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Introduction: Percutaneous thermal ablation is widely adopted as a curative treatment approach for unresectable liver neoplasms. Accurate immediate assessment of therapeutic response post-ablation is critical to achieve favourable outcomes. The conventional technique of side-by-side comparison of pre- and post-ablation scans is challenging and hence there is a need for improved methods, which will accurately evaluate the immediate post-therapeutic response. Objectives and Significance: This review summarizes the findings of studies investigating the feasibility and efficacy of the fusion imaging systems in the immediate post-operative assessment of the therapeutic response to thermal ablation in liver neoplasms. The findings could potentially empower the clinicians with updated knowledge of the state-of-the-art in the assessment of treatment response for unresectable liver neoplasms. Methods and Analysis: A rapid review will be performed on publicly available major electronic databases to identify articles reporting the feasibility and efficacy of the fusion imaging systems in the immediate assessment of the therapeutic response to thermal ablation in liver neoplasms. The risk of bias and quality of articles will be assessed using the Cochrane risk of bias tool 2.0 and Newcastle Ottawa tool. Ethics and Dissemination: Being a review, we do not anticipate the need for any approval from the Institutional Review Board. The outcomes of this study will be published in a peer-reviewed journal. Highlights Evaluation of the therapeutic response in liver neoplasms immediately post-ablation is critical to achieve favourable patient outcomes. We will examine the feasibility and technical efficacy of different fusion imaging systems in assessing the immediate treatment response post-ablation. The findings are expected to guide the clinicians with updated knowledge on the state-of-the-art when assessing the immediate treatment response for unresectable liver neoplasms.

The oxidative potential (OP) of ambient particulate matter (PM) is a metric commonly used to link the aerosol exposure to its adverse health effects. In this study, we report the first-ever real-ti...

Organic aerosols in the Arctic are predominantly fuelled by anthropogenic sources in winter and natural sources in summer, according to observations from eight sites across the Arctic Aerosols play an important yet uncertain role in modulating the radiation balance of the sensitive Arctic atmosphere. Organic aerosol is one of the most abundant, yet least understood, fractions of the Arctic aerosol mass. Here we use data from eight observatories that represent the entire Arctic to reveal the annual cycles in anthropogenic and biogenic sources of organic aerosol. We show that during winter, the organic aerosol in the Arctic is dominated by anthropogenic emissions, mainly from Eurasia, which consist of both direct combustion emissions and long-range transported, aged pollution. In summer, the decreasing anthropogenic pollution is replaced by natural emissions. These include marine secondary, biogenic secondary and primary biological emissions, which have the potential to be important to Arctic climate by modifying the cloud condensation nuclei properties and acting as ice-nucleating particles. Their source strength or atmospheric processing is sensitive to nutrient availability, solar radiation, temperature and snow cover. Our results provide a comprehensive understanding of the current pan-Arctic organic aerosol, which can be used to support modelling efforts that aim to quantify the climate impacts of emissions in this sensitive region.

In recent years, the Indian capital city of Delhi has been impacted by very high levels of air pollution, especially during winters. Comprehensive knowledge of the composition and sources of the organic aerosol (OA), which constitutes a substantial fraction of total particulate mass (PM) in Delhi, is central to formulating effective public health policies. Previous source apportionment studies in Delhi identified key sources of primary OA (POA) and showed that secondary OA (SOA) played a major role, but were unable to resolve specific SOA sources. We address the latter through the first field deployment of an extractive electrospray ionization time-of-flight mass spectrometer (EESI-TOF) in Delhi, together with a high-resolution aerosol mass spectrometer (AMS). Measurements were conducted during the winter of 2018/2019, and positive matrix factorization (PMF) was used separately on AMS and EESI-TOF datasets to apportion the sources of OA. AMS PMF analysis yielded three primary and two secondary factors which were attributed to hydrocarbon-like OA (HOA), biomass burning OA (BBOA-1 and 2), more oxidized oxygenated OA (MO-OOA), and less oxidized oxygenated OA (LO-OOA). On average, 40 % of the total OA mass was apportioned to the secondary factors. The SOA contribution to total OA mass varied greatly between daytime (76.8 %, 10:00–16:00 local time (LT)) and nighttime (31.0 %, 21:00–04:00 local time). The higher chemical resolution of EESI-TOF data allowed identification of individual SOA sources. The EESI-TOF PMF analysis in total yielded six factors, two of which were primary factors (primary biomass burning and cooking-related OA). The remaining four factors were predominantly of secondary origin: aromatic SOA, biogenic SOA, aged biomass burning SOA, and mixed urban SOA. Due to the uncertainties in the EESI-TOF ion sensitivities, mass concentrations of EESI-TOF SOA dominated factors were related to the total AMS SOA (i.e., MO-OOA + LO-OOA) by multi-linear regression (MLR). Aromatic SOA was the major SOA component during the day-time, with 55.2 % contribution to total SOA mass (42.4 % contribution to total OA). Its contribution to total SOA, however, decreased to 25.4 % (7.9 % of total OA) during night-time. This factor was attributed to the oxidation of light aromatic compounds emitted mostly from traffic. Biogenic SOA accounted for 18.4 % of total SOA mass (14.2 % of total OA) during day-time and 36.1 % of total SOA mass (11.2 % of total OA) during night-time. Aged biomass burning and mixed urban SOA accounted for 15.2 % and 11.0 % of total SOA mass ( 11.7 % and 8.5 % of total OA mass) during day-time respectively and 15.4 % and 22.9 % of total SOA mass (4.8 % and 7.1 % of total OA mass) during night-time, respectively. A simple dilution/partitioning model was applied on all EESI-TOF factors to estimate the fraction of observed day-time concentrations resulting from local photochemical production (SOA) or emissions (POA). Aromatic SOA, aged biomass burning, and mixed urban SOA were all found to be dominated by local photochemical production, likely from the oxidation of locally emitted VOCs. In contrast, biogenic SOA was related to the oxidation of diffuse regional emissions of isoprene and monoterpenes. The findings of this study show that in Delhi, the night-time high concentrations are caused by POA emissions led by traffic and biomass burning, and the daytime OA is dominated by SOA, with aromatic SOA accounting for the largest fraction. Because aromatic SOA is possibly more toxic than biogenic SOA and primary OA, its dominance during the day-time suggests an increased OA toxicity and health-related consequences for the general public.

Krakow is routinely affected by very high air pollution levels, especially during the winter months. Although a lot of effort has been done on characterization of ambient aerosols, there is a lack of online and long-term measurements of non-refractory aerosols. Our measurements at AGH University provide online long-term chemical composition of ambient submicron particulate matter (PM1) between January 2018 and April 2019. Here we report the chemical characterization of non-refractory submicron aerosols and source apportionment of the organic fraction by positive matrix factorization (PMF). In contrast to other long-term source apportionment studies, we let a small PMF window roll over the dataset instead of performing PMF over the full dataset or on separate seasons. In this way, the seasonal variation of the source profiles can be captured. The uncertainties of the PMF solutions are addressed by the bootstrap resampling strategy and the random a-value approach for constrained factors.We observe clear seasonal patterns in concentration and composition of PM1, with high concentrations during the winter months and lower concentrations during the summer months. Organics are the dominant species throughout the campaign. Five organic aerosol (OA) factors are resolved, of which three are of primary nature (hydrocarbon-like OA (HOA), biomass burning OA (BBOA) and coal combustion OA (CCOA)) and two are of secondary nature (more oxidized oxygenated OA (MO-OOA) and less oxidized oxygenated OA (LO-OOA)). While HOA contributes on average 8.6 % ± 2.3 % throughout the campaign, the solid fuel combustion related BBOA and CCOA show a clear seasonal trend with average contributions of 10.4 % ± 2.7 % and 14.1 %, ± 2.1 % respectively. The highest contributions are observed during wintertime as a result of residential heating. Throughout the campaign, the OOA can be separated into MO-OOA and LO-OOA with average contribution of 38.4 % ± 8.4 % and 28.5 % ± 11.2 %, respectively.

Characteristics and sources of volatile organic compounds (VOCs) were investigated with highly time-resolved measurements by a proton-transfer-reaction time-of-flight mass spectrometer (PTR-ToF-MS) at an urban site in Beijing in winter 2017. During the measurement period, high mixing ratios of VOCs (48.9 ppbv) and trace gases were observed, with alternating episodes of strong haze pollution and clean air. Ten VOC families showed clear dependence on the VOC concentration. Aromatics increased the most during haze, with significantly elevated benzene concentration at high VOC concentration, while CxHyO3 and CxHy increased the least. The positive matrix factorization (PMF) receptor model was applied to the VOC mass spectra, yielding four major VOC factors: traffic emissions (21.0%), solid fuel combustion (SFC, 24.4%), and two oxygenated VOC (OVOC) factors (32.3% and 22.3%). Traffic and solid fuel combustion were dominant during the periods of high total VOC concentration, while the OVOC1 fraction was reduced. Comparisons with organic aerosol (OA) sources showed increased oxygenated organic aerosol (OOA) concentration during high VOC concentration periods, indicating the importance of OVOCs to secondary organic aerosol formation. Furthermore, trajectory analysis showed that most of the clean days were associated with northerly winds with high ratios of OVOC1. In contrast, the haze periods were not only due to high primary emissions under stagnant conditions, but also influenced by air masses from a more regional scale.

Characteristics and sources of ambient particle elements in urban Beijing were studied by hourly observations in two size fractions (PM

We present highly time-resolved (30 to 120 min) measurements of size-fractionated (PM10 and PM2.5) elements in two cities in Asia (Delhi and Beijing) and Europe (Krakow and London). For most elements, the mean concentrations in PM10 and PM2.5 are higher in Asian cities (up to 24 and 28 times, respectively) than in Krakow, and often higher in Delhi than in Beijing. Among European cities, Krakow shows higher elemental concentrations (up to 20 and 27 times, respectively) than London. The enrichment factor of an element together with the size distribution allows for a rough classification of elements by major sources. We define five groups: (1) dust-related, (2) non-exhaust traffic emissions, (3) solid fuel combustion, (4) mixed traffic/industrial emissions, and (5) industrial/coal/waste burning emissions, with the last group exhibiting the most site-to-site variability. Hourly maximum concentrations of Pb and Zn reach up to 1 µg m−3 in Delhi, substantially higher than at the other sites. We demonstrate that the high time resolution and size-segregated elemental dataset can be a powerful tool to assess aerosol composition and sources in urban environments. Our results highlight the need to consider the size distributions of toxic elements, diurnal patterns of targeted emissions, and local vs. regional effects in formulating effective environmental policies to protect public health.

National Capital Region (NCR) encompassing New Delhi is one of the most polluted urban metropolitan areas in the world. Real-time chemical characterization of fine particulate matter (PM1 and PM2.5) was carried out using three aerosol mass spectrometers, two aethalometers, and one single particle soot photometer (SP2) at two sites in Delhi (urban) and one site located ~40 km downwind of Delhi, during January–March 2018. The campaign mean PM2.5 (NR-PM2.5 + BC) concentrations at the two urban sites were 153.8 ± 109.4 μg.m−3 and 127.8 ± 83.2 μg.m−3, respectively, whereas PM1 (NR-PM1 + BC) was 72.3 ± 44.0 μg.m−3 at the downwind site. PM2.5 particles were composed mostly of organics (43–44)% followed by chloride (14–17)%, ammonium (9–11)%, nitrate (9%), sulfate (8–10)%, and black carbon (11–16)%, whereas PM1 particles were composed of 47% organics, 13% sulfate as well as ammonium, 11% nitrate as well as chloride, and 5% black carbon. Organic aerosol (OA) source apportionment was done using positive matrix factorization (PMF), solved using an advanced multi-linear engine (ME-2) model. Highly mass-resolved OA mass spectra at one urban and downwind site were factorized into three primary organic aerosol (POA) factors including one traffic-related and two solid-fuel combustion (SFC), and three oxidized OA (OOA) factors. Whereas unit mass resolution OA at the other urban site was factorized into two POA factors related to traffic and SFC, and one OOA factor. OOA constituted a majority of the total OA mass (45–55)% with maximum contribution during afternoon hours ~(70–80)%. Significant differences in the absolute OOA concentration between the two urban sites indicated the influence of local emissions on the oxidized OA formation. Similar PM chemical composition, diurnal and temporal variations at the three sites suggest similar type of sources affecting the particulate pollution in Delhi and adjoining cities, but variability in mass concentration suggest more local influence than regional.

A completely eco-friendly and straightforward protocol for the biologically important isochromeno[4,3-b]indoles derivatives has been developed employing beta cyclodextrin in aqueous medium. This documented strategy includes the elimination of hazardous catalysts and volatile organic solvents. Additionally this protocol highlights environmentally benign reaction conditions, short reaction times, operational simplicity, easy workup and purification procedure and good yield of products.

Herein, we present the synthesis of pyrrolo[2,3-d]pyrimidine derivatives, which are important heterocyclic scaffolds in the field of synthetic and pharmaceutical research, via biomimetic catalysis. This strategy involves the use of β-cyclodextrin as a reusable promoter and water as an eco-friendly reaction medium. The merits of this protocol are high atom economy, mild reaction conditions, good yields of desired products in short reaction times, and reusable reaction medium.

A new approach for 5-amino-pyrazole-4-carbonitriles has been developed employing visible light photoredox catalysis. The green attributes of our work exploit on the utilization of visible light and Eosin Y organo photocatalyst as inexpensive, non-toxic, readily-available and eco-compatible reagents. In this strategy atmospheric O2 served as an. economical and eco sustainable desulfurizing agent, efficiently promotes the formation of C C and C N bonds in a simple one-pot operation under mild conditions thus increase the efficiency of proposed protocol.

Megacities worldwide are suffering from elevated air pollution due, e.g., to continuously increasing urbanization, and a sizeable amount of the population in such areas is exposed to particulate matter (PM) concentrations exceeding the WHO limits. Huge efforts are therefore undertaken to characterize the air pollution situation and to reduce or mitigate the impact on the population and the environment. Modern instrumentation allows for a quantitative determination of aerosol concentration and composition with high time resolution (minutes to hours), and subsequent source apportionment.We collected PM10 and PM2.5 aerosols alternatingly with an online X-ray fluorescence (XRF) spectrometer in the cities of New Delhi (India) in 2019, Beijing (China) in 2017, and Krakow (Poland) in 2018, with time resolutions from 30 to 120 min, and in London (UK) in 2012 with 3-stage rotating drum impactors and subsequent offline SR-XRF analysis. Campaigns lasted for two to seven weeks in fall and winter. Elements from Al to Bi were analyzed in near-real time, except for London.Our results show that some of the cities experience episodic extreme events, whereas extremely high elemental concentrations are chronic in others. Toxic metals are shown to be strongly location-dependent, and may occur in extreme plumes. Meteorological conditions also play an important role and will be discussed. The regional influence of fine PM, in comparison to the more local origin of coarse PM will be evaluated. The differences among the four cities, with substantially higher concentrations in the Asian cities than the European ones will be discussed. Highly time-resolved size-segregated sampling allowed for a rough classification of elements into five groups and will be described in detail. We demonstrate that the use of size information on toxic elements, diurnal patterns of targeted emissions, and local vs. regional effects are advantageous for formulating effective environmental policies to protect public health.

Size resolved data of chemical species carries a lot of latent information about the sources and atmospheric processes which lead to their formation and growth. Source apportionment techniques on organic or inorganic aerosols provide a fair amount of information about the sources but this analysis only provides a partial picture owing to the complicated nature of the ambient aerosols which may contain both, organic as well as inorganic particulate matter. Traditionally, potential emission sources are distinguished by either the organic or inorganic tracers present in ambient aerosol, but recently several studies have performed PMF on both the species (Sun et al, 2012). However, it tells more about the final transformed products which could be formed from different pathways but not much about the transformation pathways. Insights about the source and the atmospheric processes involved can be derived from the analysis of size-resolved data of the ambient aerosol. PMF on Size-resolved information helps us to narrow down the possible pathways of the transformed products.However, there is very limited literature available to help us understand more about size-resolved bulk particulate matter. In this manuscript, a novel approach to perform Positive Matrix Factorization (PMF) on real-time size-resolved Unit Mass Resolution (UMR) data from Aerosol Mass Spectrometer (AMS) is presented. Both size- and time-resolved PMF is performed on non-refractory particle composition (organic & inorganic) on the UMR PTOF data of two sites in one of the most polluted cities in the world. The sampling through Long Time of flight mass spectrometer (LToF-AMS) was carried out at Indian Institute of Technology, Delhi which is located in Hauz Khaz area, at the heart of Delhi NCR, whereas parallel sampling through High-resolution Time of flight aerosol mass spectrometer (HR-ToF-AMS) was carried out at Manav Rachna University which is located in Faridabad within Delhi NCR at a downwind location. PMF was performed on the data by using Multi-linear Engine (ME-2) on PMF model by SoFi (Source Finder) tool. A seven-factor solution was chosen based on the factor profiles, time series, diurnals and correlation with the external factors obtained by supplementary instruments. The size-resolved spectra of the species at an individual site was studied and the difference between the sites was compared.

Characteristics and sources of volatile organic compounds (VOCs) were investigated with highly time-resolved simultaneous measurements by two proton-transfer-reaction time-of-flight mass spectrometers (PTR-ToF-MS) at an urban and a suburban site in New Delhi, India from January to March 2018. During the measurement period, high mixing ratios of VOCs and trace gases were observed, with high nocturnal mixing ratios and strong day-night variations. The positive matrix factorization (PMF) receptor model was applied separately to the two sites, and six major factors of VOCs were identified at both sites, i.e., two factors related to traffic emissions, two to solid fuel combustion, and two secondary factors. At the urban IITD site, traffic-related emissions comprising mostly mono-aromatic compounds were the dominant sources, contributing 56.6 % of the total mixing ratio, compared to 36.0 % at the suburban MRIU site. Emissions from various solid fuel combustion processes, particularly in the night, were identified as a significant source of aromatics, phenols and furans at both sites. The secondary factors accounted for 15.9 % of the total VOC concentration at IITD and for 33.6 % at MRIU. They were dominated by oxygenated VOCs and exhibited substantially higher contributions during daytime.

Delhi, the capital of India, suffers from heavy local emissions as well as regional transport of air pollutants, resulting in severe aerosol loadings. To determine the sources of these pollutants, we have quantified the mass concentrations of 26 elements in airborne particles, measured by an online X-ray fluorescence spectrometer with time resolution between 30 min and 1 h. Measurements of PM10 and PM2.5 (particulate matter

The key objective of this study was to unravel the major sources of PM10-2.5 (defined as PM10-PM2.5 or coarse particles) within and near the city of Kanpur. Airborne particulate matter (PM) samples were collected from 1st April to 15th July, 2011. The average mass concentration of coarse particles was found to be 64.3 ± 51.16 µg/m3. In addition to the mass concentrations of coarse particles their black carbon (BC), water soluble inorganic carbon (WSIC), water soluble organic carbon (WSOC), water-soluble ions and elemental composition were also determined. The size-resolved data set was processed via Positive Matrix Factorization (PMF) to carefully identify major sources and an attempt was made to quantify their respective source strengths. The contribution of these sources to the coarse PM mass concentration was also assessed. The identified sources and their contributions for the coarse particles were paved road dust (53%), vehicular emission (7%), coal combustion & brick kilns (2.5%), construction activities and incineration (0.5%), crustal dust (32%) and biomass burning and oil combustion (5%).

Delhi is one of the most polluted cities globally, with frequent severe air pollution episodes and haze events occurring in recent years, thereby compelling us to understand the sources to develop effective mitigation plans. Complete chemical characterization of fine particulate matter (PM2.5) components (non-refractory, refractory and elements) with high time resolution has been done during the summer season (June–July 2019). The total PM equivalent (PM2.5(eq)) was 28.7 ± 13.2 μg m−3 of which elements dominated the PM2.5(eq) with 34% contribution followed by organics (28%), black carbon (BC) (17%), SO42− (10%), Cl− (5%) NH4+ (3.5%) and NO3− (2.5%). The contributions from organic aerosols (OA) and SO42− were observed to be more than Cl− and NO3−. The total elemental mass concentration (PMEl) was mostly contributed (~96%) by Si, S, Cl, Ca, K, Fe and Al with Si and S alone contributing around 50% of PMEl. Crustal elements (Al, Fe, Ca and Si) were highly enhanced in summer than elements emitted from anthropogenic emissions (Cl, S, K, Pb and Zn). Source apportionment (SA) of PM was performed using positive matrix factorization (PMF) together with ME-2 (multilinear engine) for OA and elements, separately. PMF on both datasets helped resolve sources such as combustion, industrial, dust-related, incineration and traffic. OA PMF identified three factors related to primary emissions: hydrocarbon-like OA (HOA, 12.3%), solid fuel combustion (SFC, 16.2%) and cooking OA (COA, 7.3%) and two oxygenated OA (OOA): semi-volatile OOA (SVOOA, 15.2%) and low-volatile OOA (LVOOA, 49.1%). The elemental PMF resolved 8 factors: dust (52.5%), S-rich (16.2%), Cl-rich (10.7%), 2 SFC factors (10.5%), non-exhaust (7.2%), Cu-rich (1.5%) and industrial (1.4%). The contribution of BC to total PM mass is shown to increase in the summer compared to previous studies reported for the winter season. The secondary oxidized sources dominated both the OA and elements SA during the summer with 64.3% and 27% (dust not considered) contribution, respectively. The domination of secondary sources implies that it is crucial to control the secondary aerosols' precursors in Delhi for developing pollution control strategies. The ME-2 resolved factors, coupled with concentration weighted trajectory (CWT) showed the probable major elemental source regions of local origin (Delhi- National Capital Region (Delhi-NCR)) as well as regional (from Punjab, Haryana, Uttar Pradesh and Pakistan). The local sources included Cu-rich (Haryana) and SFC-II (Delhi and Uttar Pradesh), while the regional sources were dust (south-west (SW)), industrial, Cl-rich (north-west (NW)), SFC-I (east and south-east (SE)) and S-rich (SE).

Characteristics and sources of ambient particle elements in urban Beijing were studied by hourly observations in two size fractions (PM10 and PM2.5) during November and December 2017 using an online multi-element analyzer. The reconstructed oxide concentrations of 24 elements (from Al to Pb) comprise an appreciable fraction of PM10 and PM2.5, accounting for 37% and 17%, respectively on average. We demonstrate the benefit of using high-time-resolution chemical speciation data in achieving robust source apportionment of the total elemental PM10 (PM10el) and elemental PM2.5 (PM2.5el) mass using positive matrix factorization (PMF). Biomass burning, coal combustion, secondary sulfate, industry, non-exhaust traffic and dust were identified in both size fractions (with varying relative concentrations), which accounted on average for 4%, 12%, 5%, 2%, 14%, and 63%, respectively to the total PM10el, and 14%, 35%, 21%, 6%, 12% and 12%, respectively to the total PM2.5el. Biomass burning and coal combustion exhibited higher concentrations during haze episodes of the heating season. In contrast, secondary sulfate and industry contributed more to haze episodes during the non-heating season. The fractional contribution of dust was mostly high during clean days, while the fractional non-exhaust traffic emission contribution was similar throughout the measurement period. The non-exhaust traffic emissions contributed locally, while the remaining sources were dominated by neighboring areas. Furthermore, trajectory analysis showed that the origin of the industrial sources roughly agreed with the locations of the main point sources. Overall, this work provides detailed information on the characteristics of the elements during different haze events during heating and non-heating seasons.

This study examines the light absorption characteristics of fine atmospheric particulates using the co-located real-time measurements of chemical and optical aerosol characteristics at a site located in Delhi during winter. The contribution of absorption by black carbon and brown carbon (BC and BrC) to the total absorption (babs) is computed using the absorption Angstrom exponent (AAE) method. The period average contribution of BrC absorption (babs_BrC) to babs is found to be highest at 370 nm (23%) that decreased exponentially with increasing wavelengths, i.e.,18, 12, 10, and 4% at 470, 520, 590, and 660 nm, respectively. The absorption spectrum of BrC is used to study the bulk composition of BrC, which indicates that primary BrC was dominant during morning and night time, whereas secondary BrC was significant during the rest of the time. Further, organic aerosols (OA) were divided into different factors using positive-matrix factorization (PMF) analysis, and the mass absorption efficiency (Eabs) of each factor was assessed through multivariate linear regression of babs_BrC with OA factors. The biomass burning OA (BBOA) exhibited the highest Eabs at 370 nm (0.86 m2 g−1), followed by semi-volatile oxygenated OA (SVOOA; 0.67 m2 g−1) and hydrocarbon-like OA (HOA; 0.42 m2 g−1). Further, although the composition of OA was dominated by LVOOA (32%) and BBOA (32%), followed by SVOOA (22%), and HOA (14%), their contribution to bBrC followed different order due to differences in their mass absorption efficiencies. The BBOA contributed almost half (48%) of babs_BrC followed by SVOOA (26%), and HOA (10%). This study provides quantitative information on the sources of BrC and their relative contribution to BrC absorption over a heavily polluted region, which is still lacking in the literature. These results have implications in understanding the source-specific BrC absorption.

The keratocystic odontogenic tumor (KCOT), earlier considered as the odontogenic keratocyst (OKC), is now classified as a benign neoplasm owing to its aggressive nature which includes a high recurrence rate. This case report describes a symptomatic large intraosseous odontogenic cystic neoplasm in the left mandible presenting radiographically as a large multilocular radiolucency and associated with an impacted tooth. The typical clinical and distinguishing histological features of KCOT morphed by the presence of inflammation are discussed here together with an intriguing clear cell component and epithelial theques and their clinical relevance. The newly acknowledged neoplastic potential serving significant role in treatment planning has also been addressed. Various lesions can present intraosseously as large multilocular radiolucencies in the jaws. Histopathological examination remains the mainstay for the diagnosis of such lesions.

In this work, we disclose a convenient and eco-friendly protocol for the synthesis of spiropyran derivatives by one-pot three-component reaction of ninhydrin, active methylene compounds and 1,3-dicarbonyl using Compact fluorescent lamp as a source of light in the absence of any additional catalyst. In view of the various advantages this strategy gives an efficient and straightforward pathway to construct spiropyrans in an eco-friendly fashion.

This study addresses the three major questions: (1) what are the emission sources of PM1 which are affecting the study area; (2) where do these emission sources come from; and (3) is there any temporal variation in the emission sources. To address these issues, two advanced statistical methods are described in this paper. Identification of emission sources was performed by EPA PMF (v 5.0) and to understand the temporal variability, sampling was done for three winter seasons 2008–09, 2009–10 and 2011–12 within Kanpur city. To identify the possible source directions, Conditional Bivariate Probability function (CBPF) was used. The average PM1 concentration was higher in 2008–09 followed by 2011–12 and 2009–10 winter seasons. 2008–09 winter showed sources such as secondary sources mixed with power plant emission (42.8%), industrial emission (32.3%), coal combustion, brick kilns and vehicular emission (13.2%) and residual oil combustion and road dust (11.7%). The major contributors during winter season 2009–10 were secondary sources (33.1%), biomass burning (23.3%), heavy oil combustion (13%), vehicular emission mixed with crustal dust (11.3%), leather tanning industries (10.3%), industrial emission (4%), coal combustion and brick kilns (3.4%) and solid waste burning and incineration (1.5%) compared to secondary sources mixed with biomass burning (42.3%), industrial emission and crustal dust (35.1%) and vehicular emission and brick kilns (22.6%) during 2011–12 winter season. PMF model revealed that secondary sources were the main contributors for all the three winter seasons followed by biomass burning and power plant emission. The results of CBPF analysis agreed well with the locations of known local point sources., e.g. in the case of industrial emissions, the maximum probability was in the direction between NES direction where almost all the major industries are located in and around Kanpur while in the opposite direction the probability of biomass burning was high due to a rural area in NWS direction.

A new high yielding protocol has been developed for the convenient and rapid synthesis of 2-amino-4H-pyrans by one-pot sequential reaction of aldehydes, malononitrile and cyanoketones in aqueous micellar medium using chitosan as an efficient heterogeneous, biodegradable and reusable green catalyst. Mild conditions with excellent conversions, cost effectiveness, short reaction times, environmental friendliness, and operational simplicity are noteworthy advantages of this method. The micellar catalytic system can be reused several times without any noticeable decrease in its activity.

Trace element measurements in PM10 were performed with 1 h time resolution at a rural freeway site during summer 2015 in Switzerland using the Xact multi-metals monitor. On average the Xact 625 elements (without accounting for oxygen and other associated elements) make up about 20 % of the total PM10 mass (14.6 µg m−3). Subsequently, a source apportionment by positive matrix factorization (PMF) implemented via the Source Finder software (SoFi Pro) was applied. Eight different sources were identified (notable elements in brackets) for PM10: fireworks-I (K, S, Ba, Cl), fireworks-II (K), sea salt (Cl), secondary sulfate (S), background dust (Si, Ti), road dust (Ca), traffic-related (Fe) and industrial (Zn, Pb). The major components were secondary sulfate and traffic-related followed by background dust and road dust factors, explaining 21 %, 20 %, 18 % and 16 % of the analysed PM10 elemental mass, respectively, with the factor mass not corrected for oxygen content. Further, there are minor contributions (on the order of a few percent) of sea salt and industrial sources. The regionally influenced secondary sulfate factor experiences negligible resuspension, and concentrations are similar throughout the day. The significant loads of the traffic-related and road dust factors with strong diurnal variations highlight the continuing importance of vehicle-related air pollutants at this site. Enhanced control of PMF using SoFi Pro allowed for a successful apportionment of transient sources such as the two firework factors and sea salt, which remained mixed when analysed by unconstrained PMF.

A combination of ZnO nanoparticles and β-cyclodextrin was used as an efficient and green catalytic system for the synthesis of 3-aryl-4H-benzo[1,4]thiazin-2-amine via a one-pot, three-component reaction of an o-amino thiophenol, aromatic aldehydes and isocyanides in good to excellent yields at 60 °C in water. The nano size of ZnO was confirmed by transmission electron microscopy (TEM), XRD and UV-visible spectral techniques. A high catalytic activity and easy recovery and reuse for several cycles with consistent activity are additional eco-friendly attributes of this catalytic system.

An efficient, three-component strategy for synthesis of 1,3-thiazines with high atom economy in one-pot mediated by room temperature basic ionic liquid is described here. The strategy involves basic ionic liquid, [bmim]OH-catalyzed Knoevenagel condensation between ethyl cyanoacetate and aromatic aldehyde and subsequent thia-Michael addition with substituted thioureas. The reaction sequence is smooth and quantitative under ambient temperature. [bmim]OH was recovered and reused four times without any appreciable decrease in its reactivity and product yield.

A versatile, operationally simple and highly efficient one-pot three-component approach for the synthesis of spiro oxazolidine oxindole derivatives has been developed by the domino reaction of isatins, arylacetylenes, and N -tosyl aldimines in acetonitrile catalyzed by InBr 3 at ambient temperature. The significant advantages of this protocol are highlighted by excellent yields, cleaner reaction profiles, avoidance of toxic catalyst, broader substrate scope, and successful assembly of three new C–C, C–N and C–O bonds.

A facile, efficient and environmentally friendly approach has been developed for the diverse synthesis of 1,4-dihydropyridazines from (E)-2-benzylidene-1-phenylhydrazine and α,β-unsaturated aldehyde under aqueous condition using molecular iodine as a green and recoverable catalyst. This procedure features low cost and easily available starting materials, an inexpensive and recoverable catalyst, short reaction time, reliable scalability, excellent yield and mild reaction conditions, as well as use of aqueous medium. The scope of this method was thoroughly explored under three different reaction conditions resulting in the generation of a library of title compounds. In view of the various advantages of the present investigation, this methodology gives a convenient and straightforward pathway to construct 1,4-dihydropyridazines in an eco-friendly fashion.

A simple and highly efficient strategy has been documented for the rapid and convenient synthesis of 1-methyl-5-phenylbenzo[g]pyrimido[4,5-b]quinoline-2,4,6,11(1H,3H)-tetraone from aldehydes, 2-hydroxynaphthalene1,4dione and 6-aminouracil in the presence of nano ZnO under an aqueous admicellar system at 80 °C. Results show that nano ZnO is a potential catalyst for the synthesis of pyrimido[4,5-b]quinoline. Nano ZnO was recovered and reused efficiently several times for the synthesis of the desired product which is an essential parameter of green synthesis. The reported method represents an eco-friendly alternative to classical protocols. Nano size of ZnO was confirmed by EDS, transmission electron microscopy (TEM) and XRD techniques.