks like nevus flammeus, nevus anemicus or nevus spilus is termed as phakomatosis pigmentovascularis. This review focuses on the important associations of Mongolian spots and stresses upon the importance of screening babies with extensive MS.展开更多
A high precision method used for on-spot calibration of distributed stereoreference position setting is presented. The high measuring accuracy in stereo reference calibrationis derived from using a high precision wate...A high precision method used for on-spot calibration of distributed stereoreference position setting is presented. The high measuring accuracy in stereo reference calibrationis derived from using a high precision water level instrument and an accurate height verniercaliper. It settles the problem of reference calibration effectively and accurately, without usinglarge coordinate measuring machines (CMM). It is more adaptable and precise than traditionalcalibration methods applying theodolites or autocollimators. The error sources of this method areanalyzed in detail and several methods are developed to eliminate the calibration error.Anoptimizing swallowtail-like anchor target is developed. Experiments show that the calibrationaccuracy can be limited within 0.06 mm in the range of 3～5 m and 0.03 mm with optimizing anchortarget. This method can be widely used in on-spot calibration.展开更多
文摘Mongolian spots(MS) are congenital birthmarks seen most commonly over the lumbosacral area. They are bluish-green to black in color and oval to irregular in shape. They are most commonly found in individuals of African or Asian ethnic background. Although these lesions resolve by one to two years of age, widespread, extrasacral and dark colored MS sometimes persist into adulthood. Aberrant MS over occiput, temple, mandibular area, shoulders and limbs may be confused with other dermal melanocytoses and bruises secondary to child abuse, thus necessitating documentation at birth. Although traditionally believed to be benign in nature, they have now been shown to co-exist with inborn errors of metabolism, most commonly GM1 gangliosidosis and mucopolysaccharidosis type Ⅰ(Hurler's disease), followed by mucopolysaccharidosis type Ⅱ(Hunter's syndrome), mucolipidosis, Niemann-Pick disease and mannosidosis. They have also been seen to co-exist with various vascular or other pigmented birthmarks like café-au-lait macules. Co-existing Mongolian spots and vascular birthmarks like nevus flammeus, nevus anemicus or nevus spilus is termed as phakomatosis pigmentovascularis. This review focuses on the important associations of Mongolian spots and stresses upon the importance of screening babies with extensive MS.
基金This project is supported by 863 Program Committee of China (No. 863-512-9804-11).
文摘A high precision method used for on-spot calibration of distributed stereoreference position setting is presented. The high measuring accuracy in stereo reference calibrationis derived from using a high precision water level instrument and an accurate height verniercaliper. It settles the problem of reference calibration effectively and accurately, without usinglarge coordinate measuring machines (CMM). It is more adaptable and precise than traditionalcalibration methods applying theodolites or autocollimators. The error sources of this method areanalyzed in detail and several methods are developed to eliminate the calibration error.Anoptimizing swallowtail-like anchor target is developed. Experiments show that the calibrationaccuracy can be limited within 0.06 mm in the range of 3～5 m and 0.03 mm with optimizing anchortarget. This method can be widely used in on-spot calibration.
