Crystals of Au(PPh3)2Cl, Au(PPh3)3BPh4, and other three-coordinate bis(phosphine)gold(I) compounds are luminescent. Solutions of [Au(tht)2]PF6 (tht = tetrahydrothiophene) with added PPh3 in CH3CN luminesce with Xmax = 512 nm and an excited-state lifetime of 10µ$. The emission intensity is sensitive to the phosphine concentration. The luminescent species is postulated to be the tris(phosphine)gold(I) cation, Au(PPh3)3+, in equilibrium with Au(PPh3)2+. Other PR3 phosphine complexes (R = n-octyl, n-butyl, ethyl) also luminesce in solution when excess (>3:1 PR3:Au) phosphine is present. The emission is attributed to a metal-centered Pz -* (dx:_^, dx>) transition which can be dipole allowed under spin-orbit coupling or by Jahn-Teller splitting of the *123E" excited state. resce both in the solid state and, like5 the isoelectronic Pt°(PPh3)3, in solution. Experimental SectionThe following compounds were made by literature methods: Au-(PPh3)2Cl,6 Au(PPh3)3BPh4 (confirmed by unit cell X-ray measurements),7 Au(PPh3)2PF6,8 Au(tht)Cl,9 AuN(CH2CH2PPh2)3[PF6] and Au2(N(CH2CH2PPh2)3)2[BPh4]2.10

Cobalt ferrite nanoparticle (CFN) has received attention in magnetic resonance imaging (MRI) as a promising contrast agent due to its higher saturation magnetization and magneto-crystalline anisotropy. However, the in vitro cytotoxicity of CFN has raised concern for its biomedical application as a diagnostic agent. The coating of CFN by a biocompatible polymer such as chitosan (CH) might lessen the biocompatibility concern. Therefore, in this study, we examined the applicability of chitosan-coated cobalt ferrite nanoparticle (CCN) as an MRI contrast dye and investigated its biocompatibility in vivo. Phantom MRI images revealed that the relaxivity of CCN was 121 (±8) mM–1s–1, indicating the potential of CCN as a T 2-weighted contrast agent. A single intravenous (iv) administration of CCN (10 mg/kg) improved the contrast of magnetic-resonance-imaging-based angiography (MRA) and brain-MRI in male albino Wistar rats compared to the control. Furthermore, toxicity studies dependent on dose (1–20 mg/kg) and time (1–28 days) in male albino Wistar rats confirmed the in vivo biocompatibility of CCN. The physical, hematological, biochemical, and histopathological observation assured that a single iv injection of CCN up to 20 mg/kg was well adjusted with liver, kidney, heart, and brain functions. The findings of the current study consolidate CCN as a promising candidate for MRI contrast dye.

Colostrum has enough humoral and cellular elements to protect babies. Therefore, immune protection derived from breastfeeding depends on the immunoglobulin level of the colostrum as well as the amount of colostrum ingested.

No abstract