Displaying publications 1 - 20 of 42 in total

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  1. Ethnic differences in parents' coresidence with adult children in Peninsular Malaysia
    Chan A, Davanzo J
    J Cross Cult Gerontol, 1996 Mar;11(1):29-59.
    PMID: 24389944 DOI: 10.1007/BF00116264
    In this paper we use data from the Second Malaysian Family Life Survey (MFLS-2) to examine the extent to which ethnic differences in the living arrangements of the older population in Peninsular Malaysia can be explained by ethnic differences in demographic and socioeconomic characteristics. We also investigate whether the three main ethnic groups of Malaysia differ in the extent to which their living arrangements are influenced by these factors. For the married, the higher incidence of remarriage and lower housing costs for Malays each contribute importantly to their lower coresidence rates. The relatively poorer health of Indians and better health of Malays also contribute to the ethnic differences in coresidence rates for the married, as does the higher incidence of daughter-only families among Malays. The explanatory variables considered here explain less of the ethnic differences in coresidence rates for the unmarried.
    Study name: Malaysian Family Life Survey (MFLS-2)
  2. Living arrangements of older Malaysians: who coresides with their adult children?
    DaVanzo J, Chan A
    Demography, 1994 Feb;31(1):95-113.
    PMID: 8005345
    More than two-thirds of Malaysians age 60 or older coreside with an adult child. Data from the Senior sample of the Second Malaysian Family Life Survey (MFLS-2) are used to investigate which "seniors" (persons age 60 or older) live in this way. The analysis generally supports the notion that coresidence is influenced by the benefits, costs, opportunities, and preferences for coresidence versus separate living arrangements. For example, married seniors are more likely to coreside with adult children when housing costs are greater in their area or when the husband or wife is in poor health. This finding suggests that married parents and children live together to economize on living costs or to receive help with household services. Unmarried seniors who are better off economically are less likely to live with adult children, presumably because they use their higher incomes to "purchase privacy."
  3. Ethnic variation in deep lateral orbital anatomy and its implications on decompression surgery
    Kumaran A, Chan A, Yong K, Shen S
    Orbit, 2019 Apr;38(2):95-102.
    PMID: 29482415 DOI: 10.1080/01676830.2018.1441316
    AIM: To describe differences in the deep lateral orbital wall (specifically, trigone) between Chinese, Malay, Indian and Caucasian subjects Methods: Single-centre retrospective Computed Tomogram (CT)-based study; 20 subjects of each ethnicity were used from existing databases, matched for gender, average age and laterality. Subjects below 16 years of age were excluded. DICOM image viewing software CARESTREAM Vue PACS (Carestream Health Inc., USA) and OsiriX version 7.5 (Pixmeo., Switzerland) were used to measure deep lateral wall length, thickness and volume, as well as orbital depth and statistical analyses performed using Statistical Package for Social Sciences version 21 (IBM, USA).

    RESULTS: In each group, there were 12 males (60%) and average age was not significantly different (p = 0.682-0.987). Using Chinese subjects as a reference, in Chinese, Malay, Indian and Caucasian subjects, mean trigone thickness was 13.68, 14.02, 11.60 (p 

  4. Fulltext Outcome of 85 lupus nephritis patients treated with intravenous cyclophosphamide: a single centre 10 year experience
    Chan AYK, Hooi LS
    Med J Malaysia, 2000 Mar;55(1):14-20.
    PMID: 11072485
    Retrospective analysis was done on 85 patients (76 female, 9 male) with lupus nephritis who started intravenous cyclophosphamide between 1/1/1989 and 31/12/1998. The initial renal biopsy (World Health Organisation) classification was III (4.7%), IV (89.4%) and V (5.9%). Average serum creatinine at time of biopsy was 0.12 +/- 0.12 mmol/l. Median duration of nephritis before biopsy was 2 months (range 0-133). Median duration of follow-up from time of biopsy to outcome (death or end-stage renal failure) was 3.3 years (range 0.3-11.8). Nineteen patients died. The calculated proportion alive at 5 years was 75% and at 10 years 64%. The calculated proportion alive with renal function was 74% and 54% at 5 and 10 years respectively. Fifty-two patients completed cyclophosphamide therapy at the end of the study. There were ten episodes of herpes zoster, the most common infection seen. No malignancy was reported.
  5. Response to Wang et al. Re: How to choose and compare between radiofrequency ablation and transarterial chemoembolization for recurrent hepatocellular carcinoma?
    Koh PS, Chan AC
    HPB (Oxford), 2017 12;19(12):1133.
    PMID: 28943394 DOI: 10.1016/j.hpb.2017.08.007
  6. Fulltext Emphysematous pyelonephritis in a diabetic patient with pelvic-ureteric stone
    Chan AC, Rohan MJ, Hamid A, Azam A
    Med J Malaysia, 2007 Jun;62(2):166-7.
    PMID: 18705456 MyJurnal
    Emphysematous pyelonephritis is a rare but life threatening infection of kidney that is characterized by gas formation within or around the kidney. We describe a case of emphysematous pyelonephritis as a consequence of inadequately treated pelvic-ureteric stone in a diabetic man and complement this with a brief review of the literature pertaining in particular to the management of this condition.
  7. Fulltext Synthesis of a new biocomposite for fertiliser coating: assessment of biodegradability and thermal stability
    Ketabchi MR, Masoudi Soltani S, Chan A
    Environ Sci Pollut Res Int, 2023 Sep;30(41):93722-93730.
    PMID: 37515618 DOI: 10.1007/s11356-023-28892-0
    The bio- and thermal degradation as well as the water absorption properties of a novel biocomposite comprising cellulose nanoparticles, natural rubber and polylactic acid have been investigated. The biodegradation process was studied through an assembled condition based on the soil collected from the central Malaysian palm oil forests located in the University of Nottingham Malaysia. The effects of the presence of the cellulose nanoparticles and natural rubber on the biodegradation of polylactic acid were investigated. The biodegradation process was studied via thermal gravimetric analysis and scanning electron microscopy. It was understood that the reinforcement of polylactic acid with cellulose nanoparticles and natural rubber increases the thermal stability by ~ 20 °C. Limited amorphous regions on the surface of the cellulose nanoparticles accelerated the biodegradation and water absorption processes. Based on the obtained results, it is predicted that complete biodegradation of the synthesised biocomposites can take place in 3062 h, highlighting promising agricultural applications for this biocomposite.
  8. Self reported pain severity among multiethnic older Singaporeans: does adjusting for reporting heterogeneity matter?
    Chan A, Malhotra C, Do YK, Malhotra R, Ostbye T
    Eur J Pain, 2011 Nov;15(10):1094-9.
    PMID: 21646030 DOI: 10.1016/j.ejpain.2011.05.006
    The objective of this paper is to test and correct for systematic differences in reporting of pain severity among older adults by age, gender, ethnic group and socio-economic status using anchoring vignettes. Data from a national survey of community-dwelling older Singaporeans (aged 60 years and over) conducted in 2009 was used. Respondents were asked to rate the severity of their own pain as well as that of others described in the vignettes on a five-point scale ranging from none to extreme. An ordered probit model was used to estimate the coefficients of the independent variables (age, gender, ethnic group, education, housing type) on self-reported pain. Reporting heterogeneity in pain severity was then corrected using a Hierarchical Ordered Probit model. The results showed that before correcting for reporting heterogeneity, women, those older, and those of Malay ethnicity reported greater severity of pain, while there was no association of reported pain severity with housing type and education. However, after correcting for reporting heterogeneity, while women and those older were found to have an even greater severity of pain than what they had reported, Malays were found to have a lower severity of pain than what they had reported. We conclude that there are systematic differences in reporting pain severity by age, gender and ethnic group. We propose that pain management may be improved if medical professionals take into account reporting heterogeneity for pain severity among various population sub-groups in Singapore.
  9. Effects of atmospheric deposition nitrogen flux and its composition on soil solution chemistry from a red soil farmland, southeast China
    Cui J, Zhou J, Peng Y, Chan A, Mao J
    Environ Sci Process Impacts, 2015 Dec;17(12):2082-91.
    PMID: 26515781 DOI: 10.1039/c5em00383k
    A detailed study on the solution chemistry of red soil in South China is presented. Data are collected from two simulated column-leaching experiments with an improved setup to evaluate the effects of atmospheric N deposition (ADN) composition and ADN flux on agricultural soil acidification using a (15)N tracer technique and an in situ soil solution sampler. The results show that solution pH values decline regardless of the increase of the NH4(+)/NO3(-) ratio in the ADN composition or ADN flux, while exchangeable Al(3+), Ca(2+), Mg(2+), and K(+) concentrations increase at different soil depths (20, 40, and 60 cm). Compared with the control, ADN (60 kg per ha per year N, NH4(+)/NO3(-) ratio of 2 : 1) decreases solution pH values, increases solution concentrations of NO3(-)-N, Al(3+), Ca(2+) and Mg(2+) at the middle and lower soil depths, and promotes their removal. NH4(+)-N was not detected in red soil solutions of all the three soil layers, which might be attributed to effects of nitrification, absorption and fixation in farmland red soil. Some of the NO3(-)-N concentrations at 40-60 cm soil depth exceed the safe drinking level of 10 mg L(-1), especially when the ADN flux is beyond 60 kg ha(-1) N. These features are critical for understanding the ADN agro-ecological effects, and for future assessment of ecological critical loads of ADN in red soil farmlands.
  10. Follow-up care practices and barriers to breast cancer survivorship: perspectives from Asian oncology practitioners
    Ng T, Toh MR, Cheung YT, Chan A
    Support Care Cancer, 2015 Nov;23(11):3193-200.
    PMID: 25791392 DOI: 10.1007/s00520-015-2700-2
    PURPOSE: The aim of this study is to evaluate the perspectives of Asian oncology practitioners on the physical and psychosocial issues experienced by breast cancer survivors (BCS), current survivorship care practices, and the barriers to follow-up care.

    METHODS: This was a cross-sectional survey study. Oncology practitioners were recruited from a major cancer center in Singapore and through two regional cancer meetings that took place in Singapore and Malaysia in 2013.

    RESULTS: A total of 126 oncology practitioners from various Southeast Asian countries, mostly nurses (58.7 %) and physicians (37.3 %), were recruited. The majority of the respondents agreed that fatigue (78.4 %) and anxiety (69.1 %) were the most common physical and psychosocial problems experienced by BCS. Monitoring for physical and treatment-related adverse effects (80.7 %) and reviewing patients' noncancer medical history (65.3 %) were the most practiced aspects of follow-up care. Compared with the other practitioners, the physicians were more likely to communicate with other healthcare professionals (adjusted OR = 4.24, 95 % CI 1.54 to 11.72; p = 0.005). Most of the respondents also agreed that patient-specific barriers were the main impediments to follow-up care.

    CONCLUSION: This study provides insights into the various aspects of breast cancer survivorship care from the perspectives of oncology practitioners and shows that survivorship care is relatively inadequate in Asia. There is a need for new survivorship care models to meet the needs of Asian BCS and to complement the unique healthcare systems of Asia.

  11. Fulltext Outcome of 235 renal transplant recipients followed up at ministry of health hospitals in the State of Johor
    Chan AYK, Hooi LS, Liu WJ
    Med J Malaysia, 2001 Mar;56(1):82-7.
    PMID: 11503302
    Retrospective analysis was done on 235 recipients, 133 males and 102 females, who were transplanted between 25th September 1979 and 25th June 1999. 85.1% were Chinese, 7.7% were Indians and 7.2% Malays. 23% (54) were living related renal transplants (LRRT) all except 5 done at Hospital Kuala Lumpur. 60% (141) were living unrelated donor renal transplants (LURT) done in India. 17% (40) were cadaveric transplants (CADT) (all done in China except 2 at Hospital Kuala Lumpur and one in London). 97% (228) were first transplants. Primary renal disease was unknown in 69.4%, 17% (40) glomerulonephritis, 5.5% diabetic nephropathy and 8.1% 19 others. All were on prednisolone, 93.2% were on azathioprine and 96.6% were on cyclosporin A. The acute rejection rate was 23.4% (55 episodes). Patient survival was 88% at five years and patients alive with functioning graft was 84% at 5 years. LRRT had significantly better survival compared to LURT. 34 grafts were lost to chronic allograft nephropathy. 46 recipients died (33 died with functioning graft).
  12. Sources and trends of oxidized and reduced nitrogen wet deposition in a typical medium-sized city of eastern China during 2010-2016
    Cui J, Cui J, Peng Y, Yao D, Chan A, Chen Z, et al.
    Sci Total Environ, 2020 Jun 27;744:140558.
    PMID: 32711301 DOI: 10.1016/j.scitotenv.2020.140558
    Fluxes and composition dynamics of atmospheric nitrogen deposition play key roles in better balancing economic development and ecological environment. However, there are some knowledge gaps and difficulties in urban ecosystems, especially for small and medium-sized cities. In this study, both flux and composition (ratio of NH4+-N to NO3--N, RN) of wet-deposited dissolved inorganic nitrogen (DIN, sum of NO3--N and NH4+-N) were estimated and sources were identified at a long-term urban observation station in Tongling, a typical medium-sized city in eastern China during 2010-2016, respectively. Results showed that wet-deposited DIN fluxes were 33.20 and 28.15 kgN ha-1 yr-1 in Tongling city during 2010-2011 and 2015-2016, respectively. Compared to these two periods, both DIN and NO3--N fluxes decreased by 15.2% and 31.8% for a series of NOx abatement measures applied effectively, respectively. At the same time, the NH4+-N flux remained stable and ranged from 19.53 to 20.62 kgN ha-1 yr-1, and the RN increased from 1.7 to 2.2. Seasonally, winds from the southwest and west-southwest with higher frequencies and speeds in spring and summer brought more NH4+-N and DIN wet deposition from an ammonia plant, which could threaten the safety of regional hydrosphere ecosystems. On the whole, the wet-deposited NH4+-N was threatening regional ecosystems of both the hydrosphere and forest. The wet-deposited DIN including NH4+-N in Tongling city stemmed mainly from a combined source of coal combustion and dust from Cu extraction and smelting, ammonia production, and roads. Therefore, production lines should be updated for Cu extraction and smelting industries, thermal power generations and the ammonia plant, old vehicles should be eliminated, and the use of new energy vehicles should be promoted for regional sustainable development and human health in the medium-sized city.
  13. Cost-effectiveness analysis of olanzapine-containing antiemetic therapy for managing highly emetogenic chemotherapy in Southeast Asia: a multinational study
    Chanthawong S, Lim YH, Subongkot S, Chan A, Andalusia R, Ahmad Bustamam RS, et al.
    Support Care Cancer, 2019 Mar;27(3):1109-1119.
    PMID: 30112718 DOI: 10.1007/s00520-018-4400-1
    PURPOSE: Recent studies suggested that olanzapine, together with dexamethasone and serotonin-3 receptor antagonist (5HT3RA), is effective in preventing chemotherapy-induced nausea and vomiting (CINV) following highly emetogenic chemotherapy (HEC). This regimen is particularly useful in Southeast Asia (SEA) countries where resources are limited. We aimed to evaluate the cost-effectiveness of incorporating olanzapine into standard antiemetic regimens for the prevention of CINV in patients receiving HEC among SEA countries.

    METHODS: Using a decision tree model, clinical and economic outcomes associated with olanzapine-containing regimen and standard antiemetic regimen (doublet antiemetic regimen: dexamethasone+first generation 5HT3RA) in most SEA countries except in Singapore (triplet antiemetic regimen: dexamethasone+first generation 5HT3RA + aprepitant) for CINV prevention following HEC were evaluated. This analysis was performed in Thailand, Malaysia, Indonesia, and Singapore, using societal perspective method with 5-day time horizon. Input parameters were derived from literature, network meta-analysis, government documents, and hospital databases. Outcomes were incremental cost-effectiveness ratio (ICER) in USD/quality-adjusted life year (QALY) gained. A series of sensitivity analyses including probabilistic sensitivity analysis were also performed.

    RESULTS: Compared to doublet antiemetic regimen, addition of olanzapine resulted in incremental QALY of 0.0022-0.0026 with cost saving of USD 2.98, USD 27.71, and USD 52.20 in Thailand, Malaysia, and Indonesia, respectively. Compared to triplet antiemetic regimen, switching aprepitant to olanzapine yields additional 0.0005 QALY with cost saving of USD 60.91 in Singapore. The probability of being cost-effective at a cost-effectiveness threshold of 1 GDP/capita varies from 14.7 to 85.2% across countries.

    CONCLUSION: The use of olanzapine as part of standard antiemetic regimen is cost-effective for the prevention of CINV in patients receiving HEC in multiple SEA countries.

  14. Seasonal fluxes and sources apportionment of dissolved inorganic nitrogen wet deposition at different land-use sites in the Three Gorges reservoir area
    Cui J, Zhang Y, Yang F, Chang Y, Du K, Chan A, et al.
    Ecotoxicol Environ Saf, 2020 Apr 15;193:110344.
    PMID: 32092583 DOI: 10.1016/j.ecoenv.2020.110344
    To identify seasonal fluxes and sources of dissolved inorganic nitrogen (DIN) wet deposition, concentrations and δ15N signatures of nitrate (NO3-) and ammonium (NH4+) in wet precipitation were measured at four typical land-use types in the Three Gorges reservoir (TGR) area of southwest China for a one-year period. Higher DIN fluxes were recorded in spring and summer and their total fluxes (averaged 7.58 kg N ha-1) were similar to the critical loads in aquatic ecosystems. Significant differences of precipitation δ15N were observed for NH4+-N between town and wetland sites in spring and between urban and rural sites in summer. For NO3--N, significant differences of precipitation δ15N were observed between town and rural sites in spring and between urban and town sites in autumn, respectively. Quantitative results of NO3--N sources showed that both biomass burning and coal combustion had higher fluxes at the urban site especially in winter (0.18 ± 0.09 and 0.19 ± 0.08 kg N ha-1), which were about three times higher than those at the town site. A similar finding was observed for soil emission and vehicle exhausts in winter. On the whole, DIN wet deposition averaged at 12.13 kg N ha-1 yr-1 with the urban site as the hotspot (17.50 kg N ha-1 yr-1) and regional NO3--N fluxes had a seasonal pattern with minimum values in winter. The contribution to NO3--N wet deposition from biomass burning was 26.1 ± 14.1%, which is the second dominant factor lower than coal combustion (26.5 ± 12.6%) in the TGR area during spring and summer. Hence N emission reduction from biomass burning, coal combustion and vehicle exhausts should be strengthened especially in spring and summer to effectively manage DIN pollution for the sustainable development in TGR area.
  15. Fulltext Applicability of the National Comprehensive Cancer Network/Multinational Association of Supportive Care in Cancer Guidelines for Prevention and Management of Chemotherapy-Induced Nausea and Vomiting in Southeast Asia: A Consensus Statement
    Chan A, Abdullah MM, Ishak WZBW, Ong-Cornel AB, Villalon AH, Kanesvaran R
    J Glob Oncol, 2017 Dec;3(6):801-813.
    PMID: 29244998 DOI: 10.1200/JGO.2016.005728
    A meeting of regional experts was convened in Manila, Philippines, to develop a resource-stratified chemotherapy-induced nausea and vomiting (CINV) management guideline. In patients treated with highly emetogenic chemotherapy in general clinical settings, triple therapy with a serotonin (5-hydroxytryptamine-3 [5-HT3]) antagonist (preferably palonosetron), dexamethasone, and aprepitant is recommended for acute CINV prevention. In resource-restricted settings, triple therapy is still recommended, although a 5-HT3 antagonist other than palonosetron may be used. In both general and resource-restricted settings, dual therapy with dexamethasone (days 2 to 4) and aprepitant (days 2 to 3) is recommended to prevent delayed CINV. In patients treated with moderately emetogenic chemotherapy, dual therapy with a 5-HT3 antagonist, preferably palonosetron, and dexamethasone is recommended for acute CINV prevention in general settings; any 5-HT3 antagonist can be combined with dexamethasone in resource-restricted environments. In general settings, for the prevention of delayed CINV associated with moderately emetogenic chemotherapy, corticosteroid monotherapy on days 2 and 3 is recommended. If aprepitant is used on day 1, it should be continued on days 2 and 3. Prevention of delayed CINV with corticosteroids is preferred in resource-restricted settings. The expert panel also developed CINV management guidelines for anthracycline plus cyclophosphamide combination schedules, multiday cisplatin, and chemotherapy with low or minimal emetogenic potential, and its recommendations are detailed in this review. Overall, these regional guidelines provide definitive guidance for CINV management in general and resource-restricted settings. These consensus recommendations are anticipated to contribute to collaborative efforts to improve CINV management in Southeast Asia.
  16. Impact of socioeconomic and meteorological factors on reservoirs' air quality: a case in the Three Gorges Reservoir of Chongqing (TGRC), China over a 10-year period
    Peng Y, Zhou F, Cui J, Du K, Leng Q, Yang F, et al.
    Environ Sci Pollut Res Int, 2017 Jul;24(19):16206-16219.
    PMID: 28540543 DOI: 10.1007/s11356-017-9221-0
    The Three Gorges Dam's construction and industrial transfer have resulted in a new air pollution pattern with the potential to threaten the reservoir eco-environment. To assess the impact of socioeconomic factors on the pattern of air quality vairation and economical risks, concentrations of SO2, NO2, and PM10, industry genres, and meteorological conditions were selected in the Three Gorges Reservoir of Chongqing (TGRC) during 2006-2015. Results showed that air quality had improved to some extent, but atmospheric NO2 showed an increased trend during 2011-2015. Spatially, higher atmospheric NO2 extended to the surrounding area. The primary industry, especially for agriculture, had shown to be responsible for the remarkable increase of atmospheric NO2 (p 
  17. Frequent occurrence of gastric cancer in Asian kindreds with Li-Fraumeni syndrome
    Ariffin H, Chan AS, Oh L, Abd-Ghafar S, Ong GB, Mohamed M, et al.
    Clin Genet, 2015 Nov;88(5):450-5.
    PMID: 25318593 DOI: 10.1111/cge.12525
    Type of cancer and age of onset in individuals with inherited aberrations in the tumour suppressor gene TP53 are variable, possibly influenced by genetic modifiers and different environmental exposure. Since 2009, the modified Chompret criteria (MCC) have been used to identify individuals for TP53 mutation screening. Using the TP53 mutation database maintained by the International Agency for Research on Cancer (IARC), we investigated if the MCC, mainly developed for a Caucasian population, was also applicable in Asia. We identified several differences in Asian families compared with similar Caucasian cohorts, suggesting that identification and management of Li-Fraumeni syndrome in Asia do not completely mirror that of North America and Western Europe. Early gastric cancer (<40 years) may be considered a new addition to the MCC especially for Asian families.
  18. Nonlinear effects of increasing nitrogen deposition on rice growth and heavy metal uptake in a red soil ecosystem of southeastern China
    Wang J, Yi X, Cui J, Chang Y, Yao D, Zhou D, et al.
    Sci Total Environ, 2019 Jun 20;670:1060-1067.
    PMID: 31018421 DOI: 10.1016/j.scitotenv.2019.03.245
    With the population growth, urbanization and industrialization, China has become a hotspot of atmospheric deposition nitrogen (ADN), which is a threat to ecosystem and food safety. However, the impacts of increased ADN on rice growth and grain metal content are little studied. Based on previous long-term ADN studies, greenhouse experiment was conducted with four simulated ADN rates of 0, 30, 60 and 90 kg N ha-1 yr-1 (CK, N1, N2 and N3 as δ15N, respectively) to assess rice growth and metal uptake in a red soil ecosystem of southeast China during 2016-2017. Results showed that simulated ADN could promote rice growth and increase yields by 15.68-24.41% (except N2) and accumulations of cadmium (Cd) or copper (Cu) in organs. However, there was no linear relationship between ADN rate and rice growth or Cd or Cu uptake. The 15N-ADN was mainly accumulated in roots (21.31-67.86%) and grains (25.26-49.35%), while Cd and Cu were primarily accumulated in roots (78.86-93.44% and 90.00-96.24%, respectively). 15N-ADN and Cd accumulations in roots were significantly different between the two growing seasons (p 
  19. Fulltext The silver lining of COVID-19: estimation of short-term health impacts due to lockdown in the Yangtze River Delta region, China
    Huang L, Liu Z, Li H, Wang Y, Li Y, Zhu Y, et al.
    Geohealth, 2020 Jul 07.
    PMID: 32838101 DOI: 10.1029/2020GH000272
    The outbreak of COVID-19 in China has led to massive lockdowns in order to reduce the spread of the epidemic and control human-to-human transmission. Subsequent reductions in various anthropogenic activities have led to improved air quality during the lockdown. In this study, we apply a widely used exposure-response function to estimate the short-term health impacts associated with PM2.5 changes over the Yangtze River Delta (YRD) region due to COVID-19 lockdown. Concentrations of PM2.5 during lockdown period reduced by 22.9% to 54.0% compared to pre-lockdown level. Estimated PM2.5-related daily premature mortality during lockdown period is 895 (95% confidential interval: 637-1081), which is 43.3% lower than pre-lockdown period and 46.5% lower compared with averages of 2017-2019. According to our calculation, total number of avoided premature death associated PM2.5 reduction during the lockdown is estimated to be 42.4 thousand over the YRD region, with Shanghai, Wenzhou, Suzhou (Jiangsu province), Nanjing, and Nantong being the top five cities with largest health benefits. Avoided premature mortality is mostly contributed by reduced death associated with stroke (16.9 thousand, accounting for 40.0%), ischemic heart disease (14.0 thousand, 33.2%) and chronic obstructive pulmonary disease (7.6 thousand, 18.0%). Our calculations do not support or advocate any idea that pandemics produce a positive note to community health. We simply present health benefits from air pollution improvement due to large emission reductions from lowered human and industrial activities. Our results show that continuous efforts to improve air quality are essential to protect public health, especially over city-clusters with dense population.
  20. Increasing atmospheric deposition nitrogen and ammonium reduced microbial activity and changed the bacterial community composition of red paddy soil
    Zhou F, Cui J, Zhou J, Yang J, Li Y, Leng Q, et al.
    Sci Total Environ, 2018 Aug 15;633:776-784.
    PMID: 29602116 DOI: 10.1016/j.scitotenv.2018.03.217
    Atmospheric deposition nitrogen (ADN) increases the N content in soil and subsequently impacts microbial activity of soil. However, the effects of ADN on paddy soil microbial activity have not been well characterized. In this study, we studied how red paddy soil microbial activity responses to different contents of ADN through a 10-months ADN simulation on well managed pot experiments. Results showed that all tested contents of ADN fluxes (27, 55, and 82kgNha-1 when its ratio of NH4+/NO3--N (RN) was 2:1) enhanced the soil enzyme activity and microbial biomass carbon and nitrogen and 27kgNha-1 ADN had maximum effects while comparing with the fertilizer treatment. Generally, increasing of both ADN flux and RN (1:2, 1:1 and 2:1 with the ADN flux of 55kgNha-1) had similar reduced effects on microbial activity. Furthermore, both ADN flux and RN significantly reduced soil bacterial alpha diversity (p<0.05) and altered bacterial community structure (e.g., the relative abundances of genera Dyella and Rhodoblastus affiliated to Proteobacteria increased). Redundancy analysis demonstrated that ADN flux and RN were the main drivers in shaping paddy soil bacteria community. Overall, the results have indicated that increasing ADN flux and ammonium reduced soil microbial activity and changed the soil bacterial community. The finding highlights how paddy soil microbial community response to ADN and provides information for N management in paddy soil.
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