From Nano-Crystals to Periodically Aggregated Assembly in Arylate Polyesters-Continuous Helicoid or Discrete Cross-Hatch Grating?

This work used several model arylate polymers with the number of methylene segment n = 3, 9, 10, and 12, which all crystallized to display similar types of periodically banded spherulites at various Tc and kinetic factors. Universal mechanisms of nano- to microscale crystal-by-crystal self-assembly to final periodic aggregates showing alternate birefringence rings were probed via 3D dissection. The fractured interiors of the birefringent-banded poly(decamethylene terephthalate) (PDT) spherulites at Tc = 90 °C revealed multi-shell spheroid bands composed of perpendicularly intersecting lamellae bundles, where each shell (measuring 4 µm) was composed of the interior tangential and radial lamellae, as revealed in the SEM results, and its shell thickness was equal to the optical inter-band spacing (4 µm). The radial-oriented lamellae were at a roughly 90° angle perpendicularly intersecting with the tangential ones; therefore, the top-surface valley band region appeared to be a submerged "U-shape", where the interior radial lamellae were located directly underneath. Furthermore, the universal self-assembly was proved by collective analyses on the three arylate polymers.

Prognostic Comparison between Oncotype DX® and a 23-Gene Classifier, RecurIndex®, on the Taiwan Breast Cancer Population.

The applicability of the Oncotype DX® (Genomic Health, Inc., Redwood City, CA, USA) recurrence score (RS) in Asian populations is unclear. A 23-gene classifier, RecurIndex® (Amwise Diagnostics, Pte. Ltd., Singapore), has been developed based on the gene expression profiles of early-stage breast cancer patients of ethnic Han Chinese population in Taiwan. This study aimed to compare the performance of the Oncotype DX® RS with the RecurIndex® recurrence index (RI) for predicting relapse-free survival. Therefore, we calculated both the RI and RS for 110 early stage breast cancer patients, with the cut-off value for high-risk recurrence set at 26 and 29 for the RS and the RI, respectively. With relapse-free interval (RFI) as the primary endpoint, the concordance between RS and RI was 78.2% (Kappa value = 0.297). For a median follow-up interval of 27 months, there was a statistically significant difference in RFI between the high- and low-risk groups defined by the RI (p = 0.04) but not between risk groups defined by the RS (p = 0.66). In conclusion, whereas there was high concordance between the RecurIndex® RI and the Oncotype DX RS, the current data showed that the RI had a better discrimination for recurrence risk than the RS. Subsequent studies with larger sample sizes will be needed to confirm the superiority of the RI over the RS in the Asian population.

Projections of future wildfires impacts on air pollutants and air toxics in a changing climate over the western United States.

Wildfires emit smoke particles and gaseous pollutants that greatly aggravate air quality and cause adverse health impacts in the western US (WUS). This study evaluates how wildfire impacts on air pollutants and air toxics evolve from the present climate to the future climate under a high anthropogenic emission scenario at regional and city scales. Through employing multiple climate and chemical transport models, small changes in domain-averaged air pollutant concentrations by wildfires are simulated over WUS. However, such changes significantly increase future city-scale pollutant concentrations by up to 53 ppb for benzene, 158 ppb for formaldehyde, 655 µg/m3 for fine particulate matter (PM2.5), and 102 ppb for ozone, whereas that for the present climate are 104 ppb for benzene, 332 ppb for formaldehyde, 1,378 µg/m3 for PM2.5, and 140 ppb for ozone. Despite wildfires induce smaller changes in the future, the wildfire contribution ratios can increase by more than tenfold compared to the present climate, indicating wildfires become a more critical contributor to future air pollution in WUS. In addition, additional 6 exceedance days/year for formaldehyde and additional 3 exceedance days/year for ozone suggest increasing health impacts by wildfires in the future.

Microstructural Periodic Arrays in Poly(Butylene Adipate) Featured with Photonic Crystal Aggregates.

Poly(butylene adipate) (PBA) self-aggregation into unique periodicity correlating to its interfacial photonic properties is probed in detail. Investigations on the unique periodic morphology and top-surface and interior architectures in specifically crystallized PBA are focused on its novel photonic patterns with periodic gratings. Detailed analysis of the interior lamellae from ringless to periodically ordered aggregates (crystallized at 33-35 °C vs. Tc = 30 °C) serves as ideal comparisons. Each interior arc-shape shell is composed of tangential and radial lamellae mutually intersecting at 90o angle. The interior layer thickness in SEM-revealed arc-shape shish-kebab shell is exactly equal to the optical inter-band spacing (≈6 µm). A 3D assembly mechanism of periodically banded PBA crystals is proposed, where the orderly arrays on top surfaces as well as the interior microstructures of strut-rib alternate-layered assembly resemble nature's photonic crystals and collectively account for the interfacial photonic properties in the ring-banded PBA crystal that is novel and has potential applications in future.

Potential ecological impacts of climate intervention by reflecting sunlight to cool Earth.

As the effects of anthropogenic climate change become more severe, several approaches for deliberate climate intervention to reduce or stabilize Earth's surface temperature have been proposed. Solar radiation modification (SRM) is one potential approach to partially counteract anthropogenic warming by reflecting a small proportion of the incoming solar radiation to increase Earth's albedo. While climate science research has focused on the predicted climate effects of SRM, almost no studies have investigated the impacts that SRM would have on ecological systems. The impacts and risks posed by SRM would vary by implementation scenario, anthropogenic climate effects, geographic region, and by ecosystem, community, population, and organism. Complex interactions among Earth's climate system and living systems would further affect SRM impacts and risks. We focus here on stratospheric aerosol intervention (SAI), a well-studied and relatively feasible SRM scheme that is likely to have a large impact on Earth's surface temperature. We outline current gaps in knowledge about both helpful and harmful predicted effects of SAI on ecological systems. Desired ecological outcomes might also inform development of future SAI implementation scenarios. In addition to filling these knowledge gaps, increased collaboration between ecologists and climate scientists would identify a common set of SAI research goals and improve the communication about potential SAI impacts and risks with the public. Without this collaboration, forecasts of SAI impacts will overlook potential effects on biodiversity and ecosystem services for humanity.

Associations of wildfire smoke PM2.5 exposure with cardiorespiratory events in Colorado 2011-2014.

BACKGROUND: Substantial increases in wildfire activity have been recorded in recent decades. Wildfires influence the chemical composition and concentration of particulate matter ≤2.5 µm in aerodynamic diameter (PM2.5). However, relatively few epidemiologic studies focus on the health impacts of wildfire smoke PM2.5 compared with the number of studies focusing on total PM2.5 exposure. OBJECTIVES: We estimated the associations between cardiorespiratory acute events and exposure to smoke PM2.5 in Colorado using a novel exposure model to separate smoke PM2.5 from background ambient PM2.5 levels. METHODS: We obtained emergency department visits and hospitalizations for acute cardiorespiratory outcomes from Colorado for May-August 2011-2014, geocoded to a 4 km geographic grid. Combining ground measurements, chemical transport models, and remote sensing data, we estimated smoke PM2.5 and non-smoke PM2.5 on a 1 km spatial grid and aggregated to match the resolution of the health data. Time-stratified, case-crossover models were fit using conditional logistic regression to estimate associations between fire smoke PM2.5 and non-smoke PM2.5 for overall and age-stratified outcomes using 2-day averaging windows for cardiovascular disease and 3-day windows for respiratory disease. RESULTS: Per 1 µg/m3 increase in fire smoke PM2.5, statistically significant associations were observed for asthma (OR = 1.081 (1.058, 1.105)) and combined respiratory disease (OR = 1.021 (1.012, 1.031)). No significant relationships were evident for cardiovascular diseases and smoke PM2.5. Associations with non-smoke PM2.5 were null for all outcomes. Positive age-specific associations related to smoke PM2.5 were observed for asthma and combined respiratory disease in children, and for asthma, bronchitis, COPD, and combined respiratory disease in adults. No significant associations were found in older adults. DISCUSSION: This is the first multi-year, high-resolution epidemiologic study to incorporate statistical and chemical transport modeling methods to estimate PM2.5 exposure due to wildfires. Our results allow for a more precise assessment of the population health impact of wildfire-related PM2.5 exposure in a changing climate.

Uncertainty Quantification of Extratropical Forest Biomass in CMIP5 Models over the Northern Hemisphere.

Simplified representations of processes influencing forest biomass in Earth system models (ESMs) contribute to large uncertainty in projections. We evaluate forest biomass from eight ESMs outputs archived in the Coupled Model Intercomparison Project Phase 5 (CMIP5) using the biomass data synthesized from radar remote sensing and ground-based observations across northern extratropical latitudes. ESMs exhibit large biases in the forest distribution, forest fraction, and mass of carbon pools that contribute to uncertainty in forest total biomass (biases range from -20 Pg C to 135 Pg C). Forest total biomass is primarily positively correlated with precipitation variations, with surface temperature becoming equally important at higher latitudes, in both simulations and observations. Relatively small differences in forest biomass between the pre-industrial period and the contemporary period indicate uncertainties in forest biomass were introduced in the pre-industrial model equilibration (spin-up), suggesting parametric or structural model differences are a larger source of uncertainty than differences in transient responses. Our findings emphasize the importance of improved (1) models of carbon allocation to biomass compartments, (2) distribution of vegetation types in models, and (3) reproduction of pre-industrial vegetation conditions, in order to reduce the uncertainty in forest biomass simulated by ESMs.

Analysis of the Co-existence of Long-range Transport Biomass Burning and Dust in the Subtropical West Pacific Region.

Biomass burning and wind-blown dust has been well investigated during the past decade regarding their impacts on environment, but their co-existence hasn't been recognized because they usually occur in different locations and episodes. In this study we reveal the unique co-existence condition that dust from the Taklamakan and Gobi Desert (TGD) and biomass burning from Peninsular Southeast Asia (PSEA) can reach to the west Pacific region simultaneously in boreal spring (March and April). The upper level trough at 700hPa along east coast of China favors the large scale subsidence of TGD dust while it travels southeastwards, and drives the PSEA biomass burning plume carried by the westerlies at 3-5 km to descend rapidly to around 1.5 km and mix with dust around southeast China and Taiwan. As compared to the monthly averages in March and April, surface observations suggested that concentrations of PM10, PM2.5, O3, and CO were 69%, 37%, 20%, and 18% higher respectively during the 10 identified co-existence events which usually lasted for 2-3 days. Co-existence also lowers the surface O3, NOx, and SO2 by 4-5% due to the heterogeneous chemistry between biomass burning and mineral dust as indicated by model simulations.

Effectiveness of SO2 emission control policy on power plants in the Yangtze River Delta, China-post-assessment of the 11th Five-Year Plan.

Facing the air pollution problems in China, emission control strategies have been implemented within the framework of national Five-Year Plan (FYP). According to the lack of post-assessment studies in the literature, this study assessed the effectiveness of the SO2 emission control policies on power plants after the 11th FYP (2006-2010) by modeling emission control scenarios. The idealized emission control policy (the PS90 scenario with assumption of 90% SO2 emission reduction from power plants) could reduce the SO2 and SO42- concentrations by about 51 and 14%, respectively, over the Yangtze River Delta region. While the actual emission control condition (the P2010 scenario based on the actual emissions from power plants in 2010) demonstrated that the actual reduction benefits were 30% of SO2 and 9% of SO42-. On the city scale, the P2010 scenario imposed positive benefits on Shanghai, Nanjing, Nantong, and Hangzhou with SO2 reductions of about 55, 12, 30, and 21%, respectively, while an 11% increase of SO2 concentration was found in Ningbo. The number of days exceeding China's National Ambient Air Quality Standard of Class I daily SO2 concentration was estimated to be 75, 52, 7, 77, and 40 days for Shanghai, Nanjing, Nantong, Ningbo, and Hangzhou under the real SO2 control condition (P2010). The numbers could be decreased by 16, 11, 2, 21, and 11% if the control effect reaches the level of the PS90 scenario. This study serves as a scientific basis to design capable enforcement of emission control strategies in China in the future national plans.

[Experimental study on Raman spectroscopy of alkane gases in simulated deep-sea extreme environments].

In the present work, Raman spectra of alkane gases aqueous solution under simulated deep-sea hydrothermal environment were acquired by high temperature and high pressure deep-sea simulation experiment system. The variation laws of the Raman spectral features with various temperature and pressure were analyzed and mathematical model between them were established. The results show that for all Raman peaks of these alkane gases in aqueous solution the frequency is lower than gaseous state because of hydrogen bond; the variations of their Raman spectrum were not obvious as the pressure increased (< or = 40 MPa) in room temperature; and all peak positions move to lower wave number and their full width at half maximum (FWHM) increased along with changing temperature in the range of room temperature to 350 degrees C at 40 MPa pressure. The results provide an experimental basis for the in-situ detection of deep sea by Raman laser spectroscopy system in hydrothermal environment.