Micro- and nano-structural analyses of damage in bone

Skeletal fractures represent a significant medical and economic burden for our society. In the US alone, age-related hip, spine, and wrist fractures accounted for more than $17 billion in direct health care costs in 2001. Moreover, skeletal fractures are not limited to the elderly; stress fractures and impact/trauma-related fractures are a significant problem in younger people also. Gaining insight into the mechanisms of fracture and how these mechanisms are modulated by intrinsic as well as extrinsic factors may improve the ability to define fracture risk and develop and assess preventative therapies for skeletal fractures. Insight into failure mechanisms of bone, particularly at the ultrastructural-level, is facilitated by the development of improved means of defining and measuring tissue quality. Included in these means are microscopic and spectroscopic techniques for the direct observation of crack initiation, crack propagation, and fracture behavior. In this review, we discuss microscopic and spectroscopic techniques, including laser scanning confocal microscopy (LSCM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectroscopic imaging for visually observing microdamage in bone, and the current understanding of damage mechanisms derived from these techniques.     

Nanoporous gold electrode prepared from gold compact disk as the anode for the microbial fuel cell

The electrodes (anode and cathode) have an important role in the efficiency of a microbial fuel cell (MFC), as they can determine the rate of charge transfer in an electrochemical process. In this study, nanoporous gold electrode, prepared from commercially available gold-made compact disk, is utilized as the anode in a two-chamber MFC. The performance of nanoporous gold electrode in the MFC is compared with that of gold film, carbon felt and acid-heat-treated carbon felt electrodes which are usually employed as the anode in the MFCs. Electrochemical surface area of nanoporous gold electrode exhibits a 7.96-fold increase rather than gold film electrode. Scanning electron microscopy analysis also indicates the homogeneous biofilm is formed on the surface of nanoporous gold electrode, while the biofilm formed at the surface of acid-heat-treated carbon felt electrode shows rough structure. Electrochemical studies show although modifications applied on carbon felt electrodes improve its performance, nanoporous gold electrode, due to its structure and better electrochemical properties, acts more efficiently as the MFC’s anode. The maximum power density produced by nanoporous gold anode is 4.71 mW m^?2 at current density of 16.00 mA m^?2, while this value for acid-heat-treated carbon felt anode is 3.551 mW m^?2 at current density of 9.58 mA m^?2.     

Ring‐Opening Copolymerization of Maleic Anhydride with Functional Epoxides: Poly(propylene fumarate) Analogues Capable of Post‐Polymerization Modification

Three functional epoxides were copolymerized with maleic anhydride to yield degradable poly(propylene fumarate) analogues. The polymers were modified post‐polymerization and post‐printing with either click‐type addition reactions or UV deprotection to either attach bioactive species or increase the hydrophilicity. Successful dye attachment, induced wettability, and improved cell spreading show the viability of these analogues in biomaterials applications.     

Preparation,crystal structure,spectroscopic studies,DFT calculations,antibacterial activities and molecular docking of a tridentate Schiff base ligand and its cis‐MoO2 complex

We synthesized a tridentate Schiff base ligand, 6‐(((2‐hydroxyphenyl)amino)methylene)‐2‐methoxycyclohexa‐2,4‐dienone [H₂L], as well as its Mo(VI) complex [MoO₂(L)(DMSO)], and then characterized them completely using elemental analysis, FT‐IR, UV–Vis and ¹HNMR spectroscopy techniques. X‐ray single crystal diffraction method was used for the determination of the structure of the synthesized ligand and complex. All other spectroscopic techniques performed, confirmed that [MoO₂(L)(DMSO)]had an octahedral geometry around the Mo(VI) central ion coordinated by the donor atoms of the deprotonated ligand, two oxido groups and one oxygen atom of DMSO molecule. Hybrid functional B3LYP with DGDZVP as basis set was applied for DFT calculations of the compounds in their ground state. The MEP, Mulliken, HOMO‐LUMO energy gap and thermodynamic properties of the compounds were also theoretically predicted. In‐vitro antimicrobial studies on the synthesized compounds indicated the great antibacterial activities of the Mo(VI) complex against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Bacillus cereus bacteria.     

A unique two-photon fluorescent probe based on ICT mechanism for imaging palladium in living cells and mice

Palladium(0) as one of the vital transition metals, is employed in numerous industries, such as drug synthesis, aerospace high-tech field and automobile industry. When the Pd(0) enter into the body, it will bind with thiol-containing amino acids, DNA, RNA, and other biomolecules damaging to human health. Thus, developing a novel tool for monitoring and imaging of Pd(0) in vivo is very urgent. In the work, based on a intramolecular charge transfer (ICT) mechanism a two-photon fluorescent probe NIPd had been designed and synthesized for the recognition Pd(0). In vitro experiments data displayed that probe NIPd exhibited a 13-fold fluorescent increase for Pd(0) in 30 min in the aqueous solution with a detection limit of 16 nmol/L. It also showed the outstanding selectivity and antijamming performance. More importantly, NIPd could be served as a two-photon fluorescent probe for real-time monitoring Pd(0) in living cells and mice.     

Synthesis and Biological Evaluation of Bicalutamide Analogues for the Potential Treatment of Prostate Cancer

The androgen receptor (AR) is a pivotal target for the treatment of prostate cancer (PC) even when the disease progresses toward androgen-independent or castration-resistant forms. In this study, a series of 15 bicalutamide analogues (sulfide, deshydroxy, sulfone, and O-acetylated) were prepared and their antiproliferative activity evaluated against four different human prostate cancer cell lines (22Rv1, DU-145, LNCaP, and VCap). Bicalutamide and enzalutamide were used as positive controls. Seven of these compounds displayed remarkable enhancement in anticancer activity across the four PC cell lines. The deshydroxy analogue (16) was the most active compound with IC₅₀ = 6.59–10.86 µM. Molecular modeling offers a plausible explanation of the higher activity of the sulfide analogues compared to their sulfone counterparts.     

Synthesis and bioactivity evaluation of new pyrimidinone-5-carbonitriles as potential anticancer and antimicrobial agents

Research on Chemical Intermediates - New series of pyrimidinone-5-carbonitriles 3a–i, 4a–e, 5a–c, 6 and 7 have been synthesized and explored for their activities as anticancer,...