Probing the Ligand Exchange of N-Heterocyclic Carbene-Capped AgS Nanocrystals with Amines and Carboxylic Acids.

N-Heterocyclic carbenes (NHCs) are versatile L-type ligands that have been shown to stabilize coinage metal chalcogenide nanocrystals, such as AgS, remarkably well. However, very little research has been done on the interaction between NHC ligands and coinage metal chalcogenide nanocrystal surfaces and subsequent ligand exchange reactions. Herein, solution H nuclear magnetic resonance methods were used to monitor ligand exchange reactions on stoichiometric AgS nanocrystal platforms with various primary amine and carboxylic acid ligands.

The Surface Chemistry and Structure of Colloidal Lead Halide Perovskite Nanocrystals.

ConspectusSince the initial discovery of colloidal lead halide perovskite nanocrystals, there has been significant interest placed on these semiconductors because of their remarkable optoelectronic properties, including very high photoluminescence quantum yields, narrow size- and composition-tunable emission over a wide color gamut, defect tolerance, and suppressed blinking. These material attributes have made them attractive components for next-generation solar cells, light emitting diodes, low-threshold lasers, single photon emitters, and X-ray scintillators. While a great deal of research has gone into the various applications of colloidal lead halide perovskite nanocrystals, comparatively little work has focused on the fundamental surface chemistry of these materials.

Surface Termination of CsPbBr Perovskite Quantum Dots Determined by Solid-State NMR Spectroscopy.

Cesium lead halide perovskite quantum dots (QDs) have gained significant attention as next-generation optoelectronic materials; however, their properties are highly dependent on their surface chemistry. The surfaces of cuboidal CsPbBr QDs have been intensively studied by both theoretical and experimental techniques, but fundamental questions still remain about the atomic termination of the QDs. The binding sites and modes of ligands at the surface remain unproven.

Phase control in the colloidal synthesis of well-defined nickel sulfide nanocrystals.

Morphologically well-defined colloidal nanocrystals of Ni3S4, NiS, Ni9S8, and Ni3S2 were independently prepared through a solution-phase synthesis using N,N'-disubstituted thioureas as the sulfur precursor. Synthetic control over phase and composition of the resulting colloidal nickel sulfide nanocrystals was achieved by primarily adjusting the reactivity of substituted thioureas as well as tuning the key reaction parameters of temperature and precursor ratio. In general, the more reactive N,N'-diphenyl thiourea yields more sulfur-rich phases (Ni3S4 and NiS) while less reactive N,N'-dibutyl thiourea yields sulfur-poor phases (Ni9S8 and Ni3S2).

Quantifying the Thermodynamics of Ligand Binding to CsPbBr Quantum Dots.

Cesium lead halide perovskites are an emerging class of quantum dots (QDs) that have shown promise in a variety of applications; however, their properties are highly dependent on their surface chemistry. To this point, the thermodynamics of ligand binding remain unstudied. Herein, H NMR methods were used to quantify the thermodynamics of ligand exchange on CsPbBr QDs.

Mono- and Mixed-Valence Tetrathiafulvalene Semiconductors (TTF)BiI and (TTF)BiI with 1D and 0D Bismuth-Iodide Networks.

Two new compounds containing tetrathiafulvalene (TTF) cations with extended and discrete anions based on Bi and I are reported. The compound (TTF)BiI comprises [BiII] chains of edge-shared octahedra that are interspersed with stacks of TTF. The compound (TTF)BiI has mixed-valence stacks of TTF and TTF and discrete molecules of TTF separated by discrete [BiI] anions.

Inhibition of spleen tyrosine kinase attenuates IgE-mediated airway contraction and mediator release in human precision cut lung slices.

Background And Purpose: Asthma presents as a heterogeneous syndrome characterized by airway obstruction, inflammation and hyper-reactivity (AHR). Spleen tyrosine kinase (Syk) mediates allergen-induced mast cell degranulation, a central component of allergen-induced inflammation and AHR. However, the role of Syk in IgE-mediated constriction of human small airways remains unknown.

Phenotypic responses of differentiated asthmatic human airway epithelial cultures to rhinovirus.

Objectives: Human airway epithelial cells are the principal target of human rhinovirus (HRV), a common cold pathogen that triggers the majority of asthma exacerbations. The objectives of this study were 1) to evaluate an in vitro air liquid interface cultured human airway epithelial cell model for HRV infection, and 2) to identify gene expression patterns associated with asthma intrinsically and/or after HRV infection using this model.

Methods: Air-liquid interface (ALI) human airway epithelial cell cultures were prepared from 6 asthmatic and 6 non-asthmatic donors.

The development of the Solution Building Inventory.

Throughout the past 70 years, a great deal of research conducted on defining and testing problem-solving skills has led toward solution-focused practices and philosophies. As a result, some literature exists illustrating the efficacy of solution-focused practices. However, no published research exists on the factors that contribute to solution building.

Molecular requirements for induction of CTGF expression by TGF-beta1 in primary osteoblasts.

Connective tissue growth factor (CTGF/CCN2) is a cysteine rich, extracellular matrix protein that acts as an anabolic growth factor to regulate osteoblast differentiation and function. In osteoblasts, CTGF is induced by TGF-beta1 where it acts as a downstream mediator of TGF-beta1 induced matrix production. The molecular mechanisms that control CTGF induction by TGF-beta1 in osteoblasts are not known.

Solution-focused group therapy for level 1 substance abusers.

The present study compared solution-focused group therapy (SFGT) with a traditional problem-focused treatment for level 1 substance abusers. Outcome research on the effectiveness of solution-focused group therapy is minimal, especially in treating substance abusers. In the present study, clients were measured before and after treatment to determine therapeutic effectiveness.

Proline-rich tyrosine kinase 2 regulates osteoprogenitor cells and bone formation, and offers an anabolic treatment approach for osteoporosis.

Bone is accrued and maintained primarily through the coupled actions of bone-forming osteoblasts and bone-resorbing osteoclasts. Cumulative in vitro studies indicated that proline-rich tyrosine kinase 2 (PYK2) is a positive mediator of osteoclast function and activity. However, our investigation of PYK2-/- mice did not reveal evidence supporting an essential function for PYK2 in osteoclasts either in vivo or in culture.

Challenges of an outcome-based perspective for marriage and family therapy education.

Marriage and family therapy (MFT) and marriage and family therapy education (MFTE) have undergone many changes during the short history of MFT. This article describes the current trends and controversies in MFTE, including shifts toward outcome-based education (OBE). We present recommendations for MFTE, including the move toward OBE, the development of core competencies of MFT, attention to interdisciplinary issues, and recognition of the need for both foundational education and encouragement of trainees' unique styles and approaches.

Anti-osteoactivin antibody inhibits osteoblast differentiation and function in vitro.

Osteoactivin (OA) is a novel protein identified by mRNA differential display using bone from osteopetrotic versus normal rats. Bioinformatic analysis showed that OA cDNA has an open reading frame of 1716 bp encoding a protein of 572 aa, the first 21 aa constitute a signal peptide. OA sequence analysis also demonstrated 13 putative N-glycosylation sites suggestive of a heavily glycosylated protein.

Identification and characterization of the genes encoding human and mouse osteoactivin.

Osteoactivin (OA) is more highly expressed in the bones of osteopetrotic mutant rats (op/op) than in those of their normal littermates and is the homologue of human nmb, a cDNA more highly expressed in melanoma-derived cell lines of low metastatic potential, and of mouse DC-HIL, which has been implicated in endothelial cell adhesion. The human OA gene is found on chromosome 7p15.1 and consists of 11 exons spanning 28.

Expression of connective tissue growth factor in bone: its role in osteoblast proliferation and differentiation in vitro and bone formation in vivo.

Connective tissue growth factor (CTGF) is a secreted, extracellular matrix-associated signaling protein that regulates diverse cellular functions. In vivo, CTGF is expressed in many tissues with highest levels in the kidney and brain. The purpose of this study was twofold; first, to localize CTGF in normal bone in vivo during growth and repair, and second, to examine CTGF expression and function in primary osteoblast cultures in vitro and test its effect on bone formation in vivo.

Molecular cloning and functional characterization of the canine parathyroid hormone/parathyroid hormone related peptide receptor (PTH1).

Parathyroid hormone (PTH) is a major mediator of calcium and phosphate metabolism through its interactions with receptors in kidney and bone. PTH binds with high affinity to PTH1 and PTH2, members of the superfamily of G protein-coupled receptors. In order to clone the canine PTH1 receptor, a canine kidney cDNA library was screened using the human PTH1 receptor cDNA and two clones were further characterized.

Regulation of BMP-7 expression by retinoic acid and prostaglandin E(2).

Bone morphogenetic proteins (BMPs) are members of the transforming growth factor-beta (TGF-beta) gene superfamily of growth and differentiation factors. Members of the BMP family were originally cloned and characterized by their ability to induce ectopic bone formation. Of the various BMPs cloned, the bone inductive ability of BMP-7 (OP-1) and BMP-2 has been well characterized.

Molecular cloning and functional characterization of the canine androgen receptor.

Sex steroids, including testosterone, play a major role in determining peak bone mass in mammals and the subsequent loss of total bone mass with advancing age. Testosterone, and its active metabolite dihydrotestosterone (DHT), bind with high affinity to the androgen receptor (AR), a member of the nuclear hormone receptor superfamily. These receptors function as transcription factors, binding together with accessory proteins to specific DNA response elements in the promoters of androgen responsive genes.

Cloning and characterization of osteoactivin, a novel cDNA expressed in osteoblasts.

Osteoblast development is a complex process involving the expression of specific growth factors and regulatory proteins that control cell proliferation, differentiation, and maturation. In this study, we used the rat mutation, osteopetrosis (op), to examine differences in skeletal gene expression between mutant op and normal littermates. Total RNA isolated from long bone and calvaria was used as a template for mRNA differential display.

Molecular cloning and functional characterization of the canine prostaglandin E2 receptor EP4 subtype.

Prostaglandin E2 (PGE2) is an important mediator of diverse biologic functions in many tissues and binds with high affinity to four cell surface, seven-transmembrane domain, G protein-coupled receptors (EP1-EP4). The EP4 receptor subtype has a long intracellular carboxy-terminal region and is functionally coupled to adenylate cyclase, resulting in elevated intracellular cyclic adenosine 5' monophosphate (cAMP) levels upon activation. To further study EP4 receptor subtype function, a canine kidney cDNA library was screened and three clones were isolated and sequenced.

Cloning the full-length cDNA for rat connective tissue growth factor: implications for skeletal development.

The mammalian osteopetroses represent a pathogenetically diverse group of skeletal disorders characterized by excess bone mass resulting from reduced osteoclastic bone resorption. Abnormalities involving osteoblast function and skeletal development have also been reported in many forms of the disease. In this study, we used the rat mutation, osteopetrosis (op), to examine differences in skeletal gene expression between op mutants and their normal littermates.

Cloning, structural characterization, and chromosomal localization of the gene encoding the human prostaglandin E(2) receptor EP2 subtype.

Northern blot analysis of human placental RNA using a probe to the 5' end of the human prostaglandin E(2) (PGE(2)) EP2 receptor subtype coding region revealed the existence of a high abundance, low molecular weight transcript. To investigate the origin of this transcript, and its possible relationship to the human EP2 mRNA, we have cloned and characterized the gene encoding the human PGE(2) EP2 receptor subtype, identified transcriptional initiation and termination sites in two tissues (spleen and thymus), and determined its chromosomal localization. The human EP2 gene consists of two exons separated by a large intron, utilizes a common initiation site in both spleen and thymus at 1113 bp upstream of the translation initiation site, and has 3' transcript termini at 1140 bp and 1149 bp downstream of the translation stop site in spleen and thymus respectively.