Response of Harbin aerosol to latest clean air actions in China

Cities in Northeast China, e.g., Harbin, were brought to the forefront of air pollution control by a national-level policy promulgated in 2021, i.e., the Circular on Further Promoting the Pollution Prevention and Control Battle (the FP3CB Circular) which aimed at eliminating heavy or severe air pollution events. In this study, we explored the response of Harbin aerosol to the FP3CB Circular, based on observational results from two campaigns conducted during 2020-2021 and 2021-2022. A clear decreasing trend was identified for the impact of domestic biomass burning between the two winters, presumably driven by the clean heating actions. The 2021-2022 winter was also characterized by reduced formation of secondary organic aerosol but enhanced production of nitrate, which could be attributed to the less humid conditions but higher temperatures, respectively, compared to the 2020-2021 winter. The overall effect of these changes was a decrease in the contribution of organic species to wintertime aerosol in Harbin. In addition, the number of heavy or severe pollution days rebounded in the 2021-2022 winter compared to 2020-2021 (5 vs. 3), indicating that the emissions of primary particles and gaseous precursors must be further reduced to achieve the ambitious goals of the FP3CB Circular.

[Mediating effect of hypertension on risk of stroke associated with hyperuricemia]

Objective: To investigate the association between hyperuricemia and the risk for stroke occurrence, as well as the mediating effect of hypertension on this association. Methods: In this study, the China Chronic Diseases and Nutrition Surveillance system in 2015 was used as baseline data. We identified hospital admissions for stroke using the electronic homepage of inpatient medical records from 2013-2020, and death data were obtained from the 2015-2020 National Mortality Surveillance System. A retrospective cohort was established after matching and linking the database. The Cox proportional hazard regression model was used to analyze the relationship between hyperuricemia and the risk of stroke and its subtypes. Restricted cubic spline analysis was conducted to examine the dose-response relationship between serum uric acid levels and the risk for stroke. Mediation analysis was performed to investigate the mediating effect of hypertension on the association between hyperuricemia and the risk for stroke and its subtypes. Subgroup analyses were conducted based on gender and age groups. Results: A total of 124 352 study subjects were included, with an accumulative follow-up time of 612 911.36 person-years. During the follow-up period, 4 638 cases of stroke were found, including 3 919 cases of ischemic stroke and 689 cases of hemorrhagic stroke. The incidence density of stroke was 756.72 per 100 000 person-years, 641.37 per 100 000 person-years for ischemic stroke, and 114.60 per 100 000 person-years for hemorrhagic stroke. Multivariable Cox proportional hazards regression models showed that after adjusting for covariates, compared to those without hyperuricemia, individuals with hyperuricemia had a 16% higher risk for stroke [hazard ratio (HR)=1.16, 95%CI: 1.06-1.27], a 12% higher risk of ischemic stroke (HR=1.12, 95%CI: 1.01-1.24), and a 39% higher risk of hemorrhagic stroke (HR=1.39, 95%CI: 1.11-1.75). Mediation analysis showed that hypertension partially mediated the associations between hyperuricemia and the risk for stroke, ischemic stroke, and hemorrhagic stroke, with mediation proportions of 36.07%, 39.98%, and 25.34%, respectively. The mediating effect is pronounced in the male population and individuals below 65. Conclusion: Hyperuricemia is a risk factor for stroke, and hypertension partially mediates the effect of hyperuricemia on stroke.

Considerable contribution of secondary aerosol to wintertime haze pollution in new target of the latest clean air actions in China

Fine particulate matter (PM2.5) in Northeast China was targeted by national-level clean air policy for the first time in 2022, with the release of Action Plan to eliminate heavy air pollution events. In this study, we investigated sources of PM2.5 during three successive winters in Harbin, a megacity in Northeast China, based on observational results from several recent campaigns in 2018-2021. During the 2020-2021 campaign, daytime and nighttime samples were collected in specific months in addition to 24-h integrated measurements, and the two sets of samples were combined in different ways to run a positive matrix factorization model. The source apportionment results suggested that the resolved secondary organic carbon (SOCPMF) had an uncertainty of ∼12%. Secondary aerosols were found to show the following features for the typical winters without agricultural fires. First, SOCPMF could be properly constrained by results from another widely-used approach for SOC estimation, the elemental carbon-tracer method. Second, secondary PM2.5 calculated using SOCPMF and secondary inorganic ions were generally in line with the independent estimations based on air quality data. Third, secondary components accounted for more than 50% of PM2.5 on average and contributed even more significantly during severe haze episodes, which were the focus of the latest Action Plan. This study also found that the wintertime PM2.5 decreased more slowly during 2017-2021 compared to 2013-2017, by ∼1 and 10 μg/m3 per year, respectively, for the metropolitan area where Harbin is located at. Our results highlighted the importance of secondary aerosols for further improving air quality in Northeast China, and for avoiding heavy pollution as required by the latest Action Plan.

A Model of Type II Collagen-Induced Spondylitis and Arthritis in F1 Hybrid Male Mice

In this study, we tested a new model of ankylosing spondylitis in order to determine its histological and radiological features needed to investigate peripheral arthritis, spondylitis, and formation of the new bone tissues. F1 hybrid male mice (BALB/c×DBA/1), a progeny of spondylitis-susceptible BALB/c male mice and rheumatoid arthritis-susceptible DBA/1 female mice, were immunized intraperitoneally with bovine type II collagen (CII) mixed with adjuvant dimethyldioctadecylammonium bromide. Radiological and histological studies were performed at the peak of swelling, redness, and stiffness. The incidence of peripheral arthritis and spondylitis induced by CII in F1 hybrid mice were 66 and 62%, respectively. X-ray examination revealed bone erosion and spondylitis in the peripheral joints, as well as the formation of new bone tissues in the coccygeal vertebrae and between LIII and LIV vertebrae. The histological study showed lymphocyte and plasma cell infiltration, capillary dilation, congestion, and endochondral ossification of the lumbar vertebrae. This novel model of CII-induced spondylitis in F1 hybrid mice provoked axial and peripheral arthritides inducing chronic inflammation. In this model, the formation of new bone tissue in the stiff spine is characterized by endochondral ossification. The advanced model is an additional and valuable tool for investigation of the autoimmune reactions in spondylitis.

[Influencing factors of futile recanalization after endovascular therapy in acute ischemic stroke patients with large vessel occlusions]

Objective: To analyze the influencing factors of futile recanalization after endovascular therapy (EVT) in acute ischemic stroke patients with large vessel occlusions (AIS-LVO). Methods: AIS-LVO patients who underwent EVT with successful recanalization between January 2019 and December 2021 in Neurovascular Center of Changhai Hospital of Naval Medical University were retrospectively selected. Modified Rankin scale (mRS) score 3 months after EVT was used as the prognostic evaluation index, and patients with mRS scores≤2 were classified as the meaningful recanalization group and mRS scores 3-6 as the futile recanalization group. The risk factors, National Institutes of Health stroke scale (NIHSS) score, Glasgow coma scale (GCS) score, Alberta Stroke Program Early CT (ASPECT) score, core infarct volume, etc. in both groups were analyzed, and the influencing factors of futile recanalization after EVT were analyzed by multivariate logistic regression. Continuous variables that do not conform to the normal distribution are represented by [M(Q1,Q3)]. Results: A total of 368 patients meeting the inclusion criteria were collected, including 228 males and 140 females, and aged 68 (61, 77) years. There are 196 patients and 172 patients in the meaningful recanalization and futile recanalization groups, respectively, with the rate of futile recanalization 3 months after EVT of 46.74% (172/368). Comparing the general information and risk factors between the two groups found that the age of patients in the futile recanalization group [71 (65, 79) years] was higher than that in the meaningful recanalization group [65 (59, 72) years]. The baseline NIHSS score [18 (14, 22)] and the rate of not achieving modified Thrombolysis in Cerebral Ischemia grade 3 (mTICI 3) reperfusion (36.1%) were higher in the futile recanalization group than those in the meaningful recanalization group [12 (7, 17) and 19.9%]. The baseline GCS score [11 (9, 13)] was lower in the futile recanalization group than that in the meaningful recanalization group [14 (11, 15)]. The core infarct volume in the futile recanalization group [28 (7, 65) ml] was larger than that in the meaningful recanalization group [6 (0, 17) ml]. The ASPECT score [7 (5, 9)] was lower in the futile recanalization group than that in the meaningful recanalization group [9 (7, 10)]. In addition, the proportion of hypertension, atrial fibrillation, general anesthesia, and symptomatic intracranial hemorrhage was higher in the futile recanalization group (all P<0.05). The time from symptom onset to puncture and from symptom onset to reperfusion was longer in the futile recanalization group (both P<0.05). There were statistically significant differences in trial of Org 10172 in acute stroke treatment (TOAST) classification and the site of occluded blood vessels between the two groups (both P<0.05). Multivariate logistic regression indicated that age ≥80 years(OR=1.935,95%CI: 1.168-3.205), baseline NIHSS score (OR=1.999,95%CI: 1.202-3.325), GCS score (OR=2.299,95%CI: 1.386-3.814), previous stroke history (OR=1.977,95%CI: 1.085-3.604), general anesthesia (OR=1.981,95%CI: 1.143-3.435), not achieving grade 3 recanalization (OR=2.846, 95%CI: 1.575-5.143), ASPECT score<6 (OR=2.616, 95%CI: 1.168-5.857), and core infarct volume>70 ml (OR=2.712, 95%CI: 1.130-6.505) were risk factors for futile recanalization. Conclusion: Age≥80 years, previous stroke history, baseline NIHSS score≥20, GCS score≤8, general anesthesia, ASPECT score<6, core infarct volume>70 ml, and failure to achieve Grade 3 recanalization are independent influencing factors for futile recanalization after endovascular therapy in AIS-LVO patients.

[Secular trends of age at menarche and age at menopause in women born since 1951 from a county of Shandong Province, China]

OBJECTIVE

To describe the secular trends of age at menarche and age at natural menopause of women from a county of Shandong Province.

METHODS

Based on the data of the Premarital Medical Examination and the Cervical Cancer and Breast Cancer Screening of the county, the secular trends of age at menarche in women born in 1951 to 1998 and age at menopause in women born in 1951 to 1975 were studied. Joinpoint regression was used to identify potential inflection points regarding the trend of age at menarche. Average hazard ratios (AHR) of early menopause among women born in different generations were estimated by performing multivariate weighted Cox regression.

RESULTS

The average age at menarche was (16.43±1.89) years for women born in 1951 and (13.99±1.22) years for women born in 1998. The average age at menarche was lower for urban women than that for rural women, and the higher the education level, the lower the average age at menarche. Joinpoint regression analysis identified three inflection points: 1959, 1973 and 1993. The average age at menarche decreased annually by 0.03 (P < 0.001), 0.08 (P < 0.001), and 0.03 (P < 0.001) years respectively for women born during 1951-1959, 1960-1973, and 1974-1993, while it remained stable for those born during 1994-1998 (P=0.968). As for age at menopause, compared with women born during 1951-1960, those born during 1961-1965, 1966-1970 and 1971-1975 showed a gradual decrease in the risk of early menopause and a tendency to delay the age at menopause. The stratified analysis presented that the risk of early menopause gradually decreased and the age of menopause showed a significant delay among those with education level of junior high school and below, but this trend was not obvious among those with education level of senior high school and above, where the risk of early menopause decreased and then increased among those with education level of college and above, and the corresponding AHRs were 0.90 (0.66-1.22), 1.07 (0.79-1.44) and 1.14 (0.79-1.66).

CONCLUSION

The age at menarche for women born since 1951 gradually declined until 1994 and leveled off, with a decrease of nearly 2.5 years in these years. The age at menopause for women born between 1951 and 1975 was generally delayed over time, but the trend of first increase and then decrease was observed among those with relatively higher education levels. In the context of the increasing delay in age at marriage and childbearing and the decline of fertility, this study highlights the necessity of the assessment and monitoring of women' s basic reproductive health status, especially the risk of early menopause.

Agricultural fire impacts on brown carbon during different seasons in Northeast China

Brown carbon (BrC) represents not only a major component of haze pollution but also a non-negligible contributor to positive radiative forcing, making it a key species for coordinating air quality and climate policies. In China, field observations on BrC remain limited given the highly variable emission sources and meteorological conditions across different regions. Here we focused on the optical properties of BrC in a distinct but rarely studied megacity in Northeast China, which is within a major agricultural region and experiences extremely cold winter. Agricultural fires were evident in April of 2021 and the fall of 2020, although open burning was strictly prohibited. Such emissions enhanced BrC's mass absorption efficiency at 365 nm (MAE₃₆₅), more efficiently by the fall fires which were inferred to have relatively high combustion efficiencies (CE). After taking CE into consideration, the relationships between MAE₃₆₅ and the levoglucosan to organic carbon ratio (a measure of the significance of agricultural fire influence) roughly converged for the fire episodes in different seasons, including those identified in February and March of 2019 by a previous campaign. Agricultural fires also influenced the determination of absorption Ångström exponent (AAE), by resulting in non-linearity for BrC's absorption spectra shown on ln-ln scale. Based on three indicators developed by this study, the non-linearity was inferred to be caused by similar chromophores although the fires were characterized by various CE levels in different seasons. In addition, for the samples without significant influence of open burning, coal combustion emissions were identified as the dominant influencing factor for MAE₃₆₅, whereas none solid link was found between the solution-based AAE and aerosol source.

Exchange bias effect in polycrystalline Bi0.5Sr0.5Fe0.5Cr0.5O3 bulk

Bulk Bi_0.5Sr_0.5Fe_0.5Cr_0.5O₃ (BSFCO) is a new compound comprising the R3c structure. The structural, magnetic property and exchange bias (EB) details are investigated. The material was in the super-paramagnetic (SP) state at room temperature. Exchange bias usually occurs at the boundary between different magnetic states after field cooling (H_FC) acts on the sample. Here the result shows that changing H_FC from 1 to 6 T reduces the H_EB value by 16% at 2 K at the same time. Meanwhile, H_EB diminishes as the ferromagnetic layer thickness increases. The variation of (the thickness of ferromagnetic layer) t_FM with the change of H_FC leads to the tuning of H_EB by H_FC in BSFCO bulk. These effects are obviously different from the phenomenon seen in other oxide types.

[Pathological evaluation of endoscopic submucosal dissection for early gastric cancer and precancerous lesion in 411 cases]

OBJECTIVE

To evaluate the pathological characteristics of endoscopic submucosal dissection (ESD) specimens for early gastric cancer and precancerous lesions, accumulating experience for clinical management and pathological analysis.

METHODS

A total of 411 cases of early gastric cancer or precancerous lesions underwent ESD. According to the Japanese guidelines for ESD treatment of early gastric cancer and classification of gastric carcinoma, the clinicopathological data, pathologic evaluation, concordance rate of pathological diagnosis between preoperative endoscopic forceps biopsies and their ESD specimens (in 400 cases), as well as the risk factors of non-curative resection of early gastric cancer, were analyzed retrospectively.

RESULTS

23.4% (96/411) of the 411 cases were adenoma/low-grade dysplasia and 76.6% (315/411) were early gastric cancer. The latter included 28.0% (115/411) non-invasive carcinoma/high-grade dysplasia and 48.7% (200/411) invasive carcinoma. The concordance rate of pathological diagnosis between endoscopic forceps biopsies and ESD specimens was 66.0% (264/400), correlating with pathological diagnosis and lesion location (P < 0.01). The rate of upgraded diagnosis and downgraded diagnosis after ESD was 29.8% (119/400) and 4.2% (17/400), respectively. Among the 315 cases of early gastric cancer, there were 277 cases (87.9%) of differentiated type and 38 cases (12.1%) of undifferentiated type. In the study, 262 cases (83.2%) met with absolute indication, while 53 cases (16.8%) met relative indication. En bloc and curative resection rates were 98.1% and 82.9%, respectively. Risk factors for non-curative resection included a long diameter >20 mm (OR=3.631, 95%CI: 1.170-11.270, P=0.026), tumor infiltration into submucosa (OR=69.761, 95%CI: 21.033-231.376, P < 0.001)and undifferentiated tumor histology (OR=16.950, 95%CI: 4.585-62.664, P < 0.001).

CONCLUSION

Several subjective and objective factors, such as the limitations of biopsy samples, the characteristics and distribution of the lesions, different pathological understanding, and the endoscopic sampling and observation, can lead to the differences between the preoperative and postoperative pathological diagnosis of ESD. In particular, the pathological upgrade of postoperative diagnosis was more significant and should receive more attention by endoscopists and pathologists. The curative resection rate of early gastric cancer in ESD was high. Non-curative resection was related to the long diameter, the depth of tumor invasion and histological classification. ESD can also be performed in undifferentiated early gastric cancer if meeting the indication criteria. The comprehensive and standardized pathological analysis of ESD specimens is clinically important to evaluate the curative effect of ESD operation and patient outcomes.

[Forecasting the burden of disease from diabetes under the scenarios of specific risk factors control in China in 2030]

Objective: To forecast mortality, age-standardized mortality, and probability of premature mortality from diabetes, and to simulate the impact of controlling risk factors by 2030 in China. Methods: We simulated the burden of disease from diabetes in six scenarios according to the development goals of risk factors control by the WHO and Chinese government. Based on the theory of comparative risk assessment and the estimates of the burden of disease for China from the Global Burden of Disease Study 2015, we used the proportional change model to project the number of deaths, age-standardized mortality, and probability of premature mortality from diabetes under different scenarios of risk factors control in 2030. Results: If the trends in exposures to risk factors from 1990 to 2015 continued. Mortality, age-standardized mortality, and probability of premature mortality from diabetes would increase to 32.57/100 000, 17.32/100 000, and 0.84% by 2030, respectively. During that time, mortality, age-standardized mortality and probability of premature mortality for males would all be higher than for females. If the goals of controlling risk factors were all achieved, the number of deaths from diabetes in 2030 would decrease by 62.10% compared to the predicted numbers based on the historical trends in exposure to risk factors, and the probability of premature mortality would drop to 0.29%. If only the exposure to a single risk factor were achieved by 2030, high fasting plasma glucose control would have the greatest impact on diabetes, resulting in a 56.00% reduction in deaths compared to the predicted numbers based on the historical trends, followed by high BMI (4.92%), smoking (0.65%), and low physical activity (0.53%). Conclusions: Risk factors control plays an important role in reducing the number of deaths, age-standardized mortality rate, and probability of premature mortality from diabetes. We suggest taking comprehensive measures to control relevant risk factors for certain populations and regions, to achieve the goal of reducing the burden of disease from diabetes as expected.

[Status of home blood pressure monitoring and influencing factors of regular home blood pressure monitoring among elderly uncontrolled hypertensive patients in Central and Western China]

Objective: To describe the prevalence of home blood pressure monitoring and analyze the factors influencing regular blood pressure monitoring among elderly uncontrolled hypertensive patients in Central and Western China. Methods: It was a cross-sectional study, which enrolled hypertensive patients aged over 60 years with office blood pressure ≥140/90 mmHg (1 mmHg=0.133 kPa) from September 2019 to July 2020 in 72 hospitals in Central and Western China. Patients completed the electronic questionnaires, and were divided into regular and irregular home blood pressure monitoring groups. The proportion of patients using different types of sphygmomanometers and the percentage of patients with regular home blood pressure monitoring (at least weekly) were explored. The generalized linear mixed model was used to define the influencing factors of regular home blood pressure monitoring. Results: A total of 3 857 patients were included in this study. Age was 67(64,71) years old and there were 2 163 males (56.1%). Overall, sphygmomanometer was available at home for 3 044(78.9%) patients, 2 168(56.2%) patients conducted regular home blood pressure monitoring. Among the patients with a sphygmomanometer at home, 2 370(77.9%) of the sphygmomanometers were upper arm electronic device. Older age, higher income, longer history of hypertension, multiple antihypertensive medications and awareness of diagnostic criteria of hypertension and hypertension complications were associated with a higher prevalence of regular home blood pressure monitoring (all P<0.05). Conclusions: Among the elderly hypertensive patients with uncontrolled blood pressure in Central and Western China, there is a relatively high prevalence of home sphygmomanometer ownership and regular monitoring. Age, family income, history of hypertension, number of antihypertensive drugs and knowledge of hypertension are the influencing factors of regular home blood pressure monitoring in this population.

[Effect analysis of treating intracranial wide-neck bifurcation aneurysms through Woven EndoBridge]

Objective: To explore the clinical effect of Woven EndoBridge (WEB) in the treatment of wide-neck bifurcation aneurysms. Methods: The clinical and imaging data of 11 patients with intracranial wide-neck bifurcation aneurysms treated by WEB alone at Department of Neurosurgery of the Northern Theater General Hospital from September 2017 to May 2018, were retrospectively analyzed. The patients were 7 males and 4 females, aged (54±11) years (ranged from 31 to 66 years). The aneurysms of 5 patients were located in the anterior communicating artery, 3 in the top of the basilar artery, and 3 in the bifurcation of the middle cerebral artery. The intraoperative and postoperative conditions of the patients were recorded, and the degree of aneurysm embolization was evaluated by WEB embolization aneurysm occlusion scale (WOS). Results: The intraoperative WEB release of all the 11 patients was good, with 3 cases of WOS grade A, 1 of grade B and 7 of grade C, with no intraoperative acute complications occurring. The imaging follow-up was not carried out in 1 patient due to economic reason, and the clinical follow-up was good until 3 years after the operation; 10 patients were followed up by imaging for 6 months to 3 years, and no postoperative complications occurred in the target treatment area. Among the 2 patients with WOS grade A and 1 patient with grade B during operation, according to the postoperative follow-up, all were WOS grade A; among the 7 patients with WOS grade C during operation, 4 were still of grade C and 3 were of grade D according to the follow-up. Among the 3 patients with WOS grade D, 1 patient received secondary embolization due to poor recurrence morphology, unstable hemodynamics and high possibility of rupture of aneurysm, stent assisted coil embolization was adopted, with good immediate effect; the other 2 cases had recurrent aneurysms, but the aneurysms had good morphology and stable hemodynamics, therefore, clinical follow-up was continued and no secondary surgery was performed. No complications occurred in all these 11 patients. Conclusions: The operation of treating unruptured intracranial wide-neck bifurcation aneurysms with WEB device alone is simple, and there is no need for anticoagulation and antiplatelet treatment before and after the operation, the clinical effect is being good. WEB device provides a new treatment option for intracranial wide-neck bifurcation aneurysms.

[Prediction on the cardio-cerebrovascular death and probability of premature death caused by common risk factors in China in 2030]

Objective: Predictive models were used to evaluate the impact of common risk factors on the number of cardio-cerebrovascular deaths and the probability of premature death. Methods: Using the data for China estimated by the Global Burden of Disease study 2015 (GBD 2015), we calculated the population attribution fraction (PAF) of risk factors. The proportional change model was used to estimate the number of unattributable deaths by 2030, and to predict the number of deaths, mortality, standardized mortality and probability of premature death by 2030. Results: According to the natural change trend of risk factors from 1990 to 2015, the number of deaths and mortality would reach 6.12 million and 428.53/100 000 by 2030, with an increase of 59.92% and 52.87%. By 2030, the probability of premature death from cardio-cerebrovascular diseases among Chinese aged 30-70 years old would continue to decline, from 11.43% to 11.28% for men, and from 5.79% to 4.43% for women. If the goals of all included risk factors were reached by 2030, 2 289 200 cardio-cerebrovascular deaths would be avoided. If only the exposure to a single risk factor was achieved by 2030, blood pressure, total cholesterol, and fine particulate matter exposure were the three most important factors affecting cardio-cerebrovascular deaths, which would reduce 1 332 800, 609 100 and 306 800 deaths, respectively. Among the involved risk factors, the control of blood pressure would mostly decrease the number of deaths due to ischemic heart disease and hemorrhagic stroke, about 677 300 and 391 100 deaths, accordingly. Conclusion: The control of risk factors is of great significance in reducing deaths and probability of premature death due to cardio-cerebrovascular diseases. If the control targets of all risk factors could be achieved by 2030, the burden of cardio-cerebrovascular diseases would be reduced greatly.

Non-equilibrium influence on G/P partitioning of PAHs: Evidence from the diurnal and nocturnal variation

Gas/particle (G/P) partitioning is an important behavior for the atmospheric transport of polycyclic aromatic hydrocarbons (PAHs). In this study, paired daytime and nighttime air samples were collected for one year in order to study the diurnal and nocturnal variations of concentration and G/P partitioning of PAHs. Higher PAHs concentrations in total phase were observed in nighttime. The geomean (GM) concentrations of Σ₁₅PAHs in total phase were 69.6 and 52.8 ng/m³ in nighttime and daytime, respectively. More obviously diurnal and nocturnal variations were observed in non-heating season, with the GM ratios of Σ₁₅PAHs in nighttime to daytime of 1.65 and 1.06 in non-heating season and heating season, respectively. The results could be attributed to emission sources and meteorological conditions. The values of particulate phase fraction (ϕ_P) and G/P partitioning quotient (log K_P) were used to quantify the phase distribution of PAHs. For most high molecular weight PAHs, the values of ϕ_P and log K_P in nighttime were higher than those in daytime, which could be mainly attributed to the lower temperature in nighttime. However, for the three light molecular weight PAHs (Acy, Ace and Flu), higher values of ϕ_P and log K_P were observed in daytime. The regression of log K_P against log K_OA for the three PAHs in daytime differed from those in nighttime. The chemical losses of PAHs in different phases might be responsible for the result. These findings suggested that the chemical loss of PAHs in gas phase should be considered for the G/P partitioning process.

Exploring chemical changes of the haze pollution during a recent round of COVID-19 lockdown in a megacity in Northeast China

COVID-19 rebounded in China in January 2021, with Heilongjiang as one of the worst-affected provinces. This resulted in a new round of lockdown in Harbin, the capital city of Heilongjiang, from 20 January to 22 February of 2021. A field campaign was conducted to explore the responses of haze pollution in Harbin to the lockdown. Levoglucosan was used to reflect biomass burning emissions, while the molar ratio of sulfur (the sum of sulfur dioxide and sulfate) to nitrogen (the sum of nitrogen dioxide and nitrate), i.e., R_S/N, was used as an indicator for the relative importance of coal combustion and vehicle emissions. Based on a synthesis of the levoglucosan and R_S/N results, reference period was selected with minimal influences of non-lockdown-related emission variations. As indicated by the almost unchanged sulfur dioxide concentrations, coal combustion emissions were relatively stable throughout the lockdown and reference periods, presumably because the associated activities, e.g., heating supply, power generation, etc., were usually uninterruptible. On the other hand, as suggested by the increase of R_S/N, vehicle emissions were considerably reduced during lockdown, likely due to the stay-at-home orders. Compared to results from the reference samples, the lockdown period exhibited higher levels of ozone and various indicators for secondary aerosol formation, pointing to an enhancement of secondary pollution. In addition, photochemistry-related reactions in aqueous phase appeared to be present during the lockdown period, which have not been reported in the frigid atmosphere over Northeast China.

New open burning policy reshaped the aerosol characteristics of agricultural fire episodes in Northeast China

The massive agricultural sector in the Northeast Plain, which is of great importance for the food security in China, results in a huge amount of crop residues and thus substantial concern on haze pollution due to biomass burning (BB). To seek for effective control measures on BB emissions, a dramatic transition of open burning policy occurred in Heilongjiang Province, from the "legitimate burning" policy released in 2018 to the "strict prohibition" policy implemented in 2019 and beyond. Here we explored the BB aerosols during 2020-2021 in Harbin, the capital city of Heilongjiang. Although open burning was strictly prohibited by mandatory bans, agricultural fires were not actually eliminated, as indicated by the levoglucosan levels and fire count results. In general, the BB aerosols in Harbin were attributed to the overlaying of household burning and agricultural fire emissions. The former factor laid the foundation of biomass burning impacts, with BB contributions to organic carbon and elemental carbon (f_BBOC and f_BBEC) of 35 and 47%, respectively. The latter further enhanced the BB impacts during specific episodes breaking out in the spring of 2021 as well as the fall of 2020, when f_BBOC and f_BBEC increased to 64 and 57%, respectively. In addition, comparing to the fires of 2018-2019 which occurred in winter (in response to the "legitimate burning" policy), the agricultural fires were shifted to spring and fall in the 2020-2021 campaign, accompanied with an increase of combustion efficiency. This study illustrated how the agricultural fire emissions were influenced by the transition of open burning policy.

Primary nature of brown carbon absorption in a frigid atmosphere with strong haze chemistry

Severe haze hovered over Harbin during the heating season of 2019-2020, making it one of the ten most polluted Chinese cities in January of 2020. Here we focused on the optical properties and sources of brown carbon (BrC) during the extreme atmospheric pollution periods. Enhanced formation of secondary BrC (BrC_sec) was evident as relative humidity (RH) became higher, accompanied with a decrease of ozone but concurrent increases of aerosol water content and secondary inorganic aerosols. These features were generally similar to the characteristics of haze chemistry observed during winter haze events in the North China Plain, and indicated that heterogeneous reactions involving aerosol water might be at play in the formation of BrC_sec, despite the low temperatures in Harbin. Although BrC_sec accounted for a substantial fraction of brown carbon mass, its contribution to BrC absorption was much smaller (6 vs. 28%), pointing to a lower mass absorption efficiency (MAE) of BrC_sec compared to primary BrC. In addition, emissions of biomass burning BrC (BrC_BB) were inferred to increase with increasing RH, coinciding with a large drop of temperature. Since both the less absorbing BrC_sec and the more absorbing BrC_BB increased as RH became higher, the MAE of total BrC were largely unchanged throughout the measurement period. This study unfolded the contrast in the source apportionment results of BrC mass and absorption, and could have implications for the simulation of radiative forcing by brown carbon.

[Prediction of disease burden caused by malignant cancer in the context of risk factor control in China, 2030]

Objective: To predict the number of deaths, standardized mortality and probability of premature mortality caused by malignant cancer in the context of risk factor control at different levels in China in 2030, and assess the possibility of achieving the target of reducing the probability of premature mortality of malignant cancer. Methods: According to the risk factor control standard for malignant cancer used both at home and abroad, the results of China from Global Burden of Disease Study 2015 were used to calculate the population attributable fraction of the risk factors. Based on the comparative risk assessment theory, the deaths of malignant cancer were classified as attributable deaths and un-attributable deaths. Proportional change model was used to predict risk factor exposure and un-attributable deaths of malignant cancer in the future, then the number of deaths, standardized mortality rate and probability of premature mortality of malignant cancer in 2030 was estimated. Data analyses were performed by using software R 3.6.1. Results: If the risk factor exposure level during 1990-2015 remains, the number of deaths, standardized mortality rate, and probability of premature mortality of malignant cancer would increase to 3.62 million, 153.96/100 000 and 8.92% by 2030, respectively. If the risk factor exposure control level meets the requirement, the probability of premature mortality from cancer in people aged 30-70 years would drop to 7.57% by 2030. Conclusions: The control of risk factor exposure will play an important role in reducing deaths, standardized mortality rate and probability of premature mortality of malignant cancer. But more efforts are needed to achieve the goals of Health China Action.

[Mortality trend of chronic respiratory diseases in China, 1990-2019]

Objective: To analyze mortality and its trend of chronic respiratory diseases (CRD) in China from 1990 to 2019. Methods: Based on the provincial results of China from the 2019 Global Burden of Disease (GBD) study, the average annual percent change (AAPC) of standardized mortality rates of different CRDs were analyzed by using Joinpoint 4.8.0.1, and the age-standardized mortality rate of CRD was calculated by using the GBD 2019 world standard population. Based on the comparative risk assessment theory of GBD, the attributable deaths due to 12 CRD risk factors were estimated, including smoking, indoor air pollution, occupational gas exposure, particulates and smog exposure, environmental particulate pollution, low temperature, passive smoking, ozone pollution, occupational exposure to silica, occupational asthma, high body mass index, high temperature and occupational exposure to asbestos. Results: From 1990 to 2019, the number of deaths and standardized mortality of chronic obstructive pulmonary disease (COPD) showed a downward trend (P<0.001). The number of COPD deaths decreased from 1 244 000 (912 000 - 1 395 000) in 1990 to 1 037 000 (889 000 - 1 266 000) in 2019. AAPC=-0.9% (95%CI: -1.5% - -0.3%), P<0.001; The standardized mortality rate decreased from 217.9/100 000 (163.3/100 000 - 242.0/100 000) in 1990 to 65.2/100 000 (55.5/100 000 - 80.1/100 000) in 2019. AAPC= -4.2% (95%CI:-5.2% - -3.2%), P<0.001. The number of deaths from asthma decreased from 40 000 (30 000 - 58 000) in 1990 to 25 000 (20 000 - 31 000) in 2019. AAPC=-2.0% (95%CI: -2.6% - -1.4%), P<0.001; The standardized mortality rate of asthma decreased from 6.4/100 000 (4.7/100 000 - 9.5/100 000) in 1990 to 1.5/100 000 (1.2/100 000 - 1.9/100 000) in 2019. AAPC=-5.1% (95%CI: -5.8% - -4.4%), P<0.001. The number of pneumoconiosis deaths decreased from 11 000 (8 000 - 14 000) in 1990 to 10 000 (8 000 - 14 000) in 2019, AAPC=-0.2%(95%CI:-0.4% - 0.1%), P=0.200; The standardized mortality rate of pneumoconiosis decreased from 1.4/100 000 (1.0/100 000 - 1.7/100 000) in 1990 to 0.5/100 000 (0.4/100 000 - 0.7/100 000) in 2019. AAPC=-3.1% (95%CI: -3.4% - -2.8%), P<0.001. The number of deaths from pulmonary interstitial diseases and pulmonary sarcoidosis increased from 3 000 (3 000 - 6 000) in 1990 to 8 000 (6 000 - 10 000) in 2019, AAPC=3.5% (95%CI: 2.7% - 4.2%), P<0.001; The corresponding standardized mortality rate changed little from 1990 to 2019, and AAPC was not statistically significant.The age-standardized mortality rates of different CRDs were higher in men than those in women. In 1990 and 2019, the mortality rates of COPD, asthma, pneumoconiosis and interstitial pulmonary disease and pulmonary sarcoidosis increased with age. In 2019, the population attributable fractions (PAFs) for smoking, environmental particulate pollution, occupational gas exposure, particulate and smog exposure, low temperature exposure and passive smoking were 71.1% (68.0% - 74.3%), 24.7% (20.1% - 30.0%), 19.3% (13.0% - 25.4%), 15.7% (13.6% - 18.3%) and 8.8% (4.5% - 13.1%) respectively in men, and the PAFs for environmental particulate pollution, smoking, low temperature exposure, occupational gas exposure, particulate and smog exposure, and passive smoking were 24.1% (19.6% - 29.3%), 21.9% (18.7% - 25.2%), 16.4% (14.0% - 19.2%), 15.6% (10.2% - 21.1%) and 14.7% (7.9% - 21.3%) respectively in women. Conclusions: During 1990-2019, the overall death level of CRD decreased significantly in China, but it is still at high level in the world. Active prevention and control measures should be taken to reduce the death level caused by CRD.

[Analysis on factors associated with the place of death among individuals with cardiovascular diseases in China, 2018]

Objective: To understand the distribution patterns of the place of death (PoD) among individuals with cardiovascular disease (CVD) in the provinces of China in 2018. Relationships between CVD deaths in healthcare/medical institutions and individual demographics, social-economic status (SES), the underlying cause of death, and local cultural factors were also explored. Methods: Using data from the National Cause-of-death Reporting System, we examined potential, influential factors of CVD deaths in healthcare/medical institutions through multilevel logistic regression. Results: In 2018, there were 853 832 CVD deaths in disease surveillance points in the country, with 661 625 (77.49%) home deaths and 156 441 (18.32%) occurring in healthcare and medical institutions. Factors including sex, age, nationality, marital status, education level, occupation, the underlying cause of death, criterion for diagnosis, and urban/rural residency, were significantly influential on CVD deaths in healthcare/medical institutions. Meanwhile, spatial variations were shown at factors the subnational level, with 45.39% related to factors at the individual level. Conclusion: Home was the dominant place for CVD deaths in the country, with substantial spatial variations in PoD between provinces. The probability of dying in healthcare/medical settings was comparatively higher among CVD patients with superior socioeconomic status and who lived in urban areas. Adequate information should be collected and included in further studies on exploring influential factors of PoD. Since both social factors, individual preferences, and acute and chronic CVD deaths are critical, it is necessary to enhance treatment capacity. A booming approach incorporating home/hospice care with on-site medical services might also improve the quality of end-of-life care among CVD patients in China.

[Analysis on all-cause mortality rate and life expectancy in China, 2005-2018]

Objective: To understand the geographical variations and temporal trends of all-cause mortality rate and life expectancy in China at national and subnational levels during 2005-2018. Methods: Using data from National Cause-of-death Reporting System, China National Maternal and Child Health Surveillance System, Under-reporting Surveys, and related social determinants covariates, we estimated all-cause mortality rate and life expectancy at national and subnational levels in China during 2005-2018. We depicted the geographical variations and temporal trends between provinces on mortality rate and life expectancy. We then decomposed changes in national and subnational deaths into three explanatory components: change due to age-specific mortality rate, change due to the population structure by age, and change due to growth of the total population. Results: In 2018, it was estimated that there were 10 482 297 total deaths (95%CI: 9 723 233-11 466 875 deaths) in China, with 6 113 926 men (95%CI: 5 773 158-6 572 407 men) and 4 368 241 women (95%CI: 3 950 075-4 894 468 women). The all-cause mortality rate was 755.54 per 100 000 (95%CI: 701.49 per 100 000-825.78 per 100 000), with 861.78 per 100 000 (95%CI: 813.75 per 100 000-926.40 per 100 000) in men and 642.73 per 100 000 (95%CI: 581.20 per 100 000-720.15 per 100 000) in women, while age-standardized all-cause mortality rate was 652.27 per 100 000 (95%CI: 599.22 per 100 000-721.71 per 100 000), with 806.38 per 100 000 (95%CI: 755.10 per 100 000-874.31 per 100 000) in men and 503.37 per 100 000 (95%CI: 450.50 per 100 000-572.01 per 100 000) in women. In 2018, it was estimated that the life expectancy in the whole country was 77.15 years old (95%CI: 75.92-78.11 years old), with 74.81 (95%CI: 73.57-75.76) in men and 79.87 (95%CI: 78.61-80.91) in women. Developed areas as Shanghai, Beijing, Jiangsu, and Zhejiang owned comparatively higher life expectancy, while undeveloped areas like Tibet, Guizhou, Xinjiang, and Qinghai showed lower levels. During 2005-2018, there was a 29.87% increase in total deaths at the national level, with 27.74% in men and 31.29% in women. Changes due to age-specific mortality rate, the population structure by age, and the growth of the total population constituted -35.74%, 7.34%, and 58.28% of the total increase, respectively. Conclusions: From 2005 to 2018, the all-cause mortality rate increased while the age-standardized mortality rate decreased substantially among Chinese residents. Change due to population structure by age was the dominant driver. An upward trend of life expectancy was observed in all provinces, with marked differences between the provinces.

[Influences of using different spatial weight matrices in analyzing spatial autocorrelation of cardiovascular diseases mortality in China]

Objective: To explore the potential influences and applicability of different spatial weight matrices used in analyzing spatial autocorrelation of cardiovascular disease (CVD) mortality in China. Methods: Using data from the National Cause-of-death Reporting System, we used adjacency-based Rook and Queen contiguity and distance-based K nearest neighbors/distance threshold. We then conducted global and local spatial autocorrelation analysis of CVD mortality at the county level in China, 2018. Results: All four categories and 26 types of spatial weight matrices had detected significant global and local spatial autocorrelation of CVD mortality in China. Global Moran's I statistics reached its peak when using first-order Rook (0.406), first-order Queen (0.406), K nearest neighbors including five spatial units (0.409), and distance threshold with 100 kilometers (0.358). Meanwhile, apparent local spatial autocorrelation was found in CVD mortality. Substantial disparities were observed when detecting "High-High clusters", "Low-Low clusters", "High-Low clusters" and "Low-High clusters" of CVD mortality spatial distribution by using different weight matrices. Conclusions: Using different spatial weight matrices in analyzing the spatial autocorrelation of CVD mortality, we could understand the spatial distribution characteristics of CVD mortality in-depth at the county level in China. In this way, adequate supports could also be provided on CVD premature death control and rational medical resource allocation regionally.

[Analysis of the effect of stent-assisted embolization for low-grade subarachnoid hemorrhage caused by V4 segment dissecting aneurysm of vertebral artery]

Objective: To investigate the efficacy and safety of different stents assisted embolization in the treatment of subarachnoid hemorrhage(SAH) caused by V4 dissecting aneurysm of vertebral artery. Methods: The clinical data of 39 patients with spontaneous SAH V4 dissecting aneurysm treated at the Department of Neurosurgery, the Northern Theater General Hospital from January 2016 to June 2019 were analyzed retrospectively.There were 21 males and 18 females, aged (48±17) years(range:35 to 68 years).There were 24 cases of HUNT-HESS grade Ⅰ and 15 cases of grade Ⅱ.Among them, 20 cases were treated with single stent-assisted embolization, 9 cases with multi-stent-assisted embolization, 9 cases with semi-dense mesh-assisted embolization, and 1 case with dense-mesh stent-assisted embolization.The perioperative and postoperative complications, postoperative recurrence were collected. Results: Intraoperative complications included 2 cases of aneurysm rupture and 2 cases of acute thrombosis.All aneurysms were densely packed according to the angiography performed immediately after operation.Postoperative complications included 3 cases of long-term responsible vascular ischemia(modified Rankin score<2). The patients were followed up for 15.1 months(range: 12 to 29 months). At the last follow-up, aneurysms recurrence occured in 10 cases, the recurrence rate was 25.6%(10/39). There were 6 cases of recurrence and 2 cases of complications in 20 cases with single stent-assisted embolization, 3 cases of recurrence and 4 cases of complications in 9 cases with multi-stent-assisted embolization, 1 case of recurrence and 1 case of complications in 9 cases with semi-dense mesh stent. Conclusion: Endovascular treatment is feasible for patients with vertebral artery dissecting aneurysm, and the appropriate surgical method should be selected according to the vascular structure and the location of the aneurysm.

[Disease burden of breast cancer in women in China, 1990-2017]

Objective: To analyze the trend of the incidence, mortality and disease burden of breast cancer in women in China during 1990-2017. Methods: Based on the estimation of data in China from the Global Burden of Disease 2017 (GBD2017), the incidence,mortality, disability- adjusted life years (DALY), years of life lost (YLL), and years lived with disability (YLD) on breast cancer for women in China during 1990-2017 were standardized by the world standard population used for GBD2017. The GBD study applied the attributable burden formula to estimate the attributable deaths by five risk factors of breast cancer, including alcohol use, high body mass index (BMI), high fasting plasma glucose, low physical activity and tobacco smoking. The incidence, mortality, attributable deaths and the disease burden due to breast cancer in women in China were analyzed. Results: In 2017, a total of 357.6 thousand female breast cancer cases, including 84.8 thousand deaths, were reported in China, with the age-standardized incidence rate of 35.62/100 000, which increased by 286.18%, 114.14% and 88.77% respectively compared with 1990. The age-standardized mortality rate decreased from 8.57/100 000 in 1990 to 7.84 /100 000 in 2007, then increased to 8.71 /100 000 in 2015, and then decreased to 8.47/100 000 in 2017. The mortality of breast cancer increased with age in 1990 and 2017. From 1990 to 2017, the trend of standardized DALY rate and standardized YLL rate were the same as that of standardized mortality, while the standardized YLD rate and the proportion of YLD in DALY increased year by year. In 2017, the standardized DALY rate, standardized YLL rate and standardized YLD rate of breast cancer were 253.00/100 000, 228.96/100 000, and 24.05/100 000, respectively. Compared with 1990, the change rates were -6.88% and -11.73% and 95.85% respectively. The proportion of breast cancer deaths attributable to high BMI increased significantly by 165.76%, from 5.49% in 1990 to 14.59% in 2017. The proportion of breast cancer deaths attributable to alcohol use and high fasting blood glucose increased; and the proportion of breast cancer deaths attributed to low physical activity and smoking remained stable. In 2017, the three provinces with the highest age-standardized mortality rate of female breast cancer were Hongkong (9.93/100 000), Guangxi (9.52/100 000) and Liaoning (9.49/100 000). Compared with 1990, the age-standardized mortality of 19 provinces decreased, and Beijing (-27.17%), Macao (-26.06%) and Jilin (-23.89%) had the fastest decrease. The two provinces with the highest growth rates were Hebei (28.85%) and Henan (24.34%). Conclusions: The disease burden of female breast cancer in China increased during 1990-2017. Therefore it is necessary to strengthen the prevention and treatment of breast cancer.

The true incidence of chromosomal mosaicism after preimplantation genetic testing is much lower than that indicated by trophectoderm biopsy

STUDY QUESTION

What is the true incidence of chromosomal mosaicism in embryos analyzed by preimplantation genetic testing (PGT).

SUMMARY ANSWER

The true incidence of chromosomal mosaicism is much lower than we usually surmise.

WHAT IS KNOWN ALREADY

In recent years, contemporary methods for chromosome analysis, along with the biopsy of more than one cell, have given rise to an increased rate of chromosomal mosaicism detection after preimplantation genetic testing for aneuploidy. However, the exorbitant incidence of mosaicism represents a dilemma and imposes restrictions on the application of PGT treatment. Concern has been raised about the possibility that the incidence of chromosomal mosaicism is overestimated and quite a few of the results are false-positive errors. However, studies verifying the diagnosis of chromosomal mosaicism and assessing the true incidence of chromosomal mosaicism are limited.

STUDY DESIGN, SIZE, DURATION

A total of 1719 blastocysts from 380 patients who underwent PGT treatment were retrospectively analyzed to evaluate the typical incidence of mosaicism. Then 101 embryos donated by 70 couples were re-biopsied and dissected into three portions if available: trophectoderm (TE), inner cell mass (ICM), and the remaining portions. All the portions were tested using next-generation sequencing (NGS), and the results were compared to the original diagnosis.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The setting for this study was a university-affiliated center with an in-house PGT laboratory. All samples were amplified with multiple annealing and looping-based amplification cycles (MALBACs) and the NGS was carried out on a Life Technologies Ion Proton platform.

MAIN RESULTS AND THE ROLE OF CHANCE

A clinical TE biopsy revealed an incidence of 11.9% for diploid-aneuploid mosaicism (DAM), 17.3% for aneuploid mosaicism (AM) and 29.1% in total. After rebiopsy, 94.1% whole-chromosome aneuploidies and 82.8% segmental-chromosome aneuploidies were confirmed in the embryos. As for the mosaic errors, only 32 (31.7%) out of 101 embryos presented with uniform chromosomal aberrations in agreement with the original biopsy results, 15 (14.8%) embryos presented with de novo chromosomal aberrations, and 54 (53.5%) embryos showed a euploid profile in all portions. Among the 32 uniform embryos, the true mosaicism was confirmed in only 4 cases, where a reciprocal chromosomal aberration was identified; 14 embryos presented with identical mosaicism, providing the moderate evidence for true mosaicism; and 14 embryos displayed uniform full aneuploidies in all portions of embryo, revealing a high-grade mosaicism or a false-negative diagnosis. Logistical regression analysis revealed that the concordance rate with ICM was associated with the type and level of mosaicism. The concordance rate of segmental-chromosome mosaicism was significantly lower than whole-chromosome mosaicism (adjusted Odds Ratio (aOR): 5.137 (1.061, 24.876), P = 0.042) and compared to DAM, the concordance rate of AM was significantly higher (aOR: 6.546 (1.354, 31.655), P = 0.019). The concordance rate also increased with increasing levels of mosaicism (P < 0.001).

LIMITATIONS, REASONS FOR CAUTION

This study was limited by a small sample size and the use of a single whole-genome amplification (WGA) method and NGS platform. These findings are only applicable to samples subjected to MALBAC amplification and Ion Proton platform, and studies involving larger sample sizes and multiple WGA methods and NGS platforms are required to prove our findings.

WIDER IMPLICATIONS OF THE FINDINGS

TE biopsy is reliable to detect whole-chromosome aneuploidies, but the ability to diagnose mosaicism is doubtful. More attention should be paid to false-positive and false-negative errors in NGS-based PGT, especially for laboratories using less stringent criteria for mosaicism classification (i.e. 20-80%), which might be subject to a much higher false-positive mosaicism rate in the practice.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by grants from the National Key R&D Program of China (No. 2016YFC1000206-5) and the National Natural Science Foundation of China (No. 81701509).

TRIAL REGISTRATION NUMBER

N/A.

[Dysregulated proportion of intrahepatic Treg cells and Th17 along with CD8+ T lymphocytes drives disease progression after kasai biliary atresia surgery]

Objective: To analyze the clinicopathological characteristics and intrahepatic immune cells infiltration condition after Kasai biliary atresia surgery. Methods: Data of 28 cases who underwent liver transplantation in the liver transplantation center of our hospital from June 2017 to March 2019 were enrolled. Of which, 20 cases were in the biliary atresia group (divided into two subgroups: 10 cases without Kasai surgery and 10 cases after Kasai surgery, and latter subsided cholestasis) and 8 cases in the control group. Clinical and pathological morphological characteristics of the groups were compared. Liver tissue sections were stained with immunohistochemistry and CD3, CD4, CD8, CD20, Foxp3, and interleukin-17A were quantitatively analyzed. Kruskal-Wallis test was used to measure the above indicators, and rank-sum test or Fisher's exact test was used to compare the count data. Results: The degree of clinical and pathological cholestasis in the biliary atresia group after Kasai surgery was significantly lower than that of the group without Kasai surgery, and the degree of liver fibrosis was also significantly reduced (P < 0.05), but there was no statistically significant difference in the degree of inflammation in the portal vein area between the two groups (P > 0.05). There was statistically significant difference in the types of immune cells infiltrated in the liver (P < 0.05). Compared with the group without Kasai surgery, the infiltration of CD3, CD8, IL-17A and Foxp3 positive cells in the portal vein area after Kasai surgery group (P < 0.05) was significantly reduced, but there was no statistically significant difference in the proportion of Foxp3/CD4 positive cells between the two groups (P > 0.05), which continued to be lower than that of the control group (P < 0.05). Compared with the non-Kasai surgery group, the proportion of Foxp3/IL-17A and Foxp3/CD8 positive cells in the portal vein area did not increase significantly after Kasai surgery group (P > 0.05), and remained lower than the control group. However, the proportion of Foxp3/IL-17A and Foxp3/CD8 positive cells was significantly reduced (P ​​< 0.05). Conclusion: Intrahepatic inflammatory cell infiltration and regulatory/effector T lymphocyte proportion dysregulation exist in patients with subsided cholestasis after Kasai biliary atresia surgery, which may be an important factor to promote the disease progression.

Abstract PS10-51: TAA013 a trastuzumab antibody drug conjugate phase I dose escalation study in recurrent her2 positive breast cancer

Background: A phase 1 dose escalation study of TAA013, an antibody drug conjugate linking trastuzumab to a cytotoxic small molecule, DM1, through an SMCC linker, in previously treated recurrent Her2 positive breast cancer patients. Material and Methods: This phase I study follows the traditional 3+3 design, dosing started at 0.6mg/kg, followed by 1.2, 2.4, 3.6, 4.8mg/kg, one intravenous infusion was given every 3 weeks, the initial infusion had to be over 90 minutes, infusion times were later shortened if treatment was well tolerated. The subsequent recommended dose would be expanded to include at least 10 patients. Patients were observed for dose-limiting toxicity (DLT) during a 21-day DLT observation period. Toxicities were graded according to the National Cancer Institute Common Terminology Criteria for Adverse Events v5.0. Maximum-tolerated dose (MTD) was defined as the highest dose level that resulted in a DLT in no more than 1 of 6 patients. Study endpoints included safety and tolerability, pharmacokinetic and immunogenicity parameter evaluation, with preliminary evaluation of efficacy. Results: The study enrolled 22 female patients with histologically confirmed Her-2 positive metastatic breast cancer, median age of 50yrs (25-67), median time from initial diagnosis to TAA013 dosing was 39 months (5-99), median prior treatment regimen was 4 (2-10), all had received trastuzumab for a mean of 8.2 months (2-10), alone or in combination with chemotherapy, other prior Her2 targeting drugs given included pertuzumab (2), lapatinib (7), and pyrotinib (8). All patients received at least 2 (median of 6 infusions, range of 1-15) infusions, except for the last 4.8mg/kg patient, but all patients passed the dose limiting toxicity (DLT) observation period of 21 days. There were no dose limiting toxicities, no serious adverse events, nor that resulting in mortality, the maximum tolerated dose was not reached. The most common treatment emergent adverse events (TEAE) included 9 (40.9%) grade 1-2 infusion reactions associated with fever(5) and/or chills(1), the reaction often abated in subsequent cycles. There were no grade 4 TEAE, but there were 3 grade 3 thrombocytopenia, one grade 3 neutropenia, and one grade 3 hyperbilirubinemia which all recovered for the patients to continue treatment, there was also one grade 3 dermatitis in a patient with a history of chronic dermatitis. Antibody drug antibodies were not detected emanating from the TAA013 therapy. Pharmacokinetic studies included evaluation of TAA013, trastuzumab and DM1. Preliminary efficacy evaluation in the 2.4-4.8mg/kg dosing group of heavily pretreated patients resulted in 2 partial responses, including patients who had previously received pyrotinib therapy. Conclusion: TAA013 is a Her2 targeting antibody drug conjugate that is safe and tolerable, with efficacy demonstrated in heavily pretreated Her2 positive breast cancer patients. Keywords: breast cancer, antibody drug conjugates, TAA013.

Citation Format: J M Liu, Y M Yin, Hao Wu, W Li, X Huang, XX Li. TAA013 a trastuzumab antibody drug conjugate phase I dose escalation study in recurrent her2 positive breast cancer [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS10-51.

[Expert consensus on the treatment of oral and maxillofacial space infections]

Oral and maxillofacial space infections (OMSI) are common diseases of the facial region involving fascial spaces. Recently, OMSI shows trends of multi drug-resistance, severe symptoms, and increased mortality. OMSI treatment principles need to be updated to improve the cure rate. Based on the clinical experiences of Chinese experts and with the incorporation of international counterparts' expertise, the principles of preoperative checklist, interpretation of examination results, empirical medication principles, surgical treatment principles, postoperative drainage principles, prevention strategies of wisdom teeth pericoronitis-related OMSI, blood glucose management, physiotherapy principles, Ludwig's angina treatment and perioperative care were systematically summarized and an expert consensus on the diagnosis and treatment of OMSI was reached. The consensus aims to provide criteria for the diagnosis and treatment of OMSI in China so as to improve the level of OMSI treatment.

Strong biomass burning contribution to ambient aerosol during heating season in a megacity in Northeast China: Effectiveness of agricultural fire bans?

Sustainable use of crop residues remains a challenge in main agricultural regions of China such as the Northeast Plain. Here we investigated the impacts of biomass burning on fine particle (PM_2.5) during a six-month long heating season in the Harbin-Changchun (HC) metropolitan area, China's only national-level city cluster located in the severe cold climate region. Temporal variation of PM_2.5 was found to coincide with that of levoglucosan. This was attributed to the strong contribution of biomass burning to organic aerosol (the dominant component in PM_2.5), as supported by the source apportionment results and high levoglucosan-to-organic carbon (OC) ratios. Furthermore, the variation of biomass burning contribution was inferred to be driven mainly by agricultural fires with relatively low combustion efficiencies, based on a synthesis of the relationship between OC and elemental carbon (EC), the dependence of EC on carbon monoxide, and the relative abundances of different tracers for biomass burning. Nitrate formation was enhanced during biomass burning episodes whereas no evidence was observed to indicate enhanced sulfate formation or net increase of OC mass due to secondary formation. This study demonstrates the importance of open burning as a source of haze pollution in the HC region.

Model vs. observation discrepancy in aerosol characteristics during a half-year long campaign in Northeast China: The role of biomass burning

Complex air pollutant sources and distinct meteorological conditions resulted in unique wintertime haze pollution in the Harbin-Changchun (HC) metropolitan area, China's only national-level city cluster located in the severe cold climate region. In this study, field observation and air quality modeling were combined to investigate fine particulate matter (PM_2.5) pollution during a six-month long heating season in HC's central city (Harbin). The model significantly underpredicted PM_2.5 and organic carbon (by up to ∼230 μg/m³ and 110 μgC/m³, respectively, in terms of daily average) when levoglucosan concentrations were above 0.5 μg/m³. Based on a synthesis of levoglucosan concentrations and fire counts, the large gaps were attributed to underestimation of open burning emissions by the model. However, the model tended to overpredict elemental carbon (more significantly at higher NO₂), likely pointing to an overestimation of vehicle emissions. With increasing levoglucosan, the difference between observed and simulated nitrate (nitrate_obs ‒ nitrate_mod, i.e., Δnitrate) showed a transition from negative to positive values. The positive Δnitrate were attributed to underprediction of the open-burning related nitrate, whereas the negative Δnitrate were likely caused by overprediction of nitrate from other sources (presumably vehicle emissions). The dependence of Δnitrate on levoglucosan indicated that with stronger impact of open burning, the overprediction effect was gradually offset and finally overwhelmed. Influence of open burning on sulfate formation was evident as well, but less apparent compared to nitrate. This study illustrates how the uncertainties in open burning emissions will influence PM_2.5 simulation, on not only primary components but also secondary species.

Secondary inorganic aerosol during heating season in a megacity in Northeast China: Evidence for heterogeneous chemistry in severe cold climate region

The characteristics of secondary inorganic aerosol including sulfate, nitrate and ammonium (SNA) were investigated during a six-month long heating season in the Harbin-Changchun metropolitan area, i.e., China's only national-level city cluster located in the severe cold climate region. The contribution of SNA to fine particulate matter (PM_2.5) tended to decrease with increasing PM_2.5 concentration, opposite to the trend repeatedly observed during winter in Beijing. Heterogeneous sulfate formation was still evident when the daily average temperature was as low as below -10 °C, with the preconditions of high relative humidity (RH; above ∼80%) and high nitrogen dioxide (above ∼60 μg/m³). Both the sulfur oxidation ratio (SOR) and nitrogen oxidation ratio (NOR) were enhanced at high RH, reaching ∼0.3. However, the high RH conditions were not commonly seen during the heating season, which should be responsible for the overall lack of linkage between the SNA contribution and PM_2.5 temporal variation.

Burden of colorectal cancer attributable to diet low in milk in China, 1990-2017: findings from the global burden of disease study 2017

BACKGROUND

Colorectal cancer (CRC) has emerged as a major public health concern. However, little is known about the burden attributable to specific risk factors. The present study aimed to estimate the temporal trends and geographical variation of CRC burden attributable to a diet low in milk in China.

METHODS

Following the general analytic strategy used in the 2017 Global Burden of Disease study, we assessed the age-, sex-, and province-specific mortality and disability-adjusted life-years (DALYs) of CRC caused by a diet low in milk in China from 1990 to 2017.

RESULTS

In 2017, a diet low in milk contributed 32 032 [95% uncertainty interval (UI) = 11 350-53 806] deaths and 726 710 (95% UI = 256 651-1 218 153) DALYs for CRC with a population attributable fraction of 17.1%. The age-standardised mortality and DALY rates per 100 000 were 1.7 (95% UI = 0.6-2.9) and 36.8 (95% UI = 13.0-61.7), respectively. An upward trend with age in rates of mortality and DALYs was observed. Males had higher age-standardised rates than females. The number of deaths and DALYs increased significantly from 1990 to 2017, whereas the corresponding age-standardised rates showed relatively stable trends. In 2017, Hunan and Liaoning were ranked as the top two provinces in terms of disease burden. Socio-demographic index had a weak correlation with the age-standardised mortality (r = 0.348, P = 0.047).

CONCLUSIONS

The present study shows a substantial increase in the CRC burden attributable to a diet low in milk over the past three decades. Greater priority in CRC prevention should be given to males and the elderly population throughout China, particularly in less-developed provinces.

[Analysis of risk factors for lymphoma patients dying of cardiovascular disease]

Objective: To understand and explore the risk factors of the death of lymphoma patients from cardiovascular disease. Methods: The medical records and death information of 1 173 patients with lymphoma were collected, cases that died from cardiovascular disease were screened. A binary logistic regression model was used to analyze the independent risk factors of patients with lymphoma died from cardiovascular disease. Results: Among 1 173 patients with lymphoma, 75 (6.4%) died of cardiovascular disease, including 27 cases of coronary heart disease, 25 cases of stroke, 7 cases of hypertension, 5 cases of sudden cardiac death, 4 cases of pulmonary embolism, 3 cases of heart failure, 4 cases of others. Among the patients who survived for more than 5 years, 16.1% (35/217) died of cardiovascular disease. Among those who survived for more than 10 years, 11.7% (7/60) died of cardiovascular disease. Multivariate Logistic regression analysis showed that the primary site of lymphoma (OR=0.521, P=0.039), stage (stage Ⅱ: OR=2.487, P=0.016; stage Ⅲ: OR=3.233, P=0.002) and cardiovascular toxicity in the course of diagnosis and treatment (OR=3.019, P=0.001) are independent influencing factors for the death of cardiovascular disease in patients with lymphoma. Patients whose primary sites of lymphoma were lymph nodes had lower risk of dying from cardiovascular disease, while the patients with stage Ⅱ to Ⅲ stage and cardiovascular toxicity during diagnosis and treatment had higher risk of dying from cardiovascular disease. Conclusions: Cardiovascular disease is an important factor affecting the survival of patients with lymphoma. With the extension of survival time, the risk of dying from cardiovascular disease increases significantly. The primary site, tumor stage, and cardiovascular toxicity that occur during the diagnosis and treatment may be the independent influencing factors for patients with lymphoma that die from cardiovascular disease.

[Burden of disease attributed to high level serum low-density lipoprotein cholesterol in China in 2017]

Objective: To quantitatively analyze the death and disability-adjusted life years (DALY) attributed to high level serum LDL-C in Chinese population in 2017. Methods: Data were obtained from the '2017 Global Burden of Disease Study (GBD2017)'. Population attributable fraction (PAF), number and rate of deaths and DALY attributable to high LDL-C were used to describe the burden of disease by gender, age groups, diseases and provinces in China. Both rates on mortality and DALY were standardized by GBD world population. Results: In 2017, 862 759 deaths were caused by high level serum LDL-C in China, that accounting for 8.25% of the total deaths. Of the attributable deaths, 705 355 (81.76%) persons died from ischemic heart disease (IHD), while the remaining 18.24% from ischemic stroke (IS). High LDL-C accounted for 40.30% of the total deaths from ischemic heart disease and 18.49% from ischemic stroke. The highest PAF of death (13.70%) appeared in Jilin province and the lowest in Zhejiang province (4.65%). PAF of death was seen higher in females than in males, while both age-standardized rates of mortality and DALY appeared higher in males than in females. High LDL-C attributed mortality rate appeared as 61.08/100 000 after standardization in Chinese population. High LDL-C attributed DALYs were 18.16 million person years, among which 76.76% were caused by IHD (13.94 million person years), with DALY rate as 1285.83/100 000. Among provinces, Heilongjiang showed the highest standardized DALY rate, and Zhejiang the lowest. The PAF, number of deaths, rates on mortality and DALY caused by high LDL-C were high among residents above 70 years old, with the DALY number as 8.56 million person years, highest seen in the age group from 50 to 69 years old. Conclusion: The burden of disease attributed to high level LDL-C was quite high and with gender, age group and interprovincial differences, in China in 2017.

[Relationship of plasma vitamin A levels between neonates and pregnant women in third trimester]

OBJECTIVE

To study the correlation of plasma vitamin A (VitA) levels between neonates and pregnant women in third trimester.

METHODS

A total of 688 pregnant women were recruited in Yuanshi and Laoting counties of Hebei Province, from May to June 2009. Venous blood samples of women before delivery and cord blood samples of newborns were collected and measured for retinol (retinol concentration was used to reflect VitA level) using high performance liquid chromatography assay. According to venous blood plasma retinol concentration, maternal VitA nutritional status was divided into deficiency (<0.70 μmol/L), marginal deficiency (0.70-<1.05 μmol/L), and sufficiency (≥1.05 μmol/L). According to cord blood plasma retinol concentration, neonatal VitA nutritional status was divided into deficiency (<0.35 μmol/L), marginal deficiency (0.35-<0.70 μmol/L), and sufficiency (≥0.70 μmol/L); neonatal VitA relative deficiency was further defined as cord blood plasma retinol concentration lower than the 10th percentile. VitA placental transport ratio was defined as retinol concentration in the neonates divided by that in pregnant women. Multivariable fractional polynomials (MFP) model and Pearson correlation were used to study the dose-response relationship between maternal and neonatal plasma VitA levels, Logistic regression model to estimate the effect of maternal VitA nutritional status on neonatal VitA deficiency, and MFP model and Spearman correlation to describe the relationship between maternal VitA level and VitA placental transport ratio.

RESULTS

The average retinol concentration of the pregnant women was (1.15±0.30) μmol/L, and the prevalence of VitA deficiency and marginal deficiency were 4.5% and 37.8%, respectively. Average retinol concentration of the neonates was (0.78±0.13) μmol/L, and no neonates were VitA deficiency, 28.2% of the neonates were marginal deficiency. After multivariable adjustment, the VitA level of the neonates was positively and linearly related to maternal VitA level (p^m=1, P<0.05), with the corresponding Pearson correlation coefficient of 0.13 (P<0.01). As compared with the women with sufficient VitA, those with VitA deficiency (crude OR=2.20, 95%CI:1.04-4.66) and marginal deficiency (crude OR=1.43, 95%CI:1.01-2.02) had higher risks to deliver neonates with VitA marginal deficiency; while the risks turned to be non-significant after multivariable adjustment. The pregnant women with VitA deficiency had higher risk to deliver neonates with relative VitA deficiency before and after multivariable adjustment (crude OR=3.02, 95%CI:1.21-7.50; adjusted OR=2.76, 95%CI:1.05-7.22). The maternal VitA level was negatively and non-linearly correlated with placental transport ratio (p^m= -0.5, P<0.05), with corresponding adjusted Spearman correlation coefficient of -0.82 (P<0.001).

CONCLUSION

There was a positive linear dose-response relationship between VitA levels of newborns and pregnant women in third trimester, indicating that neonatal VitA storing levels at birth was affected by maternal VitA nutritional status.

Integration of field observation and air quality modeling to characterize Beijing aerosol in different seasons

Fine particulate matter (PM_2.5) pollution in Beijing was investigated based on field observation and air quality modeling. Measurement results showed that when using elemental carbon (EC) as the reference component, concurrent increases were observed in the relative abundances of sulfate, nitrate, organic carbon (OC) and water-soluble organic carbon (WSOC) when RH exceeded ∼65% during winter. The observed increases could not be explained by variations of primary biomass burning emissions, instead they likely pointed to heterogeneous chemistry and presumably indicated that formation of secondary inorganic and organic aerosols might be related during winter haze events in Beijing. Large gaps were found in winter when comparing the observational and modeling results. In summer, RH exhibited little influence on the observed sulfate/EC, OC/EC or WSOC/EC, and the observed and modeled results were in general comparable for the concentrations of sulfate, EC and OC. This study suggests that distinct yet poorly-understood atmospheric chemistry may be at play in China's winter haze events, and it could be a substantial challenge to properly incorporate the related mechanisms into air quality models.

Comparison of Aspiration versus Stent Retriever Thrombectomy as the Preferred Strategy for Patients with Acute Terminal Internal Carotid Artery Occlusion: A Propensity Score Matching Analysis

BACKGROUND AND PURPOSE

There is no consensus on endovascular treatment for terminal ICA. The purpose of this study was to evaluate the comparative safety and efficacy of preferred aspiration thrombectomy and stent retriever thrombectomy for revascularization in patients with isolated terminal ICA occlusion.

MATERIALS AND METHODS

We conducted a retrospective analysis of patients with terminal ICA occlusion treated with aspiration thrombectomy or stent retriever thrombectomy in our center, from September 2013 to November 2018. To minimize the case bias, propensity score matching was performed. The primary outcomes were successful reperfusion defined by expanded TICI grades 2b-3 at the end of all endovascular procedures and puncture-to-reperfusion time.

RESULTS

A total of 109 consecutive patients with terminal ICA occlusion were divided into the aspiration thrombectomy group (40 patients) and the stent retriever thrombectomy group (69 patients), and 30 patients were included in each group after propensity score matching. The proportion of complete reperfusion was significantly higher in the aspiration thrombectomy group (OR 4.75 [95% CI, 1.10-1.38]; P = .002). The median puncture-to-reperfusion time in the aspiration thrombectomy group was shorter than that in the stent retriever thrombectomy group (38  versus 69 minutes; P = .001). Fewer intracerebral hemorrhage events were recorded in the aspiration thrombectomy group (OR 0.29 [95% CI, 0.09-0.90]; P = .028). No significant differences were observed for good outcomes (OR 1.92 [95% CI, 0.86-4.25]) and mortality (OR 0.84 [95% CI, 0.29-2.44]) at 90 days.

CONCLUSIONS

For the treatment of terminal ICA occlusion, aspiration thrombectomy was technically superior to stent retriever thrombectomy in the absence of a balloon guide catheter in achieving successful reperfusion with shorter puncture-to-reperfusion time and procedure-related adverse events.

[Analysis of the characteristics of second primary malignancy affecting the survival of lymphoma patients]

Objective: To analyze the characteristics of the second primary tumor affecting the survival of patients with lymphoma, and to explore the risk factors of death from the second primary tumor. Methods: The medical records and related death information of 1 173 lymphoma patients who had already died with known causes were collected. The basic causes of death and the characteristics of patients who died of the second primary tumor were analyzed. Cox regression model was used to analyze the risk factors of lymphoma patients who died of the second primary tumor. Results: Among the 1 173 patients who had died, 94 (8.0%) died of the second primary tumor, 935 (79.7%) died of the primary lymphoma and 144 (12.3%) died of other diseases. The second primary tumor accounted for 17.5% (38/217) of all causes of death in patients with the survival period of more than 5 years, and the second primary tumor accounted for 28.3% (17/60) of all causes of death in patients with the survival period of more than 10 years. Among 94 cases who died of second primary tumors, 31 died of lung cancer, 15 died of gastric cancer, 13 died of liver cancer, 9 died of pancreatic cancer, 6 died of colorectal cancer, 6 died of second primary lymphoma and 14 died of other types of tumors. Univariate Cox regression analysis showed that age, first-line treatment effect, and chest or mediastinal radiotherapy were associated with the death from second primary tumors for lymphoma patients (all P<0.05). Multivariate Cox regression analysis showed that the effect of first-line treatment (P=0.030) and the chest or mediastinal radiotherapy (P=0.039) were independent factors for the death of lymphoma patients from the second primary tumor. Conclusions: The second primary tumor is an important factor affecting the survival of lymphoma patients, and the risk of death from second primary tumors increases significantly over time. The effect of first-line treatment and radiotherapy in the chest or mediastinum are independent factors for the death of lymphoma patients from the second primary tumor.

[Keratinized tissue augmentation techniques around dental implants]

Research have indicated that inadequate keratinized tissue has a negative effect on patient oral hygiene, resulting in peri-implant inflammation. It has been recommended that an apically repositioned flap alone or in combination with autogenous soft tissue grafts can increase the width of keratinized mucosa around dental implants, which promotes long term peri-implant health. This review summarized research progress on augmentation techniques of keratinized tissue arround implants in recent years, so as to provide reference for clinical practice and research design in the future.

[Institutional delivery rate in minority inhabited areas of China from 1996 to 2017]

Objective: To describe the secular trends of institutional delivery (ID) rate in minority inhabited areas of China from 1996 to 2017 according to national health policies. Methods: The number of live births and IDs for each county/district in 31 provinces of China were derived from the datasets collected by the Office for National Maternal & Child Health Statistics of China. Information on health policies and ethnical areas was derived from official governmental websites. The calendar years were divided into three periods: pre-program period (1996 to 1999), program implementation period (2000 to 2008) and post-program period (2009 to 2017). Minority autonomous regions, autonomous prefectures, and autonomous counties were defined as minority inhabited areas. The ethnic that a county was classified into was determined by a principle of close proximity to the name of the county or its next higher level administrative division. A total of 700 counties in minority inhabited areas were included in the analysis. Results: A total of 45 684 265 live births including 35 098 855 delivered in institutions were analyzed. The ID rate in minority inhabited areas was 37.5% (696 221/1 856 164) in 1996 and 99.2% (2 371 209/2 390 131) in 2017, with an annual growth rate of 4.7%. During the 22-years period, the ID rates in the eastern, central and western regions increased simultaneously, with the annual growth rates of 3.1%, 4.2% and 4.9% respectively. The difference between the eastern and western regions decreased steadily from 16% in 1996 to <1% in 2017 and the difference between the urban and rural areas decreased from 32.1% in 1996 to <1% in 2017. Besides, the ID rates in Tibetan and Yi inhabited areas with lower baseline levels increased 73 and 63 percentage points respectively. The number of counties with the ID rate of <96% were substantially reduced from 589 in 1996 to 72 in 2017; the 71 counties were all located in national deep poverty-stricken areas named Three Districts and Three States, predominantly involving Tibetan (58), Yi (6), Uygur (2) and Lisu (2) ethnics. Conclusion: During the past 22 years, the ID rate in minority inhabited areas in China has dramatically increased, achieving the goal of 2 020 ahead of schedule, but there remains a few western counties where ID rates are still<96%, indicating that minority inhabited western areas should be focused in developing national policies concerning institutional delivery.

Ultrasonic modulation of phase separation and corrosion resistance for ternary Cu-Sn-Bi immiscible alloy

The effect of power ultrasound on the liquid phase separation of ternary Cu-32%Sn-20%Bi immiscible alloy is experimentally investigated, which shows that as compared with the layered structure formed under static condition, the macrosegregation resulted from liquid phase separation is remarkably reduced with the increase of ultrasonic amplitude. A homogenous microstructure characterized by refined (Bi) particles dispersing uniformly on the (Cu₃Sn) matrix is obtained when the ultrasonic amplitude reaches the highest value of 24 μm. This is mainly ascribed to the ultrasonically induced cavitation and acoustic streaming, which promotes the nucleation, the fragmentation, and the dispersion of (Bi) droplets. The finally solidified immiscible alloy exhibits obvious improvements in electrochemical corrosion resistance, microhardness and wear-resisting if compared with those in static solidification. These results prove that applying power ultrasound is an effective way to modulate the liquid phase separation and enhance the applied performance for immiscible alloys.

[Mortality attributable to inadequate intake of fruits among population aged 25 and above in China, 2013]

Objective: To assess the mortality attributable to low fruit intake among people over 25 years old in China, 2013, and its effect on life expectancy. Methods: Based on data collected from China Chronic Disease and Risk Factor Surveillance in 2013, the average fruit intake in different genders and areas were calculated. Potential impact fraction (PIF) was used to examine the impact on deaths, mortality and life expectancy. Results: The average daily fruit intake was (113.3±168.9) g among people over 25 years old, with (103.6±160.1) g for men and (122.7±176.6) g for women, in China in 2013. Fruit intake for urban residents was significantly higher than that in rural residents and higher in eastern regions than that in central or western regions. Scores that attributable to low fruit intake accounted for 15.21% of the total deaths and the population attributable fraction of inadequate intake of fruits to associated diseases was 35.00%. PIF for all the deaths in rural residents (16.50%) appeared higher than that of the urban residents (13.88%), and higher in the residents living in the eastern region (15.48%) than that in the central (16.27%) or western (13.75%) regions. Number of deaths that attributable to low fruit intake was 1.348 4 million. Deaths caused by related diseases appeared as: ischemic heart disease (472.5 thousands), hemorrhagic stroke (338.8 thousands), ischemic stroke (259.0 thousands), lung cancer (208.4 thousands), esophageal cancer (60.7 thousands), laryngeal cancer (5.4 thousands) and oral cancer (3.6 thousands). Numbers of all deaths and related diseases for urban residents were lower than that of the rural residents, with central regions (452.7 thousands) higher than that in the eastern (531.1 thousands) or western (364.6 thousands) regions. The average life expectancy loss caused by low fruit intake was 1.73 years, 1.80 years for men and 1.58 years for women, in this country. Loss of life expectancy in the rural residents was higher than that of the urban residents, and higher in central regions than that in the eastern or western regions. Conclusions: The intake of fruit was far lower than the recommended standard set for the Chinese people. Population attributable fraction was related to the associated diseases caused by inadequate intake of fruits which also made serious impact on life expectancy.

[Effects of insufficient physical activity on motality and life expectancy in adult aged 25 and above among Chinese population]

Objective: To analyze the attribution of mortality and impact on life expectancy caused by insufficient physical activity in different gender and areas in adults aged ≥25 years among Chinese people. Methods: Data from the programs related to Chinese death surveillence, risk factors of chronic survey, health outcomes of physical activity as well as relative risk (RR) on Global Burden of Disease (GBD) study were used. Population attributable fraction (PAF) of different health outcomes attributable to deaths that caused physical activity and the influence of life expectancy in adults aged ≥25 years in Chinese people were calculated. Results: The overall PAF for all cause of death due to physical activity in adults aged ≥25 years was 4.24%, with 4.86% in females and 3.82% in males. The health outcomes of inadequate physical activity would include breast cancer, colorectal cancer, ischemic heart disease, ischemic stroke and diabetes with relative PAFs as 9.04%, 13.96%, 14.96%, 17.80% and 16.92%, respectively. The attribution of death on Physical activity was 388 954. The most attributed death was ischemic heart disease, followed by ischemic stroke. With the elimination of physical inactivity, the total life expectancy was expected to lose by 0.43 years, with 0.47 years in women, and 0.39 years in men. Conclusion: The increase of physical activity may benefit on health condition so to reduce the burden of chronic diseases and increase the life expectancy.

[Death and impact of life expectancy attributable to smoking in China, 2013]

Objective: To analyze the death attributable to smoking and impact of life expectancy in China in 2013. Methods: According to the characteristics of different diseases, we calculated the population attributable fractions of different diseases, death and impact of life expectancy which caused by smoking, using direct method (current smoking rate as exposure levels) and indirect method (smoking impact ratio as exposure levels), based on data from both programs of death surveillance and Chinese chronic disease risk factor surveillance of 2013. Results: In 2013, smoking caused around 1.59 million deaths which accounted for 17.38% of all deaths in China. Constituent ratio of death caused by smoking in males (23.66%) was much higher than that in females (8.30%). However, in urban areas (17.24%), it was slightly lower than that in rural areas (17.51%). Constituent ratio of death caused by smoking in the eastern regions appeared the lowest (16.81%), with western regions the highest (17.91%). In 2013, lung cancer, COPD and ischemia heart disease were the top three diseases causing deaths that related to smoking, but the top three population attributable fractions were lung cancer, COPD and nasopharyngeal carcinoma in China. In 2013, smoking caused a reduction of 2.04 years of life expectancy loss in China, with males in the western regions the highest (3.05 years). Conclusion: Smoking is still an important public health problem in China. Tobacco-control-targeted programs in the heavily involved areas could reduce the number of deaths from related diseases that caused by smoking.

Uncertainties in thermal-optical measurements of black carbon: Insights from source and ambient samples

Black carbon (BC) is important due to its complex influences on the environment and on climate in particular. However, reported BC data are largely dependent on measurement techniques due to the multitude of measurement principles. Here we focused on thermal-optical method which has been widely used to determine BC mass (as elemental carbon, EC). Several factors influencing EC measurement were investigated. Results from source samples representing vehicle engine emissions pointed to a continuum of EC components in thermal stability and provided direct observational evidence for the premature evolution of EC in inert atmosphere. It was also found that EC masses may be substantially underestimated for the vehicle exhaust samples if the adopted protocol requires an oxidizing atmosphere to define the split point between organic carbon (OC) and EC. Results from a field campaign conducted during winter in Beijing showed that the optical attenuation (ATN; i.e., the filter transmittance signal, I) was largely saturated for the samples with relatively high loadings, indicating their EC results were unreliable. Improved measurement of EC was achieved by extracting these heavily loaded filters using methanol, given that ATN was considerably reduced by the extraction and, moreover, saturation of ATN (or I) became not evident for the extracted samples. The methanol extraction also significantly reduced the transformation of OC to char-OC, by removing the majority (i.e., ~85%) of the deposited organic aerosols. Higher EC were measured for the extracted samples compared with the untreated ones, indicating that EC tends to be underestimated due to the charring-induced uncertainties. In addition, the methanol extraction largely reduced the inter-protocol discrepancy in the EC measurement results. Similar effects of methanol extraction have been observed during summer in Beijing, despite the seasonal variations of aerosol sources and compositions. This study indicates the potential benefits of methanol extraction for EC measurement.

[Peripheral small airway dysfunction differences between idiopathic pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension]

Objective: To investigate the peripheral small airway dysfunction differences between idiopathic pulmonary arterial hypertension (IPAH) and chronic thromboembolic pulmonary hypertension (CTEPH). Methods: Impulse oscillmetory system testing (IOS) and pulmonary function testing (PFT) were performed in IPAH and CTEPH patients and 30 healthy control group. We also carried out a subgroup analysis depending on their medical history of airway diseases. Results: We included 42 IPAH and 47 CTEPH patients (with or without airways disease: 8 vs. 34 and 17 vs. 34, respectively). Compared with CTEPH patients, IPAH patients were younger but had more serious pulmonary vessel resistance and mean pulmonary arterial resistance. Compared with IPAH patients, CTEPH patients had significant impaired peripheral small airway dysfunction with decreased of MEF(50) (% pred), MMEF(75/25) evaluated by PFT and R5-R20, Δ R5-R20 and AX measured by IOS [10.6(2.0, 33.0) vs. 2.5(-5.0, 16.5); 22.1(14.0, 32.6) vs. 15.5 (7.0, 23.2); 7.64(4, 18.6) vs. 6(3, 11) respectively, all P<0.05]. Subgroup analysis revealed there were no significant peripheral small dysfunction differences in IPAH patients with or without airway diseases. CTEPH patients had a higher proportion of airway diseases and more serious peripheral dysfunction than IPAH patients with airway diseases. Compared with control healthy group, peripheral airway dysfunction was more obvious even in IPAH and CTEPH patients without airway diseases. Conclusion: Compared with IPAH, CTEPH patients were older, but had better hemodynamics and a higher proportion of airway diseases. The peripheral airway dysfunction were more serious in CTEPH patients without airway diseases than IPAH patients without airway diseases and healthy controls group.

The characteristics of carbonaceous aerosol in Beijing during a season of transition

Carbonaceous aerosol was measured during fall of 2010 in Beijing. Daily variation of organic carbon (OC) was found to coincide with that of relative humidity (RH), and the OC to elemental carbon (EC) ratios were more than doubled during the more humid periods (RH above 0.75) compared to other conditions. This large increase in OC/EC could not be explained by the variations of primary biomass burning emissions but was accompanied by a five-fold increase in the sulfate to EC ratio. It was then inferred that secondary organic aerosol (SOA) formation was enhanced under the more humid conditions, presumably through aqueous-phase processes. This enhanced SOA formation might be partially associated with particles externally mixed with black carbon, as indicated by the RH-dependent relationships between aerosol optical attenuation and EC loading. In addition, organic aerosols exhibited different properties between the more humid and the other periods, such that they were less volatile and charred more significantly during thermal-optical analysis in the former case. These differences coincided with the evidence of enhanced SOA formation under the more humid conditions. This study highlights the necessity of incorporating aqueous-phase chemistry into air quality models for SOA.

[Estimation of the impact of risk factors control on non-communicable diseases mortality, life expectancy and the labor force lost in China in 2030]

Objective: To estimate the impact of risk factors control on non-communicable diseases (NCDs) mortality, life expectancy and the numbers of labor force lost in China in 2030. Methods: We used the results of China from Global Burden of Disease Study 2013, according to the correlation between death of NCDs and exposure of risk factors and the comparative risk assessment theory, to calculate population attributable fraction (PAF) and disaggregate deaths of NCDs into parts attributable and un-attributable. We used proportional change model to project risk factors exposure and un-attributable deaths of NCDs in 2030, then to get deaths of NCDs in 2030. Simulated scenarios according to the goals of global main NCDs risk factors control proposed by WHO were constructed to calculate the impact of risk factors control on NCDs death, life expectancy and the numbers of labor force lost. Results: If the risk factors exposure changed according to the trend of 1990 to 2013, compared to the numbers (8.499 million) and mortality rate (613.5/100 000) of NCDs in 2013, the death number (12.161 million) and mortality rate (859.2/100 000) would increase by 43.1% and 40.0% respectively in 2030, among which, ischemic stroke (increasing by 103.3% for death number and 98.8% for mortality rate) and ischemic heart disease (increasing by 85.0% for death number and 81.0% for mortality rate) would increase most quickly. If the risk factors get the goals in 2030, the NCDs deaths would reduce 2 631 thousands. If only one risk factor gets the goal, blood pressure (1 484 thousands NCDs deaths reduction), smoking (717 thousands reduction) and BMI (274 thousands reduction) would be the most important factors affecting NCDs death. Blood pressure control would have greater impact on ischemic heart disease (662 thousands reduction) and hemorrhagic stroke (449 thousands reduction). Smoking control would have the greatest effect on lung cancer (251 thousands reduction) and chronic obstructive pulmonary disease (201 thousands reduction). BMI control would have the greatest impact on ischemic heart disease (86 thousands reduction) and hypertensive heart disease (45 thousands reduction). If the risk factors exposure changed according to the trend of 1990 to 2013, in 2030, the life expectancy of Chinese population would reach to 79.0 years old, compared to 2013, increasing by 3.3 years old, the labor force at the age of 15-64 years old would loss 1.932 million. If the risk factors get the goals in 2030, life expectancy would increase to 81.7 years old and the number of labor force lost would decrease to 1.467 million. Blood pressure, smoking and BMI control would have much greater impact on life expectancy (4.9, 4.0 and 3.8 years old respectively) and labor force lost (630 thousands, 496 thousands and 440 thousands respectively). Conclusion: Risk factors control would play an important role in reducing NCD death, improving life expectancy of residents and reducing loss of labor force. Among them, the control of blood pressure raising, smoking and BMI raising would have a greater contribution to the improvement of population health status.