Proteomic and Physiological Responses of Kineococcus radiotolerans to Copper

Copper is a highly reactive, toxic metal; consequently, transport of this metal within the cell is tightly regulated. Intriguingly, the actinobacterium Kineococcus radiotolerans has been shown to not only accumulate soluble copper to high levels within the cytoplasm, but the phenotype also correlated with enhanced cell growth during chronic exposure to ionizing radiation. This study offers a first glimpse into the physiological and proteomic responses of K. radiotolerans to copper at increasing concentration and distinct growth phases. Aerobic growth rates and biomass yields were similar over a range of Cu(II) concentrations (0–1.5 mM) in complex medium. Copper uptake coincided with active cell growth and intracellular accumulation was positively correlated with Cu(II) concentration in the growth medium (R2 = 0.7). Approximately 40% of protein coding ORFs on the K. radiotolerans genome were differentially expressed in response to the copper treatments imposed. Copper accumulation coincided with increased abundance of proteins involved in oxidative stress and defense, DNA stabilization and repair, and protein turnover. Interestingly, the specific activity of superoxide dismutase was repressed by low to moderate concentrations of copper during exponential growth, and activity was unresponsive to perturbation with paraquot. The biochemical response pathways invoked by sub-lethal copper concentrations are exceptionally complex; though integral cellular functions are preserved, in part, through the coordination of defense enzymes, chaperones, antioxidants and protective osmolytes that likely help maintain cellular redox. This study extends our understanding of the ecology and physiology of this unique actinobacterium that could potentially inspire new biotechnologies in metal recovery and sequestration, and environmental restoration

Pseudopterosin synthesis from a chiral cross-conjugated hydrocarbon through a series of cycloadditions

The pseudopterosins are a family of diterpene marine natural products, which, by virtue of their interesting anti-inflammatory and analgesic properties, have attracted the attentions of many synthetic chemists. The most efficient syntheses reported to date are 14 and 20 steps in the longest linear sequence for chiral pool and enantioselective approaches, respectively, and all start with precursors that are easily mapped onto the natural product structure. Here, we describe an unconventional approach in which a chiral cross-conjugated hydrocarbon is used as the starting material for a series of three cycloadditions. Our approach has led to a significant reduction in the step count required to access these interesting natural products (10 steps chiral pool and 11 steps enantioselective). Furthermore it demonstrates that cross-conjugated hydrocarbons, erroneously considered by many to be too unstable and difficult to handle, are viable precursors for natural product synthesis

Manual therapy with and without vestibular rehabilitation for cervicogenic dizziness: a systematic review

<p>Abstract</p> <p>Background</p> <p>Manual therapy is an intervention commonly advocated in the management of dizziness of a suspected cervical origin. Vestibular rehabilitation exercises have been shown to be effective in the treatment of unilateral peripheral vestibular disorders, and have also been suggested in the literature as an adjunct in the treatment of cervicogenic dizziness. The purpose of this systematic review is to evaluate the evidence for manual therapy, in conjunction with or without vestibular rehabilitation, in the management of cervicogenic dizziness.</p> <p>Methods</p> <p>A comprehensive search was conducted in the databases Scopus, Mantis, CINHAL and the Cochrane Library for terms related to manual therapy, vestibular rehabilitation and cervicogenic dizziness. Included studies were assessed using the Maastricht-Amsterdam criteria.</p> <p>Results</p> <p>A total of fifteen articles reporting findings from thirteen unique investigations, including five randomised controlled trials and eight prospective, non-controlled cohort studies were included in this review. The methodological quality of the included studies was generally poor to moderate. All but one study reported improvement in dizziness following either unimodal or multimodal manual therapy interventions. Some studies reported improvements in postural stability, joint positioning, range of motion, muscle tenderness, neck pain and vertebrobasilar artery blood flow velocity.</p> <p>Discussion</p> <p>Although it has been argued that manual therapy combined with vestibular rehabilitation may be superior in the treatment of cervicogenic dizziness, there are currently no observational and experimental studies demonstrating such effects. A rationale for combining manual therapy and vestibular rehabilitation in the management of cervicogenic dizziness is presented.</p> <p>Conclusion</p> <p>There is moderate evidence to support the use of manual therapy, in particular spinal mobilisation and manipulation, for cervicogenic dizziness. The evidence for combining manual therapy and vestibular rehabilitation in the management of cervicogenic dizziness is lacking. Further research to elucidate potential synergistic effects of manual therapy and vestibular rehabilitation is strongly recommended.</p

Sequencing three crocodilian genomes to illuminate the evolution of archosaurs and amniotes

The International Crocodilian Genomes Working Group (ICGWG) will sequence and assemble the American alligator (Alligator mississippiensis), saltwater crocodile (Crocodylus porosus) and Indian gharial (Gavialis gangeticus) genomes. The status of these projects and our planned analyses are described

A Scalable Process for the Synthesis of 1,2-Dialkyldiselanes and 1-Alkaneselenols

A four-step telescoped process for the synthesis of 1-alkaneselenols entails (1) the rapid formation of potassium selenocyanate from potassium cyanide and selenium in methanol, (2) the nucleophilic substitution of bromoalkanes or alkyl tosylates with potassium selenocyanate, (3) the mild base-catalyzed conversion of the resultant 1-alkaneselenocyanates to 1,2-dialkyldiselanes (the Krief reaction), and (4) the reduction of the resultant 1,2-dialkyldiselanes with hypophosphorous acid to give the desired 1-alkaneselenols. The process has been used to produce 1-octaneselenol on a 10.4 mol scale. Nine examples of the process are described

Oxidative Pictet-Spengler cyclisations through acceptorless iridium-catalysed dehydrogenation of tertiary amines

The valuable tetrahydro-β- and γ-carboline skeleta can be accessed through Pictet-Spengler cyclisation initiated by acceptorless dehydrogenation of saturated cyclic amines. The substrate scope for the β-isomers is found to be somewhat limited, but access to the γ-isomers through the more reactive 2-(aminoethyl)indoles is more general. The synthetic utility of hydrogen transfer catalysis is highlighted in a two-step preparation of the alkaloid desbromoarborescidine A by sequential redox-neutral alkylation/dehydrogenative cyclisation

Active Packaging Technologies with an Emphasis on Antimicrobial Packaging and its Applications

In response to the dynamic changes in current consumer demand and market trends, the area of Active Packaging (AP) is becoming increasingly significant. Principal AP systems include those that involve oxygen scavenging, moisture absorption and control, carbon dioxide and ethanol generation, and antimicrobial (AM) migrating and nonmigrating systems. Of these active packaging systems, the AM version is of great importance. This article reviews: (1) the different categories of AP concepts with particular regard to the activity of AM packaging and its effects on food products, (2) the development of AM and AP materials, and (3) the current and future applications of AM packaging