Hazardous state lifetimes of biodegradable plastics in natural environments.

Plastic pollution is a critical problem that has the potential for long-lasting impact. While all plastics eventually break down to at least some degree, they can remain in different transition states, such as microplastics and nanoplastics, for extended periods of time before reaching complete mineralisation to non-hazardous end products. Each of the transition states represents different types of hazards, so it is critical to understand the factors driving the lifetimes of plastics within these states. To do this, we propose a framework for assessing plastic lifetimes in natural environments based on the flow of material through potentially hazardous states: macroplastic and mesoplastic, microplastic, nanoplastic and soluble products. State changes within this framework are underpinned by three key processes: fragmentation, depolymerisation, and bioassimilation, with the pathways for generation of the different plastic states, and the lifetimes within these states, varying widely for individual materials in different environments due to their dependence on polymer material type, form and properties, and environmental factors. The critical factors driving these processes can therefore appear complex, but molecular weight, crystallinity, oxygen and water diffusivity, and inherent polymer chain reactivity (including to enzymes) are key to our understanding. By analysing currently available data that take factors such as these into consideration, we have generated information on the most likely states in which a range of plastics with different environmental degradation behaviour may exist over time in natural environments. Polyethylene (PE), for example, should be expected to fragment and accumulate in the environment as microplastic and nanoplastic. Interestingly, the state-profile for the biodegradable plastic polylactic acid (PLA) is similar, albeit over shorter timeframes. PLA also likely fragments, but then the relatively slow process of abiotic depolymerisation results in accumulation of microplastic and nanoplastic. By contrast, the state-profile for the biodegradable plastic polyhydroxyalkanoate (PHA) would be expected to be very different. The bulk material is less susceptible to embrittlement and fragmentation as a primary path to biodegradation, since the rapid enzyme catalysed depolymerisation of exposed surfaces proceeds in conjunction with bioassimilation.

Influence of surface oxidation on the quantification of polypropylene microplastics by pyrolysis gas chromatography mass spectrometry.

The influence of photo-oxidation on the quantification of isotactic polypropylene by Pyrolysis Gas Chromatography/Mass Spectrometry (Pyr-GC/MS) was assessed. Beads (oval shape, ~5 mm) and fragments (irregular shaped, 250-50 µm and 500-1000 µm) were subjected to relatively harsh simulated accelerated weathering conditions (using a filtered xenon-arc reproducing sunlight's full spectrum) for up to 37 and 80 days, respectively. Samples collected (n = 10 replicates for each treatment) at increasing number of weathering days were analysed by Fourier-transform infrared spectroscopy with Attenuated Total Reflection (FTIR-ATR), scanning electron microscopy, and differential scanning calorimetry in order to assess the extent and the rate of degradation. The rate of surface oxidation occurred faster for fragments compared to beads, probably due to their higher surface area. Quantification of the polypropylene trimer (2,4-dimethyl-1-heptene) via double shot Pyr-GC/MS, showed that the signal of the trimer relative to the mass of polypropylene was reduced through weathering with a degradation rate of 1:3 faster for fragments over beads. Signal reduction and carbonyl index were correlated to show that polypropylene with a carbonyl index of ≥13 has a significantly reduced 2,4-dimethyl-1-heptene signal when compared to virgin material. Consequently, the quantification of polypropylene subjected to weathering under harsh conditions may be underestimated by 42% (fragments, carbonyl index: 18) to 49% (beads, carbonyl index: 30) when quantified by Pyr-GC/MS and using virgin polypropylene calibration standards. Pyrolysis at a lower temperature (350 °C) identified six degradation specific markers (oxidation products) that increased in concentration with weathering. Further comparisons between virgin and weathered microplastics may need to be considered to avoid underestimation of microplastic concentrations in future studies.

Microplastic pollution alters forest soil microbiome.

The impact of microplastic pollution on terrestrial biota is an emerging research area, and this is particularly so for soil biota. In this study, we addressed this knowledge gap by examining the impact of aged low-density polyethylene (LDPE) and polyester fibres (i.e. polyethylene terephthalate, PET) on a forest microbiome composition and activity. We also measured the corresponding physicochemical changes in the soil. We observed that bacteria community composition diverged in PET and LDPE treated soils from that of the control by day 42. These changes occurred at 0.2% and 0.4% (w/w) of PET and at 3% LDPE. Additionally, soil respiration was 8-fold higher in soil that received 3% LDPE compared to other treatments and control. There were no clear patterns linking these biological changes to physicochemical changes measured. Taken together, we concluded that microplastics aging in the environment may have evolutionary consequences for forest soil microbiome and there is immediate implication for climate change if the observed increase in soil respiration is reproducible in multiple ecosystems.

Sexualised video games, sexist attitudes and empathy towards victims of rape: Correlational evidence for a relationship is minimal in an online study.

BACKGROUND: There is continued debate about whether sexualisation in games can influence sexist attitudes and reduced empathy towards women in real life. There is research evidence both supporting and refuting the possibility. AIMS: Our aim was to examine the relationship between sexualised content in video games and players' sexist attitudes and empathy. Our research question was, do any such relationships exist once other factors including gender and trait aggression are controlled? METHODS: An online sample of 125 participants were recruited and asked to rate their video game playing experience, complete a trait aggression scale and record responses to a vignette about rape. Scores were first correlated, and then hierarchical multiple regression was employed followed by PROCESS examination of interactions between sexualised game content and trait aggression. RESULTS: Exposure to sexualised content in video games was neither correlated with higher sexist attitude ratings nor with lower empathy scores. Sexualised content in games was associated with slightly lower sexist belief scores for those with higher scores on trait aggression (the 12.8% of our current sample at one standard deviation above the mean). No effects were observed for those low in trait aggression. CONCLUSIONS AND IMPLICATIONS: While it is natural to be concerned about the impact of potentially arousing video games, actual effects may be counterintuitive, so if seeking to regulate, it is important to act from actual information. Further research with groups of particular concern will be important.

Sensors: A Highly Sensitive Diketopyrrolopyrrole-Based Ambipolar Transistor for Selective Detection and Discrimination of Xylene Isomers (Adv. Mater. 21/2016).

An ambipolar organic field-effect transistor (OFET) based on poly(diketopyrrolopyrrole-terthiophene) (PDPPHD-T3) is shown by P. Sonar, H. Haick, and co-workers on page 4012 to sensitively detect xylene isomers at low to 40 ppm level in multiple sensing features. Combined with pattern-recognition algorithms, a sole ambipolar FET sensor, rather than arrays of sensors, is able to discriminate highly similar xylene structural isomers from each other.

A Highly Sensitive Diketopyrrolopyrrole-Based Ambipolar Transistor for Selective Detection and Discrimination of Xylene Isomers.

An ambipolar poly(diketopyrrolopyrrole-terthiophene)-based field-effect transistor (FET) sensitively detects xylene isomers at low ppm levels with multiple sensing features. Combined with pattern-recognition algorithms, a sole ambipolar FET sensor, rather than arrays of sensors, can discriminate highly similar xylene structural isomers from one another.

Investigation on Temperature-Dependent Electrical Conductivity of Carbon Nanotube/Epoxy Composites for Sustainable Energy Applications.

Composites with carbon nanotubes are becoming increasingly used in energy storage and electronic devices, due to incorporated excellent properties from carbon nanotubes and polymers. Although their properties make them more attractive than conventional smart materials, their electrical properties have been found to be temperature-dependent which is important to consider for the design of devices. To study the effects of temperature in electrically conductive multi-wall carbon nanotube/epoxy composites, thin films were prepared and the effect of temperature on the resistivity, thermal properties and Raman spectral characteristics of the composite films was evaluated. Resistivity-temperature profiles showed three distinct regions in as-cured samples and only two regions in samples whose thermal histories had been erased. In the vicinity of the glass transition temperature, the as-cured composites exhibited pronounced resistivity and enthalpic relaxation peaks, which both disappeared after erasing the composites' thermal histories by temperature cycling. Combined DSC, Raman spectroscopy, and resistivity-temperature analyses indicated that this phenomenon can be attributed to the physical aging of the epoxy matrix and that, in the region of the observed thermal history-dependent resistivity peaks, structural rearrangement of the conductive carbon nanotube network occurs through a volume expansion/relaxation process. These results have led to an overall greater understanding of the temperature-dependent behaviour of conductive carbon nanotube/epoxy composites, including the positive temperature coefficient effect.

Does aspirin use reduce cardiovascular risk in diabetes?

The use of aspirin for the primary prevention of cardiovascular events in patients with type 2 diabetes mellitus is controversial. According to the findings of a Japanese trial, aspirin does not reduce the risk of cardiovascular events in this group of patients, unless they are aged 65 years and above.

Racial disparities in trends for cardiovascular disease and procedures among hospitalized diabetic patients.

METHODS: To determine if racial differences exist for trends in diabetes-related cardiovascular disease (CVD) hospitalization rates, we analyzed data from an inpatient hospital discharge database maintained by the South Carolina Office of Research and Statistics. All hospitalizations involving a diagnosis of diabetes were collected from 1996 through 2003. International Classification of Diseases codes were used to determine diagnosis for diabetes, acute myocardial infraction (AMI), stroke, and other CVD outcomes. Multiple linear regression was performed to model the age-standardized rates during the study period. An interaction parameter for race and discharge year was used in the models to determine if the trend slopes varied between African Americans and Caucasians. RESULTS: The diabetes-related hospitalization rates for AMI and stroke declined for both race groups. Although the stroke rates for African Americans were consistently higher than those for Caucasians, the African American trend declined more sharply (P=.027). AMI rates showed sharper declines among Caucasians (P<.001). Rates of CVD procedures (percutaneous transluminal coronary angioplasty and coronary artery bypass graft) were two to three times greater among Caucasians. Cardiomyopathy rates were significantly greater among African Americans and showed a larger increasing trend (P<.001), and findings for congestive heart failure trends were similar (P<.001). CONCLUSIONS: Diabetes-related CVD rates and trends vary considerably by race. Rates of AMI and stroke declined in African Americans and Caucasians from 1996 through 2003, while other CVD rates increased. Further research is needed to understand the underlying components of these disparities.

An empirical test of sex differences in the emphasis on physical attractiveness in mate selection.

Within a context provided by social structural theory, social evolutionary theory, and physical attractiveness stereotyping, the importance of physical attractiveness in heterosexual mate selection was explored by presenting 50 male and 50 female psychology students (M age = 22.5 yr.) during a scheduled class with an opposite sex personals advertisement, wherein the advertiser was described as 'average' or 'good-looking'. Dependent variables consisted of a written paragraph and measures of evaluation (Semantic Differential), attraction, advertisement appeal, and success. An interaction for sex x looks on the qualitative measure showed no effect for men, but the good-looking female advertiser was evaluated more positively. However, for quantitative data, the advertisement was seen as more appealing and likely to be successful when the advertiser was good looking as opposed to average looking, irrespective of sex of advertiser. Findings are discussed in relation to theoretical perspectives.

Diabetes-related lower extremity amputation rates fall significantly in South Carolina.

BACKGROUND: The aims of this study are to compare the diabetes-related lower extremity amputation (LEA) rate trend in South Carolina (SC) to that of the United States (US) and to determine changes in LEA rates in SC according to age, race, gender, and amputation METHODS: National Hospital Discharge Survey (NHDS) and SC hospital discharge data for 1996 to 2002 were analyzed. ICD-9-CM codes identified all diabetic patients and occurrences of LEA. Linear regression was used to compare the LEA rate trends between SC and the US. RESULTS: LEA rates are decreasing throughout the study period. The slope is greater in SC compared with US (US slope = -0.00082; SC slope = -0.0015; P = 0.002), signifying a decrease in LEA rates of 1.5/1000 per year in SC and 0.8/1000 per year in the US. Furthermore, LEA rate decreases in SC are significant throughout all ages, races, genders, and amputation levels. CONCLUSIONS: Diabetes-related LEA rates are decreasing in SC more rapidly than in the US. Ongoing community-level education may be assisting in the favorable trends.

Aspirin for the primary prevention of cardiovascular events.

There is significant evidence that low-dose aspirin is effective in preventing the first myocardial infarction in men and ischemic stroke in women. There is also an increased risk for major gastrointestinal tract hemorrhage and a suggestive, but nonsignificant, increase in the risk for hemorrhagic stroke. If there is a history of ulcer disease or upper-gastrointestinal tract bleeding, Helicobacter pylori should be eradicated (if present) and a proton pump inhibitor used with aspirin therapy. In conclusion, the benefits of low-dose aspirin (75-162 mg/day) in the prevention of myocardial infarction in men and thrombotic stroke in women generally outweigh the risks of serious bleeding in adults with a coronary heart disease risk >1% per year or >1% in 10 years.

Evidence of nephropathy and peripheral neuropathy in US adults with undiagnosed diabetes.

PURPOSE: Nearly one third of diabetes cases in the United States is undiagnosed, with mounting evidence that complications accrue even before clinical diagnosis. We wanted to determine whether persons with undiagnosed diabetes have signs of nephropathy and peripheral neuropathy. METHODS: We examined the prevalence of positive screening tests for nephropathy and peripheral neuropathy in adults aged > or = 40 years with undiagnosed diabetes using secondary analysis of survey and examination data from the population-based United States National Health and Nutrition Examination Survey 1999-2002. We defined a positive screening test for nephropathy as a spot urine albumin-creatinine ratio > 30.0 mg/g, representing at least microalbuminuria. We defined > or = 1 insensate area on Semmes-Weinstein monofilament testing as a positive finding for neuropathy. Undiagnosed diabetes was defined as a combination of no history of diagnosed diabetes and a measured fasting glucose > or = 126 mg/dL. We used SUDAAN for chi2 and regression analyses. RESULTS: The prevalence of a positive test when screening for nephropathy among those with undiagnosed diabetes was 26.5% compared with 7.1% in those with no diabetes (chi2, P <.01). After adjusting for age and diagnosed or undiagnosed hypertension, the association of undiagnosed diabetes with nephropathy persisted (odds ratio = 2.35; 95% confidence interval, 1.38-4.01). For peripheral neuropathy, 21.5% with undiagnosed diabetes had positive screening tests compared with 10.1% with no diabetes (chi2, P <.01); however, this effect was not significant after adjustment for age. There was no significant difference in positive screening tests for nephropathy or neuropathy when comparing those with undiagnosed and diagnosed diabetes. CONCLUSIONS: A significant proportion of adults with undiagnosed diabetes have signs of nephropathy and peripheral neuropathy. These findings may influence policies about early screening for diabetes.

Aspirin for the primary prevention of cardiovascular events.

There is significant evidence that low-dose aspirin is effective in preventing the first myocardial infarction in men and ischemic stroke in women. There is also an increased risk for major gastrointestinal tract hemorrhage and a suggestive, but nonsignificant, increase in the risk for hemorrhagic stroke. If there is a history of ulcer disease or upper-gastrointestinal tract bleeding, Helicobacter pylori should be eradicated (if present) and a proton pump inhibitor used with aspirin therapy. In conclusion, the benefits of low-dose aspirin (75-162 mg/day) in the prevention of myocardial infarction in men and thrombotic stroke in women generally outweigh the risks of serious bleeding in adults with a coronary heart disease risk >1% per year or >1% in 10 years.

Antiplatelet agents for the prevention of cardiovascular disease in diabetes mellitus.

Patients with diabetes mellitus (DM) have accelerated atherothrombotic disease of coronary, cerebral, leg, and other vessels. The major cause of death is cardiovascular, and the risk for a myocardial infarction (MI) in a patient with DM who has never had a MI is the same as a nondiabetic individual who has already had one. In this paper, we review the major reasons for a prothrombotic state in patients with DM: alterations in the intrinsic coagulation and fibrinolytic systems and many abnormalities of platelet function. Increased platelet thromboxane production as well as activation of platelet receptors for fibrinogen and or adenosine diphosphate (ADP) are often present, and can be treated with aspirin (acetylsalicylic acid) and/or receptor blockers. Review of the major primary prevention trials in DM indicates that a significantly reduced risk for MI or major cardiovascular events may be obtained by enteric-coated aspirin, 81-325 mg/day. There is emerging consensus that this is recommended strategy in adult (aged >30 years) patients with DM who are at high vascular risk. Surveys suggest that this includes virtually every patient with type 2 DM in the US, as well as many patients with complicated type 1 DM. These recommendations are also appropriate for secondary prevention. Data supporting the use of clopidogrel as an alternative drug in the case of aspirin allergy or other contraindications are reviewed. Evidence is presented in support of using aspirin plus clopidogrel in acute coronary syndromes (ACS), and a meta-analysis of six trials of platelet glycoprotein (GP) IIb/IIIa inhibitors and aspirin in diabetic patients with ACS establishes this regimen as an effective choice. Although bleeding episodes are more common with combined antiplatelet therapy for ACS than for aspirin alone, the benefit of a significant reduction in 30-day mortality appears to outweigh the risk of major bleeding. It is concluded that major advances in our understanding of the prothrombotic state in DM have been made. Evidence from controlled clinical trials supports the use of enteric-coated aspirin, 81-325 mg/day, as a primary and a secondary prevention strategy in adults with DM with high vascular risk. In ACS, combination therapy with aspirin plus clopidogrel or alternatively, aspirin plus a platelet GP IIb/IIIa inhibitor is supported by prospective trial data. These approaches should be added to the other multifactorial preventive strategies directed at lowering the risk for major vascular events in patients with DM.