In urban environments, airborne particles are continuously emitted, followed by atmospheric aging. Also, particles emitted elsewhere, transported by winds, contribute to the urban aerosol. We studied ...the effective density (mass-mobility relationship) and mixing state with respect to the density of particles in central Copenhagen, in wintertime. The results are related to particle origin, morphology, and aging. Using a differential mobility analyzer-aerosol particle mass analyzer (DMA-APM), we determined that particles in the diameter range of 50–400 nm were of two groups: porous soot aggregates and more dense particles. Both groups were present at each size in varying proportions. Two types of temporal variability in the relative number fraction of the two groups were found: soot correlated with intense traffic in a diel pattern and dense particles increased during episodes with long-range transport from polluted continental areas. The effective density of each group was relatively stable over time, especially of the soot aggregates, which had effective densities similar to those observed in laboratory studies of fresh diesel exhaust emissions. When heated to 300 °C, the soot aggregate volatile mass fraction was ∼10%. For the dense particles, the volatile mass fraction varied from ∼80% to nearly 100%.
From Water Clustering to Osmotic Coefficients Frosch, Mia; Bilde, Merete; Nielsen, Ole F
The journal of physical chemistry. A, Molecules, spectroscopy, kinetics, environment, & general theory,
11/2010, Letnik:
114, Številka:
44
Journal Article
Recenzirano
Water activity is an important macroscopic property of aerosol particles and droplets in the atmosphere as well as aqueous solutions in many other fields of physical chemistry. This study focuses on ...relating water activity, described using osmotic coefficients, to the microscopic water structure in systems of atmospheric relevance, namely, aqueous solutions of each of the four electrolytes: NaCl, (NH4)2SO4, NH4Cl, and Na2SO4. The osmotic coefficients of these compounds, as reported in literature based on thermodynamic measurements, decrease as a function of molality for dilute solutions and increase as a function of molality for concentrated solutions. At an intermediate molality, a minimum value of the osmotic coefficient is observed. We explain this behavior by describing osmotic coefficients as the product of two concentration-dependent effects: incomplete electrolyte dissociation and variations in the microphysical water structure. The degree of dissociation in electrolyte solutions can be obtained directly from literature or derived from reported pK values, and in this work the water structure is quantified using low-wavenumber Raman spectroscopy. We use the band at 180 cm−1 in Raman spectra of aqueous electrolyte solutions, which has been assigned to the displacement of the central oxygen atom in a tetrahedral hydrogen bonding environment composed of five H2O units. The abundance of such translationally restricted water molecules is essential in describing the local microphysical structure of water, and the height of the band is used to estimate the amount of such translationally restricted water molecules in solution. We were able to qualitatively reproduce and explain literature values of osmotic coefficients for the four studied electrolytes. Our results indicate that the effect of electrolyte dissociation, which decreases as a function of molality, dominates in dilute solutions, whereas changes in water structure are more significant at higher concentrations.
The Multiple Chamber Aerosol Chemical Aging Study (MUCHACHAS) tested the hypothesis that hydroxyl radical (OH) aging significantly increases the concentration of first-generation biogenic secondary ...organic aerosol (SOA). OH is the dominant atmospheric oxidant, and MUCHACHAS employed environmental chambers of very different designs, using multiple OH sources to explore a range of chemical conditions and potential sources of systematic error. We isolated the effect of OH aging, confirming our hypothesis while observing corresponding changes in SOA properties. The mass increases are consistent with an existing gap between global SOA sources and those predicted in models, and can be described by a mechanism suitable for implementation in those models.
In a series of smog chamber experiments, the cloud condensation nuclei (CCN) activity of secondary organic aerosol (SOA) generated from ozonolysis of β-caryophyllene was characterized by determining ...the CCN derived hygroscopicity parameter, κCCN, from experimental data. Two types of CCN counters, operating at different temperatures, were used. The effect of semi-volatile organic compounds on the CCN activity of SOA was studied using a thermodenuder. Overall, SOA was only slightly CCN active (with κCCN in the range 0.001–0.16), and in dark experiments with no OH scavenger present, κCCN decreased when particles were sent through the thermodenuder (with a temperature up to 50 °C). SOA was generated under different experimental conditions: In some experiments, an OH scavenger (2-butanol) was added. SOA from these experiments was less CCN active than SOA produced in experiments without an OH scavenger (i.e. where OH was produced during ozonolysis). In other experiments, lights were turned on, either without or with the addition of HONO (OH source). This led to the formation of more CCN active SOA. SOA was aged up to 30 h through exposure to ozone and (in experiments with no OH scavenger present) to OH. In all experiments, the derived κCCN consistently increased with time after initial injection of β-caryophyllene, showing that chemical ageing increases the CCN activity of β-caryophyllene SOA. κCCN was also observed to depend on supersaturation, which was explained either as an evaporation artifact from semi-volatile SOA (only observed in experiments lacking light exposure) or, alternatively, by effects related to chemical composition depending on dry particle size. Using the method of Threshold Droplet Growth Analysis it was also concluded that the activation kinetics of the SOA do not differ significantly from calibration ammonium sulphate aerosol for particles aged for several hours.
It is estimated that more than 90% of the 5.2 million kilometers of European paved roads and highways are surfaced with asphalt. Also, about 44% of goods are transported by road in the EU; ...maintaining their condition whilst in transit is crucial for the economy.
The construction of a new road has a number of implications for the environment, consuming large amount of materials and energy. Also, the price of crude oil, which is the major source of bituminous binder, has significantly increased in recent years (the most noticeably in 2001–2008). This has led to an increase in the total price of asphalt mixtures.
In order to promote sustainable practices and to combat price increase, measures with sound sustainability credentials need to be widely implemented. Developing novel materials and technologies to integrate greener material, waste and recycled materials into the production cycle of asphalt mixtures is a solution that improves both sustainability and cost-efficiency of the asphalt pavement industry.
The main concept presented in this paper is the application of an eco-innovative asphalt pavement designed through partial substitution of greener materials into asphalt mixtures: reclaimed asphalt pavement (RAP), construction and demolition waste (C&DW), lignin (by-product of 2nd generation bioethanol processing) and bio-binder from vegetable oil. This paper discusses a new concept of an asphalt pavement structure with ecologically oriented attributes, achieved whilst maintaining a level of long term performance comparable or greater than that of conventional pavement structures.
The two main components of asphalt mixture – bitumen and aggregates – are focused upon. In relation to bitumen, two methods to ‘green’ the fresh binder fraction are explored: The first investigates bio-fluxing bitumen, which enables part of the petro-chemical binder to be replaced with bio-based products; the second uses a specific industrial waste, also bio-derived, to replace the crude-oil derived polymer in modified bitumen. In relation to aggregates, two different approaches are also explored: The use of high rates of reclaimed asphalt pavement (RAP) in new hot asphalt mixtures, thanks to the addition of bio-fluxing agents which will allow working at lower temperatures, and the use of construction and demolition waste (C&DW). Optimal integration of C&DW as raw material will be established using a selective process for the separation of C&DW to increase the overall quality of the recycled aggregates.
Considering the full pavement structure, the main innovations can be summarized as follows: (A) in surface course is the introduction of green bitumen modifier, derived from recovered waste bioethanol production as an alternative to the traditional additives used for polymer modification; (B) in binder and base course, bio-fluxing agents allow for the integration of higher percentage of reclaimed asphalt; and (C) the lower layers (sub-base and subgrade) are mainly composed of materials derived from construction and demolition waste.
This paper describes the systematic approach for selecting the right combination of these main pavement components in the design of asphalt mixtures, from laboratory tests to real applications. This approach has been developed by a consortium of partners in the FP7 funded Asphalt Pavements for a Sustainable Environment (APSE) project.
Correction to “From Water Clustering to Osmotic Coefficients” Frosch, Mia; Bilde, Merete; Nielsen, Ole F
The journal of physical chemistry. A, Molecules, spectroscopy, kinetics, environment, & general theory,
05/2011, Letnik:
115, Številka:
17
Journal Article
Diverse genetic, epigenetic, and developmental programs drive glioblastoma, an incurable and poorly understood tumor, but their precise characterization remains challenging. Here, we use an ...integrative approach spanning single-cell RNA-sequencing of 28 tumors, bulk genetic and expression analysis of 401 specimens from the The Cancer Genome Atlas (TCGA), functional approaches, and single-cell lineage tracing to derive a unified model of cellular states and genetic diversity in glioblastoma. We find that malignant cells in glioblastoma exist in four main cellular states that recapitulate distinct neural cell types, are influenced by the tumor microenvironment, and exhibit plasticity. The relative frequency of cells in each state varies between glioblastoma samples and is influenced by copy number amplifications of the CDK4, EGFR, and PDGFRA loci and by mutations in the NF1 locus, which each favor a defined state. Our work provides a blueprint for glioblastoma, integrating the malignant cell programs, their plasticity, and their modulation by genetic drivers.
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•Four cellular states drive glioblastoma malignant cells heterogeneity•In vivo single-cell lineage tracing supports plasticity between these four states•Genetics and the microenvironment influence the frequency of cells in each state•TCGA subtypes reflect the highest-frequency malignant states and the microenvironment
Single-cell analyses of glioblastoma samples reveal multiple cellular states, their plasticity and the genetic underpinnings of state proportions in a given tumor.
Brain metastases from lung adenocarcinoma (BM-LUAD) frequently cause patient mortality. To identify genomic alterations that promote brain metastases, we performed whole-exome sequencing of 73 ...BM-LUAD cases. Using case-control analyses, we discovered candidate drivers of brain metastasis by identifying genes with more frequent copy-number aberrations in BM-LUAD compared to 503 primary LUADs. We identified three regions with significantly higher amplification frequencies in BM-LUAD, including MYC (12 versus 6%), YAP1 (7 versus 0.8%) and MMP13 (10 versus 0.6%), and significantly more frequent deletions in CDKN2A/B (27 versus 13%). We confirmed that the amplification frequencies of MYC, YAP1 and MMP13 were elevated in an independent cohort of 105 patients with BM-LUAD. Functional assessment in patient-derived xenograft mouse models validated the notion that MYC, YAP1 or MMP13 overexpression increased the incidence of brain metastasis. These results demonstrate that somatic alterations contribute to brain metastases and that genomic sequencing of a sufficient number of metastatic tumors can reveal previously unknown metastatic drivers.
The genetic alterations that define primary central nervous system lymphoma (PCNSL) are incompletely elucidated, and the genomic evolution from diagnosis to relapse is poorly understood. We performed ...whole-exome sequencing (WES) on 36 PCNSL patients and targeted MYD88 sequencing on a validation cohort of 27 PCNSL patients. We also performed WES and phylogenetic analysis of 3 matched newly diagnosed and relapsed tumor specimens and 1 synchronous intracranial and extracranial relapse. Immunohistochemistry (IHC) for programmed death-1 ligand (PD-L1) was performed on 43 patient specimens. Combined WES and targeted sequencing identified MYD88 mutation in 67% (42 of 63) of patients, CDKN2A biallelic loss in 44% (16 of 36), and CD79b mutation in 61% (22 of 36). Copy-number analysis demonstrated frequent regions of copy loss (ie, CDKN2A), with few areas of amplification. CD79b mutations were associated with improved progression-free and overall survival. We did not identify amplification at the PD-1/PD-L1 loci. IHC for PD-L1 revealed membranous expression in 30% (13 of 43) of specimens. Phylogenetic analysis of paired primary and relapsed specimens identified MYD88 mutation and CDKN2A loss as early clonal events. PCNSL is characterized by frequent mutations within the B-cell receptor and NF-κB pathways. The lack of PD-L1 amplifications, along with membranous PD-L1 expression in 30% of our cohort, suggests that PD-1/PD-L1 inhibitors may be useful in a subset of PCNSL. WES of PCNSL provides insight into the genomic landscape and evolution of this rare lymphoma subtype and potentially informs more rational treatment decisions.
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Introduction Advances in multiple myeloma (MM) treatment improve survival but expose patients (pts) to significant financial toxicity (FT) due to lifelong administration of costly therapies. ...Financial support services (FSS) like nurse navigators (NN), financial advocates (FA), and social workers (SW) can offset healthcare costs by accessing patient assistance programs. However, these services are underused due to ad hoc referrals and reluctance to discuss financial issues. We developed a financial navigation program (FNP) that proactively identifies pts at risk of FT, comprehensively assesses their needs, systematically connects pts to resources, and follows-up to ensure needs are met. In a randomized controlled trial (RCT), we assessed whether this FNP reduces FT compared to usual care. Methods We recruited adult pts with MM receiving systemic treatment at the University of Pennsylvania at their follow-up appointments. Consenting pts completed the COmprehensive Score for financial Toxicity (COST) questionnaire; those at risk of FT (score<26) were randomized 1:1 to the intervention (FNP) or usual care. We aimed to randomize 82 participants to achieve 80% power based on prior studies (expected improvement in COST by 5 in intervention, 2 in usual care). Pts completed a baseline survey to assess socioeconomic and demographic factors, cost-coping behaviors, quality of life (QoL), and satisfaction. After 4 months, pts completed a similar, final survey. In the FNP, the NN assessed financial and transportation barriers to care by telephone, performed proactive outreach to FA and SW, and coordinated resources, followed by monthly follow-up calls. We measured patient-reported outcomes as change from baseline to study completion; the primary outcome was change in COST score. Secondary outcomes were changes in cost-coping behaviors, QoL, and satisfaction. We performed an intention-to-treat, bivariate analysis (t-test or χ 2 test) of each outcome and conducted rapid thematic analysis of free-text responses. We also observed consenting pts whose baseline COST≥26, and - in post-hoc analysis - assessed for differential change in COST score at follow-up among this cohort vs the randomized/at-risk population. Results We assessed 315 pts from Feb-Dec 2022 ( Figure): 193 consented, 106 randomized, and 83 were included in analysis (41 in intervention, 42 in usual care). Randomized pts were an average of 65 years, 53% female, 39% nonwhite, 78% college-educated, and 51% earned ≤$60,000/year. This contrasted with 8% non-white pts among the non-randomized (high baseline COST) group (p<0.001). Despite all randomized pts being insured, 55% reported that MM treatment costs posed a significant financial burden. Many (46%) were on lenalidomide containing regimens. The mean, baseline COST score was 14.4 (SD 7.5) in the intervention versus 16.0 (SD 6.5) in usual care (p=0.3). Most pts had baseline FSS use, with a higher proportion in usual care (76%) than intervention (51%), p=0.03. During a median follow-up of 4.9 months, 17% in usual care received FSS. In the intervention arm, 95% participated in the FNP, with 68% completing ≥3 follow-up calls within 4 months. Randomized (at risk) pts showed an average improvement in COST of 4.6 (SD 8.9), significantly different from the non-randomized (low risk) group's mean worsening of -15.8 (SD 7.2) at follow-up; p<0.001. The intervention arm had a greater but non-significant improvement in COST score (mean 5.7 SD 8.8) compared to usual care (mean 3.5 SD 8.9); p=0.3. There were no significant changes in cost coping behaviors, QoL, or satisfaction between the two randomized arms. There was a significantly higher number of financial assistance applications submitted among pts randomized to the FNP (34%) vs usual care (12%); p=0.02. Patient feedback indicated the FNP improved understanding of FSS and reduced stress. Conclusions In this study, we confirmed that most pts with MM experience financial hardship and are at-risk of FT, despite being insured. We observed significant racial disparities in this risk. Our RCT showed that by screening pts with the COST tool and proactively coordinating FSS for at-risk pts, we can potentially reduce financial hardship. We attribute the non-significant improvement in FT to an under-powered analysis from higher-than-expected improvement in COST among usual care pts. Our program is efficient and scalable and demonstrated high retention.
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