Publications by authors named "Zhe Yuan"

120 Publications

Public health implications of vaping in the USA: the smoking and vaping simulation model.

Popul Health Metr 2021 Apr 17;19(1):19. Epub 2021 Apr 17.

Department of Epidemiology, University of Michigan, Ann Arbor, MI, USA.

Background: Nicotine vaping products (NVPs) are increasingly popular worldwide. They may provide public health benefits if used as a substitute for smoking, but may create public health harms if used as a gateway to smoking or to discourage smoking cessation. This paper presents the Smoking and Vaping Model (SAVM), a user-friendly model which estimates the public health implications of NVPs in the USA.

Methods: SAVM adopts a cohort approach. We derive public health implications by comparing smoking- and NVP-attributable deaths and life-years lost under a No-NVP and an NVP Scenario. The No-NVP Scenario projects current, former, and never smoking rates via smoking initiation and cessation rates, with their respective mortality rates. The NVP Scenario allows for smoking- and NVP-specific mortality rates, switching from cigarette to NVP use, separate NVP and smoking initiation rates, and separate NVP and smoking cessation rates. After validating the model against recent US survey data, we present the base model with extensive sensitivity analyses.

Results: The SAVM projects that under current patterns of US NVP use and substitution, NVP use will translate into 1.8 million premature smoking- and vaping-attributable deaths avoided and 38.9 million life-years gained between 2013 and 2060. When the NVP relative risk is set to 5%, the results are sensitive to the level of switching and smoking cessation rates and to a lesser extent smoking initiation rates. When the NVP relative risk is raised to 40%, the public health gains in terms of averted deaths and LYL are reduced by 42% in the base case, and the results become much more sensitive to variations in the base case parameters.

Discussion: Policymakers, researchers, and other public health stakeholders can apply the SAVM to estimate the potential public health impact of NVPs in their country or region using their own data sources. In developing new simulation models involving NVPs, it will be important to conduct extensive sensitivity analysis and continually update and validate with new data.

Conclusion: The SAVM indicates the potential benefits of NVP use. However, given the uncertainty surrounding model parameters, extensive sensitivity analysis becomes particularly important.
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http://dx.doi.org/10.1186/s12963-021-00250-7DOI Listing
April 2021

Flavonoid-based inhibition of cyclin-dependent kinase 9 without concomitant inhibition of histone deacetylases durably reinforces HIV latency.

Biochem Pharmacol 2021 Apr 10;186:114462. Epub 2021 Feb 10.

Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada; The Wistar Institute, Philadelphia, PA, USA. Electronic address:

While combination antiretroviral therapy (cART) durably suppresses HIV replication, virus persists in CD4 T-cells that harbor latent but spontaneously inducible and replication-competent provirus. One strategy to inactivate these viral reservoirs involves the use of agents that continue to reinforce HIV latency even after their withdrawal. To identify new chemical leads with such properties, we investigated a series of naturally-occurring flavones (chrysin, apigenin, luteolin, and luteolin-7-glucoside (L7G)) and functionally-related cyclin dependent kinase 9 (CDK9) inhibitors (flavopiridol and atuveciclib) which are reported or presumed to suppress HIV replication in vitro. We found that, while all compounds inhibit provirus expression induced by latency-reversing agents in vitro, only aglycone flavonoids (chrysin, apigenin, luteolin, flavopiridol) and atuveciclib, but not the glycosylated flavonoid L7G, inhibit spontaneous latency reversal. Aglycone flavonoids and atuveciclib, but not L7G, also inhibit CDK9 and the HIV Tat protein. Aglycone flavonoids do not reinforce HIV latency following their in vitro withdrawal, which corresponds with their ability to also inhibit class I/II histone deacetylases (HDAC), a well-established mechanism of latency reversal. In contrast, atuveciclib and flavopiridol, which exhibit little or no HDAC inhibition, continue to reinforce latency for 9 to 14+ days, respectively, following their withdrawal in vitro. Finally, we show that flavopiridol also inhibits spontaneous ex vivo viral RNA production in CD4 T cells from donors with HIV. These results implicate CDK9 inhibition (in the absence of HDAC inhibition) as a potentially favorable property in the search for compounds that durably reinforce HIV latency.
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http://dx.doi.org/10.1016/j.bcp.2021.114462DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8052299PMC
April 2021

The Spatial-Temporal Variation Characteristics of Natural Vegetation Drought in the Yangtze River Source Region, China.

Int J Environ Res Public Health 2021 Feb 8;18(4). Epub 2021 Feb 8.

Department of Geographical Sciences, Faculty of Resources and Environmental Science, Hubei University, Wuhan 430062, China.

In the context of climate change, ecosystem in Yangtze River Source Region (YRSR) is under threat from severe droughts. This study introduced a new natural vegetation drought index, standardized supply-demand water index (SSDI), and identified natural vegetation drought events and parameters (e.g., duration, severity, peak, and coverage area) based on run theory. Then the drought-prone regions were investigated via 2-dimensional joint copula. The results indicate that (1) compared with traditional meteorological drought index, the SSDI is reliable and can reflect the comprehensive characteristics of the ecological drought information more easily and effectively; (2) the YRSR had witnessed the most severe drought episodes in the periods of late-1970s, mid-1980s, and mid-1990s, but the SSDI showed a wetting trend since the mid-2000s. Additionally, droughts in the Southern YRSR were relatively more severe with longer drought duration; (3) in most areas of Togton River Basin and Dam River Basin, the severe ecological drought events occurred more frequently; (4) drought duration and severity in the YRSR were more susceptible to temperature when the temperature rise was above 1.0 °C. The average drought duration and severity increased by 20.7% and 32.6% with a temperature rise of 1 °C. Investigating and evaluating drought characteristics, causes, and drought index effectiveness provide essential information for balanced water resource allocation, utilization, and drought prevention. Understanding these spatial-temporal characteristics of drought and return period was useful for drought risk assessment and sustainable development of water resources.
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http://dx.doi.org/10.3390/ijerph18041613DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7915086PMC
February 2021

Intact Human Immunodeficiency Virus (HIV) Reservoir Estimated by the Intact Proviral DNA Assay Correlates With Levels of Total and Integrated DNA in the Blood During Suppressive Antiretroviral Therapy.

Clin Infect Dis 2021 Feb;72(3):495-498

Wistar Institute, Philadelphia, Pennsylvania, USA.

Accurate characterization of the human immunodeficiency virus (HIV) reservoir is imperative to develop an effective cure. HIV was measured in antiretroviral therapy-suppressed individuals using the intact proviral DNA assay (IPDA), along with assays for total or integrated HIV DNA, and inducible HIV RNA or p24. Intact provirus correlated with total and integrated HIV.
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http://dx.doi.org/10.1093/cid/ciaa809DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7850524PMC
February 2021

Diameter Dependence of Water Filling in Lithographically Segmented Isolated Carbon Nanotubes.

ACS Nano 2021 Feb 29;15(2):2778-2790. Epub 2021 Jan 29.

Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States.

Although the structure and properties of water under conditions of extreme confinement are fundamentally important for a variety of applications, they remain poorly understood, especially for dimensions less than 2 nm. This problem is confounded by the difficulty in controlling surface roughness and dimensionality in fabricated nanochannels, contributing to a dearth of experimental platforms capable of carrying out the necessary precision measurements. In this work, we utilize an experimental platform based on the interior of lithographically segmented, isolated single-walled carbon nanotubes to study water under extreme nanoscale confinement. This platform generates multiple copies of nanotubes with identical chirality, of diameters from 0.8 to 2.5 nm and lengths spanning 6 to 160 μm, that can be studied individually in real time before and after opening, exposure to water, and subsequent water filling. We demonstrate that, under controlled conditions, the diameter-dependent blue shift of the Raman radial breathing mode (RBM) between 1 and 8 cm measures an increase in the interior mechanical modulus associated with liquid water filling, with no response from exterior water exposure. The observed RBM shift with filling demonstrates a non-monotonic trend with diameter, supporting the assignment of a minimum of 1.81 ± 0.09 cm at 0.93 ± 0.08 nm with a nearly linear increase at larger diameters. We find that a simple hard-sphere model of water in the confined nanotube interior describes key features of the diameter-dependent modulus change of the carbon nanotube and supports previous observations in the literature. Longer segments of 160 μm show partial filling from their ends, consistent with pore clogging. These devices provide an opportunity to study fluid behavior under extreme confinement with high precision and repeatability.
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http://dx.doi.org/10.1021/acsnano.0c08634DOI Listing
February 2021

Analyzing the influence of land use/land cover change on landscape pattern and ecosystem services in the Poyang Lake Region, China.

Environ Sci Pollut Res Int 2021 Jan 28. Epub 2021 Jan 28.

Changjiang Water Resources Commission of the Ministry of Water Resources of China, Changjiang River Scientific Research Institute, Wuhan, 430010, China.

The Poyang Lake Region (PLR) is well known for its ecological and economic importance. This paper first analyzed the changes in land use/land cover (LULC), followed by changes in landscape patterns and ecosystem services by landscape metrics and equivalent coefficients table method. Then, the influence of LULC change on landscape pattern and ecosystem services in both historical period (from 1990 to 2015) and future period (2030) was explored. The results showed that the area of construction land was 607.9 km in 1990 and 972.5 km in 2015. The increased construction land mainly converted from cultivated land. For the entire PLR, a higher use degree of LULC and a trend of fragmentation existed in recent years. The total ecosystem service values (ESVs) decreased by ¥2.44 × 10 from 1990 to 2015, mainly because of shrinkage of cultivated land and sharp increase in construction land. It was predicted that the areas of construction land and waterbody would increase by 34.6% and 2.2% compared with those in 2015. These changes would lead to more regular in patch shape, longer in patch edge, less connectivity of patches, and an increase of ¥6.2 × 10 ESVs in 2030.
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http://dx.doi.org/10.1007/s11356-020-12320-8DOI Listing
January 2021

Effects of climatic factors on the net primary productivity in the source region of Yangtze River, China.

Sci Rep 2021 Jan 14;11(1):1376. Epub 2021 Jan 14.

Changjiang River Scientific Research Institute, Changjiang Water Resources Commission of the Ministry of Water Resources of China, Wuhan, China.

The ecosystem of the Source Region of Yangtze River (SRYR) is highly susceptible to climate change. In this study, the spatial-temporal variation of NPP from 2000 to 2014 was analyzed, using outputs of Carnegie-Ames-Stanford Approach model. Then the correlation characteristics of NPP and climatic factors were evaluated. The results indicate that: (1) The average NPP in the SRYR is 100.0 gC/m from 2000 to 2014, and it shows an increasing trend from northwest to southeast. The responses of NPP to altitude varied among the regions with the altitude below 3500 m, between 3500 to 4500 m and above 4500 m, which could be attributed to the altitude associated variations of climatic factors and vegetation types; (2) The total NPP of SRYR increased by 0.18 TgC per year in the context of the warmer and wetter climate during 2000-2014. The NPP was significantly and positively correlated with annual temperature and precipitation at interannual time scales. Temperature in February, March, May and September make greater contribution to NPP than that in other months. And precipitation in July played a more crucial role in influencing NPP than that in other months; (3) Climatic factors caused the NPP to increase in most of the SRYR. Impacts of human activities were concentrated mainly in downstream region and is the primary reason for declines in NPP.
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http://dx.doi.org/10.1038/s41598-020-80494-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7809463PMC
January 2021

Predicting Gas Separation through Graphene Nanopore Ensembles with Realistic Pore Size Distributions.

ACS Nano 2021 Jan 13;15(1):1727-1740. Epub 2021 Jan 13.

Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States.

The development of nanoporous single-layer graphene membranes for gas separation has prompted increasing theoretical investigations of gas transport through graphene nanopores. However, computer simulations and theories that predict gas permeances through individual graphene nanopores are not suitable to describe experimental results, because a realistic graphene membrane contains a large number of nanopores of diverse sizes and shapes. With this need in mind, here, we generate nanopore ensembles by etching carbon atoms away from pristine graphene with different etching times, using a kinetic Monte Carlo algorithm developed by our group for the isomer cataloging problem of graphene nanopores. The permeances of H, CO, and CH through each nanopore in the ensembles are predicted using transition state theory based on classical all-atomistic force fields. Our findings show that the total gas permeance through a nanopore ensemble is dominated by a small fraction of large nanopores with low energy barriers of pore crossing. We also quantitatively predict the increase of the gas permeances and the decrease of the selectivities between the gases as functions of the etching time of graphene. Furthermore, by fitting the theoretically predicted selectivities to the experimental ones reported in the literature, we show that nanopores in graphene effectively expand as the temperature of permeation measurement increases. We propose that this nanopore "expansion" is due to the desorption of contaminants that partially clog the graphene nanopores. In general, our study highlights the effects of the pore size and shape distributions of a graphene nanopore ensemble on its gas separation properties and calls into attention the potential effect of pore-clogging contamination in experiments.
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http://dx.doi.org/10.1021/acsnano.0c09420DOI Listing
January 2021

Poor delineation of labrum and acetabular surface on arthrogram is a predictor of early failure of closed reduction in children aged six to 24 months with developmental dysplasia of the hip.

J Child Orthop 2020 Oct;14(5):372-378

GuangZhou Women and Children's Medical Center, GuangZhou Medical University, GuangZhou, China.

Purpose: The objective of this study was to explore the predictors for failed reduction in children with developmental dysplasia of the hip (DDH) managed by arthrogram, closed reduction (CR) and spica cast immobilization.

Methods: We retrospectively reviewed the clinical data of patients with DDH treated by CR and cast immobilization (2015-2020), including age, sex, affected side, presence/absence of an ossific nucleus, International Hip Dysplasia Institute classification, the delineation of labrum and acetabular surface on arthrogram, inverted labrum, acetabular index (AI), hip abduction angle and medial dye pool (MDP) distance. Predictors that potentially predicted failure of CR were evaluated by logistic regression analysis, simple t-test, Fisher's Exact Test and chi-square test.

Results: In total, 16 out of 187 hips failed to achieve initial CR (8.6%). Gender, age, preoperative AI and poor delineation of arthrogram were candidate predictors for failed CR in children aged six to 24 months with DDH; on the other hand, logistic regression analysis confirmed age and poor delineation of arthrogram significantly predicted failure of CR. Receive operating characteristic curve (ROC) showed MDP less than 6 mm and age higher than 14.5 months significantly increased the failure rate of CR in children aged six to 24 months with DDH.

Conclusion: Age and poor delineation of labrum and acetabular surface during arthrogram predicted failure of CR in children with DDH. In particular, age > 14.5 months and MDP distance ≥ 6 mm significantly increased the risk of CR failure.

Level Of Evidence: III.
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http://dx.doi.org/10.1302/1863-2548.14.200132DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7666794PMC
October 2020

A mutation in (c.C1849T) promotes proliferation while inhibiting hypertrophic differentiation in ATDC5 chondrocytes.

Bone Joint Res 2020 Nov;9(11):751-760

Department of Pediatric Orthopaedics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China.

Aims: This study aimed to investigate the effect of () gene mutation (identified from a hereditary multiple exostoses family) on chondrocyte proliferation and differentiation.

Methods: ATDC5 chondrocytes were cultured in insulin-transferrin-selenium medium to induce differentiation. Cells were transfected with pcDNA3.0 plasmids with either a wild-type (WT) or mutated (MUT) gene. The inorganic phosphate (Pi) concentration in the medium of cells was determined. The expression of markers of chondrocyte proliferation and differentiation, the Indian hedgehog (Ihh), and parathyroid hormone-related protein (PTHrP) pathway were evaluated by quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting.

Results: The expression of in MUT group was similar to WT group. The Pi concentration in the medium of cells in MUT group was significantly higher than WT group, which meant the mutation inhibited Pi uptake in ATDC5 chondrocytes. The proliferation rate of ATDC5 chondrocytes in MUT group was greater than WT group. The expression of aggrecan (Acan), α-1 chain of type II collagen (COL2A1), and SRY-box transcription factor 9 (SOX9) were higher in MUT group than WT group. However, the expression of Runt-related transcription factor 2 (Runx2), α-1 chain of type X collagen (COL10A1), and matrix metallopeptidase 13 (MMP13) was significantly decreased in the MUT group. Similar results were obtained by Alcian blue and Alizarin red staining. The expression of Ihh and PTHrP in MUT group was higher than WT group. An inhibitor (cyclopamine) of Ihh/PTHrP signalling pathway inhibited the proliferation and restored the differentiation of chondrocytes in MUT group.

Conclusion: A mutation in (c.C1948T) decreases Pi uptake in ATDC5 chondrocytes. mutation promotes chondrocyte proliferation while inhibiting chondrocyte differentiation. The Ihh/PTHrP signalling pathway may play an important role in this process. Cite this article: 2020;9(11):751-760.
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http://dx.doi.org/10.1302/2046-3758.911.BJR-2020-0112.R1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7649514PMC
November 2020

The Kentucky SimSmoke Tobacco Control Policy Model of Smokeless Tobacco and Cigarette Use.

Int J Health Policy Manag 2020 Oct 27. Epub 2020 Oct 27.

Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC, USA.

Background: Smokeless tobacco (SLT) prevalence was decreasing in Kentucky before 2007, but has since increased. This study examines the impact of policies on cigarette and SLT use by applying the SimSmoke tobacco control policy simulation model.

Methods: Using data from the large-scale Tobacco Use Supplement of the Current Population Survey (TUS-CPS) and information on state-specific tobacco policies, Kentucky SimSmoke is updated and extended to incorporate exclusive SLT and dual cigarette and SLT use. The model is validated using survey data through 2017. The model was used to estimate the impact on smoking and SLT prevalence and attributable deaths of policies implemented between 1993 and 2018 and the impact of stronger future policies implemented in 2018 and maintained through 2060.

Results: SimSmoke generally reflects trends in exclusive cigarette use from the TUS-CPS and the Behavioral Risk Factor Surveillance System (BRFSS), but underestimated the increase in SLT prevalence in recent years. SimSmoke projects that policies implemented between 1993 and 2018 reduced male and female cigarette use by 23.7% and 23.0%, and male and female SLT use by 4.9% by 2018, averting 9018 tobacco-attributable deaths by 2018, increasing to 89 547 by 2060. The largest reductions in cigarette and SLT use were attributed to cigarette price increases. Strengthening tobacco control policies could reduce smoking prevalence by 41% and 40%, and reduce SLT prevalence by 33% and 25% for males and females by 2060.

Conclusion: Our results suggest that cigarette-oriented policies were effective in reducing SLT use but have been less successful in recent years. Future use rates can be further reduced through more restrictive statewide policies, which also target non-combustible nicotine products.
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http://dx.doi.org/10.34172/ijhpm.2020.187DOI Listing
October 2020

miRNA-146a-5p mitigates stress-induced premature senescence of D-galactose-induced primary thymic stromal cells.

Cytokine 2021 Jan 29;137:155314. Epub 2020 Sep 29.

Research Center, Shengjing Hospital of China Medical University, 7 Mulan Road, Economic Development Zone, Benxi, China. Electronic address:

Senescent thymic stromal cells (TSCs) producing senescence-associated secretory phenotype (SASP) may play a role at later phases of thymic involution. However, the etiology and mechanisms responsible for TSC senescence remain to be elucidated. In the present study, the effects of oxidative stress on TSCs and role of miRNA-146a-5p in stress-induced premature senescence (SIPS) were identified. D-galactose (D-gal) induced oxidative stress in primary TSCs and a limited cumulative oxidative stress induced premature senescence but not apoptosis of TSCs. miRNA-146a-5p overexpression can mitigate the SIPS by targeting tumor necrosis factor receptor-associated factor 6 (TRAF6) instead of increasing autophagy clearance. Furthermore, exogenous miRNA-146a-5p reversed the upregulation of chemokines including Cxcl5, pro-inflammatory cytokines, and antimicrobial peptides in TSCs with SIPS. In conclusion, the accumulated oxidative stress may be partially responsible for senescence in TSCs and modulation of miRNA-146a-5p may attenuate this process.
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http://dx.doi.org/10.1016/j.cyto.2020.155314DOI Listing
January 2021

Integrated Plasmonics: Broadband Dirac Plasmons in Borophene.

Phys Rev Lett 2020 Sep;125(11):116802

Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.

The past decade has witnessed numerous discoveries of two-dimensional (2D) semimetals and insulators, whereas 2D metals were rarely identified. Borophene, a monolayer boron sheet, has recently emerged as a perfect 2D metal with unique electronic properties. Here we study collective excitations in borophene, which exhibit two major plasmon modes with low damping rates extending from the infrared to ultraviolet regime. The anisotropic 1D plasmon originates from electronic transitions of tilted Dirac cones in borophene, analogous to that in extreme doped graphene. These features enable borophene as an integrated platform of 1D, 2D, and Dirac plasmons, promising for directional polariton transport and broadband optical communication in next-generation optoelectronic devices.
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http://dx.doi.org/10.1103/PhysRevLett.125.116802DOI Listing
September 2020

England SimSmoke: the impact of nicotine vaping on smoking prevalence and smoking-attributable deaths in England.

Addiction 2021 May 8;116(5):1196-1211. Epub 2020 Oct 8.

National Addiction Centre, King's College London, UK.

Background And Aims: Whereas the use of nicotine vaping products (NVPs) is widespread, their impact on smoking prevalence is controversial. This study considered the potential impact of NVPs on smoking prevalence in England.

Design: Indirect simulation model. The England SimSmoke model is validated through 2012, before NVP use became more widely used by smokers. Because information on NVP-related transitions is limited, an indirect method is used; the difference in observed smoking prevalence (reflecting NVPs) is compared with a 2012-2019 counterfactual No-NVP scenario (without NVPs) to estimate the impact of NVPs on smoking and smoking-attributable deaths.

Setting: England, 2000-2019.

Participants: Nationally representative sample of population.

Measurements: England's population, mortality rates and smoking prevalence estimates from three national surveys and tobacco control policies.

Findings: Between 2000 and 2012, SimSmoke projected a decline in age 18+ smoking prevalence of 23.5% in men and 27.0% in women. These projections, as well as those by specific age groups, were generally consistent with findings from the three national surveys. Comparing 2012-2019 relative reduction in age 18+ prevalence from the Annual Population Survey (males, 27.5%) with the model-predicted No-NVP reduction (males, 7.3%), the implied NVP-attributable relative reduction in adult smoking prevalence was 20.2% (95% CI, 18.8%-22.0%) for males and 20.4% (18.7%-22.2%) for females. The NVP-attributable reduction was 27.2% (22.8%-31.6%) for males and 31.7% (27.4%-36.5%) for females ages 18-24 and 18.6% (15.2%-21.8%) for males and 15.0% (11.1%-18.8%) for females ages 25-34, with similar reductions for ages 35+. The implied reduction in smoking prevalence between 2012 and 2019 equates to 165 660 (132 453-199 501) averted deaths by 2052. Other surveys yielded smaller, but relatively consistent results.

Conclusions: An indirect method of simulation modelling indicates that substantial reductions in smoking prevalence occurred in England from 2012-2019 coinciding with the growth in nicotine vaping product use.
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http://dx.doi.org/10.1111/add.15269DOI Listing
May 2021

The Public Health Gains Had Cigarette Companies Chosen to Sell Very Low Nicotine Cigarettes.

Nicotine Tob Res 2021 02;23(3):438-446

Department of Epidemiology, School of Public Health, Cancer Epidemiology and Prevention Program, Rogel Cancer Center, University of Michigan, Ann Arbor, MI.

Introduction: The U.S. Food and Drug Administration (FDA) has proposed lowering the nicotine content of cigarettes to a minimally addictive level to increase smoking cessation and reduce initiation. This study has two aims: (1) to determine when cigarette manufacturers had the technical capability to reduce cigarette nicotine content and (2) to estimate the lost public health benefits of implementing a standard in 1965, 1975, or 1985.

Methods: To determine the technical capability of cigarette companies, we reviewed public patents and internal cigarette company business records using the Truth Tobacco Industry Documents. To evaluate the impact of a very low nicotine content cigarette (VLNC) standard on smoking attributable deaths (SADs) and life-years lost (LYLs), we applied a validated (CISNET) model that uses past smoking data, along with estimates of the potential impact of VLNCs derived from expert elicitation.

Results: Cigarette manufacturers recognized that cigarettes were deadly and addictive before 1964. Manufacturers have had the technical capability to lower cigarette nicotine content for decades. Our model projected that a standard implemented in 1965 could have averted 21 million SADs (54% reduction) and 272 million LYLs (64% reduction) from 1965 to 2064, a standard implemented in 1975 could have averted 18.9 million SADs and 245.4 million LYLs from 1975 to 2074, and a standard implemented in 1985 could have averted 16.3 million SADs and 211.5 million LYLs from 1985 to 2084.

Conclusions: Millions of premature deaths could have been averted if companies had only sold VLNCs decades ago. FDA should act immediately to implement a VLNC standard.

Implications: Prior research has shown that a mandated reduction in the nicotine content of cigarettes could reduce the prevalence of smoking and improve public health. Here we report that cigarette manufacturers have had the ability to voluntarily implement such a standard for decades. We use a well-validated model to demonstrate that millions of smoking attributable deaths and life-years lost would have been averted if the industry had implemented such a standard.
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http://dx.doi.org/10.1093/ntr/ntaa128DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7885770PMC
February 2021

Whole‑exome sequencing identifies a novel mutation of SLC20A2 (c.C1849T) as a possible cause of hereditary multiple exostoses in a Chinese family.

Mol Med Rep 2020 Sep 6;22(3):2469-2477. Epub 2020 Jul 6.

Department of Pediatric Orthopedics, Guangzhou Women and Children's Medical Center, Guangzhou, Guangdong 510623, P.R. China.

Although the main causative genes for hereditary multiple exostoses (HME) are exostosin (EXT)‑1 and EXT‑2, there are numerous patients with HME without EXT‑1 and EXT‑2 mutations. The present study aimed to identify novel candidate genes for the development of HME in patients without EXT‑1 and EXT‑2 mutations. Whole‑exome sequencing was performed in a Chinese family with HME and without EXT‑1 and EXT‑2 mutations, followed by a combined bioinformatics pipeline including annotation and filtering processes to identify candidate variants. Candidate variants were then validated using Sanger sequencing. A total of 1,830 original variants were revealed to be heterozygous mutations in three patients with HME which were not present in healthy controls. Two mutations [c.C1849T in solute carrier family 20 member 2 (SLC20A2) and c.G506A in leucine zipper and EF‑hand containing transmembrane protein 1 (LETM1)] were identified as possible causative variants for HME through a bioinformatics filtering procedure and harmful prediction. Sanger sequencing results confirmed these two mutations in all patients with HME. A mutation in SLC20A2 (c.C1849T) led to a change in an amino acid (p.R617C), which may be involved in the development of HME by inducing metabolic disorders of phosphate and abnormal proliferation and differentiation in chondrocytes. In conclusion, the present study revealed two mutations [SLC20A2 (c.C1849T) and LETM1 (c.G506A) in a Chinese family with HME. The mutation in SLC20A2 (c.C1849T)] was more likely to be involved in the development of HME.
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http://dx.doi.org/10.3892/mmr.2020.11298DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7411400PMC
September 2020

Bulk Spin Torque-Driven Perpendicular Magnetization Switching in L1 FePt Single Layer.

Adv Mater 2020 Aug 28;32(31):e2002607. Epub 2020 Jun 28.

Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology School of Physics Science and Engineering, Tongji University, Shanghai, 200092, China.

Due to its inherent superior perpendicular magnetocrystalline anisotropy, the FePt in L1 phase enables magnetic storage and memory devices with ultrahigh capacity. However, reversing the FePt magnetic state, and therefore encoding information, has proven to be extremely difficult. Here, it is demonstrated that an electric current can exert a large spin torque on an L1 FePt magnet, ultimately leading to reversible magnetization switching. The spin torque monotonically increases with increasing FePt thickness, exhibiting a bulk characteristic. Meanwhile, the spin torque effective fields and switching efficiency increase as the FePt approaches higher chemical ordering with stronger spin-orbit coupling. The symmetry breaking that generates spin torque within L1 FePt is shown to arise from an inherent structural gradient along the film normal direction. By artificially reversing the structural gradient, an opposite spin torque effect in L1 FePt is demonstrated. At last, the role of the disorder gradient in generating a substantial torque in a single ferromagnet is supported by theoretical calculations. These results will push forward the frontier of material systems for generating spin torques and will have a transformative impact on magnetic storage and spin memory devices with simple architecture, ultrahigh density, and readily application.
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http://dx.doi.org/10.1002/adma.202002607DOI Listing
August 2020

Does the size of the femoral head correlate with the incidence of avascular necrosis of the proximal femoral epiphysis in children with developmental dysplasia of the hip treated by closed reduction?

J Child Orthop 2020 Jun;14(3):175-183

Department of Pediatric Orthopaedics, GuangZhou Women and Children's Medical Center, GuangZhou, China.

Purpose: The purpose of this study was to identify if any correlation between size of the proximal femoral epiphysis and avascular necrosis (AVN) exists.

Methods: We retrospectively reviewed 111 patients with developmental dysplasia of the hip treated by closed reduction (124 hips). The diameter and height of both femoral head and ossific nucleus were assessed on preoperative MRI.

Results: The diameter and the height of the femoral head as well as of the ossific nucleus of the contralateral side were significantly greater than the dislocated side. AVN occurred in 21 (16.9%) out of 124 hips. The rate of AVN gradually decreased with age: 30.0% at six to 12 months, 18.2% at 12 to 18 months and 3.7% at 18 to 24 months. Spearman correlation analysis showed that age is negatively correlated with the incidence of AVN (r = -0.274; p = 0.002) and the diameter of the femoral head has a significantly negative association with the incidence of AVN (r = -0.287; p = 0.001). No significant association was observed between the incidence of AVN and height of the femoral head or size of the ossific nucleus. Hips with AVN were significantly smaller than hips without AVN.

Conclusions: The size of both the femoral head and the ossific nucleus increase with age although the dislocated femoral head is smaller compared with the contralateral side. The diameter of the femoral head and not the size of the ossific nucleus negatively correlate with the risk of AVN, with a bigger femoral head showing lower risk of AVN.

Level Of Evidence: III.
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http://dx.doi.org/10.1302/1863-2548.14.190176DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7302414PMC
June 2020

Risk factors associated with unsatisfactory hip function in children with late-diagnosed developmental dislocation of the hip treated by open reduction.

Orthop Traumatol Surg Res 2020 Nov 19;106(7):1373-1381. Epub 2020 Jun 19.

Department of pediatric orthopaedics, GuangZhou Women and Children's Medical Center, 9th JinSui Road, GuangZhou 510623, China. Electronic address:

Background: Open reduction with or without pelvic and femoral osteotomy is the accepted treatment option for children older than 18 months with developmental dislocation of the hip (DDH). However, few studies have investigated hip function in children with late DDH treated by open reduction. Therefore, we performed a retrospective study investigating the risk factors potentially associated with unsatisfactory hip function.

Hypothesis: We hypothesized that some risk factors can be associated with unsatisfactory hip function in patients with late DDH treated by open reduction.

Patients And Methods: We retrospectively reviewed the clinical and radiographic data of 79 children (98 hips, mean age 39.7±18.6 months; range, 19-95.3) with late-detected DDH treated by open reduction. Acetabular index (AI), Tönnis grade, Center Edge Angle (CEA), avascular necrosis of the femoral epiphysis (AVN), and Severin radiographic grade were evaluated on radiographs. Hip function was rated according to modified Outcome Evaluation Standard for Congenital Dislocation of the Hip with a maximum score of 15. According to type of surgery, patients were divided into four groups: open reduction alone (Group A), open reduction in conjunction with pelvic osteotomy (Group B), and open reduction in conjunction with femoral osteotomy and Pemberton/Salter (Group C) or Bernese-type triple pelvic osteotomy (Group D). Analysis of variance (ANOVA), t-test, chi-square test, and multivariate regression analysis were used to evaluate the independent risk factors of unsatisfactory hip function.

Results: The mean hip function score was 10.8±2.8 (4.5-15); 61 hips (62.2%) had satisfactory function (23 [23.5%] excellent and 38 [38.8%] good), while 37 hips (37.8%) had unsatisfactory function (16 [16.3%] fair and 21 [21.4%] poor). Spearman correlation analysis indicated that age at surgery was negatively correlated with function score (r=-0.326, p=0.001). The age of patients with satisfactory hip function (34.5±14.2 months; range, 19.4-74.8) was significantly lower than those with unsatisfactory function (43.7±21 months; range, 20.6-95.3) (p=0.011). The hip function score in Group A (14.2±0.8; range, 12.8-15) was significantly higher than in the other three groups (p<0.001). Hip function score in patients with type III or IV AVN was significantly lower than those without AVN, or with type II AVN (p=0.001). Multivariate regression analysis confirmed age at surgery, type of surgery and AVN were negatively correlated with hip function score. Logistic regression analysis and chi-square test confirmed age and type of surgery, and AVN were independent risk factors of unsatisfactory hip function. Multivariate regression analysis found ability to squat and amount of hip flexion and abduction, significantly decreased with age at surgery; while presence of limping, amount of hip flexion, abduction, adduction and external rotation significantly decreased with type of surgery.

Discussion: Age at surgery, type of surgery and severe AVN are independent risk factors for unsatisfactory hip function in patients with late-detected DDH treated by open reduction. The ability to squat, the amount of hip flexion and abduction are the main functional parameters affected by age and surgery.

Level Of Evidence: IV, case series.
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http://dx.doi.org/10.1016/j.otsr.2020.03.018DOI Listing
November 2020

Intact HIV reservoir estimated by the intact proviral DNA assay correlates with levels of total and integrated DNA in the blood during suppressive antiretroviral therapy.

Clin Infect Dis 2020 Jun 18. Epub 2020 Jun 18.

The Wistar Institute, Philadelphia, PA, USA.

Accurate characterization of the HIV reservoir is imperative to develop an effective cure. HIV was measured in antiretroviral therapy-suppressed individuals using the intact proviral DNA assay (IPDA), along with assays for total or integrated HIV DNA, and inducible HIV RNA or p24. Intact provirus correlated with total and integrated HIV.
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http://dx.doi.org/10.1093/cid/ciaa809DOI Listing
June 2020

Fabrication of Microfluidic Chips Based on an EHD-Assisted Direct Printing Method.

Sensors (Basel) 2020 Mar 11;20(6). Epub 2020 Mar 11.

Jiangsu Key Laboratory of 3D Printing Equipment and Manufacturing, School of NARI Electric and Automation, Nanjing Normal University, Nanjing, Jiangsu Province, China.

Microfluidic chips have been widely used in many areas such as biology, environmental monitoring, and micromixing. With the increasing popularity and complexity of microfluidic systems, rapid and convenient approaches for fabricating microfluidic chips are necessary. In this study, a method based on EHD (electrohydrodynamic)-assisted direct printing is proposed. Firstly, the principle of EHD-assisted direct printing was analyzed. The influence of the operating voltage and moving speed of the work table on the width of a paraffin wax model was studied. Then, two kinds of paraffin wax molds for micromixing with channel widths of 120 μm were prepared. A polydimethylsiloxane (PDMS) micromixer was fabricated by replicating the paraffin wax mold, and the micromixing of blue and yellow dye was realized. The results show that EHD-assisted direct printing can be used to make complex microscale structures, which has the potential to greatly simplify the manufacturing process.
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http://dx.doi.org/10.3390/s20061559DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7146459PMC
March 2020

Disorder Dependence of Interface Spin Memory Loss.

Phys Rev Lett 2020 Feb;124(8):087702

Faculty of Science and Technology and MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands.

The discontinuity of a spin-current through an interface caused by spin-orbit coupling is characterized by the spin memory loss (SML) parameter δ. We use first-principles scattering theory and a recently developed local current scheme to study the SML for Au|Pt, Au|Pd, Py|Pt, and Co|Pt interfaces. We find a minimal temperature dependence for nonmagnetic interfaces and a strong dependence for interfaces involving ferromagnets that we attribute to the spin disorder. The SML is larger for Co|Pt than for Py|Pt because the interface is more abrupt. Lattice mismatch and interface alloying strongly enhance the SML that is larger for a Au|Pt than for a Au|Pd interface. The effect of the proximity-induced magnetization of Pt is negligible.
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http://dx.doi.org/10.1103/PhysRevLett.124.087702DOI Listing
February 2020

Risk factors for carbapenem-resistant Klebsiella pneumoniae infection relative to two types of control patients: a systematic review and meta-analysis.

Antimicrob Resist Infect Control 2020 01 31;9(1):23. Epub 2020 Jan 31.

Department of Hospital Infection Control, The First Affiliated Hospital of Chongqing Medical University, No. 1 You Yi Road, Yuan Jia Gang, Yuzhong District, Chongqing, 400016, China.

Background: Studies on risk factors for carbapenem-resistant Klebsiella pneumoniae (CRKP) infection have provided inconsistent results, partly due to the choice of the control group. We conducted a systematic review and meta-analysis to assess the risk factors for CRKP infection by comparing CRKP-infected patients with two types of controls: patients infected with carbapenem-susceptible Klebsiella pneumoniae (comparison 1) or patients not infected with CRKP (comparison 2).

Methods: Data on potentially relevant risk factors for CRKP infection were extracted from studies indexed in PubMed, EMBASE, Web of Science or EBSCO databases from January 1996 to April 2019, and meta-analyzed based on the outcomes for each type of comparison.

Results: The meta-analysis included 18 studies for comparison 1 and 14 studies for comparison 2. The following eight risk factors were common to both comparisons: admission to intensive care unit (ICU; odds ratio, OR = 3.20, OR = 4.44), central venous catheter use (2.62, 3.85), mechanical ventilation (2.70, 4.78), tracheostomy (2.11, 8.48), urinary catheter use (1.99, 0.27), prior use of antibiotic (6.07, 1.61), exposure to carbapenems (4.16, 3.84) and exposure to aminoglycosides (1.85, 1.80). Another 10 risk factors were unique to comparison 1: longer length of hospital stay (OR = 15.28); prior hospitalization (within the previous 6 months) (OR = 1.91); renal dysfunction (OR = 2.17); neurological disorders (OR = 1.52); nasogastric tube use (OR = 2.62); dialysis (OR = 3.56); and exposure to quinolones (OR = 2.11), fluoroquinolones (OR = 2.03), glycopeptides (OR = 3.70) and vancomycin (OR = 2.82).

Conclusions: Eighteen factors may increase the risk of carbapenem resistance in K. pneumoniae infection; eight factors may be associated with both K. pneumoniae infections in general and CRKP in particular. The eight shared factors are likely to be 'true' risk factors for CRKP infection. Evaluation of risk factors in different situations may be helpful for empirical treatment and prevention of CRKP infections.
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http://dx.doi.org/10.1186/s13756-020-0686-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6995231PMC
January 2020

Variables influencing the pelvic radiological evaluation in children with developmental dysplasia of the hip managed by closed reduction: a multicentre investigation.

Int Orthop 2020 03 22;44(3):511-518. Epub 2020 Jan 22.

Department of Pediatric Orthopaedics, GuangZhou Women and Children's Medical Center, GuangZhou Medical University, 9th JinSui Road, GuangZhou, 510623, China.

Purpose: This study aims to evaluate (1) the probability to achieve normal pelvic radiographs in children with developmental dysplasia of the hip (DDH) treated by closed reduction and (2) the amount of time needed to achieve normal pelvic radiographs and to assess what factors influence both probability and time to achieve normal radiographic parameters following CR and spica cast immobilization for DDH.

Methods: We retrospectively reviewed 436 patients (393 girls, 43 boys; 507 hips) with DDH treated by closed reduction (CR). Tönnis grade, AVN, acetabular index (AI), centre-edge angle (CEA), and Severin radiographic grade were evaluated on plain radiographs. Criteria to rate pelvis radiographs as normal were established. Cox regression was used to evaluate the factors influencing the probability and the time to achieve normal radiographs.

Results: According to our criteria, 167 hips (32.9%) achieved normal radiographic parameters during follow-up. The overall amount of time to achieve normal pelvis radiographs was 36.1 ± 15.5 months. Patients older than 24 months of age at the time of CR needed longer time to achieve normal radiographic parameters (55.2 ± 28 months) compared with other age groups. Cox regression analysis suggested the overall cumulative probability of recovery increased by 46% at five years following CR, then it tended to plateau with an annual increase less than 5%. Age older than 24 months, bilateral dislocation, pre-operative AI greater than 40°, and AVN were risk factors for reduced probability of achieving normal radiographic parameters.

Conclusions: The cumulative probability of achieving normal pelvis radiographs increases linearly during the first five years following CR, then it tends to plateau. Age older than 24 months and Tönnis grade III and IV are associated with longer time to achieve normal radiographic parameters. Age older than 24 months, bilateral dislocation, pre-operative AI greater than 40°, and AVN are risk factors for reduced probability of achieving normal radiographic parameters in children with DDH treated by closed means.
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http://dx.doi.org/10.1007/s00264-020-04479-zDOI Listing
March 2020

Early Radiographic Changes in the Lateral Talocalcaneal Angle Following Achilles Tenotomy in Children With Idiopathic Clubfoot.

Foot Ankle Int 2020 03 19;41(3):350-355. Epub 2019 Dec 19.

Pediatric Surgery Department, University Hospital Estaing, Clermont Ferrand, France.

Background: Percutaneous Achilles tenotomy (PAT) is an important component of the Ponseti method and is performed in 85% to 90% of patients. However, there is a lack of objective data assessing early radiographic changes in children undergoing PAT.

Methods: Forty-nine patients with idiopathic clubfoot treated by Ponseti casting were prospectively enrolled between October 2017 and October 2018. Preoperative and postoperative ankle dorsiflexion (pre-ADF, post-ADF) and lateral talocalcaneal angle (pre-LTCA, post-LTCA) values with the ankle in maximal dorsiflexion as well as postoperative LTCA values with the ankle in the neutral position (post-LTCA) were measured. The relationship between the preoperative and postoperative ADF and LTCA values was studied using Pearson or Spearman correlation coefficients. Forty-nine patients (72 feet) were included; the mean age at initial treatment was 32.2 ± 24.1 days.

Results: Post-LTCA improved significantly from 18.6 ± 9.2 degrees to 25.1 ± 10.5 degrees ( < .0001). Pre-ADF and pre-LTCA showed a positive correlation in both the less than 28-day group ( = 0.42; = .015) and the Dimeglio III group ( = 0.29; = .035). However, post-ADF and post-LTCA showed a positive correlation in the Dimeglio III group ( = 0.30; = .028). The degree of improvement in post-LCTA in the Dimeglio III group was similar to that in the Dimeglio IV group ( = .28).

Conclusion: The LTCA increased immediately after PAT in clubfoot, although the improvement seemed to be unrelated to the severity of the disease. PAT led to an increase in both ADF and the LTCA, and it contributed to the improvements in subtalar joint motion and alignment.

Level Of Evidence: Level III, comparative study.
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http://dx.doi.org/10.1177/1071100719895211DOI Listing
March 2020

The Minnesota SimSmoke Tobacco Control Policy Model of Smokeless Tobacco and Cigarette Use.

Am J Prev Med 2019 10;57(4):e103-e115

Schroeder Institute, Truth Initiative, Washington, District of Columbia.

Introduction: A previous Minnesota SimSmoke tobacco control policy model is extended to more recent years and to include smokeless tobacco use.

Methods: Using data from the 1993 Tobacco Use Supplement and information on state policies, the Minnesota SimSmoke model was updated and extended to incorporate smokeless tobacco (both exclusive and dual use) and smokeless tobacco-attributable deaths. The model was then validated against the 2002, 2006/2007, and 2014/2015 Tobacco Use Supplement and the 1999, 2007, 2014, and 2018 Minnesota Adult Tobacco Survey and used to estimate the impact of policies implemented between 1993 and 2018. Analysis was conducted in April 2019.

Results: The model validated well for cigarette and earlier smokeless tobacco use, but it predicted smokeless tobacco use less well in recent years. The model projected that male (female) smoking prevalence was 35% (36%) lower in relative terms by 2018 and 43% (44%) lower by 2040 owing to policies, with lesser reductions projected for male smokeless tobacco use. Tobacco-attributable deaths were reduced by 7,800 by 2018 and 46,900 by 2040. Price increases, primarily through taxes, were projected to have had the greatest impact on cigarette use followed by smoke-free air laws, cessation treatment policies, tobacco control campaign expenditures, and youth access enforcement. Similar effects were projected for smokeless tobacco use, except that smoke-free air laws had smaller effects.

Conclusions: As cigarettes remain the dominant form of nicotine delivery product, cigarette-oriented policies may be an effective means of reducing the use of all nicotine delivery products. However, noncigarette-oriented policies may also play an important role.
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http://dx.doi.org/10.1016/j.amepre.2019.06.003DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6756173PMC
October 2019

Spatial Distribution of Precipitation in Huang-Huai-Hai River Basin between 1961 to 2016, China.

Int J Environ Res Public Health 2019 09 13;16(18). Epub 2019 Sep 13.

General Institute of Water Resources and Hydropower Planning and Design, Ministry of Water Resources, Beijing 100120, China.

The Huang-huai-hai River Basin is one of the most economically developed areas, but is also heavily impacted by drought and flood disasters. Research on the precipitation feature of the Huang-huai-hai River Basin is of great importance to the further discussion of the cause of flood disaster. Based on the selected meteorological stations of the study area from 1961-2016, the inverse distance weighting method was used to get daily precipitation grid data. Interannual variation of precipitation intensity and cover area of different precipitation classes was analyzed. The generalized extreme-value distribution method was used to analyze the spatial distribution of extreme precipitation. The results show that: (1) decrease of accumulated precipitation in light precipitation year and moderate precipitation year might be the reason why the precipitation in the whole basin decreased, but the coefficient of variation (CV) of different classes of precipitation and precipitation days does not change significantly; (2) since the cover area of precipitation > 50 mm and precipitation intensity both decreased, the extreme precipitation of the whole basin may be decreasing; (3) extreme precipitation mainly occurred in the loess plateau in the northeast of Huang-huai-hai River Basin, Dabieshan in the middle of Huang-huai-hai River Basin and other areas.
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http://dx.doi.org/10.3390/ijerph16183404DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6765816PMC
September 2019

Analytical Prediction of Gas Permeation through Graphene Nanopores of Varying Sizes: Understanding Transitions across Multiple Transport Regimes.

ACS Nano 2019 Oct 23;13(10):11809-11824. Epub 2019 Sep 23.

Department of Chemical Engineering , Massachusetts Institute of Technology , Cambridge , Massachusetts 02139 , United States.

Nanoporous graphene is a promising candidate material for gas separation membranes, due to its atomic thickness and low cross-membrane transport resistance. The mechanisms of gas permeation through graphene nanopores, in both the large and small pore size limits, have been reported in the literature. However, mechanistic insights into the crossover from the small pore size limit to the large pore size limit are still lacking. In this study, we develop a comprehensive theoretical framework to predict gas permeance through graphene nanopores having a wide range of diameters using analytical equations. We formulate the transport kinetics associated with the direct impingement from the bulk and with the surface diffusion from the adsorption layer on graphene and then combine them to predict the overall gas permeation rate using a reaction network model. We also utilize molecular dynamics simulations to validate and calibrate our theoretical model. We show that the rates of both the direct impingement and the surface diffusion pathways need to be corrected using different multiplicative factors, which are functions of temperature, gas kinetic diameter, and pore diameter. Further, we find a minor spillover pathway that originates from the surface adsorption layer, but is not included in our theoretical model. Finally, we utilize the corrected model to predict the permeances of CO, CH, and Ar through graphene nanopores. We show that as the pore diameter increases, gas transport through graphene nanopores can transition from being translocation dominated (pore diameter 0.7 nm), to surface pathway dominated (pore diameter 1-2 nm), and finally to direct pathway dominated (pore diameter 4 nm). The various gas permeation mechanisms outlined in this study will be particularly useful for the rational design of membranes made out of two-dimensional materials such as graphene for gas separation applications.
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http://dx.doi.org/10.1021/acsnano.9b05779DOI Listing
October 2019

An Examination of the Variation in Estimates of E-Cigarette Prevalence among U.S. Adults.

Int J Environ Res Public Health 2019 08 30;16(17). Epub 2019 Aug 30.

Cancer Prevention and Control, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC 20007, USA.

: Accurate estimates of e-cigarette use are needed to gauge its impact on public health. We compared the results of online and traditional, large scale surveys and provide additional estimates from the Population Assessment of Tobacco and Health (PATH) survey, with the aim of assessing the extent of variation in prevalence estimates. : We searched the peer-reviewed literature for nationally representative estimates of U.S. adult e-cigarette prevalence, and developed our own estimates from waves one, two, and three of the PATH survey. We compared estimates by age, gender, cigarette smoking status, and e-cigarette use intensity both between online and traditional surveys and among the traditional surveys. Results: For specific years, online surveys generally yielded higher adult use rates than most traditional surveys, but considerable variation was found among traditional surveys. E-cigarette prevalence was greater for less intensive than for more intensive use. Levels of use were higher among current and recent former cigarette smokers than among former smokers of longer quit duration and never smokers, and by those of younger ages. Considerable variation in e-cigarette use estimates was observed even for a specific year. Further study is needed to uncover the source of variation in e-cigarette prevalence measures, with a view towards developing measures that best explain regular use and transitions between the use of e-cigarettes and other tobacco products.
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http://dx.doi.org/10.3390/ijerph16173164DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6747488PMC
August 2019