Implementing pictorial health warning labels on waterpipe tobacco products: a qualitative study

Background

Waterpipe smoking rates in Lebanon are among the highest in the in the world. Research has documented the effectiveness of introducing pictorial health warning labels (PHWLs) in curbing waterpipe smoking. Seventeen years after ratification of the WHO Framework Convention on Tobacco Control and twelve years post adoption of a tobacco control law, PHWLs have not yet been implemented in Lebanon. This study aims to gain insight into stakeholders opinions and recommendations for adopting and implementing PHWLs on WP products within the current tobacco control policy environment.

Methods

We conducted 13 online interviews with policymakers, media, owners of establishments that serve waterpipe, as well as international and local NGO representatives whose mandate is tobacco control. During the interview process, key informants were shown PHWLs on waterpipe tobacco products and asked about feasibility of implementation and enforcement. National documents and legislations related to PHWLs were obtained from public record. We conducted content analysis on the documents. Interviews were transcribed, coded, and analyzed thematically.

Results

The majority of the key informants agreed on who is responsible for enforcement of PHWLs and on the contextual obstacles to enforcement. Main barriers to implement PHWLs on WP products were: 1) the fact that the WP is a multi-component tobacco use method that will require including all WP components (charcoal, tobacco, device); 2) WP usually is used in several locations (e.g., home, restaurants); and 3) WP is sold via multiple sources (supermarkets, tobacco shop, etc). Stakeholders recommended some solutions to address barriers to implementation.

Conclusions

Stakeholders responsible for implementation of PHWLs need to take into consideration contextual barriers as well as the particularities of waterpipe tobacco smoking in terms of multiple components used to smoke, locations of consumption, and sources where it is sold.

Key messages

• Implementing PHWLs on waterpipe tobacco products requires distinct understanding of policy environment and context.

• Implementing PHWLs on waterpipe tobacco products needs to address the complex nature of waterpipe smoking as a multi-component tobacco use method .

Evidence of Skyrmion-Tube Mediated Magnetization Reversal in Modulated Nanowires

Magnetic nanowires, conceived as individual building blocks for spintronic devices, constitute a well-suited model to design and study magnetization reversal processes, or to tackle fundamental questions, such as the presence of topologically protected magnetization textures under particular conditions. Recently, a skyrmion-tube mediated magnetization reversal process was theoretically reported in diameter modulated cylindrical nanowires. In these nanowires, a vortex nucleates at the end of the segments with larger diameter and propagates, resulting in a first switching of the nanowire core magnetization at small fields. In this work, we show experimental evidence of the so-called Bloch skyrmion-tubes, using advanced Magnetic Force Microscopy modes to image the magnetization reversal process of FeCoCu diameter modulated nanowires. By monitoring the magnetic state of the nanowire during applied field sweeping, a detected drop of magnetic signal at a given critical field unveils the presence of a skyrmion-tube, due to mutually compensating stray field components. That evidences the presence of a skyrmion-tube as an intermediate stage during the magnetization reversal, whose presence is related to the geometrical dimensions of the cylindrical segments.

A multi-technique approach to understanding delithiation damage in LiCoO2 thin films

We report on the delithiation of LiCoO₂ thin films using oxalic acid (C₂H₂O₄) with the goal of understanding the structural degradation of an insertion oxide associated with Li chemical extraction. Using a multi-technique approach that includes synchrotron radiation X-ray diffraction, scanning electron microscopy, micro Raman spectroscopy, photoelectron spectroscopy and conductive atomic force microscopy we reveal the balance between selective Li extraction and structural damage. We identify three different delithiation regimes, related to surface processes, bulk delithiation and damage generation. We find that only a fraction of the grains is affected by the delithiation process, which may create local inhomogeneities. However, the bulk delithiation regime is effective to delithiate the LCO film. All experimental evidence collected indicates that the delithiation process in this regime mimics the behavior of LCO upon electrochemical delithiation. We discard the formation of Co oxalate during the chemical extraction process. In conclusion, the chemical route to Li extraction provides additional opportunities to investigate delithiation while avoiding the complications associated with electrolyte breakdown and simplifying in-situ measurements.

Surface morphology of molybdenum silicide films upon low-energy ion beam sputtering

The surface morphology of molybdenum silicide (Mo _x Si_1-x ) films has been studied after low-energy Ar⁺ ion beam sputtering (IBS) to explore eventual pattern formation on compound targets and, simultaneously, gather information about the mechanisms behind silicide-assisted nanopatterning of silicon surfaces by IBS. For this purpose, Mo _x Si_1-x films with compositions below, equal and above the MoSi₂ stoichiometry (x  =  0.33) have been produced by magnetron sputtering, as assessed by Rutherford backscattering spectrometry (RBS). The surface morphology of silicon and silicide films before and after IBS has been imaged by atomic force microscopy (AFM), comprising conditions where typical nanodot or ripple patterns emerge on the former. In the case of irradiated Mo _x Si_1-x surfaces, AFM shows a marked surface smoothing at normal incidence with and without additional Mo incorporation (the former results in nanodot patterns on Si). The morphological analysis also provides no evidence of ion-induced phase separation in irradiated Mo _x Si_1-x . Contrary to silicon, Mo _x Si_1-x surfaces also do not display ripple formation for (impurity free) oblique irradiations, except at grazing incidence conditions where parallel ripples emerge in a more evident fashion than in the Si counterpart. By means of RBS, irradiated Mo _x Si_1-x films with 1 keV Ar⁺ at normal incidence have also been used to measure experimentally the (absolute) sputtering yield and rate of Si and Mo _x Si_1-x materials. The analysis reveals that, under the present working conditions, the erosion rate of silicides is larger than for silicon, supporting simulations from the TRIDYN code. This finding questions the shielding effect from silicide regions as roughening mechanism in metal-assisted nanopatterning of silicon. On the contrary, the results highlight the relevance of in situ silicide formation. Ripple formation on Mo _x Si_1-x under grazing incidence is also attributed to the dominance of sputtering effects under this geometry. In conclusion, our work provides some insights into the complex morphological evolution of compound surfaces and solid experimental evidences regarding the mechanisms behind silicide-assisted nanopatterning.

Multisegmented Nanowires: a Step towards the Control of the Domain Wall Configuration

Cylindrical nanowires synthesized by controlled electrodeposition constitute excellent strategic candidates to engineer magnetic domain configurations. In this work, multisegmented CoNi/Ni nanowires are synthesized for tailoring a periodic magnetic structure determined by the balance between magnetocrystalline and magnetostatic energies. High-resolution Transmission Electron Microscopy confirms the segmented growth and the sharp transition between layers. Although both CoNi and Ni segments have similar fcc cubic crystal symmetry, their magnetic configuration is quite different as experimentally revealed by Magnetic Force Microscopy (MFM) imaging. While the Ni segments are single domain with axial magnetization direction, the CoNi segments present two main configurations: a single vortex state or a complex multivortex magnetic configuration, which is further interpreted with the help of micromagnetic simulations. This original outcome is ascribed to the tight competition between anisotropies. The almost monocrystalline fcc structure of the CoNi segments, as revealed by the electron diffraction patterns, which is atypical for its composition, contributes to balance the magnetocrystalline and shape anisotropies. The results of MFM measurements performed under in-plane magnetic field demonstrate that it is possible to switch from the multivortex configuration to a single vortex configuration with low magnetic fields.

Magnetization reversal in circular vortex dots of small radius

We present a detailed study of the magnetic behavior of Permalloy (Ni₈₀Fe₂₀ alloy) circular nanodots with small radii (30 nm and 70 nm) and different thicknesses (30 nm or 50 nm). Despite the small size of the dots, the measured hysteresis loops manifestly display the features of classical vortex behavior with zero remanence and lobes at high magnetic fields. This is remarkable because the size of the magnetic vortex core is comparable to the dot diameter, as revealed by magnetic force microscopy and micromagnetic simulations. The dot ground states are close to the border of the vortex stability and, depending on the dot size, the magnetization distribution combines attributes of the typical vortex, single domain states or even presents features resembling magnetic skyrmions. An analytical model of the dot magnetization reversal, accounting for the large vortex core size, is developed to explain the observed behavior, providing a rather good agreement with the experimental results. The study extends the understanding of magnetic nanodots beyond the classical vortex concept (where the vortex core spins have a negligible influence on the magnetic behavior) and can therefore be useful for improving emerging spintronic applications, such as spin-torque nano-oscillators. It also delimits the feasibility of producing a well-defined vortex configuration in sub-100 nm dots, enabling the intracellular magneto-mechanical actuation for biomedical applications.

Now is the time to advocate for interventions designed specifically to prevent and control waterpipe tobacco smoking

Waterpipe tobacco usage is spreading rapidly worldwide, with reports of more youth being waterpipe users compared to adults. In many areas of the world, waterpipe usage surpasses cigarette smoking. Waterpipes and cigarettes are both mechanisms for inhalation of tobacco smoke and therefore have serious health consequences. However, because of the many differences between the two products, prevention and control strategies that have proven effective for cigarettes may not transfer readily to waterpipe. This report highlights the differences between waterpipes and cigarettes in toxicant exposure and physiologic effects, patterns of use, social norms, the extent of evidence, and the policy environment. There is little evidence to date around effective interventions for waterpipe prevention and control. The current state of evidence for intervention to curb or control waterpipe is at ground zero and critically needs attention from both scientists and policy makers. National and global efforts aimed at cigarette prevention have succeeded, particularly in developed countries. We suggest the time has come to harness what we know works for cigarette prevention and control and adapt it to tackle the growing epidemic of waterpipe tobacco use.

[A rare cause of eosinophilic asthma: Hyper-IgG4 syndrome (IgG4-related sclerosing disease)]

INTRODUCTION

The hyper-IgG4 syndrome is an emerging disease with various thoracic manifestations: eosinophilic asthma, adenomegalies or mediastinal fibrosis, asthma, infiltrative pneumonia, nodules or pseudo-tumors with bronchial and pleural localizations.

CASE REPORT

We report the case of a 38-year-old woman who was admitted for acute exacerbation of eosinophilic asthma with high total IgE levels. A medical history of idiopathic acute pancreatitis, associated with sclerosing cholangitis and renal failure, suggested a diagnosis of hyper-IgG4 syndrome in this woman with late-onset severe and non-atopic asthma. A previous hepatic histology and a reinterpretation of renal tomodensitometry have confirmed this hypothesis.

CONCLUSION

The hyper-IgG4 syndrome is responsible of different clinico-radiological patterns that should be evoked because of the pejorative evolution of this steroid sensitive disease.

Structural insights into magnetic clusters grown inside virus capsids

Magnetic nanoparticles have multiple applications in materials science. In particular, virus capsids have been suggested as promising templates for building up nanometric-sized magnetic clusters by taking advantage of their inner cavity as a nanoreactor. In this study we investigate the magnetization of individual cobalt-filled cowpea mosaic virus empty virus-like particles using atomic force microscopy. We also combine the analysis of the effects of dehydration on the structure of virus particles with a comparison of their magnetic signal to that provided by commercially available magnetic nanoparticles of similar size. These two approaches allow the evaluation of the structure of the metallic cluster grown inside the virus capsid. We conclude that, rather than forming solid clusters, cobalt inside viruses forms a discontinuous structure that does not completely fill the virus cavity and reaches about 10% of its volume.

Tailoring the physical properties of thin nanohole arrays grown on flat anodic aluminum oxide templates

The introduction of voids in a magnetic thin-film alters the stray field distribution and enables the tailoring of the corresponding physical properties. Here we present a detailed study on thin magnetic nanohole arrays (NhAs) grown on top of hexagonally-ordered anodic aluminum oxide (AAO) substrates. We address the effect of AAO topography on the corresponding electrical and magneto-transport properties. Optimization of the AAO topography led to NhAs with improved resistance and magnetoresistance responses, while retaining their most important feature of enhanced coercivity. This opens new pathways for the growth of more complex structures on AAO substrates, a crucial aspect for their technological viability.

Nanomagnets with high shape anisotropy and strong crystalline anisotropy: perspectives on magnetic force microscopy

We report on a new approach for magnetic imaging, highly sensitive even in the presence of external, strong magnetic fields. Based on FIB-assisted fabricated high-aspect-ratio rare-earth nanomagnets, we produce groundbreaking magnetic force tips with hard magnetic character where we combine a high aspect ratio (shape anisotropy) together with strong crystalline anisotropy (rare-earth-based alloys). Rare-earth hard nanomagnets are then FIB-integrated to silicon microcantilevers as highly sharpened tips for high-field magnetic imaging applications. Force resolution and domain reversing and recovery capabilities are at least one order of magnitude better than for conventional magnetic tips. This work opens new, pioneering research fields on the surface magnetization process of nanostructures based either on relatively hard magnetic materials-used in magnetic storage media-or on materials like superparamagnetic particles, ferro/antiferromagnetic structures or paramagnetic materials.

Patterning of rutile TiO2 surface by ion beam lithography through full-solid masks

In this work we present and discuss the nanopatterning of rutile TiO(2) single crystal surfaces following their irradiation with energetic heavy ions through a stencil mask of Ni filled self-ordered porous anodic alumina. After etching in HF a corrugated surface morphology is obtained composed of parallel alternate furrows and ridges (or nanobars) 50 nm in diameter and with 100 nm pitch. In addition, isolated, but collapsed, TiO(2) nanorods are seen lying on the patterned surface. The stability of the nanopatterned surface under high temperatures treatments and crystalline properties are analyzed.

Nanostructured Co film on ordered polymer nanohills: a base for novel magnetic nanostructures

The preparation of a nanostructured polymer (poly(methyl methacrylate)--PMMA) replicating the order of an anodized aluminium (Al) template is first described. Nanohills at the PMMA surface are structured following the ordering of the template with tailored lattice parameter and hexagonal symmetry. A nanostructured Co magnetic film is then deposited by sputtering onto the polymer surface so keeping the high ordering induced by the precursor template. The magnetic properties depend on the polymer periodicity as well as on the sputtering conditions. In particular, single-domain or multidomain structures have been identified inside every Co/polymer hill depending on the lattice parameter. Moreover, an intrinsic distribution of the magnetic anisotropy can be deduced from the hysteresis loops.

Field induced vortex dynamics in magnetic Ni nanotriangles

The magnetization states in Ni triangular dots under an applied magnetic field have been studied using variable-field magnetic force microscopy (VF-MFM) imaging. In order to understand their dynamics we performed micromagnetic simulations which are in remarkable agreement with the experimental MFM results. The nanostructures present magnetic vortices as ground states which move under an external magnetic field. The combination of micromagnetic simulations and MFM imaging allows us to identify correctly the vortex chiralities and polarizations. The triangular geometry produces an improved contrast of the vortex core. Additionally, the vortices of different chiralities present clearly different MFM images under an applied field.

Retinoblastoma: the Saudi Arabian experience

During the period March 1983-May 1987, 74 cases of retinoblastoma were evaluated at the King Khaled Eye Specialist Hospital in Riyadh, Saudi Arabia. 60% of the cases were unilateral with a female preponderance of 59.4% noted for this series. Additionally, the mean age at diagnosis was 22 months, and delay of retinoblastoma diagnosis since the first symptoms were observed ranged from two days to 36 months. Fifty-seven eyes were enucleated, and in 21 of these patients, this was the sole form of therapy. The remainder of patients were treated with radiotherapy alone or combined with chemotherapy, cryotherapy/photocoagulation. Overall, two-year survival statistics of this group of Saudi patients is 80% which compares favorably to other reports in the West. Emphasis is placed on management of the retinoblastoma patients by a multi-disciplinary group, and public educational efforts are imperative.

Penetration of intravenous moxalactam into human aqueous humor

Intraocular penetration of moxalactam disodium, a new broad-spectrum oxa-beta-lactam antibiotic, was studied in 18 patients undergoing cataract surgery. The antibiotic was administered in a 2-g single dose by intravenous drip during a 20-minute period. After 40 to 230 minutes, moxalactam aqueous humor concentrations ranged from 1.1 to 5.0 micrograms/mL (mean, 2.3 micrograms/mL). The ratio of aqueous humor concentrations to concomitant serum concentrations ranged from 1.6% to 9.8%. The achievable aqueous moxalactam concentrations were well above the minimum inhibitory concentrations of most Gram-negative enteric bacilli but not of Pseudomonas and staphylococci.