Modulation of Chiroptical and Photophysical Properties in Helicenic Rhenium(I) Systems: The Use of an N-(Aza[6]helicenyl)-NHC Ligand.

The photophysical and chiroptical properties of a novel, chiral helicene-NHC-Re(I) complex bearing an N-(aza[6]helicenyl)-benzimidazolylidene ligand are described, showing its ability to emit yellow circularly polarized luminescence. A comparative analysis of this new system with other helicene-Re(I) complexes reported to date illustrates the impact of structural modifications on the emissive and absorptive properties.

Dual-Readout of the Mechanical Response of a Bis-acridinium [2]Rotaxane.

A [2]rotaxane built around a multi-responsive bis-acridinium macrocycle has been synthesized. Structural investigation has confirmed the interlocked nature of the molecule, and MD simulations illuminated its conformational dynamics with atomic resolution. Both halochromic and redox-switching properties were explored to shed light on the mechanical response and electronic changes that occur in the bis-acridinium [2]rotaxane. The topology of the rotaxane led to different mechanical behaviors upon addition of hydroxide ions or reduction that were easily detected by UV/Vis spectroscopy and electrochemistry.

Helicenic N-heterocyclic carbene copper(I) complex displaying circularly polarized blue fluorescence.

Enantiopure copper(I) chloride complexes bearing a monodentate N-(carbo[6]helicenyl)-NHC ligand have been prepared and characterized experimentally and computationally. Their high stability enables the stereochemistry to be probed by X-ray crystallography and NMR spectroscopy. The resolved enantiomeric complexes emit circularly polarized blue fluorescence with glum ∼1.3 × 10-3 in solution. The photophysical and chiroptical properties of these systems, with their helicene-centred origin, are similar to those of the organic helicene-benzimidazole precursor proligand, although the reverse axial chirality configuration is preferentially observed for the complex compared to the ligand.

CCL5 production in lung cancer cells leads to an altered immune microenvironment and promotes tumor development.

Current immunotherapies for lung cancer are only effective in a subset of patients. Identifying tumor-derived factors that facilitate immunosuppression offers the opportunity to develop novel strategies to supplement and improve current therapeutics. We sought to determine whether expression of driver oncogenes in lung cancer cells affects cytokine secretion, alters the local immune environment, and influences lung tumor progression. We demonstrate that oncogenic EGFR and KRAS mutations, which are early events in lung tumourigenesis, can drive cytokine and chemokine production by cancer cells. One of the most prominent changes was in CCL5, which was rapidly induced by KRASG12V or EGFRL858R expression, through MAPK activation. Immunocompetent mice implanted with syngeneic KRAS-mutant lung cancer cells deficient in CCL5 have decreased regulatory T cells (Tregs), evidence of T cell exhaustion, and reduced lung tumor burden, indicating tumor-cell CCL5 production contributes to an immune suppressive environment in the lungs. Furthermore, high CCL5 expression correlates with poor prognosis, immunosuppressive regulatory T cells, and alteration to CD8 effector function in lung adenocarcinoma patients. Our data support targeting CCL5 or CCL5 receptors on immune suppressive cells to prevent formation of an immune suppressive tumor microenvironment that promotes lung cancer progression and immunotherapy insensitivity.

Test Strip Platform Spin-Off for Telomerase Activity Detection: Development of an Electrochemical Biosensor.

Telomerase overexpression has been associated directly with cancer, and the enzyme itself is recognized within the scientific community as a cancer biomarker. BIDEA's biosensing strip (BBS) is an innovative technology capable of detecting the presence of telomerase activity (TA) using electrochemical impedance spectroscopy (EIS). This BBS is an interdigital gold (GID) electrode array similar in size and handling to a portable glucose sensor. For the detection of the biomarker, BBS was modified by the immobilization of a telomere-like single strand DNA (ssDNA) on its surface. The sensor was exposed to telomerase-positive extract from commercially available cancer cells, and the EIS spectra were measured. Telomerase recognizes the sequence of this immobilized ssDNA probe on the BBS, and the reverse transcription process that occurs in cancer cells is replicated, resulting in the ssDNA probe elongation. This surface process caused by the presence of TA generates changes in the capacitive process on the electrode array microchip surface, which is followed by EIS as the sensing tool and correlated with the presence of cancer cells. The telomerases' total cell extraction protocol results demonstrate significant changes in the charge-transfer resistance (R ct) change rate after exposure to telomerase-positive extract with a detection limit of 2.94 × 104 cells/mL. Finally, a preliminary study with a small set of "blind" uterine biopsy samples suggests the feasibility of using the changes in the R ct magnitude change rate (Δ(ΔR ct/R cti)/Δt) to distinguish positive from negative endometrial adenocarcinoma samples by the presence or absence of TA.

Circularly Polarized Fluorescent Helicene-Boranils: Synthesis, Photophysical and Chiroptical Properties.

Mono- and di-boranil-substituted helicenes were prepared by BF2 -borylation of the corresponding anils, readily synthesized by condensation of 2-amino- and 2,15-diamino-helicenes with 4-(diethylamino)salicylaldehyde. After enantiomeric resolution using HPLC, their chiroptical properties including circularly polarized fluorescence in solution and in PMMA films were investigated and rationalized with the help of NMR, X-ray and quantum-chemical calculations.

Synthesis and Properties of Partially Saturated Fluorenyl-Derived [n]Helicenes Featuring an Overcrowded Alkene.

The straightforward, multigram-scale synthesis of the partially saturated H6 -fluoreno[n]helicenes (n=5 or 7) featuring a central, overcrowded alkene is described. The key cyclization step was based on an intramolecular McMurry reaction from the corresponding 1,5-diketones. Chiral stationary phase HPLC analysis and isomer separation indicate that each helicenic compound is constituted of three diastereoisomers at room temperature, i. e. the configurationally stable (R,R,P)/(S,S,M) pair of enantiomers and an apparently achiral compound resulting from the rapid interconversion between the (R,S,P) and (S,R,M) enantiomers. The partially saturated H6 -fluoreno[n]helicenes are oxidatively aromatized to give an efficient access to the corresponding fluoreno[n]helicenes. The chiroptical properties (vibrational and electronic circular dichroism) of the chiral, enantiopure compounds have been measured and analyzed by quantum-chemical calculations, confirming their helicoidal nature.

Metal-Based Multihelicenic Architectures.

The preparation of multihelicenic systems by conventional organic synthesis is a challenging task and under continuous development. In parallel, using complexing units grafted to or incorporated within the helicene core and taking advantage of coordination/organometallic chemistry constitutes a powerful strategy to obtain multihelicenic structures. This Minireview focuses on the state-of-the-art preparation of metal-based multihelicenic architectures such as coordination-driven supramolecular assemblies and organometallic architectures. Their properties and their applications are presented.

Long-Lived Circularly Polarized Phosphorescence in Helicene-NHC Rhenium(I) Complexes: The Influence of Helicene, Halogen, and Stereochemistry on Emission Properties.

The first enantiopure chiral-at-rhenium complexes of the form fac-ReX(CO)3 (:C^N) have been prepared, where :C^N is a helicene-N-heterocyclic carbene (NHC) ligand and X=Cl or I. These have complexes show strong changes in the emission characteristics, notably strongly enhanced phosphorescence lifetimes (reaching 0.7 ms) and increased circularly polarized emission (CPL) activity, as compared to their parent chiral models lacking the helicene unit. The halogen along with its position within the dissymmetric stereochemical environment strongly affect the photophysics of the complexes, particularly the phosphorescence quantum yield and lifetime. These results give fresh insight into fine tuning of photophysical and chiroptical properties of Re-NHC systems.

C-Halide bond cleavage by a two-coordinate iron(i) complex.

Iron(i) species are debated as key intermediates during the C-halide activation step in Kumuda type C-C cross-coupling catalysis. However, there is only limited knowledge on the reactivity of isolable iron(i) complexes towards organohalides. Using the known two-coordinate iron(i) complex K{18c6}[FeI(N(SiMe3)2)2] we disclose its proficiency to rapidly cleave different types of carbon halide bonds including even C-F bonds. Mechanistic studies indicate stepwise one-electron processes with the involvement of organoradicals.

Re-situating fieldwork and re-narrating disciplinary history in global mega-geomorphology.

In 1985, more than thirty geomorphologists, planetary scientists, and remote sensing specialists gathered at a conference center in Oracle, Arizona, to discuss an emerging area of research that they called "mega-geomorphology." Building on a conference of the same name held in London in 1981, they argued that new techniques of remote sensing and insights emerging from the study of extraterrestrial planets had created opportunities for geomorphology to broaden its spatial and temporal scope. This new approach was, however, neither unproblematic nor uncontested. In the discussions around mega-geomorphology that took place in the mid-1980s, the perceived conflict between the use of remote-sensing techniques to observe phenomena on vast spatial scales, on one hand, and the disciplinary centrality of fieldwork and field experience to geomorphology, on the other, was a recurrent theme. In response, mega-geomorphologists attempted to re-situate fieldwork and re-narrate disciplinary histories in such a way as to make remote sensing and planetary science not only compatible with geomorphological traditions but also means of revitalizing them. Only partially successful, these attempts reveal that the process of adopting a planetary perspective in geomorphology, as in other earth sciences, was neither straightforward nor inevitable. They also show how the field and fieldwork could remain central to geomorphology while also being extensively revised in light of new technical possibilities and theoretical frameworks.

One-step synthesis of conjugated enynenitriles from bromocyanoacetylene.

The chemical reactivity of bromocyanoacetylene has been evaluated for the first time by making it react with terminal alkynes and secondary amines in the presence of bis(triphenylphosphine)palladium dichloride and copper iodide as co-catalysts. This reaction provides new conjugated enynenitriles stereoselectively in one step in variable yields.

Trackable life: Data, sequence, and organism in movement ecology.

Over the past decade an increasing number of ecologists have begun to frame their work as a contribution to the emerging research field of movement ecology. This field's primary object of research is the movement track, which is usually operationalized as a series of discrete "steps and stops" that represent a portion of an animal's "lifetime track." Its practitioners understand their field as dependent on recent technical advances in tracking organisms and analyzing their movements. By making movement their primary object of research, rather than simply an expression of deeper biological phenomena, movement ecologists are able to generalize across the movement patterns of a wide variety of species and to draw on statistical techniques developed to model the movements of non-living things. Although it can trace its roots back to a long tradition of statistical models of movement, the field relies heavily on metaphors from genomics; in particular, movement tracks have been seen as similar to DNA sequences. Though this has helped movement ecology consolidate around a shared understanding of movement, the field may need to broaden its understanding of movement beyond the sequence if it is to realize its potential to address urgent concerns such as biodiversity loss.

Naming the Ethological Subject.

Argument In recent decades, through the work of Jane Goodall and other ethologists, the practice of giving personal names to nonhuman animals who are the subjects of scientific research has become associated with claims about animal personhood and scientific objectivity. While critics argue that such naming practices predispose the researcher toward anthropomorphism, supporters suggest that it sensitizes the researcher to individual differences and social relations. Both critics and supporters agree that naming tends to be associated with the recognition of individual animal rights. The history of the naming of research animals since the late nineteenth century shows, however, that the practice has served a variety of purposes, most of which have raised few ethical or epistemological concerns. Names have been used to identify research animals who play dual roles as pets, workers, or patients, to enhance their market value, and to facilitate their identification in the field. The multifaceted history of naming suggests both that the use of personal names by Goodall and others is less of a radical break with previous practices than it might first appear to be and that the use of personal names to recognize the individuality, sentience, or rights of nonhuman animals faces inherent limits and contradictions.

Understanding transferable supply chain lessons and practices to a "high-tech" industry using guidelines from a primary sector industry: a case study in the food industry supply chain.

Flexibility and innovation at creating shapes, adapting processes, and modifying materials characterize composites materials, a "high-tech" industry. However, the absence of standard manufacturing processes and the selection of materials with defined properties hinder the configuration of the composites materials supply chain. An interesting alternative for a "high-tech" industry such as composite materials would be to review supply chain lessons and practices in "low-tech" industries such as food. The main motivation of this study is to identify lessons and practices that comprise innovations in the supply chain of a firm in a perceived "low-tech" industry that can be used to provide guidelines in the design of the supply chain of a "high-tech" industry, in this case composite materials. This work uses the case study/site visit with analogy methodology to collect data from a Spanish leading producer of fresh fruit juice which is sold in major European markets and makes use of a cold chain. The study highlights supply base management and visibility/traceability as two elements of the supply chain in a "low-tech" industry that can provide guidelines that can be used in the configuration of the supply chain of the composite materials industry.

Three bonding modes of bis(2-picolyl)phenylphosphine at iron: isolation of a dinuclear iron complex featuring dearomatized pyridine moieties.

The coordination ability of the bis(2-picolyl)phenylphosphine (NPN) compound has been probed toward the iron precursor [Fe{N(SiMe3)2}2]. By a careful control of the experimental conditions we were able to isolate and characterize three complexes displaying different coordination modes of the NPN ligand as revealed in particular by X-ray diffraction, and multinuclear solution and solid state NMR analyses. It is shown that NPN can be used as a proton-responsive ligand with enough flexibility to allow the formation of the dinuclear complex [Fe{P(CH2(C5H4N))(CH(C5H4N))}(N(SiMe3)2)]2 with two NPN ligands spanning the two metal centres.

A systematic review of the effect of daily panty liner use on the vulvovaginal environment.

BACKGROUND: Whether panty liners predispose to vulvovaginitis is unclear. OBJECTIVES: To clarify the effects of the use of panty liners on the female genital tract. SEARCH STRATEGY: Several electronic databases (including PubMed and Embase) were searched to identify studies published in English before May 3, 2012. SELECTION CRITERIA: Case-control studies, randomized controlled trials, and cohort studies comparing young women who did and did not use panty liners in the intermenstrual period were included. DATA COLLECTION AND ANALYSIS: The quality of the studies was assessed using the Newcastle-Ottawa Scale or the Jadad Scale. Data from suitable studies were extracted for analysis. MAIN RESULTS: Five articles met the inclusion criteria. Four studies-all of which included only healthy women-found no significant clinical implications arising from the use of panty liners. The fifth study was of women with recurrent candidiasis and showed that use of panty liners was associated with new candidiasis episodes. CONCLUSIONS: The intermenstrual use of panty liners does not seem to have a negative effect on the vulvovaginal area.

New perspectives in hydrogen storage based on RCH2NH2/RCN couples.

A recent breakthrough in primary amine dehydrogenation by an oxidant-free process, and without any hydrogen acceptor, opens the possibility for RCH2NH2/RCN couples to be considered as potential hydrogen energy carriers. Both hydrogenation and dehydrogenation processes can be catalysed by ruthenium complexes under rather mild conditions. This emerging exciting approach could be the starting point for the development of valuable economical systems.

Application of proton-transfer-reaction-mass-spectrometry for Indoor Air Quality research.

In the field of Indoor Air Quality research, the measurement of volatile organic compounds (VOCs) demands instruments that are rapid, mobile, robust, highly sensitive and allow for simultaneous monitoring of multiple compounds. These instruments should also compensate for possible interferences from permanent gases and air humidity. Proton-transfer-reaction-mass-spectrometry (PTR-MS) has proved to be a valuable and promising technique that fits the mentioned requirements for a suitable online measuring device. In this study, five exemplary applications of PTR-MS are described: (i) release of paint additives during drying process, (ii) emission of VOCs from active hardcopy devices, (iii) reference material evaluation, (iv) diffusion studies, and (v) emission testing of building products. The examples are selected to illustrate possibilities and limitations of the PTR technique in this field of research. The quadruple-based PTR-QMS was able to determine the emission characteristics during the experiments, especially in case of depleting emission sources (e.g., reference material). This allows for chemometrical analysis of the measured release patterns and detection of underlying processes. However, PTR-QMS reaches a functional limit in case of compound identification. If identification of VOCs is necessary, the measurements need to be accompanied by GC/MS analytics or a PTR instrument with higher mass-resolution (e.g., PTR-TOF-MS).