On the hydrophobicity of nitrogen dioxide: Could there be a “lens” effect for NO2 reaction kinetics?

Solvent “lens” effects for the reaction kinetics of NO₂ can be evaluated on the basis of published Henry’s law constants for nitrogen dioxide in various solvents. Water-to-organic solvent partition coefficients were derived from Henry’s law constants and used to assess the tendencies of NO₂ toward fleeing the aqueous environments and concentrating in biological hydrophobic media. It is concluded, based only on the estimated aqueous medium-to-cell membrane partition coefficient for NO₂, that such tendencies will be relatively small, and that they may account for an acceleration of chemical reactions in biological hydrophobic media with reaction kinetics that are first order on NO₂ by a factor of approximately 3 ± 1. Thus, kinetic effects due to mass action will be relatively small but it is also important to recognize that because NO₂ will tend to dissolve in cell membranes, reactions with cell membrane components will not be hindered by lack of physical solubility at these loci. In comparison to other gases, nitrogen dioxide is less hydrophobic than NO, O₂ and N₂.     

Redesigning healthcare: The 2.4 billion euro question?

Although it has been possible to transfer electrocardiograms via a phone line for more than 100 years, use of internet-based patient monitoring and communication systems in daily care is uncommon. Despite the introduction of numerous health-monitoring devices, and despite most patients having internet access, the implementation of individualised healthcare services is still limited. On the other hand, hospitals have invested heavily in massive information systems offering limited value for money and connectivity. However, the consumer market for personal healthcare devices is developing rapidly and with the current healthcare-related investments by tech companies it can be expected that the way healthcare is provided will change dramatically. Although a variety of initiatives under the banner of ‘e-Health’ are deployed, most are characterised by either industry-driven developments without proven clinical effectiveness or individual initiatives lacking the embedding within the traditional organisations. However, the introduction of numerous smart devices and internet-based technologies facilitates the fundamental redesign of healthcare based on the principle of achieving the best possible care for the individual patient at the lowest possible cost. Conclusion The way healthcare is delivered will change, but to what degree healthcare professionals together with patients will be able to redesign healthcare in a structured manner is still a question.     

Formation of unidentified nitrogen in plants: an implication for a novel nitrogen metabolism

Plants take up inorganic nitrogen and store it unchanged or convert it to organic forms. The nitrogen in such organic compounds is stoichiometrically recoverable by the Kjeldahl method. The sum of inorganic nitrogen and Kjeldahl nitrogen has long been known to equal the total nitrogen in plants. However, in our attempt to study the mechanism of nitrogen dioxide (NO₂) metabolism, we unexpectedly discovered that about one-third of the total nitrogen derived from ¹⁵N-labeled NO₂ taken up by Arabidopsis thaliana (L.) Heynh. plants was converted to neither inorganic nor Kjeldahl nitrogen, but instead to an as yet unknown nitrogen compound(s). We here refer to this nitrogen as unidentified nitrogen (UN). The generality of the formation of UN across species, nitrogen sources and cultivation environments for plants has been shown as follows. Firstly, all of the other 11 plant species studied were found to form the UN in response to fumigation with ¹⁵NO₂. Secondly, tobacco (Nicotiana tabacum L.) plants fed with ¹⁵N-nitrate appeared to form the UN. And lastly, the leaves of naturally fed vegetables, grass and roadside trees were found to possess the UN. In addition, the UN appeared to comprise a substantial proportion of total nitrogen in these plant species. Collectively, all of our present findings imply that there is a novel nitrogen mechanism for the formation of UN in plants. Based on the analyses of the exhaust gas and residue fractions of the Kjeldahl digestion of a plant sample containing the UN, probable candidates for compounds that bear the UN were deduced to be those containing the heat-labile nitrogen–oxygen functions and those recalcitrant to Kjeldahl digestion, including organic nitro and nitroso compounds. We propose UN-bearing compounds may provide a chemical basis for the mechanism of the reactive nitrogen species (RNS), and thus that cross-talk may occur between UN and RNS metabolisms in plants. A mechanism for the formation of UN-bearing compounds, in which RNS are involved as intermediates, is proposed. The important broad impact of this novel nitrogen metabolism, not only on the general physiology of plants, but also on plant substances as human and animal food, and on plants as an integral part of the global environment, is discussed.Abbreviations NO Nitric oxide - NO₂ Nitrogen dioxide - RNS Reactive nitrogen species - UN Unidentified nitrogen - TNNAT, RNNAT, INNAT and UNNAT Total, Kjeldahl, inorganic and unidentified nitrogen in naturally fed plants, respectively - TNNIT, RNNIT, INNIT and UNNIT Total, Kjeldahl, inorganic and unidentified nitrogen derived from nitrate, respectively - TNNO2, RNNO2, INNO2 and UNNO2 Total, Kjeldahl, inorganic and unidentified nitrogen derived from NO₂, respectively     

Fluxes and chemistry of nitrogen oxides in the Niwot Ridge,Colorado, snowpack

The effect of snow cover on surface-atmosphere exchanges of nitrogen oxides (nitrogen oxide (NO) + nitrogen dioxide (NO₂); note, here ‘NO₂’ is used as surrogate for a series of oxidized nitrogen gases that were detected by the used monitor in this analysis mode) was investigated at the high elevation, subalpine (3,340 m asl) Soddie site, at Niwot Ridge, Colorado. Vertical (NO + NO₂) concentration gradient measurements in interstitial air in the deep (up to ~2.5 m) snowpack were conducted with an automated sampling and analysis system that allowed for continuous observations throughout the snow-covered season. These measurements revealed sustained, highly elevated (NO + NO₂) mixing ratios inside the snow. Nitrogen oxide concentrations were highest at the bottom of the snowpack, reaching levels of up to 15 ppbv during mid-winter. Decreasing mixing ratios with increasing distance from the soil–snow interface were indicative of an upwards flux of NO from the soil through the snowpack, and out of the snow into the atmosphere, and imply that biogeochemical processes in the subnival soil are the predominant NO source. Nitrogen dioxide reached maximum levels of ~3 ppbv in the upper layers of the snowpack, i.e., ~20–40 cm below the surface. This behavior suggests that a significant fraction of NO is converted to NO₂ during its diffusive transport through the snowpack. Ozone showed the opposite behavior, with rapidly declining levels below the snow surface. The mirroring of vertical profiles of ozone and the NO₂/(NO + NO₂) ratio suggest that titration of ozone by NO in the snowpack contributes to the ozone reaction in the snow and to the ozone surface deposition flux. However, this surface efflux of (NO + NO₂) can only account for a minor fraction of ozone deposition flux over snow that has been reported at other mid-latitude sites. Neither (NO + NO₂) nor ozone levels in the interstitial air showed a clear dependence on incident solar irradiance, much in contrast to observations in polar snow. Comparisons with findings from polar snow studies reveal a much different (NO + NO₂) and ozone snow chemistry in this alpine environment. Snowpack concentration gradients and diffusion theory were applied to estimate an average, wintertime (NO + NO₂) flux of 0.005–0.008 nmol m⁻² s⁻¹, which is of similar magnitude as reported (NO + NO₂) fluxes from polar snow. While fluxes are similar, there is strong evidence that processes controlling (NO + NO₂) fluxes in these environments are very different, as subnivial soil at Niwot Ridge appears to be the main source of the (NO + NO₂) efflux, whereas in polar snow (NO + NO₂) has been found to be primarily produced from photochemical de-nitrification of snow nitrate.     

Assessment of Modeled Indoor Air Concentrations of Particulate Matter,Gaseous Pollutants,and Volatile Organic Compounds Emitted from Candles

Candle burning is regarded as an important source of airborne pollutants in indoor environments. Indoor concentrations of aldehydes, benzo(a)pyrene, sulphur dioxide (SO₂), nitrogen oxides (NO_x), and particulate matter (PM) produced from the burning of scented candles and raw materials with different melting point/oil content (50/1, 55/9, and 65/6) were predicted using a single compartment mass balance model and compared to regulatory or guideline limits. Scented candles may be responsible for indoor acrolein concentrations that could become relevant to health only in the case of chronic exposure. Indoor concentrations of fine PM and SO₂ emitted from 65/6 wax burning under worst-case environmental and behavioral conditions were greater than their respective acute guideline limits. However, other waxes had levels of PM and SO₂ well below the recommended values. Indoor concentrations of nitrogen dioxide emitted from raw wax burning should be further investigated. The degree of pureness of raw waxes significantly affected the predicted indoor concentrations of PM and SO₂. In particular, 65/6 wax was criticized for its high content of impurities.     

Energy Cost of Living and Associated Pollution for Beijing Residents

China's remarkable economic growth in the last 3 decades has brought about big improvements in quality of life while simultaneously contributing to serious environmental problems. The aim of all economic activities is, ultimately, to provide the population with products and services. Analyzing environmental impacts of consumption can be valuable for illuminating underlying drivers for energy use and emissions in society. This study applies an environmentally extended input‐output analysis to estimate household environmental impact (HEI) of urban Beijing households at different levels of development. The analysis covers direct and indirect energy use and emissions of carbon dioxide (CO₂), sulfur dioxide (SO₂), and nitrogen oxide (NO_x). On the basis of observations of how HEI varies across income groups, prospects for near‐future changes in HEI are discussed. Results indicate that in 2007, an urban resident in Beijing used, on average, 52 gigajoules of total primary energy supply. The corresponding annual emissions were 4.2 tonnes CO₂, 27 kilograms SO₂, and 17 kilograms NO_x. Of this, only 18% to 34% was used or emitted by the households directly. While the overall expenditure elasticity of energy use is around 0.9, there is a higher elasticity of energy use associated with transport. The results suggest that significant growth in HEI can be expected in the near future, even with substantial energy efficiency improvements.     

Is there and do we need evidence on eHealth interventions?

The proliferation of information and communication technology (ICT) is transforming the healthcare, as an information-intensive sector, in a way that has never been witnessed before. The use of ICT in health or eHealth has the potential to improve the quality of health services, improve access to services and reduce cost. Huge investments in eHealth initiatives have been made by many countries based on this potential. A body of evidence is being developed to show the value of eHealth. Research and evaluation in eHealth should be comprehensive and not only limited to technology. There is a need for more research in this area using a multidisciplinary approach and teams.     

Microbial removal of nitrogen monoxide (NO) under aerobic conditions

Nitrogen oxide gas (NO_x), consisting of nitrogen monoxide (NO) and nitrogen dioxide (NO₂), at a low concentration corresponding to that on roads as a result of exhaust from automobiles, was supplied for 25 days through a laboratory-scale biofilter packed with soil as a packing material. The removal efficiency of NO₂ by soil was almost 100%, and the removal efficiency of NO was 60% on average and 86% at maximum. By using -irradiated soil as a packing material, NO₂ was completely removed mainly by adsorption onto or absorption into the packing material. However, the removal efficiency of NO in the sterilized soil was only 20%, suggesting that NO in soil was removed microbiologically under aerobic conditions.     

Nitrogen uptake,assimilation and transport in barley in the presence of atmospheric nitrogen dioxide

Summary Exposure of the leaves of young barley plants to nitrogen dioxide (NO₂) was shown to affect the rate of translocation of N, the form in which it is transported in the xylem stream and the partitioning of N between roots and shoots. Following its entry through the leaves, NO₂ is assimilated by the plant into reduced nitrogenous compounds which accounted for the major increases in plant N content and growth. The various effects of atmospheric NO₂ upon barley seedlings were strongly influenced by nitrate supply to the roots.     

Converting carbon dioxide to high value-added products: Microalgae-based green biomanufacturing

Today's world faces the dual pressure of carbon dioxide (CO₂) emission reduction and an energy crisis. Microalgae, which can use solar energy to convert CO₂ to organic matter, have emerged as a promising and renewable cell factory for producing nutrients, biofuels, and various high value-added compounds (HVACs). They possess numerous advantages, such as high photosynthetic efficiency, fast growth rate, and use of agro-industrial waste and nonagricultural land for cultivation. Microalgae can also effectively remove eutrophic elements (e.g., nitrogen and phosphorus) from wastewater and atmospheric pollutants (e.g., SO_x and NO_x) from flue gas, thus providing great environmental benefits. However, microalgae-based production often faces low productivity, limiting applicability in industrial settings. Genetic and metabolic modifications of certain microalgal strains have proven effective in improving productivity. Here, we review the latest developments regarding the microalgae-based production of platform compounds, biofuels, and other HVACs. Although still in the early exploration stage, the rapid development of gene editing tools, a deeper understanding of the metabolic pathways of microalgae and their regulatory mechanisms, and further optimization of cultivation procedures and photosynthetic efficiency can eventually enable the launch of microalgae-based biomanufacturing for green industrial production. Therefore, this technology is strategically important for solving the current energy crisis problems of excessive CO₂ emissions and environmental pollution. This review provides information about the advancement and development of microalgae-based production over the past two decades and discusses possible future directions in the field.     

不同生境盐地碱蓬对氮饥饿的响应

为了探讨不同生境盐地碱蓬对低氮生境的适应机制,测定了盐渍环境下(200 mmol/L Na Cl)不同浓度硝态氮(0.3、5 mmol/L NO~-_3-N)预处理两种生境盐地碱蓬经氮饥饿后的NO~-_3含量、硝酸还原酶(NR)活性、光合特性及生长状况。结果表明,0.3和5 mmol/L NO~-_3-N处理以及进行氮饥饿时,潮间带生境盐地碱蓬叶片NO~-_3含量均高于内陆生境盐地碱蓬。与内陆生境盐地碱蓬相比,氮饥饿后,潮间带生境盐地碱蓬叶绿素含量、NR活性和光合放氧速率下降幅度均小于内陆生境盐地碱蓬,在0.3mmol/L NO~-_3-N预处理进行氮饥饿时趋势更加明显。0.3 mmol/L NO~-_3-N预处理后氮饥饿对潮间带生境盐地碱蓬根冠比没有影响,却降低内陆生境盐地碱蓬根冠比。上述结果表明,低氮条件下潮间带生境盐地碱蓬具有较高的NO~-_3储存能力,在环境持续氮素缺乏时具有较高的NO~-_3-N再利用能力,能更好地维持氮代谢以及光合性能。说明潮间带生境盐地碱蓬能更好地适应低氮生境。     

Kinematic evidence that atmospheric nitrogen dioxide increases the rates of cell proliferation and enlargement to stimulate leaf expansion in Arabidopsis

To elucidate the stimulation of leaf growth by atmospheric nitrogen dioxide (NO₂), we performed a kinematic analysis of the eighth leaves of Arabidopsis thaliana (accession C24) plants grown for 17–35 days after sowing in the presence or absence of 50 ppb NO₂ (designated +NO₂ plants and –NO₂ plants, respectively). We found that the peak and mean values of the relative rates of leaf expansion, cell division and cell expansion were always greater in +NO₂ plants than in –NO₂ plants. No evidence for prolonged duration was obtained. Thus, NO₂ treatment increased the rates of both cell proliferation and enlargement to increase leaf size. Furthermore, a fold-change analysis showed that cell proliferation and enlargement differentially regulated NO₂-induced leaf expansion.     

Benefits of coordinated action in PACS evaluation

PACS, a health care technology still in its developmental stage, aims to improve the management of diagnostic imaging investigations. As the technology has not been comprehensively assessed, data and facts to justify its clinical, economic and other benefits are to date insufficient. Through internationally coordinated action, it is expected to obtain a faster and more comprehensive technology assessment of PACS as well as recommendations for optimization of the system and guidelines for its rational use in various health care environments.     

The effect of air pollution from nitrogen dioxide (NO2) on epiphytic lichens in Seville, Spain

The effect of air pollution from nitrogen dioxide (NO₂) on the epiphytic lichens of the city of Seville (Spain) has been studied. Indices of air purity (IAP) were calculated, based on the lichen flora ofMelia azedarach L. present at 25 stations distributed through the city. The arrangement and classification of the stations by principal component analysis and cluster analysis, respectively, enabled the study area to be zoned into four zones of air purity. Accordingly, the zonal map of air purity for the city of Seville yields a gradient of air purity that is very steep from the centre to the outskirts. The dependence of 77.6% of IAP variability with NO₂ pollution levels detected with air emission sensors distributed through the city suggests the relationship between NO₂ levels and zones of air purity.     

Nitrogen metabolism in haloarchaea

The nitrogen cycle (N-cycle), principally supported by prokaryotes, involves different redox reactions mainly focused on assimilatory purposes or respiratory processes for energy conservation. As the N-cycle has important environmental implications, this biogeochemical cycle has become a major research topic during the last few years. However, although N-cycle metabolic pathways have been studied extensively in Bacteria or Eukarya, relatively little is known in the Archaea. Halophilic Archaea are the predominant microorganisms in hot and hypersaline environments such as salted lakes, hot springs or salted ponds. Consequently, the denitrifying haloarchaea that sustain the nitrogen cycle under these conditions have emerged as an important target for research aimed at understanding microbial life in these extreme environments. The haloarchaeon Haloferax mediterranei was isolated 20 years ago from Santa Pola salted ponds (Alicante, Spain). It was described as a denitrifier and it is also able to grow using NO₃ ^-, NO₂ ^- or NH₄ ⁺ as inorganic nitrogen sources. This review summarizes the advances that have been made in understanding the N-cycle in halophilic archaea using Hfx mediterranei as a haloarchaeal model. The results obtained show that this microorganism could be very attractive for bioremediation applications in those areas where high salt, nitrate and nitrite concentrations are found in ground waters and soils.     

Leaf nitrogen dioxide uptake coupling apoplastic chemistry, carbon/sulfur assimilation, and plant nitrogen status

Emission and plant uptake of atmospheric nitrogen oxides (NO + NO₂) significantly influence regional climate change by regulating the oxidative chemistry of the lower atmosphere, species composition and the recycling of carbon and nutrients, etc. Plant uptake of nitrogen dioxide (NO₂) is concentration-dependent and species-specific, and covaries with environmental factors. An important factor determining NO₂ influx into leaves is the replenishment of the substomatal cavity. The apoplastic chemistry of the substomatal cavity plays crucial roles in NO₂ deposition rates and the tolerance to NO₂, involving the reactions between NO₂ and apoplastic antioxidants, NO₂-responsive germin-like proteins, apoplastic acidification, and nitrite-dependent NO synthesis, etc. Moreover, leaf apoplast is a favorable site for the colonization by microbes, which disturbs nitrogen metabolism of host plants. For most plant species, NO₂ assimilation in a leaf primarily depends on the nitrate (NO₃ ⁻) assimilation pathway. NO₂–N assimilation is coupled with carbon and sulfur (sulfate and SO₂) assimilation as indicated by the mutual needs for metabolic intermediates (or metabolites) and the NO₂-caused changes of key metabolic enzymes such as phosphoenolpyruvate carboxylase (PEPc) and adenosine 5′-phosphosulfate sulfotransferase, organic acids, and photorespiration. Moreover, arbuscular mycorrhizal (AM) colonization improves the tolerance of host plants to NO₂ by enhancing the efficiency of nutrient absorption and translocation and influencing foliar chemistry. Further progress is proposed to gain a better understanding of the coordination between NO₂–N, S and C assimilation, especially the investigation of metabolic checkpoints, and the effects of photorespiratory nitrogen cycle, diverse PEPc and the metabolites such as cysteine, O-acetylserine (OAS) and glutathione.     

Web-based consumer health information: public access, digital division, and remainders

Public access Internet portals and decreasing costs of personal computers have created a growing consensus that unequal access to information, or a "digital divide," has largely disappeared for US consumers. A series of technology initiatives in the late 1990s were believed to have largely eliminated the divide. For healthcare patients, access to information is an essential part of the consumer-centric framework outlined in the recently proposed national health information initiative. Data from a recent study of health information-seeking behaviors on the Internet suggest that a "digitally underserved group" persists, effectively limiting the planned national health information infrastructure to wealthier Americans.     

Getting more for their dollar: a comparison of the NHS with California's Kaiser Permanente

ObjectiveTo compare the costs and performance of the NHS with those of an integrated system for financing and delivery health services (Kaiser Permanente) in California.MethodsThe adjusted costs of the two systems and their performance were compared with respect to inputs, use, access to services, responsiveness, and limited quality indicators.ResultsThe per capita costs of the two systems, adjusted for differences in benefits, special activities, population characteristics, and the cost environment, were similar to within 10%. Some aspects of performance differed. In particular, Kaiser members experience more comprehensive and convenient primary care services and much more rapid access to specialist services and hospital admissions. Age adjusted rates of use of acute hospital services in Kaiser were one third of those in the NHS.ConclusionsThe widely held beliefs that the NHS is efficient and that poor performance in certain areas is largely explained by underinvestment are not supported by this analysis. Kaiser achieved better performance at roughly the same cost as the NHS because of integration throughout the system, efficient management of hospital use, the benefits of competition, and greater investment in information technology.

What is already known on this topic

Comparisons of healthcare systems in different countries have to be undertaken with great care but can be instructiveThe overall healthcare system in the United States is more expensive than the NHS and population health outcomes are no betterThe US healthcare system comprises many discrete and unique subsystems, including the health maintenance organisations

What this paper adds

An integrated, non-profit health maintenance organisation in California (Kaiser Permanente), with over six million members, costs about the same as the NHS but performs considerably betterKaiser''s superior performance is mainly in prompt and appropriate diagnosis and treatmentThese findings challenge the widely held view that the NHS is efficient and that its inadequacies are mainly due to underinvestment     

Photosynthesis and nitrogen utilization in exponentially growing nitrogen-limited cultures of Lemna gibba

The photosynthetic performance and nitrogen utilization of Lemna gibba L. G3 adapted to limited nitrogen supply was studied. The plants were adapted to two levels of nitrogen limitation where the nitrogen addition rates were calculated to sustain relative growth rates (RGR) of 0.15 day^?1 and 0.25 day^?1, respectively. The photosynthetic performance of these cultures was compared to nitrogen-sufficient cultures with an average RGR of 0.32 day^?1. Plants transferred from nitrogen-sufficient conditions attained RGR values corresponding to the nitrogen addition rates after 6 to 10 days. Light-saturated net photosynthesis declined during adaptation according to the drop in growth rate, and a concomitant decrease in the respiration rate was recorded. The efficiency of net photosynthesis on a dry weight basis increased with increased nitrogen supply, whereas it was the same in all cultures when expressed on a chlorophyll basis. The light compensation point was unaffected by the nitrogen regime. Limited nitrogen supply resulted in an increased proportion of dry matter in the roots, which led to decreased leaf area ratios. The net assimilation rates also decreased, but not to the same extent as the leaf area ratios. Growth-limiting amounts of nitrogen were added to the cultures once daily, and the net influx of N was higher than the requirement for N, also in adapted cultures with a steady growth rate. This resulted in transient, periodic fluctuations in the NO₃^?, NH₄⁺ and amino acid pools. Also the rates of NO₃^? reduction and NH₄⁺ assimilation fluctuated as did the amino acid assimilation which paralleled NH₄⁺ assimilation. The role of flux rates over the plasmalemma and tonoplast for control of nitrogen assimilation rates are discussed.