Development of human health damage factors for tropospheric ozone considering transboundary transport on a global scale

Purpose

Air pollutants such as tropospheric ozone and PM_2.5 travel through large areas. The damage factors (DFs) presented by existing researches in life cycle impact assessment do not take into consideration transboundary movement. A previous study used a global chemistry transport model (CTM), to develop health damage factors for ten different regions around the world by considering the transboundary movement of PM_2.5. Under the same assessment procedure, this research is designed to calculate the ozone DFs by region and to find the effects of wide range movement on the DFs.

Methods

The DFs by regions are defined as changes in disability-adjusted life years (DALYs) derived from changes in tropospheric ozone concentration around the world which is induced by an increase in emissions of the unit amount of nitrogen oxides (NO_x) and non-methane volatile organic compounds (NMVOC). DFs for ten regions are calculated as follows. Firstly, the concentration change of worldwide ozone caused by a change in emission of a substance from one region is estimated with a global scale CTM for both NO_x and NMVOC. Secondly, DALY changes on the world due to a change in concentration of ozone are estimated by using population data and epidemiological concentration-response functions for mortality and morbidity. Finally, the above calculations are done for all targeted ten regions.

Results and discussion

DFs of NO_x and NMVOC for ten regions were calculated as 0.3–4.2?×?10^?5 DALY/kg and 0.2–5.6?×?10^?6 DALY/kg, respectively. It was found DFs might be underestimated around 10 to 70 % by region if the transboundary movement is not taken into consideration. In many regions in the northern hemisphere, about 60 % of damage occurs outside the emission area, which is larger than that of southern hemispheric regions due to a larger population exposed to downwind places. In regions of China and India, however, the influence on other regions accounted for only 10 % because these regions involve larger influences in the source region. The impact of NO titration effect can be seen in cold seasons in many regions, but it was found that the effect is remarkable on an annual average only in Europe, a cold region with large emissions.

Conclusions

The human health DFs of NO_x and NMVOC considering effects of transboundary movement of tropospheric ozone are estimated for ten regions by using a global CTM. As a future work, it is important to show the interannual sensitivity of the DFs through chronological assessments.

     

Comparative effect of inorganic N on plant growth and N<Subscript>2</Subscript> fixation of ten legume crops: towards a better understanding of the differential response among species

Aims

A better understanding of how plant growth, N nutrition and symbiotic nitrogen fixation (SNF) are influenced by soil inorganic N availability, for a wide range of legume species, is crucial to optimise legume productivity, N₂ fixation, while limiting environmental risks such as N leaching.

Methods

A comparative analysis was performed for ten legume crops, grown in a field experiment and supplied with four N fertiliser rates. Dry matter, N concentration and SNF were measured. In parallel, root elongation rates were studied in a greenhouse experiment.

Results

For most species, N fertilisation had little effect on plant growth and N accumulation. SNF was reduced by soil inorganic N available at sowing but with large differences in the magnitude of the response among species. The response varied according to plant N requirements for growth and plant ability to retrieve inorganic N. Accordingly, root lateral expansion rate measured in RhizoTubes was highly correlated with plant ability to retrieve inorganic N measured in the field experiment.

Conclusion

Combining SNF response to soil inorganic N, shoot N and plant ability to retrieve inorganic N, allowed a robust evaluation of differential response to soil inorganic N among a wide range of legume species.

     

The effect of 1,25-dihydroxyvitamin D<Subscript>3</Subscript> on TSLP,IL-33 and IL-25 expression in respiratory epithelium

Background

Airway epithelium is an active and important component of the immunological response in the pathophysiology of obstructive lung diseases. Recent studies suggest an important role for vitamin D₃ in asthma severity and treatment response.

Objective

Our study evaluated the influence of an active form of vitamin D₃ on the expression of selected mediators of allergic inflammation in the respiratory epithelium.

Material and Methods

Primary nasal and bronchial epithelial cells were exposed to1,25D₃ for 1 hour and were then stimulated or not with IL-4, TNF-α, LPS, and poly I:C. After 24 hours TSLP, IL-33, and IL-25 protein levels were measured in culture supernatants usingELISAandmRNAlevels in cells by real time PCR.

Results

1,25D₃ increased TSLP concentration in unstimulated nasal epithelial cells, but did not influence IL-33 and IL-25 expression. In IL-4-stimulated epithelial cell cultures 1,25D₃ mostly inhibited TSLP and IL-33 expression. In LPS-treated cultures 1,25D₃ decreased IL-33 expression. Simultaneously 1,25D₃ augmented IL-25 production in the same model of stimulation.

Conclusion

Our study revealed the dual nature of vitamin D₃ manifested in both pro- and anti-inflammatory properties observed in airway epithelial cells.

     

The impact of outdoor air pollutants on outpatient visits for respiratory diseases during 2012–2016 in Jinan,China

Background

Few studies have investigated the associations between outdoor air pollution and outpatient visits for respiratory diseases (RDs) in general population.

Methods

We collected daily outpatient data of primary RDs from five hospitals in Jinan during January 2012 and December 2016, as well as daily measurements of air pollutants from the Jinan Environmental Monitoring Center and daily meteorological variables from the China Meteorological Data Sharing Service System. A generalized additive model (GAM) with quasi-Poisson regression was constructed to estimate the associations between daily average concentrations of outdoor air pollutants (PM_2.5,PM₁₀, SO₂, NO₂, CO and O₃) and daily outpatient visits of RDs after adjusting for long-time trends, seasonality, the “day of the week” effect, and weather conditions. Subgroup analysis stratified by gender, age group and the type of RDs was conducted.

Results

A total of 1,373,658 outpatient visits for RDs were identified. Increases of 10?μg/m³ in PM_2.5, PM₁₀, NO₂, CO and O₃ were associated with0.168% (95% CI, 0.072–0.265%), 0.149% (95% CI, 0.082–0.215%), 0.527% (95% CI, 0.211–0.843%), 0.013% (95% CI, 0.003–0.023%), and 0.189% (95% CI, 0.032–0.347%) increases in daily outpatient visits for RDs, respectively. PM_2.5 and PM₁₀ showed instant and continuous effects, while NO₂, CO and O₃ showed delayed effects on outpatient visits for RDs. In stratification analysis, PM_2.5 and PM₁₀ were associated with acute RDs only.

Conclusions

Exposure to outdoor air pollutants including PM_2.5, PM₁₀, NO₂, CO and O₃ associated with increased risk of outpatient visits for RDs.

     

Effectiveness of fractional CO<Subscript>2</Subscript> laser in women with stress urinary incontinence

Background

Stress urinary incontinence (SUI) is a relatively common disorder that significantly affects the quality of life. Many conservative and surgical treatment methods have been recommended for SUI, but they have major limitations.

Aims

To assess the use of the CO₂ fractional laser in the treatment of SUI.

Methods

This clinical trial included 55 patients with confirmed SUI. Patients underwent fractional CO₂ laser treatment 3 times at 30-day intervals. Data on age, smoking history, sexual activity, menopause, and history of hormone replacement therapy (HRT) were collected. Response to treatment was assessed by SUI severity and the level of sexual satisfaction was assessed using the visual analog scale (VAS). Patients were evaluated at 3 different time points: before treatment, and 45 days and 6 months after the last laser treatment.

Results

The mean patient age was 44.4±11.4 years (range: 28 to 68 years). Smoking history was positive in 6 patients (9.1%); 19 (54.3%) were menopausal on HRT. The SUI severity score at baseline (before treatment) was 8.56±0.62 and decreased to 2.28 6 months after treatment (p<0.0001). The sexual satisfaction score was 3±0.94 at baseline and increased to 7.87±0.93 6 months after treatment (day 180) (p<0.0001, slope = + 2.2)

Conclusion

Our findings are in line with a previous study that showed the value of transvaginal CO₂ fractional laser treatment for alleviation of SUI symptoms and its potential as an alternative treatment. We also observed improved sexual satisfaction in SUI patients.

     

Endophytic infection modifies organic acid and mineral element accumulation by rice under Na<Subscript>2</Subscript>CO<Subscript>3</Subscript> stress

Background and aims

Saline and alkali soils severely impact plant growth. Endophyte and plant associations are known to significantly modify plant metabolism. This study reports the effects of a type of endophyte on organic acid (OA) accumulation and ionic balance in rice under Na₂CO₃ stress.

Methods

Rice seedlings with (E+) and without (E-) endophytic infection were subjected to different levels of Na₂CO₃ stress (0, 5, 10, 15, and 20 mM) for two weeks. Organic acids and mineral elements in the leaves and roots were determined.

Results

Seedlings with endophytic infection accumulated mainly citrate and fumarate, with some malate and succinate in the leaves. In the roots, accumulation of malate and fumarate was enhanced significantly by endophytic infection, while less citrate and succinate was accumulated under Na₂CO₃ stress, which suggested that leaves and roots use different mechanisms to control OA metabolism. Endophytes reduced the total Na and Na:K ratios, but increased ST values, the percent changes of other measured nutrients, Chl content, and dry weight per plant under Na₂CO₃ stress.

Conclusions

Endophytic infection plays a key role in maintaining plant growth by improving nutrient uptake and adjusting OA accumulation under Na₂CO₃ stress. The application of endophytes can enhance the resistance of rice to salinity.

     

Relationships between nitrogen,dry matter accumulation and glucosinolates in <Emphasis Type="Italic">Eruca sativa</Emphasis> Mills. The applicability of the critical NO<Subscript>3</Subscript>-N levels approach

Background and Aims

Rocket salad (Eruca sativa Mills) is one of the major leafy vegetables produced worldwide and has been characterized as a rich source of chemoprotective glucosinolates (GSL). The relationship between N fertilization and the resulting plant biomass and N status with GSL quantity and quality in rocket leaves was examined.

Methods

A pot experiment was conducted, applying ten different N-rates and destructive sampling was carried out 15, 30 and 45 days after transplanting (DAT). The Mitscherlich equation was used to establish NO₃-N critical levels at each growth stage and as an indicator of N demand for relative maximum dry matter accumulation and glucosinolate content and composition was determined.

Results

Glucosinolate content was significantly influenced by N rate, growth stage and their interaction. Different GSL types showed dissimilar responses to N fertilization: aliphatic GSLs were significantly reduced under increased N rates whereas indole GSL showed the reverse. Under excess N fertilization (>1.04 g/plant), dry matter accumulation remained constant, NO₃-N was significantly increased and total GSL content was significantly reduced, factors that could lead to an anticipated product quality decline.

Conclusions

The application of the critical NO₃-N level approach used to identify optimal N fertilization rates for plant growth could serve as means to obtain optimized GSL content in the edible plant parts.

     

Differential elemental uptake in three pseudo-metallophyte C<Subscript>4</Subscript> grasses in situ in the eastern USA

Background and aims

Elemental uptake in serpentine floras in eastern North America is largely unknown. The objective of this study was to determine major and trace element concentrations in soil and leaves of three native pseudo-metallophyte C₄ grasses in situ at five sites with three very different soil types, including three serpentine sites, in eastern USA.

Methods

Pseudo-total and extractible concentrations of 15 elements were measured and correlated from the soils and leaves of three species at the five sites.

Results

Element concentrations in soils of pseudo-metallophytes varied up to five orders of magnitude. Soils from metalliferous sites exhibited higher concentrations of their characteristic elements than non-metalliferous. In metallicolous populations, elemental concentrations depended on the element. Concentrations of major elements (Ca, Mg, K) in leaves were lower than typical toxicity thresholds, whereas concentrations of Zn were higher.

Conclusions

In grasses, species can maintain relatively low metal concentrations in their leaves even when soil concentrations are richer. However, in highly Zn-contaminated soil, we found evidence of a threshold concentration above which Zn uptake increases drastically. Finally, absence of main characteristics of serpentine soil at one site indicated the importance of soil survey and restoration to maintain serpentinophytes communities and avoid soil encroachment.

     

Sublethal concentration of H<Subscript>2</Subscript>O<Subscript>2</Subscript> enhances the protective effect of mesenchymal stem cells in rat model of spinal cord injury

Objective

To investigate the effect of H₂O₂ on the migration and antioxidant defense of mesenchymal stem cells (MSCs) and the neurotrophic effects of H₂O₂-treated MSCs on spinal cord injury (SCI).

Results

Sublethal concentrations of H₂O₂ decreased cell migration and expression of CXCR4 and CCR2 as well as Nrf2 expression in MSCs. In the second phase, transplantation of treated and untreated MSCs to SCI caused minor changes in locomotor dysfunction. There was a significantly difference between cell-treated and spinal cord injury groups in expression of BDNF (brain-derived neurotrophic factor). Transplantation of H₂O₂-treated cells caused an increase in BDNF expression compared to non-treated cells.

Conclusion

Transplantation of H₂O₂-treated stem cells may have protective effects against SCI through by increasing neurotrophic factors.

     

Mitofusin 1 is degraded at G<Subscript>2</Subscript>/M phase through ubiquitylation by MARCH5

Background

Mitochondria exhibit a dynamic morphology in cells and their biogenesis and function are integrated with the nuclear cell cycle. In mitotic cells, the filamentous network structure of mitochondria takes on a fragmented form. To date, however, whether mitochondrial fusion activity is regulated in mitosis has yet to be elucidated.

Findings

Here, we report that mitochondria were found to be fragmented in G₂ phase prior to mitotic entry. Mitofusin 1 (Mfn1), a mitochondrial fusion protein, interacted with cyclin B1, and their interactions became stronger in G₂/M phase. In addition, MARCH5, a mitochondrial E3 ubiquitin ligase, reduced Mfn1 levels and the MARCH5-mediated Mfn1 ubiquitylation were enhanced in G₂/M phase.

Conclusions

Mfn1 is degraded through the MARCH5-mediated ubiquitylation in G₂/M phase and the cell cycle-dependent degradation of Mfn1 could be facilitated by interaction with cyclin B1/Cdk1 complexes.

     

Human health characterization factors of nano-TiO<Subscript>2</Subscript> for indoor and outdoor environments

Purpose

The increasing use of engineered nanomaterials (ENMs) in industrial applications and consumer products is leading to an inevitable release of these materials into the environment. This makes it necessary to assess the potential risks that these new materials pose to human health and the environment. Life cycle assessment (LCA) methodology has been recognized as a key tool for assessing the environmental performance of nanoproducts. Until now, the impacts of ENMs could not be included in LCA studies due to a lack of characterization factors (CFs). This paper provides a methodological framework for identifying human health CFs for ENMs.

Methods

The USEtox? model was used to identify CFs for assessing the potential carcinogenic and non-carcinogenic effects on human health caused by ENM emissions in both indoor (occupational settings) and outdoor environments. Nano-titanium dioxide (nano-TiO₂) was selected for defining the CFs in this study, as it is one of the most commonly used ENMs. For the carcinogenic effect assessment, a conservative approach was adopted; indeed, a critical dose estimate for pulmonary inflammation was assumed.

Results and discussion

We propose CFs for nano-TiO₂ from 5.5E?09 to 1.43E?02 cases/kg_emitted for both indoor and outdoor environments and for carcinogenic and non-carcinogenic effects.

Conclusions

These human health CFs for nano-TiO₂ are an important step toward the comprehensive application of LCA methodology in the field of nanomaterial technology.

     

Structures of EccB<Subscript>1</Subscript> and EccD<Subscript>1</Subscript> from the core complex of the mycobacterial ESX-1 type VII secretion system

Background

The ESX-1 type VII secretion system is an important determinant of virulence in pathogenic mycobacteria, including Mycobacterium tuberculosis. This complicated molecular machine secretes folded proteins through the mycobacterial cell envelope to subvert the host immune response. Despite its important role in disease very little is known about the molecular architecture of the ESX-1 secretion system.

Results

This study characterizes the structures of the soluble domains of two conserved core ESX-1 components – EccB₁ and EccD₁. The periplasmic domain of EccB₁ consists of 4 repeat domains and a central domain, which together form a quasi 2-fold symmetrical structure. The repeat domains of EccB₁ are structurally similar to a known peptidoglycan binding protein suggesting a role in anchoring the ESX-1 system within the periplasmic space. The cytoplasmic domain of EccD₁has a ubiquitin-like fold and forms a dimer with a negatively charged groove.

Conclusions

These structures represent a major step towards resolving the molecular architecture of the entire ESX-1 assembly and may contribute to ESX-1 targeted tuberculosis intervention strategies.

     

Elevated CO<Subscript>2</Subscript> and virus infection impacts wheat and aphid metabolism

Introduction

The aphid Rhopalosiphum padi L. is a vector of Barley yellow dwarf virus (BYDV) in wheat and other economically important cereal crops. Increased atmospheric CO₂ has been shown to alter plant growth and metabolism, enhancing BYDV disease in wheat. However, the biochemical influences on aphid metabolism are not known.

Objectives

This work aims to determine whether altered host-plant quality, influenced by virus infection and elevated CO₂, impacts aphid weight and metabolism.

Methods

Untargeted ¹H NMR metabolomics coupled with multivariate statistics were employed to profile the metabolism of R. padi reared on virus-infected and non-infected (sham-inoculated) wheat grown under ambient CO₂ (aCO₂, 400 µmol mol^?1) and future, predicted elevated CO₂ (eCO₂, 650 µmol mol^?1) concentrations. Un-colonised wheat was also profiled to observe changes to host-plant quality (i.e., amino acids and sugars).

Results

The direct impacts of virus or eCO₂ were compared. Virus presence increased aphid weight under aCO₂ but decreased weight under eCO₂; whilst eCO₂ increased non-viruliferous (sham) aphid weight but decreased viruliferous aphid weight. Discriminatory metabolites due to eCO₂ were succinate and sucrose (in sham wheat), glucose, choline and betaine (in infected wheat), and threonine, lactate, alanine, GABA, glutamine, glutamate and asparagine (in aphids), irrespective of virus presence. Discriminatory metabolites due to virus presence were alanine, GABA, succinate and betaine (in wheat) and threonine and lactate (in aphids), irrespective of CO₂ treatment.

Conclusion

This study confirms that virus and eCO₂ alter host-plant quality, and these differences are reflected by aphid weight and metabolism.

     

Engineering a glycerol utilization pathway in Corynebacterium glutamicum for succinate production under O<Subscript>2</Subscript> deprivation

Objective

To explore the glycerol utilization pathway in Corynebacterium glutamicum for succinate production under O₂ deprivation.

Result

Overexpression of a glycerol facilitator, glycerol dehydrogenase and dihydroxyacetone kinase from Escherichia coli K-12 in C. glutamicum led to recombinant strains NC-3G diverting glycerol utilization towards succinate production under O₂ deprivation. Under these conditions, strain NC-3G efficiently consumed glycerol and produced succinate without growth. The recombinant C. glutamicum utilizing glycerol as the sole carbon source showed higher intracellular NADH/NAD⁺ ratio compare with utilizing glucose. The mass conversion of succinate increased from 0.64 to 0.95. Using an anaerobic fed-batch fermentation process, the final strain produced 38.4 g succinate/l with an average yield of 1.02 g/g.

Conclusions

The metabolically-engineered strains showed an efficient succinate production using glycerol as sole carbon source under O₂ deprivation.

     

<Emphasis Type="Italic">massPix</Emphasis>: an R package for annotation and interpretation of mass spectrometry imaging data for lipidomics

Introduction

Mass spectrometry imaging (MSI) experiments result in complex multi-dimensional datasets, which require specialist data analysis tools.

Objectives

We have developed massPix—an R package for analysing and interpreting data from MSI of lipids in tissue.

Methods

massPix produces single ion images, performs multivariate statistics and provides putative lipid annotations based on accurate mass matching against generated lipid libraries.

Results

Classification of tissue regions with high spectral similarly can be carried out by principal components analysis (PCA) or k-means clustering.

Conclusion

massPix is an open-source tool for the analysis and statistical interpretation of MSI data, and is particularly useful for lipidomics applications.

     

Co-cultivation of <Emphasis Type="Italic">Chlamydomonas reinhardtii</Emphasis> with <Emphasis Type="Italic">Azotobacter chroococcum</Emphasis> improved H<Subscript>2</Subscript> production

Objectives

To improve H₂ production, the green algae Chlamydomonas reinhardtii cc849 was co-cultured with Azotobacter chroococcum.

Results

The maximum H₂ production of the co-culture was 350% greater than that of the pure algal cultures under optimal H₂ production conditions. The maximum growth and the respiratory rate of the co-cultures were about 320 and 300% of the controls, and the dissolved O₂ of co-cultures was decreased 74%. Furthermore, the in vitro maximum hydrogenase activity of the co-culture was 250% greater than that of the control, and the in vivo maximum hydrogenase activity of the co-culture was 1.4-fold greater than that of the control. In addition, the maximum starch content of co-culture was 1400% that of the control.

Conclusions

Azotobacter chroococcum improved the H₂ production of the co-cultures by decreasing the O₂ content and increasing the growth and starch content of the algae and the hydrogenase activity of the co-cultures relative to those of pure algal cultures.

     

Microbial community and associated enzymes activity influence soil carbon chemical composition in <Emphasis Type="Italic">Eucalyptus urophylla</Emphasis> plantation with mixing N<Subscript>2</Subscript>-fixing species in subtropical China

Background and aims

Microbial communities and their associated enzyme activities affect the quantity and chemical quality of carbon in soil. We aimed to evaluate the biochemical mechanisms underlying how N₂-fixing species influences soil organic carbon chemical composition through soil microbial functional groups and enzyme activities.

Methods

We examined the effects of N₂-fixing species mixed with Eucalyptus on soil carbon storage, and the chemical composition of an 8-year-old pure Eucalyptus urophylla plantation (PP) and a mixed E.urophylla and Acacia mangium plantation (MP).

Results

The soil carbon stock and recalcitrant carbon chemical component significantly increased in surface soil in MP. The total PLFAs and bacterial PLFAs increased by 29.1% and 27.0% in cool-dry season, while in the warm-wet season, the total PLFAs and bacterial PLFAs increased by 13.1% and 27.3%, respectively. However, the fungal PLFAs decreased significantly in warm-wet season in MP. The total activity of the cellulose-degrading enzyme β-glucosidase was significantly greater with mixed N₂-fixing species in both dry-cool and wet-warm season. The increase in the Alk-C/O-Alk-C ratio and SOC was strongly associated with both C-acquisition activity and bacterial community.

Conclusions

Our findings highlight the importance of N₂-fixing species in regulating both soil microbial communities and their functioning in association with soil extracellular enzyme activities, which contribute to the increased soil carbon storage and recalcitrant carbon composition in Eucalyptus plantations.

     

Trade-off between C and N recycling and N<Subscript>2</Subscript>O emissions of soils with summer cover crops in subtropical agrosystems

Aims

Biological soil crusts (biocrusts) are soil-surface communities in drylands, dominated by cyanobacteria, mosses, and lichens. They provide key ecosystem functions by increasing soil stability and influencing soil hydrologic, nutrient, and carbon cycles. Because of this, methods to reestablish biocrusts in damaged drylands are needed. Here we test the reintroduction of field-collected vs. greenhouse-cultured biocrusts for rehabilitation.

Methods

We collected biocrusts for 1) direct reapplication, and 2) artificial cultivation under varying hydration regimes. We added field-collected and cultivated biocrusts (with and without hardening treatments) to bare field plots and monitored establishment.

Results

Both field-collected and cultivated cyanobacteria increased cover dramatically during the experimental period. Cultivated biocrusts established more rapidly than field-collected biocrusts, attaining ~82% cover in only one year, but addition of field-collected biocrusts led to higher species richness, biomass (as assessed by chlorophyll a) and level of development. Mosses and lichens did not establish well in either case, but late successional cover was affected by hardening and culture conditions.

Conclusions

This study provides further evidence that it is possible to culture biocrust components from later successional materials and reestablish cultured organisms in the field. However, more research is needed into effective reclamation techniques.

     

Characterization of H<Subscript>2</Subscript> photoproduction by marine green alga <Emphasis Type="Italic">Tetraselmis subcordiformis</Emphasis> integrated with an alkaline fuel cell

Objectives

To investigate the feasibility of coupling carbonyl cyanide m-chlorophenylhydrazone-regulated photohydrogen production by Tetraselmis subcordiformis in a photobioreactor to an alkaline fuel cell (AFC).

Results

H₂ evolution kinetics in the AFC integrated process was characterized. The duration of H₂ evolution was prolonged and its yield was improved about 1.5-fold (to 78 ± 5 ml l^?1) compared with that of the process without AFC. Improved H₂ yield was possibly caused by removal of H₂ feedback inhibition by H₂ consumption in situ. Decreases in the H₂ production rate correlated with the gradual deactivation of PSII and hydrogenase activities. The H₂ yield was closely associated with catabolism of starch and protein.

Conclusion

A marine green algal CO₂-supplemented culture integrated with in situ H₂-consumption by an AFC system was developed as a viable protocol for the H₂ production.