Routes to new hafnium(IV) tetraaryl porphyrins and crystal structures of unusual phosphate-, sulfate-, and peroxide-bridged dimers.

New routes for the synthesis of mono tetraaryl porphyrinato hafnium(IV) complexes, Hf(IV)Por(L)(2), are reported, where the secondary ligands, L, are determined by the method of purification. These synthetic routes cater to the solubility of the macrocycles and provide access to Hf(IV) complexes of meso tetraaryl porphyrins bearing diverse functional groups such as phenyl, tolyl, pyridyl, pentafluorophenyl, and carboxyphenyl. The latter three derivatives significantly expand the repertoire of hafnium porphyrinates.

In a model of immunoglobulin heavy-chain (IGH)/MYC translocation, the Igh 3' regulatory region induces MYC expression at the immature stage of B cell development.

Reciprocal translocations involving the immunoglobulin loci and the cellular oncogene MYC are hallmark mutations of the human postgerminal center B cell neoplasm, Burkitt's lymphoma. They are occasionally found in other B cell lymphomas, as well. Translocations involving the heavy chain locus (IGH) place the MYC gene either in cis with both the intronic enhancer Emu and the IGH 3' regulatory region (3'RR) or in cis with only the 3'RR.

Transcription of a productively rearranged Ig VDJC alpha does not require the presence of HS4 in the IgH 3' regulatory region.

V gene assembly, class switch recombination, and somatic hypermutation are gene-modifying processes essential to the development of an effective Ab response. If inappropriately applied, however, these processes can mediate genetic changes that lead to disease (e.g.

Tessellation of porphyrazines with porphyrins by design.

The efficient self-assembly and functional characterization of arrays containing multiple types of chromophores will provide a basis for the design and applications of functional photonic materials that are unobtainable using only one type of molecule. The design, synthesis, and characterization of supramolecular systems bearing two different types of porphyrinic chromophores, porphyrins and porphyrazines, are reported. Because the porphyrins and porphyrazines bear different exocyclic ligands for self-assembly by metal ion coordination, these systems require new supramolecular synthetic strategies wherein reactants are added in a specific order.

Thermodynamics of protein-protein interactions of cMyc, Max, and Mad: effect of polyions on protein dimerization.

The Myc-Max-Mad network of proteins activates or represses gene transcription depending on whether the dimerization partner of Max is c-Myc or Mad. To elucidate the physical properties of these protein-protein interactions, fluorescence anisotropy of TRITC-labeled Max was used. The binding affinities and thermodynamics of dimerization of the Max-Max homodimer and c-Myc-Max and Mad-Max heterodimers were determined.

Room-temperature Wurtzite ZnS nanocrystal growth on Zn finger-like peptide nanotubes by controlling their unfolding peptide structures.

ZnS nanocrystal, a class of wide-gap semiconductors, has shown interesting optical, electrical, and optoelectric properties via quantum confinement. For those applications, phase controls of ZnS nanocrystals and nanowires were critical to tune their physical properties to the appropriate ones. The wurtzite ZnS nanocrystal growth at room temperature is the useful fabrication; however, the most stable ZnS structure in nanoscale is the zinc blende (cubic) structure, and scientists have just begun exploring the room-temperature synthesis of the wurtzite (hexagonal) structure of ZnS nanocrystals.

Self-organization of self-assembled tetrameric porphyrin arrays on surfaces.

The incorporation of designed self-assembled supramolecular structures into devices requires deposition onto surfaces with retention of both structure and function. This remains a challenge and can present a significant barrier to developing devices using self-organizing materials. To examine the role of peripheral groups in the self-organization of self-assembled multiporphyrinic arrays on surfaces, Pd(II)-linked square and Pt(II)-linked trapezoidal tetrameric porphyrin arrays with peripheral tert-butylphenyl or dodecyloxyphenyl functionalities were investigated using various spectroscopies and atomic force microscopy.

Factors related to childhood sexual abuse among gay/bisexual male Internet escorts.

This exploratory investigation examined the relationship between childhood sexual abuse (CSA) and related psychosocial characteristics and sexual behaviors among 46 gay/bisexual male escorts who advertise via the Internet. More than a quarter of men (28.3%) reported some history of CSA.

The Drosophila acetylcholine receptor subunit D alpha5 is part of an alpha-bungarotoxin binding acetylcholine receptor.

The central nervous system of Drosophila melanogaster contains an alpha-bungarotoxin-binding protein with the properties expected of a nicotinic acetylcholine receptor. This protein was purified 5800-fold from membranes prepared from Drosophila heads. The protein was solubilized with 1% Triton X-100 and 0.

Translation initiation factor (eIF) 4B affects the rates of binding of the mRNA m7G cap analogue to wheat germ eIFiso4F and eIFiso4F.PABP.

Previous kinetic binding studies of wheat germ protein synthesis eukaryotic translational initiation factor eIFiso4F and its subunit, eIFiso4E, with m(7)GTP and mRNA analogues indicated that binding occurred by a two-step process with the first step occurring at a rate close to the diffusion-controlled rate [Sha, M., Wang, Y., Xiang, T.

Critical role for the Oct-2/OCA-B partnership in Ig-secreting cells.

B and T lymphocytes arise from a common precursor in the bone marrow, but ultimately acquire very different functions. The difference in function is largely attributable to the expression of tissue-specific transcription factors that activate discrete sets of genes. In previous studies we and others have shown that the specialized genes expressed by Ig-secreting cells cease transcription when these cells are fused to a T lymphoma.

Porphyrins linked directly to the 5,5' positions of 2,2'-bipyridine: a new supramolecular building block and switch.

The synthesis and coordination chemistry of two porphyrin dimers linked either at the 5,5' or the 4,4' positions of 2,2'-bipyridine are described. These compounds, which may serve a molecular tectons for the constructions of a variety of supramolecular arrays of diverse function, reveal that the ground- and excited-state electronic communication between the chromophores is only moderately affected by the complexation state of the bipyridyl moiety. The nature of the metal ion chelated by the bipyridine only slightly perturbs the ground-state spectra, and differences observed in the excited state are largely ascribed to the heavy atom effect.

Spatially resolved IR microspectroscopy of single cells.

Fourier transform IR (FTIR) microspectroscopy at a spatial resolution of 18 microm was used to study skin fibroblasts and giant sarcoma cells. Both cell lines were derived from the same patient; they were metabolically active and in the exponentially growing phase. The IR spectra were acquired for the nuclei and cytosol of untreated cells, cells washed with ethanol, and cells treated with RNase or DNase.

Designing supramolecular porphyrin arrays that self-organize into nanoscale optical and magnetic materials.

Tessellation of nine free-base porphyrins into a 3 x 3 array is accomplished by the self-assembly of 21 molecular entities of four different kinds, one central, four corner, and four side porphyrins with 12 trans Pd(II) complexes, by specifically designed and targeted intermolecular interactions. Strikingly, the self-assembly of 30 components into a metalloporphyrin nonamer results from the addition of nine equivalents of a first-row transition metal to the above milieu. In this case each porphyrin in the nonameric array coordinates the same metal such as Mn(II), Ni(II), Co(II), or Zn(II).

Anatomizing the past: physicians and history in Renaissance culture.

In many different ways Renaissance physicians concerned themselves with the reading and writing of history. This article examines the role of historical interests in learned medical culture and the participation of physicians in the broader historical culture of the period.

Deletional analyses reveal an essential role for the hs3b/hs4 IgH 3' enhancer pair in an Ig-secreting but not an earlier-stage B cell line.

The Ig heavy chain (IgH) locus is controlled by multiple regulatory sequences mapping both within the IgH transcription unit (E mu) and downstream (3') of IgH coding sequences (hs3a, hs1,2, hs3b and hs4). Enhancer knockout studies in mice have implicated E mu in the control of IgH variable region gene assembly, but single-enhancer knockouts involving the 3' IgH enhancers have yet to shed light on their function. Transfection studies in mice and cell lines have suggested that the 3' enhancers behave similarly to a locus control region as first identified in the beta-globin locus.