Novel catalytic bromolactonization of alkenoic acids using iodobenzene and Oxone®

The novel catalytic reaction for bromolactonization of alkenoic acids is reported. When iodobenzene is used as recyclable catalyst in combination with Oxone® as terminal oxidant, the cyclization of various 4‐pentenoic acids with sodium bromide is easily carried out in CF₃CH₂OH at room temperature and giving five‐membered bromolactones in good yields. J. Heterocyclic Chem., 2011.     

The antimicrobial activities of a series of bis-quaternary ammonium compounds

A series of bis-quaternary ammonium compounds(bis-QACs) N,N’-hevamethylenebis(1-alkyl-4-carbamoyl pyridinium bromide)(4BCAP-6,n)(alkyl chain length,n=8,10,12,14,16 and 18) were synthesized and characterized.Their surface tensions,critical micelle concentrations(CMC),and antimicrobial activities were evaluated.4BCAP-6,10 exhibited the strongest antimicrobial activities except for that against Proteus vulgari.The activities of 4BCAP-6.n against Escherichia coli zk126 were not significantly influenced by temperature.pH and initial bacteria concentration.These results indicate that bis-QACs exhibit high antimicrobial activity regardless of the environmental conditions.     

Genetic services to the latino population in the United States

In 1998 Latinos (Hispanics) in the United States number 30 million persons and account for 11.3% of the total population, while it is predicted that by the year 2020 they will become the largest minority. This article describes the demographics and health profile of the Latino population in the United States. A brief account is given of common cultural traditions and health beliefs that modulate the interaction of this population with the health delivery system in general, and that of genetic services in particular. Further, some problems in the access to, and utilization of genetic services are outlined, and the experience of a project designed to overcome those problems in New York City is described.     

Experimental research on combustion dynamics of medium-scale fire whirl

The medium-scale fire whirl was extensively investigated by experimental means, in order to establish correlations of the burning rate, flame height and flame temperature of fire whirl, and to clarify the difference between fire whirls and general pool fires. Experimental observations and data confirmed that a free burning fire whirl is a highly stable burning phenomenon with large quasi-steady periods. Burning rates of fire whirls depend on pool diameter similarly to those of general pool fires; however the transition turbulent burning occurs sooner as the pool diameter increases. The lip height seems to have little effect on the burning rate of fire whirls. The correlation was proposed to couple the height of fire whirl to the fire release rate and ambient circulation. It correlates the data from both this work and the literature. Radial temperature profiles in the continuous region of the fire whirl were confirmed to be hump-type, implying the existence of fuel-rich inner core. The pool diameter and heat release rate do not significantly affect the radial temperature profiles in non-dimensional radial coordinates. It was found that the fire plume of fire whirl involves three distinct zones just like that of pool fire, but with different normalized ranges. Fire whirls maintain a higher ratio of continuous flame height to the overall flame height, and also higher maximum centerline excess temperature in continuous flame region, as compared to general pool fires. It was further demonstrated that the fire whirl plume at its origin behaves like a turbulent jet with moderate swirling, and then tends to become buoyancy dominated downstream, with slight swirling. With an increase in dimensionless height adjusted by the plume origin, the plume centerline excess temperature decays rapidly and approaches the theoretical value of −5/3 for free buoyancy plume.     

Coherent beam combination of two thulium-doped fiber laser beams with the multi-ditheringtechnique

Coherent beam combination of two thulium-doped fiber laser beams using a multi-dithering technique is presented for the first time. In the experiment, two fiber lasers centered at 1948.6 nm are coherently combined, and a phase modulator based on piezoelectric ceramics transducer is connected in one beam path to compensate for the phase errors between the two beams. When the phase control system is closed loop, the fringe contrast of the far-field intensity pattern is improved to be more than 75%, from 15% in open-loop, and the residual phase error is less than λ/20. The experimental results show that the performance of the phase control system is robust and the control bandwidth is more than 1 kHz, which indicates that the above approach can be scaled to facilitate the coherent beam combination of kilo-watt level thulium-doped fiberlaser.     

Ab Initio Molecular Dynamics Study of Hydrogen Cleavage by a Lewis Base [tBu3P] and a Lewis Acid [B(C6F5)3] at the Mesoscopic Level—Dynamics in the Solute–Solvent Molecular Clusters

With the help of state‐of‐the‐art ab initio molecular dynamics methods, we investigated the reaction pathway of the {tBu₃P + H₂ + B(C₆F₅)₃} system at the mesoscopic level. It is shown that: i) the onset of H₂ activation is at much larger boron???phosphorus distances than previously thought; ii) the system evolves to the product in a roaming‐like fashion because of quasi‐periodic nuclear motion along the asymmetric normal mode of P???H?H???B fragment; iii) transient configurations of a certain type are present despite structural interference from the solvent; iv) transient‐state configurations with sub‐picosecond lifetime have potentially interesting infrared activity in the organic solvent (toluene) as well as in the gas phase. The presented results should be helpful for future experimental and theoretical studies of frustrated Lewis pair (FLP) activity.     

A Novel Xanthone from Garcinia oligantha

One novel xanthone, oliganthone A ( 1 ), was isolated from the stems of the plant Garcinia oligantha. It features the O‐bearing C(3)‐atom and absence of C(4) compared with the structures of related known xanthones, which have never been reported before. The structure of this compound was elucidated by spectroscopic analysis. Compound 1 showed strong HeLa cell growth‐inhibiting effects with IC₅₀ values below 10 μM .     

Effects of Anthraquinones on Immune Responses and Inflammatory Diseases

The anthraquinones (AQs) and derivatives are widely distributed in nature, including plants, fungi, and insects, with effects of anti-inflammation and anti-oxidation, antibacterial and antiviral, anti-osteoporosis, anti-tumor, etc. Inflammation, including acute and chronic, is a comprehensive response to foreign pathogens under a variety of physiological and pathological processes. AQs could attenuate symptoms and tissue damages through anti-inflammatory or immuno-modulatory effects. The review aims to provide a scientific summary of AQs on immune responses under different pathological conditions, such as digestive diseases, respiratory diseases, central nervous system diseases, etc. It is hoped that the present paper will provide ideas for future studies of the immuno-regulatory effect of AQs and the therapeutic potential for drug development and clinical use of AQs and derivatives.