Electrochemical Control of Strong Coupling of CdSe Exciton-Polaritons in Plasmonic Cavities.

This work reports in situ (active) electrochemical control over the coupling strength between semiconducting nanoplatelets and a plasmonic cavity. We found that by applying a reductive bias to an Al nanoparticle lattice working electrode the number of CdSe nanoplatelet emitters that can couple to the cavity is decreased. Strong coupling can be reversibly recovered by discharging the lattice at oxidative potentials relative to the conduction band edge reduction potential of the emitters. By correlating the number of electrons added or removed with the measured coupling strength, we identified that loss and recovery of strong coupling are likely hindered by side processes that trap and/or inhibit electrons from populating the nanoplatelet conduction band. These findings demonstrate tunable, external control of strong coupling and offer prospects to tune selectivity in chemical reactions.

Characterizing the Semiconductor Nanocrystal Surface through Chemical Reactivity.

ConspectusMany desirable and undesirable properties of semiconductor nanocrystals (NCs) can be traced to the NC surface due to the large surface-to-volume ratio. Therefore, precise control of the NC surface is imperative to achieve NCs with the desired qualities. Ligand-specific reactivity and surface heterogeneity make it difficult to accurately control and tune the NC surface. Without a molecular-level appreciation of the NC surface chemistry, modulating the NC surface is impossible and the risk of introducing deleterious surface defects is imminent. To gain a more comprehensive understanding of the surface reactivity, we have utilized a variety of spectroscopic techniques and analytical methods in concert.This Account describes our use of robust characterization techniques and ligand exchange reactions in effort to establish a molecular-level understanding of NC surface reactivity. The utility of NCs in target applications such as catalysis and charge transfer hangs on precise tunability of NC ligands. Modulating the NC surface requires the necessary tools to monitor chemical reactions. One commonly utilized analytical method to achieve targeted surface compositions is 1H nuclear magnetic resonance (NMR) spectroscopy. Here we describe our use of 1H NMR spectroscopy to monitor chemical reactions at CdSe and PbS NC surfaces to identify ligand specific reactivity. However, seemingly straightforward ligand exchange reactions can vary widely depending on the NC materials and anchoring group. Some non-native X-type ligands will irreversibly displace native ligands. Other ligands exist in equilibrium with native ligands. Depending on the application, it is important to understand the nature of exchange reactions. This level of understanding can be obtained by extracting exchange ratios, exchange equilibrium, and reaction mechanism information from 1H NMR spectroscopy to establish precise NC reactivity.Reactivity that occurs through multiple, parallel ligand exchange mechanisms can involve both the liberation of metal-based Z-type ligands in addition to reactivity of X-type ligands. In these reactions, 1H NMR spectroscopy fails to discern between an X-type oleate or a Z-type Pb(oleate)2 because only the alkene resonance of the organic constituent is probed by this method. Multiple, parallel reaction pathways occur when thiol ligands are introduced to oleate-capped PbS NCs. This necessitated the use of synergistic characterization methods including 1H NMR spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, and inductively coupled plasma mass spectrometry (ICP-MS) to characterize both surface-bound and liberated ligands.Similar analytical methods have been employed to probe the NC topology, which is an important, but often overlooked, component to NC reactivity given the facet-specific reactivity of PbS NCs. Through the tandem use of NMR spectroscopy and ICP-MS, we have monitored the liberation of Pb(oleate)2 as an L-type ligand is titrated to the NC to determine the quantity and equilibrium of Z-type ligands. By studying a variety of NC sizes, we correlated the number of liberated ligands with the size-dependent topology of PbS NCs.Lastly, we incorporate redox-active chemical probes into our toolbox to study NC surface defects. We describe how the site-specific reactivity and relative energetics of redox-active surface-based defects are elucidated using redox probes and show that this reactivity is highly dependent on the surface composition. This Account is designed to encourage readers to consider the necessary characterization techniques needed establish a molecular-level understanding of NC surfaces in their own work.

Hacia una atención de calidad integral en las maternidades con perspectiva de derechos humanos / Towards a comprehensive quality of care in birthing facilities with human rights perspective

Resumen La calidad de la atención obstétrica hoy no solo se limita a tener profesionales con competencias técnicas basadas en evidencia científica, sino que incluye la atención centrada en la mujer, persona gestante y su familia, como expresión del respeto de sus derechos humanos. Este artículo revisa cómo el tema ha sido abordado globalmente y nacionalmente desde la Conferencia de Fortaleza en 1985 hasta la presentación reciente de proyectos de ley en el parlamento chileno.

Abstract Obstetric quality of care today means not only having skilled providers with evidence-based competences but it includes woman, pregnant person and family-centered reproductive health as expression of respect of their human rights. This article reviews how this issue has been approached in a global and national level since Fortaleza Conference in 1985 until recent bills of law proposed before Chilean parliament.

Exploring Serum Transferrin Regulation of Nonferric Metal Therapeutic Function and Toxicity.

Serum transferrin (sTf) plays a pivotal role in regulating iron biodistribution and homeostasis within the body. The molecular details of sTf Fe(III) binding blood transport, and cellular delivery through transferrin receptor-mediated endocytosis are generally well-understood. Emerging interest exists in exploring sTf complexation of nonferric metals as it facilitates the therapeutic potential and toxicity of several of them. This review explores recent X-ray structural and physiologically relevant metal speciation studies to understand how sTf partakes in the bioactivity of key non-redox active hard Lewis acidic metals. It challenges preconceived notions of sTf structure function correlations that were based exclusively on the Fe(III) model by revealing distinct coordination modalities that nonferric metal ions can adopt and different modes of binding to metal-free and Fe(III)-bound sTf that can directly influence how they enter into cells and, ultimately, how they may impact human health. This knowledge informs on biomedical strategies to engineer sTf as a delivery vehicle for metal-based diagnostic and therapeutic agents in the cancer field. It is the intention of this work to open new avenues for characterizing the functionality and medical utility of nonferric-bound sTf and to expand the significance of this protein in the context of bioinorganic chemistry.

Misuse of Trihexyphenidyl (Artane) on Réunion Island.

BACKGROUND: Trihexyphenidyl (THP) is an anticholinergic drug misused to procure hallucination, sedation, and anxiolysis. The aim of this cohort was to show and describe, within a public health risk management policy, the risks of a long-standing but relatively unknown addiction: THP addiction. METHODS: On Réunion island, a cohort with systematic data collection has been set up by addictologists working in the Centres for Addiction Prevention and Treatment, in the university hospital, and in general practices who have active lists of patients misusing THP. Data collection included socioeconomic data and clinical data concerning addiction. RESULTS: This cohort included 69 patients during November 2016. The average age of the patients was 36 years; 97% were men; 93% had living accommodation but only 32 % were employed. In this cohort drug administration was exclusively oral. The most common reasons for use were anxiolytic (46%), stimulation (26%), and sedation (10%), the main effects described were dyskinesia and behavioral disorders. Over half (61%) of the patients reported a coaddiction, mainly to benzodiazepines, cannabis, tobacco, alcohol, and buprenorphine. CONCLUSIONS: This cohort describing the clinical characteristics of 69 patients is the largest cohort studied for THP addiction. Patients from the Centres for Addiction Prevention and Treatment were the youngest and most recently addicted, whereas general practice patients had been addicted for longer and were more socially integrated. This clinical description of THP addiction therefore enables us to identify the patients who are the most at risk, to set up an adapted care protocol.

A major epidemic of chikungunya virus infection on Reunion Island, France, 2005-2006.

In January 2005, an epidemic of chikungunya fever broke out in the Comoro Islands and lasted until May 2005. In April, cases were also reported in Mayotte and Mauritius. On Réunion Island, the first cases were reported at the end of April. Surveillance of this epidemic required an adaptive system, which at first was based on active and retrospective case detection around the cases reported, then relied on a sentinel network when the incidence increased. Emerging and severe forms of infection were investigated. Death certificates were monitored. By April 2006, the surveillance estimate was 244,000 cases of chikungunya virus infection, including 123 severe cases and 41 of maternoneonatal transmission, with an overall attack rate of 35%. Chikungunya infection was mentioned on 203 death certificates and significant mortality was observed. This epidemic highlighted the need for a mutual strategy of providing information on arboviral diseases and their prevention and control between countries in the southwestern Indian Ocean.

Venous thromboembolism in passengers following a 12-h flight: a case-control study.

OBJECTIVES: There has recently been great interest in the possible relationship between air travel and venous thromboembolism (VTE). Based on a case-control survey, we measured the frequency of VTE, associated risk factors (RFs), and factors influencing the onset of pulmonary embolism (PE) or deep vein thrombosis (DVT). METHODS: The study was conducted over 1 yr. A questionnaire was sent to physicians. Patients with a diagnosis of VTE were included, provided they had traveled from France to Reunion Island. RESULTS: Over 46 cases, 33 patients showed DVT and 13 PE. RFs for VTE were present in 38 patients (82%). On comparing RFs between study and control groups, we found no differences in age, gender, alcohol, sleep-inducing drug consumption, seat allocation, or estroprogestative treatment. RFs were significantly higher in the VTE group at p < 0.005: history of previous VTE (OR 63.3), recent trauma (OR 13.6), presence of varicose veins (OR 10), obesity (OR 9.6), immobility during flight (9.3), and cardiac disease (OR 8.9). For patients with DVT or PE, no differences were observed in comparing RFs. The PE group was older and mortality occurred only in this group. The number of displacements during flight (p < 0.009) and complete immobility (p < 0.001) were strongly related with onset of PE. Delay of symptoms was less than 24 h in 69% of PE cases compared with 21% of DVT cases (p < 0.004). CONCLUSION: Long-duration air travel VTE is associated with other underlying thromboembolic RFs. Low mobility during flight is a striking modifiable RF of developing PE. Travelers with RFs for VTE should be advised to increase their mobility.