PREPs Surveillance: Summary of Existing Survey Measures and Recommendations for Ongoing Efforts

Over the past decade or more, tobacco companies have introduced cigarettes with lower content of some toxins than regular and light cigarettes. These new cigarettes, referred to as a class as Potential Reduced Exposure Products (PREPs), have typically been introduced into test markets, not nationwide, which means they are not yet widely known or recognized by name or description by most consumers. However, the introduction of these products is of great concern to public health advocates, who do not believe that enough research, particularly long term research, has been done to know whether or not the PREPs, even if proven to have reduced toxins, actually present a reduced health risk. The fear in the public health community is that smokers who might have been motivated to quit may reverse those quit plans if they perceive an alternative, safer smoking option exists with the PREPs. Likewise, there is concern that former smokers could be tempted back to smoking and non-smokers could be tempted to initiate smoking if they too perceive that PREPs present lower health risks than other cigarettes. Having faced a similar situation with the introduction of “light” cigarettes – i.e. new product, insufficient research about its health implications -- public health officials are feeling cautious about PREPs and have called for development of a science to evaluate PREPs, as well as ongoing surveillance. In order to obtain as complete a set of existing measures as possible, we reviewed published literature on consumer reactions to PREPs and solicited input about ongoing studies from members of the project advisory group, members of the Harm Reduction Network, and other members of the tobacco research community. Appendix A is a list of studies we have included in the summary of current data on the subject of PREPs surveillance. Appendix B is the full listing of PREPs-related questions for each included study

A New Class of Materials Based on Nanoporous High Entropy Alloys with Outstanding Properties

Nanoporous metals with a random, bicontinuous structure of both pores and ligaments exhibit many unique mechanical properties, but their technical applications are often limited by their intrinsic brittleness under tensile strain triggered by fracture of the weakest ligaments. Here, we use molecular dynamics simulations to study the mechanical behavior and thermal stability of two different bicontinuous nanoporous high entropy alloys, Al0.1CoCrFeNi and NbMoTaW. To isolate the properties related to the nanoporous nature of our samples, we also studied the corresponding bulk and nanocrystalline systems. The results demonstrate that the specific modulus of nanoporous HEAs are 2 to 3 times greater than that of single element nanoporous materials with specific strength reaching values 5 to 10 times higher, comparable to bulk metals with the highest specific strength. Bicontinuous HEAs also displayed excellent resistance to thermal degradation as evidenced by the absence of coarsening ligaments up to temperatures of 1273 K which ensures the durability and reliability in high-temperature applications. The findings uncover unprecedented mechanical and thermal properties of bicontinuous nanoporous high entropy alloys, paving the way for their promising utilization in advanced engineering and structural applications

Dislocation nucleation in bcc Ta single crystals studied by nanoindentation

The study of dislocation nucleation in closed-packed metals by nanoindentation has recently attracted much interest. Here, we address the peculiarities of the incipient plasticity in body centered cubic (bcc) metals using low index Ta single-crystals as a model system. The combination of nanoindentation with high-resolution atomic force microscopy provides us with experimental atomic-scale information on the process of dislocation nucleation and multiplication. Our results reveal a unique deformation behavior of bcc Ta at the onset of plasticity which is distinctly different from that of closed-packed metals. Most noticeable, we observe only one rather than a sequence of discontinuities in the load-displacement curves. This and other differences are discussed in context of the characteristic plastic deformation behavior of bcc metals

Massachusetts Adult Tobacco Survey: Tobacco Use and Attitudes After Seven Years of The Massachusetts Tobacco Control Program, Technical Report & Tables 1993 — 2000

The Massachusetts Tobacco Control Program was launched in October of 1993. At that time, the Center for Survey Research conducted the Massachusetts Tobacco Survey (MTS), a comprehensive survey of adults and teens living in Massachusetts. The purpose of the survey was to collect baseline data on the prevalence of tobacco use among adults and teens in the Commonwealth and on issues related to the likelihood of smoking cessation or initiation. The survey also assessed the prevalence of restrictive smoking policies, and attitudes about tobacco control measures. The baseline data serve as a standard against which the impact of various programs sponsored by the Department of Public Health can be assessed. Technical details about the MTS and reports of the results are available from the Massachusetts Department of Public Health. In January, 1995 the Department of Public Health contracted with the Center for Survey Research to carry out a second survey monitoring tobacco use and related attitudes and behaviors among adults in the Commonwealth. This second survey, known as the Massachusetts Adult Tobacco Survey (MATS), has been carried out monthly since March of 1995. Data are aggregated at the end of each calendar year. MATS is similar to the MTS in that initial screening interviews are carried out with a household member who provides demographic and smoking status information about other adults in the household. One member of the household is then randomly selected for extended interview. The annual sample for this survey is smaller than that used for the MTS and does not include teens. It also differs from the MTS in that smokers were not over-sampled, nor were members of minority groups. The sample was geographically stratified as was the MTS. (More details on the sampling design are presented in Chapter I.) Technical Reports are available for the 1993 MTS survey, and for the 1995 through 1999 MATS surveys. Please refer to those reports for descriptions of the respective surveys and a more general discussion of the use of the telephone survey for data collection. This report presents methodological details of the 2000 MATS. It contains an appendix of tables of major results for data collected each year. Nontechnical reports describing the major results are available from the Massachusetts Department of Public Health

Deformation Behavior of Nanoporous Metals

Nanoporous open-cell foams are a rapidly growing class of high-porosity materials (porosity {ge} 70%). The research in this field is driven by the desire to create functional materials with unique physical, chemical and mechanical properties where the material properties emerge from both morphology and the material itself. An example is the development of nanoporous metallic materials for photonic and plasmonic applications which has recently attracted much interest. The general strategy is to take advantage of various size effects to introduce novel properties. These size effects arise from confinement of the material by pores and ligaments, and can range from electromagnetic resonances to length scale effects in plasticity. In this chapter we will focus on the mechanical properties of low density nanoporous metals and how these properties are affected by length scale effects and bonding characteristics. A thorough understanding of the mechanical behavior will open the door to further improve and fine-tune the mechanical properties of these sometimes very delicate materials, and thus will be crucial for integrating nanoporous metals into products. Cellular solids with pore sizes above 1 micron have been the subject of intense research for many years, and various scaling relations describing the mechanical properties have been developed.[4] In general, it has been found that the most important parameter in controlling their mechanical properties is the relative density, that is, the density of the foam divided by that of solid from which the foam is made. Other factors include the mechanical properties of the solid material and the foam morphology such as ligament shape and connectivity. The characteristic internal length scale of the structure as determined by pores and ligaments, on the other hand, usually has only little effect on the mechanical properties. This changes at the submicron length scale where the surface-to-volume ratio becomes large and the effect of free surfaces can no longer be neglected. As the material becomes more and more constraint by the presence of free surfaces, length scale effects on plasticity become more and more important and bulk properties can no longer be used to describe the material properties. Even the elastic properties may be affected as the reduced coordination of surface atoms and the concomitant redistribution of electrons may soften or stiffen the material. If, and to what extend, such length scale effects control the mechanical behavior of nanoporous materials depends strongly on the material and the characteristic length scale associated with its plastic deformation. For example, ductile materials such as metals which deform via dislocation-mediated processes can be expected to exhibit pronounced length scale effects in the sub-micron regime where free surfaces start to constrain efficient dislocation multiplication. In this chapter we will limit our discussion to our own area of expertise which is the mechanical behavior of nanoporous open-cell gold foams as a typical example of nanoporous metal foams. Throughout this chapter we will review our current understanding of the mechanical properties of nanoporous open-cell foams including both experimental and theoretical studies

The ePetri dish, an on-chip cell imaging platform based on subpixel perspective sweeping microscopy (SPSM)

We report a chip-scale lensless wide-field-of-view microscopy imaging technique, subpixel perspective sweeping microscopy, which can render microscopy images of growing or confluent cell cultures autonomously. We demonstrate that this technology can be used to build smart Petri dish platforms, termed ePetri, for cell culture experiments. This technique leverages the recent broad and cheap availability of high performance image sensor chips to provide a low-cost and automated microscopy solution. Unlike the two major classes of lensless microscopy methods, optofluidic microscopy and digital in-line holography microscopy, this new approach is fully capable of working with cell cultures or any samples in which cells may be contiguously connected. With our prototype, we demonstrate the ability to image samples of area 6 mm × 4 mm at 660-nm resolution. As a further demonstration, we showed that the method can be applied to image color stained cell culture sample and to image and track cell culture growth directly within an incubator. Finally, we showed that this method can track embryonic stem cell differentiations over the entire sensor surface. Smart Petri dish based on this technology can significantly streamline and improve cell culture experiments by cutting down on human labor and contamination risks

Synthesis of TiO2 nanoparticles on the Au(111) surface

The growth of titanium oxide nanoparticles on reconstructed Au(111) surfaces was investigated by scanning tunneling microscopy and X-ray photoelectron spectroscopy. Ti was deposited by physical vapor deposition at 300 K. Regular arrays of titanium nanoparticles form by preferential nucleation of Ti at the elbow sites of the herringbone reconstruction. Titanium oxide clusters were synthesized by subsequent exposure to O{sub 2} at 300 K. Two- and three-dimensional titanium oxide nanocrystallites form during annealing in the temperature range from 600 to 900 K. At the same time, the Au(111) surface assumes a serrated, <110> oriented step-edge morphology, suggesting step-edge pinning by titanium oxide nanoparticles. The oxidation state of these titanium oxide nanoparticles varies with annealing temperature. Specifically, annealing to 900 K results in the formation of stoichiometric TiO{sub 2} nanocrystals as judged by the observed XPS binding energies. Nano-dispersed TiO{sub 2} on Au(111) is an ideal system to test the various models explaining the enhanced catalytic reactivity of supported Au nanoparticles

Breaking the Screen: Interaction Across Touchscreen Boundaries in Virtual Reality for Mobile Knowledge Workers.

Virtual Reality (VR) has the potential to transform knowledge work. One advantage of VR knowledge work is that it allows extending 2D displays into the third dimension, enabling new operations, such as selecting overlapping objects or displaying additional layers of information. On the other hand, mobile knowledge workers often work on established mobile devices, such as tablets, limiting interaction with those devices to a small input space. This challenge of a constrained input space is intensified in situations when VR knowledge work is situated in cramped environments, such as airplanes and touchdown spaces. In this paper, we investigate the feasibility of interacting jointly between an immersive VR head-mounted display and a tablet within the context of knowledge work. Specifically, we 1) design, implement and study how to interact with information that reaches beyond a single physical touchscreen in VR; 2) design and evaluate a set of interaction concepts; and 3) build example applications and gather user feedback on those applications.Comment: 10 pages, 8 figures, ISMAR 202

Snus use and rejection in the USA

OBJECTIVE: To determine whether snus might become a strategy for reducing the harm associated with cigarette smoking in the USA as appears to be the case in Sweden, we examined receptivity to snus use in two cities with the greatest exposure to the major brands. METHODS: A dual frame, telephone survey and a brief mail survey were conducted in 2011 and 2012 in Indianapolis, Indiana and Dallas/Fort Worth Texas. Over 5000 adults completed surveys. Trial, ever use, current use and reasons for using or quitting snus after trial were measured. RESULTS: Among male smokers, 29.9% had ever tried snus (CI 22.7 to 38.1) and 4.2% were current users (CI 1.6 to 10.7). Among female smokers, 8.5% ever tried snus (CI 4.4 to 15.7) and current use was unknown. Current use was virtually absent among former smokers and never smokers. A major predictor of any level of snus use was current use of conventional smokeless tobacco. Those who tried and gave up snus cited curiosity (41.3%) and the fact that it was available at low or no cost (30%) as reasons for trial; reasons for not continuing included preferring another form of tobacco (75.1%) and disliking the mouth feel (34.6%). Almost all current snus users indicated that they were trying to cut down on cigarettes, but few (3.9%) were using it to quit smoking entirely. CONCLUSIONS: The low rate of adoption of snus suggests that neither the hopes nor the fears surrounding this new product are likely to be realised in the USA with the current marketing patterns

Nanoporous gold as a highly active substrate for surface-enhanced Raman scattering spectroscopy

Colloidal solutions of metal nanoparticles are currently among most studied substrates for sensors based on surface-enhanced Raman scattering (SERS). However, such substrates often suffer from not being cost-effective, reusable, or stable. Here, we develop nanoporous Au as a highly active, tunable, a.ordable, stable, bio-compatible, and reusable SERS substrate. Nanoporous Au is prepared by a facile process of free corrosion of AgAu alloys followed by annealing. Results show that nanofoams with average pore sizes of {approx} 250 nm exhibit the largest SERS signal for 632.8 nm excitation. This is attributed to the electromagnetic SERS enhancement mechanism with additional field localization within pores