Heat affected zones and oxidation marks in fiber laser-oxygen cutting of mild steel

The effect of cutting speed and sheet thickness on surface oxidation and heat affected zones (HAZs) has been investigated for laser-oxygen cutting of mild steel sheet with a fiber laser. Optical and scanning electron micrographs were used to determine the extent of surface oxidation and HAZ from plan and cross-sectional views, respectively. The HAZ is consistently wider at the bottom of the cut compared to the HAZ at the top of the cut. With increasing speed, the width of the HAZ at the top of the cut decreases whereas the HAZ width at the bottom of the cut generally increases. No simple, direct relationship between HAZ width and surface oxidation was seen. However, it is possible to state that in each case considered here, the HAZ would be completely removed if they are machined back by a depth equal to the extent of the surface oxidation. (C) 2011 Laser Institute of America

Final height after combined growth hormone and GnRH analogue treatment in adopted girls with early puberty

Background: Girls adopted from developing countries often have early or precocious puberty, requiring treatment with gonadotrophin-releasing hormone (GnRH) analogues. During such treatment, decreased growth velocity is frequent. Aim: To study whether the addition of growth hormone (GH) to GnRH analogue treatment improves final height in girls with early or precocious puberty. Methods: Forty-six girls with early or precocious puberty (age less than or equal to9.5 y) adopted from developing countries were randomized for treatment for 2-4 y with GnRH analogue, or with a combination of GH and GnRH analogue. Results: During treatment, the mean growth velocity in the GH/GnRH analogue group was significantly higher compared to the control group. Combined GH/GnRH analogue treatment resulted in a higher final height: 158.9 cm compared to 155.8 cm in the GnRH analogue-treated group. Three out of 24 girls (13%) in the combined group and nine of the 22 girls (41%) treated with GnRH analogue alone attained a final height below -2 standard deviation scores (SDS). Conclusion: The difference between the two groups is statistically significant, and possibly of clinical importance. A future challenge is to identify a subgroup with clinically significant advantage of GH addition to GnRH analogue treatment. Being very short on arrival in Sweden and being short and young at start of treatment are possible indicators