A Rapid Evaluation of the US Federal Tobacco 21 (T21) Law and Lessons From Statewide T21 Policies: Findings From Population-Level Surveys.

BACKGROUND: On December 20, 2019, the minimum age for purchasing tobacco in the US was raised nationally to 21 years. We evaluated this law (Tobacco 21 [T21]) 1 year after implementation. We also compared states with versus without T21 policies during 2019 to explore potential equity impacts of T21 policies. METHODS: We examined shifts in tobacco access among 6th through 12th graders using the National Youth Tobacco Survey. To explore equity of state T21 policies among youths and young adults, the associations with tobacco use were explored separately for race and ethnicity by using data from the 2019 Behavioral Risk Factor Surveillance System (for persons aged 18 to 20 years) and the 2019 Youth Risk Behavior Survey (for high school students). RESULTS: The overall percentage of 6th to 12th graders perceiving that it was easy to buy tobacco products from a store decreased from 2019 (67.2%) to 2020 (58.9%). However, only 17.0% of students who attempted buying cigarettes in 2020 were unsuccessful because of their age. In the 2019 BRFSS, those aged 18 to 20 years living in a state with T21 policies had a lower likelihood of being a current cigarette smoker (adjusted prevalence ratio [APR], 0.58) or smoking cigarettes daily (APR, 0.41). Similar significant associations were seen when analyses were restricted to only non-Hispanic White participants but not for participants who were non-Hispanic Black, non-Hispanic Asian, Hispanic, or of other races or ethnicities. Consistent findings were seen among high school students. CONCLUSION: Greater compliance with the federal T21 law is needed as most youth who attempted buying cigarettes in 2020 were successful. Comparative analysis of states with versus states without statewide T21 policies in 2019 suggest the policies were differentially more protective of non-Hispanic White participants than other participants. Equitable and intensified enforcement of T21 policies can benefit public health.

Characteristics of non-melanoma skin cancers of the cutaneous perioral and vermilion lip treated by Mohs micrographic surgery.

BACKGROUND: The lip and surrounding perioral region are susceptible to non-melanoma skin cancer, but the distribution of basal cell and squamous cell carcinoma on the cutaneous and vermilion lips has not been fully elucidated. OBJECTIVE: To investigate the distribution of cutaneous and vermilion lip non-melanoma skin cancer and to better describe risk factors, anatomic location, treatment characteristics and oncologic outcomes. METHODS: A retrospective comparative case series of patients undergoing Mohs micrographic surgery (MMS) at a single academic centre for lip and perioral basal cell and squamous cell carcinoma was performed over a 5-year period. Demographics, medical comorbidities, surgical characteristics and recurrence status were extracted. RESULTS: Forty-five vermilion and 116 cutaneous lip cancers were identified. Basal cell carcinoma (BCC) was more common in the cutaneous perioral region, while squamous cell carcinoma (SCC) was more common on the vermilion lip (P < 0.001). BCCs were more common on the upper vermilion lip and SCCs were more common on the lower vermilion lip (P < 0.001). Within the cutaneous perioral region, both BCCs and SCCs were more common on the upper perioral surface (P = 0.002). Male gender was associated with lower lip SCC (P = 0.015). Smoking, immunosuppression, anticoagulant use and hydrochlorothiazide use were not associated with cancer type or location. Recurrences were rare, but more common in vermilion lip cancers (6.6%) compared to perioral cutaneous cancers (0.8%). Outcomes for all groups were similar; BCCs of the vermilion lip had significantly greater mean MMS stages (P < 0.001) as did SCCs (P = 0.05). CONCLUSION: Basal cell carcinoma is more commonly encountered on the cutaneous lip, whereas SCC is more common on the vermilion lip. Within the vermilion lip, BCC favours the upper lip, while SCC favours the lower lip. Within the cutaneous perioral region, both BCC and SCC favour the upper cutaneous tissue. Early stage lip cancers are curable by Mohs micrographic surgery with rare recurrences.

From amorphous to nanocrystalline: the effect of nanograins in an amorphous matrix on the thermal conductivity of hot-wire chemical-vapor deposited silicon films.

We have measured the thermal conductivity of amorphous and nanocrystalline silicon films with varying crystalline content from 85 K to room temperature. The films were prepared by the hot-wire chemical-vapor deposition, where the crystalline volume fraction is determined by the hydrogen (H2) dilution ratio to the processing silane gas (SiH4), R = H2/SiH4. We varied R from 1 to 10, where the films transform from amorphous for R < 3 to mostly nanocrystalline for larger R. Structural analyses show that the nanograins, averaging from 2 to 9 nm in sizes with increasing R, are dispersed in the amorphous matrix. The crystalline volume fraction increases from 0 to 65% as R increases from 1 to 10. The thermal conductivities of the two amorphous silicon films are similar and consistent with the most previous reports with thicknesses no larger than a few µm deposited by a variety of techniques. The thermal conductivities of the three nanocrystalline silicon films are also similar, but are about 50-70% higher than those of their amorphous counterparts. The heat conduction in nanocrystalline silicon films can be understood as the combined contribution in both amorphous and nanocrystalline phases, where increased conduction through improved nanocrystalline percolation path outweighs increased interface scattering between silicon nanocrystals and the amorphous matrix.

Excess specific heat in evaporated amorphous silicon.

The specific heat C of e-beam evaporated amorphous silicon (a-Si) thin films prepared at various growth temperatures T(S) and thicknesses t was measured from 2 to 300 K, along with sound velocity v, shear modulus G, density n(Si), and Raman spectra. Increasing T(S) results in a more ordered amorphous network with increases in n(Si), v, G, and a decrease in bond angle disorder. Below 20 K, an excess C is seen in films with less than full density where it is typical of an amorphous solid, with both a linear term characteristic of two-level systems (TLS) and an additional (non-Debye) T3 contribution. The excess C is found to be independent of the elastic properties but to depend strongly on density. The density dependence suggests that low energy glassy excitations can form in a-Si but only in microvoids or low density regions and are not intrinsic to the amorphous silicon network. A correlation is found between the density of TLS n0 and the excess T3 specific heat c(ex) suggesting that they have a common origin.

Heat transfer simulation and thermal measurements of microfabricated x-ray transparent heater stages.

A microfabricated amorphous silicon nitride membrane-based nanocalorimeter is proposed to be suitable for an x-ray transparent sample platform with low power heating and built-in temperature sensing. In this work, thermal characterization in both air and vacuum are analyzed experimentally and via simulation. Infrared microscopy and thermoreflectance microscopy are used for thermal imaging of the sample area in air. While a reasonably large isothermal area is found on the sample area, the temperature homogeneity of the entire sample area is low, limiting use of the device as a heater stage in air or other gases. A simulation model that includes conduction, as well as radiation and convection heat loss, is presented with radiation and convection parameters determined experimentally. Simulated temperature distributions show that the homogeneity can be improved by using a thicker thermal conduction layer or reducing the pressure of the gas in the environment but neither are good solutions for the proposed use. A new simple design that has improved temperature homogeneity and a larger isothermal area while maintaining a thin thermal conduction layer is proposed and fabricated. This new design enables applications in transmission x-ray microscopes and spectroscopy setups at atmospheric pressure.

Thin film nanocalorimeter for heat capacity measurements of 30 nm films.

A silicon nitride membrane-based nanocalorimeter is described for measuring the heat capacity of 30 nm films from 300 mK to 800 K and in high magnetic fields with absolute accuracy approximately 2%. The addenda heat capacity of the nanocalorimeter is less than 2 x 10(-7) J/K at room temperature and 2 x 10(-10) J/K at 2.3 K. This is more than ten times smaller than any existing calorimeter suitable for measuring thin films over this wide temperature range. The heat capacities of thin Cu and Au films are reported and agree with bulk values. The thermal conductivity of the thin low stress silicon nitride is substantially smaller than thicker membranes while the specific heat is enhanced below 20 K. Design of the nanocalorimeter will be discussed along with fabrication details and calibration results.

Screening evaluation of an ionized nanocrystalline silver dressing in chronic wound care.

The successful topical treatment of chronic wounds requires adequate debridement, bacterial balance, and moisture balance. An ionized nanocrystalline silver dressing was evaluated through an uncontrolled, prospective study of a case series of 29 patients with a variety of chronic nonhealing wounds. The four arms of the study included nine patients with foot ulcers, six patients with venous stasis ulcers, two patients with pressure ulcers, and 12 patients with miscellaneous wounds. All wounds were assessed for the usual signs of clinical infection, with most of these parameters being measured and recorded. Microbiologically, bacterial load was determined via quantitative biopsies and semi-quantitative swabs. In general, the results showed a marked clinical improvement for the majority of wounds treated with the dressing. Among improved parameters included decreased exudate and decreased purulence. The quantitative bacterial biopsies did not show any decrease in organism numbers, although the semi-quantitative swabs indicated a decrease in the wound surface bacterial loading. This was indicative of the dressing's ability to reduce surface bacteria and achieve an element of bacterial balance in the superficial dermal compartment. The proposed mechanism of action for this ionized nanocrystalline based dressing is through bacterial and moisture balance within the superficial wound space compartment.

In vitro assessment of water vapour transmission of synthetic wound dressings.

The water vapour transmission rate (WVTR) of 14 commercially available wound dressings (11 hydrocolloids, 2 hydrogels and 1 polyurethane film) was evaluated over 24 and 48 h periods using a modified ASTM standard method (ASTM E96-90). For the 48 h studies a novel microcomputer-controlled apparatus was employed. The dressings exhibited a wide range of WVTRs (76-9360 g m-2 d-1 at 24 h under forced air convection of 0.4 m s-1). The influence of air velocity of 0.4 m s-1 was not significant if the WVTR of the dressing was less than 880 g m-2 d-1 when measured under static air conditions. The influence of outer barrier layers and additional bandages on WVTR was also examined.

NURSETALK: the latest addition to the information highway.

NURSETALK is an electronic bulletin board system (BBS) developed to provide information and meet the communication needs of three different nursing organizations in North Carolina. It was designed and conceptualized from a user perspective to promote functionality and acceptance.

Evaluation of gaseous transmission (O2 and CO2) through burn wound dressings.

The rates of transmission of oxygen and carbon dioxide through various burn wound dressing materials were determined. The British Standard Vacuum technique was used to determine the Gas Transmission Rate (GTR) of hydrophobic dressings. A Gas to Liquid technique was used to determine the GTR of hydrophilic (water containing) dressings. All the materials tested showed greater GTR values for carbon dioxide than for oxygen. The role of the transmission characteristics of the dressings to influence the wound healing environment is discussed.

The preclinical evaluation of the water vapour transmission rate through burn wound dressings.

The control of evaporative water loss, following burn injury, is of major importance to the overall condition of the patient, whether this control is by natural eschar or by a dressing. It is therefore important to preclinically determine the water vapour transmission rate of these dressings, firstly to make comparisons between different materials and secondly to screen prototype materials, under controlled conditions. A preclinical (in vitro) technique is described and the results are given for several commercially available dressings which encompass foam, film and hydrogel material categories.

An in vitro assessment of wound dressing conformability.

An in vitro assessment technique has been developed to determine the conformability of wound dressings. The technique employed is based on an inflation technique which provides a measurement of the minimum radius of curvature which a specific dressing will adopt under pressure. A pressure of 40 mmHg was chosen as this had been shown to be the maximum tolerable pressure before the occurrence of tissue breakdown. This radius is then matched to the natural radii of the body surfaces and an assessment of conformability can be made. A series of commercially available dressings have been assessed with respect to their conformability, and to the enhancement of their conformability due to viscoelastic creep behaviour.

Burn wound dressings--a review.

Man has dressed wounds since life began many millions of years ago. Since this time many materials have been devised for the intention of dressing wounds. This review indicates the vast range presently available, providing a starting point for those seeking information on this subject.

The in vitro gaseous transmission of wound dressings.

The permeation properties of dressings to gases are important to the healing processes. It is necessary that dressings are permeable to water vapour, oxygen and carbon dioxide. A series of commercially available dressings have been assessed in vitro in respect of their permeability characteristics to these gases.

The physical effects of an adhesive dressing top layer on burn wound dressings.

Three hydrogels were assessed in respect of water-vapour transmission and conformability. These materials were tested alone and as part of a bilaminate dressing which incorporates an adhesive top layer. The adhesive layer used in this study was a compliant adhesive bandage, marketed under the name Mefix. It was observed that this layer reduced the normally high water-vapour transmission rates of the hydrogels to much lower, clinically more acceptable, levels. Mechanically, the Mefix layer protects the underlying hydrogel, prevents tearing and puncturing but decreases conformability by elastic restraint.

Preclinical assessment of burn wound dressings.

Preclinical assessment procedures for wound dressings have been established taking into account the important parameters of tensile mechanical properties, conformability to body surfaces, water-vapour transmission and gas permeability. A new test has been specifically developed to assess dressing conformability, while the other parameters were assessed using established techniques. The procedures aid clinicians by providing a screen reducing the number proceeding to full expensive clinical trials. They are also of assistance to manufacturers in their bid to optimize the characteristics of dressings and evaluate candidate materials.

Correlation of primary breast cancer histopathology and estrogen receptor content.

We studied the association of estrogen receptor (ER) with several histologic variables that correlate with breast tumor differentiation and with patient prognosis. Contingency table analysis revealed highly statistically significant correlations between ER content and histologic and nuclear grades, tumor necrosis, and the degree of elastosis and lymphoid cell infiltration. ER positive tumors were more likely than ER negative tumors to demonstrate histological evidence of tumor differentiation. All tumors with histologic grade 1 or nuclear grade 1 (best differentiated) were ER positive or borderline positive. Eighty-nine percent of ER negative tumors were histologic grade 3 and 78.4% were nuclear grade 3 (poor differentiation). ER positive tumors were also correlated with absent tumor necrosis, higher elastic content, and absent lymphoid cell infiltration, all features of good differentiation. Medullary carcinomas were frequently (73%) ER negative, but no relationship between ER and other morphologic types of breast cancer or 9 other morphologic variables was found. ER appears to be a biochemical marker for the degree of differentiation of human breast cancer providing a rationale for the observed differences in biological behavior between receptor positive and negative tumors.