[Impact of fine particulate matter exposure on non-accidental mortality under different apparent temperature levels].

OBJECTIVE: To assess the impact of exposure to particulate matter with aerodynamic diameter ≤2.5 µm (PM2.5) on non-accidental mortality under different apparent temperature levels and to further explore the modification effect of apparent temperature. METHODS: This study used time-series design. Tianjin and Ningbo from China, Bangkok and Chiang Mai from Thailand were selected as the research sites, and the apparent temperature was applied as the exposure index. Through the quantitative estimation of the threshold temperature, the corresponding pollutant concentration was divided into high and low levels, and the generalized Poisson additive model was used to evaluate the association between PM2.5 exposure and non-accidental death of residents at different temperature levels. RESULTS: The ave-rage concentrations of PM2.5 in Tianjin, Ningbo, Bangkok, and Chiang Mai during the study period were (73.6±35.6), (48.0±32.1), (33.5±28.4) and (32.6±28.6) µg/m3, respectively; the average daily non-accidental death counts were 148, 57, 28, and 8. The analysis of the generalized Poisson additive model showed that the daily non-accidental death counts increased by 0.43% (95%CI: 0.33%-0.54%) per 10 µg/m3 increase of PM2.5 in lag 0 day in Tianjin of China; 0.27% (95%CI: 0.08%-0.46%) per 10 µg/m3 increase of PM2.5 in lag 2 days in Ningbo of China. The effect was magnified in high temperature levels in Tianjin and in low temperatures in Ningbo and Bangkok. The mortality effect of PM2.5 in various temperature levels stayed still in co-pollutant regression models. CONCLUSION: Exposure to fine particulate matter had an adverse effect on non-accidental mortality, which reminded us to give further attention to the pollution control. The findings also indicated that apparent temperature might modify mortality effects of PM2.5 and the modification effect varied in different regions. Protective policies due to regional differences should be made and more scientific and social attention on mutual effect of air pollution and climate change needs to be appealed.

Abnormal Graphitization Behavior in Near-Surface/Interface Region of Polymer-Derived Ceramics.

The in situ free carbon generated in polymer-derived ceramics (PDCs) plays a crucial role in their unique microstructure and resultant properties. This study advances a new phenomenon of graphitization of PDCs. Specifically, whether in micro-/nanoscale films or millimeter-scale bulks, the surface/interface radically changes the fate of carbon and the evolution of PDC nanodomains, promotes the graphitization of carbon, and evolves a free carbon enriched layer in the near-surface/interface region. Affected by the enrichment behavior of free carbon in the near-surface/interface region, PDCs exhibit highly abnormal properties such as the skin behavior and edge effect of the current. The current intensity in the near-surface/interface region of PDCs is orders of magnitude higher than that in its interior. Ultrahigh conductivity of up to 14.47 S cm-1 is obtained under the action of the interface and surface, which is 5-8 orders of magnitude higher than that of the bulk prepared under the same conditions. Such surface/interface interactions are of interest for the regulation of free carbon and its resultant properties, which are the core of PDC applications. Finally, the first PDC thin-film strain gauge that can survive a butane flame with a high temperature of up to ≈1300 °C is fabricated.

Outdoor light at night, genetic predisposition and type 2 diabetes mellitus: A prospective cohort study.

BACKGROUND: According to animal and human epidemiologic studies, exposure to outdoor light at night (LAN) may cause circadian disruption, which may disturb sleep quality and lead to incident type 2 diabetes mellitus (T2DM). METHODS: We followed 283,374 persons from 2006 through 2020. Outdoor LAN exposure was estimated using satellite data for individual address with 500 m2 scale buffer during follow-up. Incidence of T2DM was confirmed by hospital inpatient records. We identified potential confounders by a directed acyclic graph, including demographic, genetic, individual and regional level socioeconomic status, and environmental risk factors, and calculated hazard ratios (HRs) and 95% confidence intervals (CIs) through time-varying Cox proportional hazard model. Furthermore, we examined the association of outdoor LAN with a defined health sleep scores and moderation of genetic predisposition and shift work on the relationship of outdoor LAN and incident T2DM. RESULTS: We identified 7,775 incident T2DM cases over 3,027,505 person-years. Higher outdoor LAN exposures were significantly associated with higher risk of T2DM. The estimated HR for incident T2DM with an interquartile range (IQR: 11.22 nW/cm2/sr) increase in outdoor LAN was 1.05 (95%CI: 1.01, 1.09) in the fully adjusted model. Participants who lived in the highest quarter of outdoor LAN area were more likely to develop T2DM (HR: 1.14,95%CI: 1.02, 1.27). Besides, those who were exposed to higher levels of outdoor LAN had poorer sleep quality. No moderation role of PRS on outdoor LAN-induced T2DM observed both on the multiplicated and additive scale. The hazards of outdoor LAN were observed in those who never owned a night shift work. CONCLUSION: Although further work is required to clarify potential mechanisms, our findings indicate that exposure to residential outdoor LAN may contribute to T2DM risk and low sleep quality.

Does air pollution modify temperature-related mortality? A systematic review and meta-analysis.

INTRODUCTION: There is an increasing interest in understanding whether air pollutants modify the quantitative relationships between temperature and health outcomes. The results of available studies were, however, inconsistent. This study aims to sum up the current evidence and provide a comprehensive understanding of this topic. METHODS: We conducted an electronic search in PubMed (MEDLINE), EMBASE, Web of Science Core Collection, and ProQuest Dissertations and Theses. The modified Navigation Guide was applied to evaluate the quality and strength of evidence. We calculated pooled temperature-related mortality at low and high pollutant levels respectively, using the random-effects model. RESULTS: We identified 22 eligible studies, eleven of which were included in the meta-analysis. Significant effect modification was observed on heat effects for all-cause and non-accidental mortality by particulate matter with an aerodynamic diameter of <10 µm (PM10) and ozone (O3) (p < 0.05). The excess risks (ERs) for all-cause and non-accidental mortality were 5.4% (4.4%, 6.4%) and 6.3% (4.8%, 7.8%) at the low PM10 level, 8.8% (7.5%, 10.1%) and 11.4% (8.7%, 14.2%) at the high PM10 level, respectively. As for O3, the ERs for all-cause and non-accidental mortality were 5.1% (3.9%, 6.3%) and 3.6% (0.1%, 7.2%) at the low O3 level, 7.6% (6.3%, 9.0%) and 12.5% (4.7%, 20.9%) at the high O3 level, respectively. Surprisingly, the heat effects on cardiovascular mortality were found to be lower at high carbon monoxide (CO) levels [ERs = 5.4% (3.9%, 6.9%)] than that at low levels [ERs = 9.4% (7.0%, 11.9%)]. The heterogeneity varied, but the results of sensitivity analyses were generally robust. Significant effect modification by air pollutants was not observed for heatwave or cold effects. CONCLUSIONS: PM10 and O3 modify the heat-related all-cause and non-accidental mortality, indicating that policymakers should consider air pollutants when establishing heat-health warning systems. Future studies with comparable designs and settings are needed.

The establishment of Air Quality Health Index in China: A comparative analysis of methodological approaches.

BACKGROUND: The Air Quality Index (AQI) has been criticized because it does not adequately account for the health effect of multi-pollutants. Although the developed Air Quality Health Index (AQHI) is a more effective communication tool, little is known about the best method to construct AQHI on long time and large spatial scales. OBJECTIVES: To further evaluate the validity of existing approaches to the establishment of AQHI on both long time and larger spatial scales. METHODS: By introducing 3 approaches addressing multi-pollutant exposures: cumulative risk index (CRI), supervised principal component analysis (SPCA), and Bayesian multi-pollutants weighted model (BMP), we constructed CRI-AQHI, SPCA-AQHI, BMP-AQHI and standard-AQHI on cardiovascular mortality in China from 2015 to 2019 at both the national and geographic regional levels. We further assessed the performance of the four methods in estimating the joint effect of multi-pollutants by simulations under various scenarios of pollution effect. RESULTS: The results of national China showed that the BMP-AQHI improved the goodness of fit of the standard-AQHI by 108.24%, followed by CRI-AQHI (5.02%), and all AQHIs performed better than AQI, consistent with 6 geographic regional results. In addition, the simulation result showed that the BMP method provided stable and relatively accurate estimations of the short-term combined effect of exposure to multi-pollutants. CONCLUSIONS: AQHI based on BMP could communicate the air pollution risk to the public more effectively than the current AQHI and AQI.

Association between exposure to air pollution and risk of allergic rhinitis: A systematic review and meta-analysis.

BACKGROUND: Allergic rhinitis (AR) is one of the most common allergic diseases in the world, and usually persists throughout the activity. Epidemiological studies have shown a positive association between air pollution and allergic rhinitis. However, we could not find any meta-analysis of the risk of air pollutants (PM2.5, PM10, NO2, SO2, O3 and CO) on the prevalence of AR in people of all ages. OBJECTIVES: Carry out a meta-analysis on the results of recent studies (up to 2020) to present valid information about exposure to air pollution and risk of prevalence of AR. METHODS: We systematically searched three databases for studies up to December 17, 2020, including air pollution and AR. Random effect models were conducted to estimate the pooled odds ratios (ORs) and 95% confidence intervals (95% CIs). Subgroup analysis, funnel plot, Egger's test, and the trim-and-fill method were also conducted. RESULTS: Thirty-five studies across 12 countries, including a total of 453,470 participants, were included. The OR per 10 µg/m3 increase of pollutants was 1.13 (1.04-1.22) for PM10 and 1.12 (1.05-1.20) for PM2.5. The OR per 10 µg/m3 increment of gaseous pollutants were 1.13 (1.07-1.20) for NO2, 1.13 (1.04-1.22) for SO2 and 1.07 (1.01-1.12) for O3. No significant association was observed between CO and AR. Children or adolescents are more sensitive to air pollution than adults. The effects of PM10 and SO2 were significantly stronger in Europe than Asia. The effects of air pollutants were more significant and higher in developing countries than in developed countries, except for PM10. A significant difference of subgroup test was found between developed and developing countries of NO2. CONCLUSION: This meta-analysis showed a positive association between air pollution and the prevalence of allergic rhinitis, and identified geographic area and economic level as the potential modifiers for the association.

An Extended Primal-Dual Algorithm Framework for Nonconvex Problems: Application to Image Reconstruction in Spectral CT.

Using the convexity of each component of the forward operator, we propose an extended primal-dual algorithm framework for solving a kind of nonconvex and probably nonsmooth optimization problems in spectral CT image reconstruction. Following the proposed algorithm framework, we present six different iterative schemes or algorithms, and then establish the relationship to some existing algorithms. Under appropriate conditions, we prove the convergence of these schemes for the general case. Moreover, when the proposed schemes are applied to solving a specific problem in spectral CT image reconstruction, namely, total variation regularized nonlinear least-squares problem with nonnegative constraint, we also prove the particular convergence for these schemes by using some special properties. The numerical experiments with densely and sparsely data demonstrate the convergence and accuracy of the proposed algorithm framework in terms of visual inspection of images of realistic anatomic complexity and quantitative analysis with metrics structural similarity, peak signal-to-noise ratio, mean square error and maximum pixel difference. We analyze the computational complexity of these schemes, and discuss the extended applications of this algorithm framework in other nonlinear imaging problems.

High-Resolution Full-3D Specimen Imaging for Lumpectomy Margin Assessment in Breast Cancer.

BACKGROUND: Two-dimensional (2D) specimen radiography (SR) and tomosynthesis (DBT) for breast cancer yield data that lack high-depth resolution. A volumetric specimen imager (VSI) was developed to provide full-3D and thin-slice cross-sectional visualization at a 360° view angle. The purpose of this prospective trial was to compare VSI, 2D SR, and DBT interpretation of lumpectomy margin status with the final pathologic margin status of breast lumpectomy specimens. METHODS: The study enrolled 200 cases from two institutions. After standard imaging and interpretation was performed, the main lumpectomy specimen was imaged with the VSI device. Image interpretation was performed by three radiologists after surgery based on VSI, 2D SR, and DBT. A receiver operating characteristic (ROC) curve was created for each method. The area under the curve (AUC) was computed to characterize the performance of the imaging method interpreted by each user. RESULTS: From 200 lesions, 1200 margins were interpreted. The AUC values of VSI for the three radiologists were respectively 0.91, 0.90, and 0.94, showing relative improvement over the AUCs of 2D SR by 54%, 13%, and 40% and DBT by 32% and 11%, respectively. The VSI has sensitivity ranging from 91 to 94%, specificity ranging from 81 to 85%, a positive predictive value ranging from 25 to 30%, and a negative predicative value of 99%. CONCLUSIONS: The ROC curves of the VSI were higher than those of the other specimen imaging methods. Full-3D specimen imaging can improve the correlation between the main lumpectomy specimen margin status and surgical pathology. The findings from this study suggest that using the VSI device for intraoperative margin assessment could further reduce the re-excision rates for women with malignant disease.

The construction of the air quality health index (AQHI) and a validity comparison based on three different methods.

The most common currently used air quality risk communication tool, the Air Quality Index (AQI), has been criticized. As a result, Canada proposed the Air Quality Health Index (AQHI) to communicate the health risks of multiple pollutants. However, the AQHI is calculated by directly summing the excess risks from single-pollutant models, which may overestimate the effects of the pollutants. To solve this problem, we introduced two methods for estimating the joint effects of multiple pollutants: the cumulative risk index (CRI) and supervised principal component analysis (SPCA). Based on three methods, i.e., the standard, CRI and SPCA methods, we constructed three types of AQHIs and compared their validity to select the best communication tool. Our results showed that compared with the AQI, all three AQHIs had a linear relationship with mortality. In addition, the CRI-AQHI had the best goodness of fit and captured the overall health risk of pollution mixtures most robustly among various cause-specific mortalities when identifying health risks. Our study indicated that the CRI-AQHI may have the potential to be a better alternative to the standard AQHI in communicating air pollution-related health risks to the public.

The burden of sulfur dioxide pollution on years of life lost from chronic obstructive pulmonary disease: A nationwide analysis in China.

BACKGROUND: Sulfur dioxide (SO2) is one of the major gaseous pollutants in China and other developing countries. Few multicity studies have been done to examine the short-term effect of SO2 on cause-specific years of life lost (YLL). This study was designed to investigate the burden of chronic obstructive pulmonary disease (COPD) associated with SO2 exposure. METHODS: A 5-year time-series study was conducted in 48 Chinese cities from 2013 to 2017. Generalized additive models were first used to estimate the city-specific relationship. Then, random-effects meta-analyses were applied to pool the estimates. Furthermore, the roles of potential modifiers and the related economic loss estimated by the method of value per statistical life year were also evaluated. RESULTS: The annual mean concentration of SO2 was 27.1 µg/m3. A 10 µg/m3 increase in 4-day moving average (lag03) of SO2 concentration was associated with 0.83% (95% CI: 0.13%, 1.53%) relative increment in YLL from COPD, and relevant percent change of mortality was 0.78% (95% CI: 0.16%, 1.41%). Moreover, a significantly higher effect was observed in the warm season, particularly in the south region. SO2 exposure was estimated to account for 1.89% of the total economic loss due to YLL from COPD. CONCLUSIONS: Our findings showed a positive association between short-term exposure to SO2 and YLL from COPD and highlighted the importance of continuous control of SO2 pollution to reduce corresponding attributable disease burden.

Dual-energy CT imaging over non-overlapping, orthogonal arcs of limited-angular ranges.

BACKGROUND: Interest exists in dual-energy computed tomography (DECT) imaging with scanning arcs of limited-angular ranges (LARs) for reducing scan time and radiation dose, and for enabling scan configurations of C-arm CT that can avoid possible collision between the rotating X-ray tube/detector and the imaged subject. OBJECTIVE: In this work, we investigate image reconstruction for a type of configurations of practical DECT interest, referred to as the two-orthogonal-arc configuration, in which low- and high-kVp data are collected over two non-overlapping arcs of equal LAR α, ranging from 30° to 90°, separated by 90°. The configuration can readily be implemented, e.g., on CT with dual sources separated by 90° or with the slow-kVp-switching technique. METHODS: The directional-total-variation (DTV) algorithm developed previously for image reconstruction in conventional, single-energy CT is tailored to enable image reconstruction in DECT with two-orthogonal-arc configurations. RESULTS: Performing visual inspection and quantitative analysis of monochromatic images obtained and effective atomic numbers estimated, we observe that the monochromatic images of the DTV algorithm from LAR data are with substantially reduced LAR artifacts, which are observed otherwise in those of existing algorithms, and thus visually correlate reasonably well, in terms of metrics PCC and nMI, with their reference images obtained from full-angular-range data. In addition, effective atomic numbers estimated from LAR data of DECT with two-orthogonal-arc configurations are in reasonable agreement, with relative errors up to ∼ 10%, with those estimated from full-angular-range data in DECT. CONCLUSIONS: The results acquired in the work may yield insights into the design of LAR configurations of practical dual-energy application relevance in diagnostic CT or C-arm CT imaging.

Modifiers of the effect of short-term variation in PM2.5 on mortality in Beijing, China.

INTRODUCTION: Epidemiologic studies have reported associations between short-term exposure to particulate matter <2.5 µm in aerodynamic diameter (PM2.5) and mortality, but the role of modifiers remains unclear with studies reporting inconsistent results. We evaluated the impact of individual (age, gender and education) and township (geographic area, socioeconomic status, background air pollution and road density) level factors on the relationship between short-term variation in PM2.5 with cause-specific mortality in Beijing (population: 21.7 million in 2016), China. METHODS: Daily PM2.5 concentrations in each township (n = 327; township population: 2000-359,400; township area: 1-392 km2) within Beijing were estimated by kriging with external drift using measurements from 35 air quality monitoring stations and geographic variables. Time-stratified case-crossover analysis with township-level mortality data from Oct. 1st, 2012 to Dec. 31st, 2013 was then used to examine associations between PM2.5 exposure estimates and cause-specific mortality, stratified by the potential effect modifiers. RESULTS: A 10-µg/m3 increase in PM2.5 concentration was associated with a 0.17% [95% confidence interval (CI): 0.05%-0.29%] and 0.27% (95%CI:0.01%-0.52%) increase in non-accidental and stroke mortality with no lag, a 0.81% (95%CI:0.39%-1.23%) and 0.96% (95%CI:0.35%-1.57%) increase in respiratory disease (RD) and chronic obstructive pulmonary disease (COPD) mortality at a lag of two-day moving average. For individual-level effect modifiers, the elderly showed higher effects for all the specific causes of mortality; those with lower education level showed higher effects for non-accidental, cardiovascular disease and stroke mortality; females showed higher effects for non-accidental and cause-specific cardiovascular diseases. For township-level effect modifiers, effect estimates tended to be larger for suburban areas, areas of lower road density, lower PM2.5 and lower socioeconomic status. CONCLUSIONS: Short-term exposure to township-level ambient PM2.5 was associated with increased mortality in Beijing, with indications of effect modification by both individual and township-level factors.

Years of life lost from ischaemic and haemorrhagic stroke related to ambient nitrogen dioxide exposure: A multicity study in China.

Few multicity studies have been conducted in developing countries to distinguish the acute effects of ambient nitrogen dioxide (NO2) on the years of life lost (YLL) from different subtypes of stroke. We aimed to differentiate the associations between NO2 exposure and YLL from major pathological types of stroke in China, and estimate the relevant economic loss. A time-series study was conducted to explore the associations between short-term NO2 exposure and YLL from ischaemic and haemorrhagic stroke from 2013 to 2017 in 48 Chinese cities. Daily NO2 data and stroke mortality counts for each city were obtained from the National Urban Air Quality Real-time Publishing Platform and Chinese Center for Disease Control and Prevention, respectively. Generalized additive models were applied to estimate the cumulative effects of NO2 in each city, and meta-analysis was used to combine the city-specific estimates. The relevant economic loss was estimated using the method of the value per statistical life year (VSLY). A 10 µg/m3 increase in ambient NO2 concentration on the present day and previous day (lag 0-1) would lead to relatively higher increments in percentage change of YLL from ischaemic stroke (0.82%, 95% CI: 0.46%, 1.19%) than haemorrhagic stroke (0.46%, 95% CI: 0.09%, 0.84%). The association was significantly stronger in the low-education population than high-education population for ischaemic stroke. Furthermore, significantly higher association was found in South China than those in North China for both subtypes of stroke. Economic loss due to excess YLL from ischaemic stroke related to NO2 exposure was higher than that for haemorrhagic stroke. Our study indicated higher association and economic loss of ischaemic than haemorrhagic stroke related to NO2 exposure in China, which informed priorities for type-specific stroke prevention strategies related to NO2 pollution and vulnerable population protection.

[Stimulus and reward information encoded by population neurons in the primate prefrontal cortex and striatum].

It has been reported that single-unit activity in the prefrontal cortex (PFC) and striatum represented visual stimulus and reward information. But how to encode these pieces of information is quite complex from the view of single-neuron activity. Different neurons represented stimulus or reward information in different task epochs with increasing or decreasing their activities relative to their baseline firing rates. The present paper was aimed to study whether population neurons in the two brain areas could stably encode task-relevant parameters in a whole trial period. We recorded single-unit activities in the lateral PFC (LPFC) and striatum while the monkey was performing a stimulus- reward prediction task, and analyzed the neuronal activities by the method of a multi-variable regression model and the linear support vector machine. The results showed that, although proportions of task-related neurons in the two areas varied largely in the whole trial period, LPFC population neurons encoded reward and stimulus information stably and reliably. Population neurons in the striatum encoded only reward information, not stimulus information. A group of neurons in the two areas represented combined information of stimulus and reward. Further analysis showed that LPFC neurons encoded reward information for a group of relevant stimuli, while striatal neurons encoded reward information for a specific stimulus. These results suggest that both LPFC and striatal population neurons are able to stably represent task-relevant information, but from different aspects of the task. The different strategies to encode information in the LPFC and striatum suggest their different contributions in reward-based decision making.

Exposure to Heat Wave During Pregnancy and Adverse Birth Outcomes: An Exploration of Susceptible Windows.

BACKGROUND: Several studies have investigated the acute effects of high ambient temperature or extreme weather on preterm birth and stillbirth. However, little was known about whether there are any particular stages during which high ambient temperature or heat wave exposure is most harmful to fetal growth. The aim of this study was to examine the effects of heat wave exposure in different gestational months on the risk of preterm birth and stillbirth. METHODS: Based on all singleton birth records between 2000 and 2010 and the corresponding environmental data in Brisbane, Australia, we explored relationships between heat wave exposure in different months of pregnancy and preterm birth or stillbirth. Six heat wave definitions were used in this study. After controlling for confounding factors, hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using extended Cox proportional hazards regression models with time-dependent covariates. RESULTS: For most heat wave definitions, the adjusted HRs of preterm birth varied by different gestational months and ranged from 1.08 (HR = 1.08; 95% CI = 1.00, 1.18) to 1.53 (HR = 1.53; 95% CI = 1.41, 1.68). Heat wave exposure in early pregnancy was more likely to increase the risk of stillbirth compared with heat wave exposure in late pregnancy. CONCLUSIONS: Overall, we found relationships between preterm birth and heat wave exposure in all months of pregnancy based on most heat wave definitions. We did not find a specifically high period of susceptibility during pregnancy for preterm birth associated with heat wave exposure. However, earlier gestational months might be key exposure windows for heat-wave-affected stillbirth.

Projections of the effects of global warming on the disease burden of ischemic heart disease in the elderly in Tianjin, China.

BACKGROUND: Ischemic heart disease (IHD) is one of the leading causes of deaths worldwide and causes a tremendous disease burden. Temperature is an important environmental determinant among the many risk factors for IHD. However, the emerging temperature-related health risks of IHD in the elderly is limited because of the lack of estimates that integrate global warming and demographic change. METHODS: Data on daily IHD deaths in the elderly aged ≥65 years and meteorological conditions were collected in Tianjin, a megacity of China, from 2006 to 2011. First, the baseline relationship between the temperature and years of life lost (YLL) from IHD was established. Then, future assessments were performed in combination with temperature projections for 19 global-scale climate models (GCMs) under 3 representative concentration pathways (RCPs) for the 2050s and 2070s. RESULTS: Increased YLL from IHD in the elderly was found to be associated with future ambient temperatures. The annual temperature-related YLL from IHD in the 2050s and 2070s were higher than the baseline. For instance, increases of 4.5, 14.9 and 38.3% were found under the RCP2.6, RCP4.5 and RCP8.5 scenarios, respectively, in the 2070s. The most significant increases occurred in warm season months. The increase in heat-related YLL will not be completely offset, even with the 25% adaptation assumed. When considering demographic change, the temperature-related disease burden of IHD in the elderly will be exacerbated by 158.4 to 196.6% under 3 RCPs in the 2050s and 2070s relative to the baseline. CONCLUSIONS: These findings have significant meaning for environmental and public health policy making and interventions towards the important issue of the health impacts of global warming on the elderly.

Collision-avoiding imaging trajectories for linac mounted cone-beam CT.

BACKGROUND: Some patients cannot be imaged with cone-beam CT for image-guided radiation therapy because their size, pose, or fixation devices cause collisions with the machine. OBJECTIVE: To investigate imaging trajectories that avoid such collisions by using virtual isocenter and variable magnification during acquisition while yielding comparable image quality. METHODS: The machine components most likely to collide are the gantry and kV detector. A virtual isocenter trajectory continuously moves the patient during gantry rotation to maintain an increased separation between the two. With dynamic magnification, the kV detector is dynamically moved to increase clearance for an angular range around the potential collision point while acquiring sufficient data to maintain the field-of-view. Both strategies were used independently and jointly with the resultant image quality evaluated against the standard circular acquisition. RESULTS: Collision avoiding trajectories show comparable contrast and resolution to standard techniques. For an anthropomorphic phantom, the RMSE is <7×10- 4, multi-scale structural similarity index is >0.97, and visual image fidelity is >0.96 for all trajectories when compared to a standard circular scan. CONCLUSIONS: The proposed trajectories avoid machine-patient collisions while providing comparable image quality to the current standard thereby enabling CBCT imaging for patients that could not otherwise be scanned.

Projected Temperature-Related Years of Life Lost From Stroke Due To Global Warming in a Temperate Climate City, Asia: Disease Burden Caused by Future Climate Change.

BACKGROUND AND PURPOSE: Global warming has attracted worldwide attention. Numerous studies have indicated that stroke is associated with temperature; however, few studies are available on the projections of the burden of stroke attributable to future climate change. We aimed to investigate the future trends of stroke years of life lost (YLL) associated with global warming. METHODS: We collected death records to examine YLL in Tianjin, China, from 2006 to 2011. We fitted a standard time-series Poisson regression model after controlling for trends, day of the week, relative humidity, and air pollution. We estimated temperature-YLL associations with a distributed lag nonlinear model. These models were then applied to the local climate projections to estimate temperature-related YLL in the 2050s and 2070s. We projected temperature-related YLL from stroke in Tianjin under 19 global-scale climate models and 3 different greenhouse gas emission scenarios. RESULTS: The results showed a slight decrease in YLL with percent decreases of 0.85%, 0.97%, and 1.02% in the 2050s and 0.94%, 1.02%, and 0.91% in the 2070s for the 3 scenarios, respectively. The increases in heat-related annual YLL and the decreases in cold-related YLL under the high emission scenario were the strongest. The monthly analysis showed that the most significant increase occurred in the summer months, particularly in August, with percent changes >150% in the 2050s and up to 300% in the 2070s. CONCLUSIONS: Future changes in climate are likely to lead to an increase in heat-related YLL, and this increase will not be offset by adaptation under both medium emission and high emission scenarios. Health protections from hot weather will become increasingly necessary, and measures to reduce cold effects will also remain important.

Spatio-temporal analysis of the relationship between meteorological factors and hand-foot-mouth disease in Beijing, China.

BACKGROUND: Hand-foot-mouth disease (HFMD) is a common infectious disease in China and occurs mostly in infants and children. Beijing is a densely populated megacity, in which HFMD has been increasing in the last decade. The aim of this study was to quantify spatio-temporal characteristics of HFMD and the relationship between meteorological factors and HFMD incidence in Beijing, China. METHODS: Daily counts of HFMD cases from January 2010 to December 2012 were obtained from the Beijing Center for Disease Prevention and Control (CDC). Seasonal trend decomposition with Loess smoothing was used to explore seasonal patterns and temporal trends of HFMD. Bayesian spatiotemporal Poisson regression models were used to quantify spatiotemporal patterns of HFMD incidence and associations with meteorological factors. RESULTS: There were 114,777 HFMD cases reported to Beijing CDC from 1 January 2010 to 31 December 2012 and the raw incidence was 568.6 per 100,000 people. May to July was the peak period of HFMD incidence each year. Low-incidence townships were clustered in central, northeast and southwest regions of Beijing. Mean temperature, relative humidity, wind velocity and sunshine hours were all positively associated with HFMD. The effect of wind velocity was significant with a RR of 3.30 (95%CI: 2.37, 4.60) per meter per second increase, as was sunshine hours with a RR of 1.20 (95%CI: 1.02, 1.40) per 1 hour increase. CONCLUSIONS: The distribution of HFMD in Beijing was spatiotemporally heterogeneous, and was associated with meteorological factors. Meteorological monitoring could be incorporated into prediction and surveillance of HFMD in Beijing.

Projection of temperature-related mortality due to cardiovascular disease in beijing under different climate change, population, and adaptation scenarios.

Human health faces unprecedented challenges caused by climate change. Thus, studies of the effect of temperature change on total mortality have been conducted in numerous countries. However, few of those studies focused on temperature-related mortality due to cardiovascular disease (CVD) or considered future population changes and adaptation to climate change. We present herein a projection of temperature-related mortality due to CVD under different climate change, population, and adaptation scenarios in Beijing, a megacity in China. To this end, 19 global circulation models (GCMs), 3 representative concentration pathways (RCPs), 3 socioeconomic pathways, together with generalized linear models and distributed lag non-linear models, were used to project future temperature-related CVD mortality during periods centered around the years 2050 and 2070. The number of temperature-related CVD deaths in Beijing is projected to increase by 3.5-10.2% under different RCP scenarios compared with that during the baseline period. Using the same GCM, the future daily maximum temperatures projected using the RCP2.6, RCP4.5, and RCP8.5 scenarios showed a gradually increasing trend. When population change is considered, the annual rate of increase in temperature-related CVD deaths was up to fivefold greater than that under no-population-change scenarios. The decrease in the number of cold-related deaths did not compensate for the increase in that of heat-related deaths, leading to a general increase in the number of temperature-related deaths due to CVD in Beijing. In addition, adaptation to climate change may enhance rather than ameliorate the effect of climate change, as the increase in cold-related CVD mortality greater than the decrease in heat-related CVD mortality in the adaptation scenarios will result in an increase in the total number of temperature-related CVD mortalities.