Scanning Tunneling Spectroscopy on the novel superconductor CaC6

We present scanning tunneling microscopy and spectroscopy of the newly discovered superconductor CaC$_6$. The tunneling conductance spectra, measured between 3 K and 15 K, show a clear superconducting gap in the quasiparticle density of states. The gap function extracted from the spectra is in good agreement with the conventional BCS theory with $\Delta(0)$ = 1.6 $\pm$ 0.2 meV. The possibility of gap anisotropy and two-gap superconductivity is also discussed. In a magnetic field, direct imaging of the vortices allows to deduce a coherence length in the ab plane $\xi_{ab}\simeq$ 33 nm

Safer tattooing interventions in prisons: A systematic review and call to action

© 2018 The Author(s). Background: Worldwide more than ten million people are detained at any given time. Between 5 and 60% of people experiencing incarceration report receipt of a tattoo in prison - mostly clandestine, which is associated with risks of blood-borne infections (BBIs). Although safer tattooing techniques are effective in preventing BBI transmission and available to the general population, there is limited knowledge about the impact of safer tattooing strategies in prisons in terms of health outcomes, changes in knowledge and behaviors, and best practice models for implementation. The objective of this research was to identify and review safer tattooing interventions. Methods: We conducted a systematic review of the literature. Studies of all design types were included if they were published until 27 June 2018, the population was incarcerated adults, they reported quantitative outcomes, and were published in English, French, or Spanish. Results: Of 55 papers retrieved from the initial search, no peer-reviewed article was identified. One paper from the grey literature described a multi-site pilot project in Canada. Its evaluation suggested that the project was effective in enhancing knowledge of incarcerated people and prison staff on standard precautions, had the potential to reduce harm, provided vocational opportunities, and was feasible although enhancements were needed to improve implementation issues and efficiency. Conclusions: Although access to preventive services, including to safer tattooing interventions, is a human right and recommended by United Nations agencies as part of a comprehensive package of harm reduction interventions in prisons, this review identified only a few promising strategies for safer tattooing interventions in carceral settings. We call upon governments, criminal justice authorities, non-governmental organizations, and academic institutions to implement safer tattooing projects that adhere to the following guiding principles: i) integration of methodologically-rigorous implementation research; ii) involvement of key stakeholders (incarcerated people, prison authorities, research partners) in the project design, implementation, and research; iii) integration into a comprehensive package of BBI prevention, treatment, and care, using a stepwise approach that considers local resources and acceptability; and iv) publication and dissemination of findings, and scaling up efforts. Prospero Registration: CRD42017072502

The Leiodolide B Puzzle

Out of options? Even though a systematic approach was chosen, which led to a set of four diastereomeric macrolides modeled around the proposed structure of leiodolide B (see picture), the puzzle concerning the stereostructure of this cytotoxic metabolite derived from a deep-sea sponge still remains unsolved

Apple, condom, and cocaine - Body stuffing in prison: A case report

© 2018 The Author(s). Background: Drug dealers and drug users resort to body stuffing to hastily conceal illicit drugs by ingesting their drug packets. This practice represents a medical challenge because rupture of the often insecure packaging can be toxic and even lethal. In an emergency setting, official guidelines are needed to help the medical team decide on the proper treatment. A preliminary observation period is generally accepted but its duration varies from hours to eventual packet expulsion. Case presentation: This case involves a 20-year-old white man in detention who claimed to have ingested one cocaine packet wrapped in plastic food-wrap and a condom in anticipation of an impending cell search. He reached out to medical professionals on day 4 after having unsuccessfully tried several methods to expel the drug packet, including swallowing olive oil, natural laxatives, liters of water, and 12 carved apple chunks. An initial computed tomography scan confirmed multiple packet-sized images throughout his stomach and bowel. After 24 hours of observation and normal bowel movements without expelling any packets, a subsequent scan found only one air-lined packet afloat in the gastric content. Due to the prolonged retention of the package there was an increased risk of rupture. The packet was eventually removed by laparoscopic gastrotomy. Conclusions: This case report illustrates that observation time needs to be adapted to each individual case of body stuffing. Proof of complete drug package evacuation ensures secure patient discharge. Body stuffers should be routinely asked for a detailed history, including how the drug is wrapped, and whether or not they ingested other substances to help expel the packets. The history enables the accurate interpretation of imaging. Repeated imaging can help follow the progress of packets if not all have been expelled during the observation period. Drug packets should be surgically removed in case of prolonged retention. To ensure the best possible outcomes, patients should have access to high-quality, private, and confidential medical care, which is equal to that offered to the general population. This is paramount to earning trust and collaboration from people in detention who resort to body stuffing

IL-6 gene amplification and expression in human glioblastomas

The aggressiveness of human gliomas appears to be correlated with the upregulation of interleukin 6 (IL-6) gene. Using quantitative PCR methods, we detected amplification and expression of the IL-6 gene in 5 of 5 primary glioblastoma samples and in 4 of 5 glioblastoma cell lines. This finding suggests that the amplification of IL-6 gene may be a common feature in glioblastomas and may contribute to the IL-6 over-expression. © 2001 Cancer Research Campaign http://www.bjcancer.co

Electric pulse induced electronic patchwork in the Mott insulator GaTa4Se8

Following a recent discovery of the Insulator-to-Metal Transition induced by electric field in GaTa4Se8, we performed a detailed Scanning Tunneling Microscopy/Spectroscopy study of both pristine (insulating) and transited (conducting) crystals of this narrow gap Mott insulator. The spectroscopic maps show that pristine samples are spatially homogeneous insulators while the transited samples reveal at nanometer scale a complex electronic pattern that consists of metallic and superinsulating patches immersed in the pristine insulating matrix. Surprisingly, both kinds of patches are accompanied by a strong local topographic inflation, thus evidencing for a strong electron-lattice coupling involved in this metal-insulator transition. Finally, using a strong electric field generated across the STM tunneling junction, we demonstrate the possibility to trig the metal-insulator transition locally even at room temperature

Electric Pulse Induced Resistive Switching, Electronic Phase Separation, and Possible Superconductivity in a Mott insulator

Metal-insulator transitions (MIT) belong to a class of fascinating physical phenomena, which includes superconductivity, and colossal magnetoresistance (CMR), that are associated with drastic modifications of electrical resistance. In transition metal compounds, MIT are often related to the presence of strong electronic correlations that drive the system into a Mott insulator state. In these systems the MIT is usually tuned by electron doping or by applying an external pressure. However, it was noted recently that a Mott insulator should also be sensitive to other external perturbations such as an electric field. We report here the first experimental evidence of a non-volatile electric-pulse-induced insulator-to-metal transition and possible superconductivity in the Mott insulator GaTa4Se8. Our Scanning Tunneling Microscopy experiments show that this unconventional response of the system to short electric pulses arises from a nanometer scale Electronic Phase Separation (EPS) generated in the bulk material.Comment: Highlight in Advanced Functional Materials 18, 1-4 (2008) doi : 10.1002/adfm.20080055