Biosorption of rare earth elements from luminophores by G. sulphuraria (Cyanidiophytina, Rhodophyta).

Lanthanides are indispensable constituents of modern technologies and are often challenging to acquire from natural resources. The demand for REEs is so high that there is a clear need to develop efficient and eco-friendly recycling methods. In the present study, freeze-dried biomass of the polyextremophile Galdieria sulphuraria was employed to recover REEs from spent fluorescent lamps (FL) luminophores by pretreating the freeze-dried biomass with an acid solution to favour ion exchange and enhance the binding sites on the cell surface available for the metal ions. Lanthanides were extracted from the luminophores using sulfuric acid solutions according to standardised procedures, and the effect of biosorbent dosage (0.5-5 mg/ml) and biosorption time (5-60 min) were evaluated. The content of individual REEs in the luminophores and the resulting algal biomass were determined using inductively coupled plasma mass spectrometry (ICP-MS). The most abundant REE in the luminophores was yttrium (287.42 mg/g dm, 91.60% of all REEs), followed by europium (20.98 mg/g, 6.69%); cerium, gadolinium, terbium and lanthanum was in trace. The best biosorption performances were achieved after 5 min and at the lowest biosorbent dosage (0.5 mg/mL). The highest total metal amount corresponded to 41.61 mg/g dried mass, and yttrium was the most adsorbed metal (34.59 mg/g dm, 82.88%), followed by cerium (4.01 mg/g); all other metals were less than 2 mg/g. The rapidity of the biosorption process and the low biosorbent dosage required confirmed this microalga as a promising material for creating an eco-sustainable protocol for recycling REEs.

Singlet Molecular Oxygen: from COIL Lasers to Photodynamic Cancer Therapy.

Translation of experimental techniques from one scientific discipline to another is often difficult but rewarding. Knowledge gained from the new area can lead to long lasting and fruitful collaborations with concomitant development of new ideas and studies. In this Review Article, we describe how early work on the chemically pumped atomic iodine laser (COIL) led to the development of a key diagnostic for a promising cancer treatment known as photodynamic therapy (PDT). The highly metastable excited state of molecular oxygen, a1Δg, also known as singlet oxygen, is the link between these disparate fields. It powers the COIL laser and is the active species that kills cancer cells during PDT. We describe the fundamentals of both COIL and PDT and trace the development path of an ultrasensitive dosimeter for singlet oxygen. The path from COIL lasers to cancer research was relatively long and required medical and engineering expertise from numerous collaborations. As we show below, the knowledge gained in the COIL research, combined with these extensive collaborations, has resulted in our being able to show a strong correlation between cancer cell death and the singlet oxygen measured during PDT treatments of mice. This progress is a key step in the eventual development of a singlet oxygen dosimeter that could be used to guide PDT treatments and improve outcomes.

Selective biosorption of lanthanides onto Galdieria sulphuraria.

The recovering of trivalent Lanthanides from aqueous solutions, by biosorption process onto Galdieria sulphuraria lifeless cells, was investigated. Potentiometry, UV-Vis, FTIR-ATR spectroscopy and SEM-EDS analysis were used. All the experiments were performed at 25 °C, in 0.5 M NaCl. Ln3+ biosorption is greater in the 5-6 pH range with values ranging from 80 µmol/g to 130 µmol/g (dry weight). The adsorbed Ln3+ ions can be recovered at higher acidity (pH<1) and the biosorbent can be reused. Specific molecular interactions between Ln3+ ions and the functional groups on G. sulphuraria surface were highlighted. Particularly, proteins are involved if Ln3+=Pr3+, Sm3+, Eu3+, Tb3+, Dy3+, Tm3+, while Ce3+, Ho3+, Er3+ form bonds with carbohydrates. Finally, both proteins and carbohydrates are involved if Gd3+ and Yb3+. A Surface Complexation approach, with a good graphical fitting to potentiometric experimental collected data, was used to describe the biosorption mechanism. This study could be of great applicative utility for removing of trivalent actinides, from waste aqueous solutions, by biosorption. As well known the lanthanides were used as model to simulate the chemical behaviour of actinides in the same oxidation state.

Do group 1 metal salts form deep eutectic solvents?

Mixtures of metal salts such as ZnCl2, AlCl3 and CrCl3·6H2O form eutectic mixtures with complexing agents, such as urea. The aim of this research was to see if alkali metal salts also formed eutectics in the same way. It is shown that only a limited number of sodium salts form homogeneous liquids at ambient temperatures and then only with glycerol. None of these mixtures showed eutectic behaviour but the liquids showed the physical properties similar to the group of mixtures classified as deep eutectic solvents. This study focussed on four sodium salts: NaBr, NaOAc, NaOAc·3H2O and Na2B4O7·10H2O. The ionic conductivity and viscosity of these salts with glycerol were studied, and it was found that unlike previous studies of quaternary ammonium salts with glycerol, where the salt decreased the viscosity, most of the sodium salts increased the viscosity. This suggests that sodium salts have a structure making effect on glycerol. This phenomenon is probably due to the high charge density of Na+, which coordinates to the glycerol. 1H and 23Na NMR diffusion and relaxation methods have been used to understand the molecular dynamics in the glycerol-salt mixtures, and probe the effect of water on some of these systems. The results reveal a complex dynamic behaviour of the different species within these liquids. Generally, the translational dynamics of the 1H species, probed by means of PFG NMR diffusion coefficients, is in line with the viscosity of these liquids. However, 1H and 23Na T1 relaxation measurements suggest that the Na-containing species also play a crucial role in the structure of the liquids.

Putative calcium-binding domains of the Caenorhabditis elegans BK channel are dispensable for intoxication and ethanol activation.

Alcohol modulates the highly conserved, voltage- and calcium-activated potassium (BK) channel, which contributes to alcohol-mediated behaviors in species from worms to humans. Previous studies have shown that the calcium-sensitive domains, RCK1 and the Ca(2+) bowl, are required for ethanol activation of the mammalian BK channel in vitro. In the nematode Caenorhabditis elegans, ethanol activates the BK channel in vivo, and deletion of the worm BK channel, SLO-1, confers strong resistance to intoxication. To determine if the conserved RCK1 and calcium bowl domains were also critical for intoxication and basal BK channel-dependent behaviors in C. elegans, we generated transgenic worms that express mutated SLO-1 channels predicted to have the RCK1, Ca(2+) bowl or both domains rendered insensitive to calcium. As expected, mutating these domains inhibited basal function of SLO-1 in vivo as neck and body curvature of these mutants mimicked that of the BK null mutant. Unexpectedly, however, mutating these domains singly or together in SLO-1 had no effect on intoxication in C. elegans. Consistent with these behavioral results, we found that ethanol activated the SLO-1 channel in vitro with or without these domains. By contrast, in agreement with previous in vitro findings, C. elegans harboring a human BK channel with mutated calcium-sensing domains displayed resistance to intoxication. Thus, for the worm SLO-1 channel, the putative calcium-sensitive domains are critical for basal in vivo function but unnecessary for in vivo ethanol action.

Optically pumped microplasma rare gas laser.

The optically pumped rare-gas metastable laser is a chemically inert analogue to three-state optically pumped alkali laser systems. The concept requires efficient generation of electronically excited metastable atoms in a continuous-wave (CW) electric discharge in flowing gas mixtures near atmospheric pressure. We have observed CW optical gain and laser oscillation at 912.3 nm using a linear micro-discharge array to generate metastable Ar(4s, 1s(5)) atoms at atmospheric pressure. We observed the optical excitation of the 1s(5) → 2p(9) transition at 811.5 nm and the corresponding fluorescence, optical gain and laser oscillation on the 2p(10) ↔ 1s(5) transition at 912.3 nm, following 2p(9)→2p(10) collisional energy transfer. A steady-state kinetics model indicates efficient collisional coupling within the Ar(4s) manifold.

Aflibercept for the treatment of neovascular age-related macular degeneration.

Age-related macular degeneration (AMD) can have devastating effects on vision, especially in its neovascular form. In the last decade, the use of intravitreal pharmacotherapy targeted to vascular endothelial growth factor (VEGF) has significantly improved the visual outcomes in patients with neovascular AMD. Although we have become accustomed to these unprecedented improvement outcomes, maintaining good visual results with anti-VEGF therapy requires tremendous effort, time and cost, typically involving monthly clinic visits and intravitreal injections. The introduction of aflibercept, an anti-VEGF drug that targets all isoforms of VEGF as well as placenta growth factor, has shown promise throughout recent clinical trials as an equally effective treatment for neovascular AMD that requires less frequent dosing than either ranibizumab or bevacizumab. Based on clinical trial results, the U.S. Food and Drug Administration approved aflibercept in November 2011 for use in neovascular AMD, giving patients the hope of alleviating some of the burden associated with treatment.

Cs 894.3 nm laser pumped by photoassociation of Cs-Kr pairs: excitation of the Cs D(2) blue and red satellites.

Lasing on the D(1) transition (6P1/22-->6S1/22) of Cs has been observed by photoassociating Cs-Kr atomic pairs with a tunable, pulsed dye laser. Pumping of the blue or red satellites of the Cs D(2) line (62P3/2<==>62S1/2), peaking at approximately 841.1 nm and approximately 853 nm (respectively) in Cs/Kr/C(2)H(6) gas mixtures, provides a photodissociation laser in which the CsKr excimer parent molecule is not, at any point in the pumping process, in a bound electronic state. Relative to the absorbed pump pulse energy, laser slope efficiencies greater than or approximately 5% have been measured when the Cs number density is in the range of 5x10(14)-1.5x10(15) cm(-3) and the pump wavelength is 841.1 nm. Direct photoexcitation of the Cs 6P3/22 state at 852.1 nm under these conditions is a less efficient pathway for pumping the 894.3 nm laser, presumably as a result of competing nonlinear optical processes such as 1+2 resonantly enhanced multiphoton ionization of the alkali atom.

A functional role for the ventrolateral prefrontal cortex in non-spatial auditory cognition.

Spatial and non-spatial sensory information is hypothesized to be evaluated in parallel pathways. In this study, we tested the spatial and non-spatial sensitivity of auditory neurons in the ventrolateral prefrontal cortex (vPFC), a cortical area in the non-spatial pathway. Activity was tested while non-human primates reported changes in an auditory stimulus' spatial or non-spatial features. We found that vPFC neurons were reliably modulated during a non-spatial auditory task but were not modulated during a spatial auditory task. The degree of modulation during the non-spatial task correlated positively with the monkeys' behavioral performance. These results are consistent with the hypotheses that the vPFC is part of a circuit involved in non-spatial auditory processing and that the vPFC plays a functional role in non-spatial auditory cognition.

Increased signs of acute rejection with ischemic time in a rat musculocutaneous allotransplant model.

BACKGROUND: Composite tissue allotransplantation (CTA) may restore a variety of tissue defects, but carries the potential risks of graft failure and/or immunosuppression-related complications. Ischemia-reperfusion injury has been documented in CTA is known to contribute to acute rejection of solid organ grafts. This study describes the influence of subcritical ischemic time (ie, ischemia sufficient to generate reversible cell damage) on signs of rejection of musculocutaneous allograft components of subcritical ischemic time, namely, ischemia sufficient to generate reversible cell injury. Although skin is considered the most antigenic component of a composite allograft and is currently used for rejection surveillance, muscle and adipose are more susceptible to ischemia-related injury. METHODS: Vascularized epigastric flaps were transplanted from WKY to Fisher 344 rats after 1 or 3 hours of ischemia. Biopsies taken on postoperative day 6 were graded for signs of acute rejection according to criteria modified from previously published grading systems for CTA rejection. RESULTS: Skin and muscle exposed to 3 hours of ischemia showed significantly higher rejection scores than after 1 hour of ischemia, as evidenced by a more aggressive diffuse lymphocytic infiltration with disruption of tissue architecture. The rejection score in skin with 3-hour ischemia was 5.0 +/- 0.1 versus 3.7 +/- 0.2 with 1-hour (Mann-Whitney U test; P < .05). The rejection score in muscle exposed to 3-hour ischemia was 3.6 +/- 0.3 versus 2.5 +/- 0.1 with 1-hour (P < .05). CONCLUSIONS: Muscle and skin demonstrated increased acute rejection of allotransplants with increased subcritical ischemic time. This study supports the use of aggressive methods to reduce subcritical ischemic injury during allotransplantation of composite tissue and inclusion of muscle in postoperative biopsies in this early investigational period of CTA.

Miller Fisher syndrome: a diagnosis not to be missed.

We report a case of Miller Fisher syndrome presenting in an ENT setting. The referral was made on the basis of worsening nasal regurgitation following Campylobacter jejuni enteritis. The aim of this report is not to add to the recorded instances of Miller Fisher syndrome, but to help raise the level of its awareness amongst otolaryngologists. Emphasis is placed on the mode of presentation and management issues, as early diagnosis is crucial and confers a favourable prognosis. In that respect, we consider this case noteworthy and instructive.

Circadian rhythms: rho-related signals in time-specific light perception.

A recent study shows that a small GTPase, LIF1, helps to coordinate the plant circadian clock with the daily light-dark cycle.

Hyperspectral infrared imaging of HF(v, J) chemiluminescence and gain in chemically reacting flowfields.

This paper presents results from investigations of chemically reacting flowfields and optical gain profiles in HF chemical laser media by infrared hyperspectral imaging. Subsonic and supersonic chemiluminescent F+H2 reacting flowfields, produced in high-fluence microwave-driven reactors, were imaged at a series of wavelengths, 2.6-3.1 microm, by a low-order, spectrally scanning Fabry-Perot interferometer mated to an infrared camera. The resulting hyperspectral data cubes define the spectral and spatial distributions of the emission. Spectrally resolved images at high spatial resolution were processed to determine spatial distributions of the excited-state concentrations of the product HF(v, J) molecules, as well as spatial distributions of small-signal gain on specific laser transitions. Additional high-resolution Fourier transform spectroscopy and spectral fitting analysis determined detailed excited-state distributions in the reacting flowfields. The measurements showed that energetic HF(v, J) state distributions were generated by both the supersonic and fast-flow subsonic mixing schemes. In particular, the subsonic reactor produced a spatially distributed field of inverted, near-nascent state populations, with small-signal gains near 2-3%/cm.

Eukaryotic expression: developments for structural proteomics.

The production of sufficient quantities of protein is an essential prelude to a structure determination, but for many viral and human proteins this cannot be achieved using prokaryotic expression systems. Groups in the Structural Proteomics In Europe (SPINE) consortium have developed and implemented high-throughput (HTP) methodologies for cloning, expression screening and protein production in eukaryotic systems. Studies focused on three systems: yeast (Pichia pastoris and Saccharomyces cerevisiae), baculovirus-infected insect cells and transient expression in mammalian cells. Suitable vectors for HTP cloning are described and results from their use in expression screening and protein-production pipelines are reported. Strategies for co-expression, selenomethionine labelling (in all three eukaryotic systems) and control of glycosylation (for secreted proteins in mammalian cells) are assessed.

Covering ENT out of hours: how confident are senior house officers?

BACKGROUND: The implementation of the European working time directive has led to an increase in cross-speciality out-of-hours cover. This survey illustrates ENT out-of-hours cover arrangements and assesses the implications for senior house officers (SHOs) responsible for managing emergencies. METHODS: A telephone survey of 100 ENT departments was conducted, asking the on-call SHO about departmental structure, on-call rota design, their previous ENT experience, access to SHO training and their confidence in managing emergencies. RESULTS: 44 per cent of departments used only ENT SHOs on the on-call rota. 73 per cent always had an ENT middle grade on call. In 60 per cent of hospitals, the ENT consultant was sometimes on call with only a non-ENT SHO. At the time of the study, 5 per cent of SHOs had no ENT experience, no access to training, were not confident in managing simple emergencies and were on-call without middle-grade cover. CONCLUSION: The current junior on-call structure for ENT has implications for patient management.

PDCD1: a tissue-specific susceptibility locus for inherited inflammatory disorders.

Variation in genes encoding costimulatory molecules expressed on lymphocytes has been expected to contribute to the genetic component of inflammatory disease, but only the gene encoding the inhibitory protein, CTLA-4, seems consistently to confer disease susceptibility. Studies in murine models implicate the inhibitory product of the pd1 gene, programmed death-1, in the maintenance of peripheral tolerance to self-antigens. We identify 22 single-nucleotide polymorphisms (SNPs) in the equivalent human gene, PDCD1, a number of which show significant associations with the specific immunoglobulin E response to grass allergens in atopic individuals. Stepwise analyses indicate that four of the disease-associated SNPs have independent effects. The two most common haplotypes show positive and negative associations but rarer haplotypes are also likely to be of influence. In a case-control study, multiple regression analysis of genotypic data implies that PDCD1 also confers susceptibility to rheumatoid arthritis. Along with work linking PDCD1 with susceptibility to another autoimmune condition, systemic lupus erythematosus, our data identify PDCD1 as a second immunomodulatory gene with pleiotropic effects in human disease. Genes encoding negative regulators may generally confer a significant fraction of the genetic risk associated with inherited inflammatory disorders.

Bacteriophytochromes are photochromic histidine kinases using a biliverdin chromophore.

Phytochromes comprise a principal family of red/far-red light sensors in plants. Although phytochromes were thought originally to be confined to photosynthetic organisms, we have recently detected phytochrome-like proteins in two heterotrophic eubacteria, Deinococcus radiodurans and Pseudomonas aeruginosa. Here we show that these form part of a widespread family of bacteriophytochromes (BphPs) with homology to two-component sensor histidine kinases. Whereas plant phytochromes use phytochromobilin as the chromophore, BphPs assemble with biliverdin, an immediate breakdown product of haem, to generate photochromic kinases that are modulated by red and far-red light. In some cases, a unique haem oxygenase responsible for the synthesis of biliverdin is part of the BphP operon. Co-expression of this oxygenase with a BphP apoprotein and a haem source is sufficient to assemble holo-BphP in vivo. Both their presence in many diverse bacteria and their simplified assembly with biliverdin suggest that BphPs are the progenitors of phytochrome-type photoreceptors.

The immunological synapse and CD28-CD80 interactions.

According to the two-signal model of T cell activation, costimulatory molecules augment T cell receptor (TCR) signaling, whereas adhesion molecules enhance TCR-MHC-peptide recognition. The structure and binding properties of CD28 imply that it may perform both functions, blurring the distinction between adhesion and costimulatory molecules. Our results show that CD28 on naïve T cells does not support adhesion and has little or no capacity for directly enhancing TCR-MHC-peptide interactions. Instead of being dependent on costimulatory signaling, we propose that a key function of the immunological synapse is to generate a cellular microenvironment that favors the interactions of potent secondary signaling molecules, such as CD28.

CD2F-10: a new member of the CD2 subset of the immunoglobulin superfamily.

The CD2 subset of the immunoglobulin superfamily consists of a rapidly expanding family of leukocyte cell surface receptors, at least five of which (CD2, CD48, CD58, CD150, and CD244) are involved in lymphocyte activation as either receptors or ligands. Completion of the draft sequence of the human genome offers the possibility of systematically identifying the full set of proteins and interactions of this important family. Here we describe the identification and characterization of the first new member of the subset, CD2F-10, found exclusively by genome searching.