Synthesis of hard magnetic NdFeB composite particles by recycling the waste using microwave assisted auto-combustion and reduction method.

The present work provides a facile and energy-saving approach to recycle Nd-Fe-B wastes. Employing the severely oxidized and contaminated sintered Nd-Fe-B scraps as the raw materials, sub-micro sized Nd-Fe-B/α-Fe composite magnetic powders were successfully synthesized by microwave assisted auto-combustion method followed by a reduction diffusion process. In details, the waste magnets were dissolved in HNO3 solution and both the rare earth oxides and iron oxide were obtained by auto-combustion approach with the help of microwave heating. These oxides were then reduced to achieve Nd-Fe-B alloys with the reducing agent CaH2. To modify the composition of the final product, Nd(NO3)3·6H2O and H3BO3 were added during dissolving and consequently three compositions of the final products were obtained. TEM results demonstrate that the sizes of α-Fe and Nd2Fe14B grains are below 10 nm and 20 nm, respectively. The magnetic properties of the composite powders obtained from the wastes in this study are comparable to those obtained by other methods using pure reagents. The room temperature coercivity of as-synthesized Nd15Fe77B8 is higher than 400 kA/m. In addition, an appropriate mass ratio of CaH2 to Nd-Fe-B oxides is required in order to obtain good magnetic properties.

Plasma levels of Th1/Th2 type cytokine are associated with change of prolactin and GH/IGF-I in hemodialysis patients.

Patients undergoing chronic hemodialysis (HD) have an impaired immune system involving both B and T cell-mediated immune responses. Since T helper type 1 (Th1) and type 2 (Th2) cytokines are implicated in regulating the immune responses, while the pituitary hormones, prolactin (PRL) and growth hormone (GH) are known to be involved in the regulation of the immune response, all of them may, therefore, be involved in impaired status. The aims of the present study were to estimate the serum concentrations of Th1-Th2 cytokine, GH, insulin-like growth factor-I (IGF-I) and PRL, and to determine whether there are any correlations between the release of T-cell cytokines and disturbance of hormones in a group of patients on maintenance hemodialysis (MHD). The study included 35 HD patients (23 males and 12 females, mean age 56.8+/-12.8 years) and a control group of 20 age-matched healthy subjects. Baseline serum concentrations of GH/IGF-I, PRL, IL-2, sIL-2R, IFN-gamma, IL-4 and IL-10 were measured in all patients and control subjects. Our results demonstrate that the fasting serum concentration of IGF-I, PRL, sIL-2R and Th1-type cytokine, including IL-2 and IFN-gamma, were significantly higher in HD patients compared to the healthy subjects. GH and Th2-type cytokine including IL-4 and IL-10 levels were slightly reduced, but no significant differences were observed between HD patients and the control group. In the group of HD patients, PRL correlated directly with IFN-gamma and correlated inversely with IL-10; IFN-gamma correlated inversely with IL-4; and GH also correlated inversely with IGF-I and IL-4. However, IGF-I correlated directly with IL-2 and IL-10. These data suggest that the Th1/Th2 imbalance in HD patients with an increase of Th1 type cytokines, associated with the altered GH/IGF-I axis and prolactin and immuno-endocrine dysfunction, probably plays a role in an impaired immune system in HD patients.

Isolation and some characterization of the prothoracicotropic hormone from Bombyx mori.

The prothoracicotropic hormone (PTTH) was isolated from adult heads of Bombyx mori. Fifty micrograms of pure PTTH was obtained from 648,000 heads through a 15-step purification procedure with a 2 X 10(6)-fold purification and an 8% recovery. Chemical analyses of this PTTH have shown that it is a single-chain peptide consisting of 40-43 amino acid residues (MW, 4330-4740), the N-terminus of which is glycine. As little as 0.1 ng of PTTH elicited adult development in a debrained pupa of Samia cynthia ricini. Five picograms of PTTH directly stimulated the prothoracic glands in vitro so as to enhance ecdysone release. The hemolymph ecdysteroids of brainless Samia pupae that were developed by PTTH injection increased with essentially the same pattern as in developing normal pupae.

Large-scale purification of prothoracicotropic hormone of the silkworm (Bombyx mori).

Prothoracicotropic hormone has been successfully extracted from as many as 2,800,000 silkworm male adult heads and purified partially through an 8-step procedure. Approximately 7 microgram of the crude preparation ("crude PTTH") shows activity in the debrained Samia pupa test. A further 4-step chromatographic purification of the "crude PTTH" derived from 100,000 Bombyx heads yields 3.4 mg of purified preparation ("highly purified PTTH"), of which 7 ng causes adult development in a debrained Samia pupa.