Spheroidisation Treatment for Steels

The materials used in components are now highly diversified with many applicationshistorically reserved for steels now taken by plastics, composites, and ceramics. There are, ofcourse, many applications for which steels are still the most suitable material. Presently, it isimportant that the type of steel chosen for a given application and the heat treatment given toit be critically examined to justify its use. This study highlights the selection of steels forspheroidisation treatments and their commercial uses

Plasma adrenocorticotropin (ACTH) values and cortisol response to 250 and 1 μ g ACTH stimulation in patients with hyperthyroidism before and after carbimazole therapy: Case-control comparative study

Context: Although the production and metabolic clearance rate of cortisol is increased during thyrotoxic state, the net effect on adrenocortical reserves is not clear. Objective: We assessed circulating ACTH levels, cortisol binding globulin (CBG), and adrenocortical reserves in hyperthyroid patients (before and after carbimazole therapy) and healthy controls. Design and Setting: This was a case-control investigative study in a tertiary care setting. Patients and Methods: Plasma ACTH and free cortisol index (FCI; serum cortisol/CBG) were measured in 49 consecutive patients with hyperthyroidism and 50 controls. ACTH1-24 stimulation tests (250 and 1 μ g) were carried out in the first 29 patients and 15 controls. Peak FCI less than the mean -3 SD of healthy controls was considered subnormal. ACTH1-24 stimulation tests were repeated in 24 patients in the euthyroid state. Results: The mean basal plasma ACTH and FCI were higher and CBG was lower in thyrotoxic patients in comparison with controls. The peak cortisol was less than 18 μ g/dl in 10 of 29 and 14 of 29 on 250 and 1 μ g ACTH1-24 stimulation. Peak FCI was subnormal only in three of 27 (11.1%) and two of 21 (7.4%) on 250 and 1 μg ACTH1-24 stimulation, respectively. The mean plasma ACTH, basal FCI, and subnormal peak FCI (two of the three) normalized after euthyroidism. Plasma ACTH and FCI did not correlate with severity of thyrotoxicosis. Conclusions: Up to 11% of thyrotoxics have subnormal peak FCI on ACTH1-24 stimulation. Such changes occur despite high basal plasma ACTH and FCI. Use of FCI, rather than total cortisol, is required for the interpretation of cortisol values in thyrotoxicosis due to the variation in CBG

CFD Modeling of Fluidized Bed Reactor for the Synthesis of Dimethyl Ether

The syngas-to-DME reaction is highly exothermic, and the catalyst temperature window is very narrow. The fluidized-bed reactor is, therefore, an ideal choice to carry out these reactions. RTI is developing a circulating fluidized bed design for DME synthesis. This paper discusses a two-phase CFD model and optimization of the solids circulation rate

Pattern of 25-hydroxy vitamin D response at short (2 month) and long (1 year) interval after 8 weeks of oral supplementation with cholecalciferol in Asian Indians with chronic hypovitaminosis D

Hypovitaminosis D is common in Asian Indians. Physicians often prescribe 1500 μ g (60 000 IU) cholecalciferol per week for 8 weeks for vitamin D deficiency in India. Its efficacy to increase serum 25-hydroxy vitamin D (25(OH)D) over short (2 months) and long (1 year) term is not known. We supplemented a group of twenty-eight apparently healthy Asian Indians detected to have low serum 25(OH)D (mean 13.5 (sd 3.0) nmol/l) on screening during January-March 2005. Serum parathyroid hormone (PTH) level was supranormal in 30 % of them. Oral supplementation included 1500 μ g cholecalciferol per week and 1g elemental Ca daily for 8 weeks. Serum 25(OH)D, total Ca, inorganic P and intact (i) PTH were reassessed in twenty-three subjects (twelve females and eleven males) who had follow up at both 8 weeks and 1 year. At 8 weeks the mean 25(OH)D levels increased to 82.4 (SD 20.7) nmol/l and serum PTH normalized in all. Twenty-two of the twenty-three subjects had 25(OH)D levels>49.9 nmol/l. At 1 year, though the mean 25(OH)D level of 24.7 (SD 10.9) nmol/l was significantly higher than the baseline, all subjects were 25(OH)D deficient. Five subjects with supranormal iPTH at baseline showed recurrence of biochemical hyperparathyroidism. Thus, with 8 weeks of cholecalciferol supplementation in Asian Indians with chronic hypovitaminosis D, mean serum 25(OH)D levels would be normalized and serum PTH value would be reduced to half. However, such quick supplementation would not maintain their 25(OH)D levels in the sufficient range for 1 year. For sustained improvement in 25(OH)D levels vitamin D supplementation has to be ongoing after the initial cholecalciferol loading

Prevalence of clinical remission in patients with sporadic idiopathic hypoparathyroidism

Background: Remission of disease activity is a characteristic feature of autoimmune endocrine disorders such as Graves' disease, Addison's disease and occasionally in patients with premature ovarian failure. Autoimmunity is also implicated in sporadic idiopathic hypoparathyroidism (SIH) with clinical remission of disease reported in three cases. Objective: To assess the rate of remission in patients with sporadic idiopathic hypoparathyroidism and review the cases reported so far. Subjects and methods: Subjects included 53 patients (M:F, 24:29) with SIH who had been symptomatic for at least 1 year (range 1-31 years). They were treated with calcium and 1-α -(OH)D3/cholecalciferol therapy and had a mean duration of follow up of 5.0 ± 3.2 years. Treatment was withdrawn in two stages in the patients who maintained normal levels of serum total calcium during the preceding year of treatment. In stage-1, the dose of therapy was reduced to half and subsequently all treatment was stopped (stage 2) in those patients who maintained normal serum total calcium levels on the reduced dose. Remission of SIH was defined as maintenance of normal serum total (≥ 2.12 mmol/l) and ionized calcium, inorganic phosphorus and serum intact parathyroid hormone (iPTH) for at least 3 months after withdrawal of calcium and 1-α -(OH)D3/cholecalciferol therapy. Calcium sensing receptor autoantibodies (CaSRAb) were determined by Western blot. Results: Two of the 53 patients (3.8%) with SIH stayed in remission for 1 year after complete withdrawal of therapy. CaSRAb was absent in both the cases. The clinical features, age at onset and duration of hypocalcaemic symptoms in cases with remission were comparable to those who did no show remission. Conclusion: Sporadic idiopathic hypoparathyroidism is not irreversible as is widely believed and spontaneous remission of disease may occur in 3.8% of patients

Bone mineral parameters in healthy young Indian adults with optimal vitamin D availability

Background: Several recent studies indicate a marked prevalence of vitamin D deficiency in asymptomatic, apparently healthy urban subjects from different socioeconomic groups in north India. Methods: To further examine this trend, we studied 40 men and 50 women, 20–30 years of age, from the Indian paramilitary forces. These individuals consume a nutritious, high-protein diet, have optimal exposure to sunlight and undertake strenuous outdoor physical exercise. Results: The mean serum calcium, phosphorus and alkaline phosphatase levels were normal in both men and women. The mean (SD) serum intact parathyroid hormone and 25-hydroxy-vitamin D3 levels were 19.3 (8.2) pg/ml and 18.4 (5.3) ng/ml in men, and 11.9 (6.6) pg/ml and 25.3 (7.4) ng/ml in women. Bone mineral density estimated in 20 men and 22 women revealed that in comparison with white Caucasians, 35%–50% of men and 14%–32% of women were osteopenic at different sites, while an additional 10% of men had osteoporosis of the lumbar spine. Conclusion: We found that with optimal nutrition, good sunlight exposure and regular physical exercise, healthy young individuals have normal bone and mineral biochemical values. The reasons for the abnormalities detected in bone mineral density in them needs further study. The impact of childhood nutrition on accumulation of peak bone mass may contribute to our findings. There is a need for establishing normative bone mineral density data for Indians

Prevalence and functional significance of 25-hydroxyvitamin D deficiency and vitamin D receptor gene polymorphisms in Asian Indians

Background: Recent studies show a wide prevalence of hypovitaminosis D in Asian Indians. Objective: The objective was to assess the functional significance of 25-hydroxyvitamin D [25(OH)D] deficiency, vitamin D receptor (VDR) gene, and parathyroid hormone (PTH) gene polymorphisms in relation to bone mineral density (BMD) in urban Asian Indians. Design: Serum total calcium, inorganic phosphorus, alkaline phosphatase, 25(OH)D, intact PTH, and BMD at lumbar spine, proximal femur, and forearm were measured in 105 adult subjects. The genotyping related to VDR (BsmI, FokI, and TaqI) and PTH (BstBI and DraII) gene single-nucleotide polymorphisms was carried out by polymerase chain reaction-restriction fragment length polymorphism analysis. Results: The mean serum 25(OH)D concentration in the whole cohort was 9.8 ± 6.0 ng/mL, which was inversely related with serum intact PTH values (P = 0.042). Ninety-nine (94.3%) of the 105 subjects had vitamin D deficiency with 25(OH)D concentrations < 20 ng/mL. The age- and body mass index (BMI)-adjusted BMD value at the hip was higher in subjects with serum 25(OH)D values > 9.0 ng/mL than in those with values ≤9.0 ng/mL (0.893 ± 0.114 compared with 0.839 ± 0.112 g/cm2, respectively; P = 0.001). The mean forearm and spine BMD values in subjects with TT (VDR, TaqI) or bb (PTH, BstBI) genotypes were significantly higher than the values in subjects with Tt genotype and BB or Bb genotype, respectively. Conclusion: Functionally significant 25(OH)D deficiency affecting BMD at the hip region is prevalent in urban Asian Indians. However, variation in BMD at the spine and forearm is related to VDR and PTH gene polymorphisms rather than to vitamin D status, at least in this hypovitaminotic D population

Prevalence of thyroid autoimmunity in sporadic idiopathic hypoparathyroidism in comparison to type 1 diabetes and premature ovarian failure

Context: Thyroid autoimmunity is the most common coexistent endocrinopathy in type 1 diabetes (T1D), Addison's disease, and premature ovarian failure (POF). Although the role of autoimmunity is being investigated in patients with sporadic idiopathic hypoparathyroidism (SIH), there is little information on coexistent thyroid autoimmunity. Objective: Our objective was to assess the prevalence of thyroid peroxidase autoantibodies (TPOAb) and thyroid dysfunction in patients with SIH and its comparison with that in T1D, POF, and Hashimoto's thyroiditis (HT) and age- and sex-matched healthy controls (for SIH). Design and Setting: We conducted a case control study in a tertiary care setting. Patients and Methods: Subjects were consecutive patients with SIH (n = 87), T1D (n = 100), POF (n = 58), and HT (n = 47) and healthy controls (100 females and 64 males). Serum free T3, free T4, TSH, and TPOAb (normal ≤ 34 IU/ml) were measured by electrochemiluminescence assay. Subjects with 1) serum TSH at least 5 μ U/ml along with TPOAb more than 34 IU/ml; 2) TSH at least 10 μ U/ml but normal TPOAb titers; or 3) Graves' disease were considered to have thyroid dysfunction. Results: TPOAb positivity (>34 IU/ml) in females was 14.6% in SIH, 24.1% in POF, and 42.1% in T1D compared with 76.6% in HT and 9% in healthy controls. The frequencies of TPOAb positivity and thyroid dysfunction in patients with SIH were comparable to those in control and POF groups, but significantly less than in T1D and HT groups. Conclusion: The frequencies of TPOAb and thyroid dysfunction were not significantly higher in patients with SIH than in healthy controls, unlike in patients with T1D and POF