Ozone pollution in the Southeast US involves complex chemistry driven by emissions of anthropogenic nitrogen oxide radicals (NO(x) triple bond NO + NO2) and biogenic isoprene. Model estimates of ...surface ozone concentrations tend to be biased high in the region and this is of concern for designing effective emission control strategies to meet air quality standards. We use detailed chemical observations from the SEAC(exp 4)RS aircraft campaign in August and September 2013, interpreted with the GEOS-Chem chemical transport model at 0.25 deg x 0.3125 deg horizontal resolution, to better understand the factors controlling surface ozone in the Southeast US. We find that the National Emission Inventory (NEI) for NO(x) from the US Environmental Protection Agency (EPA) is too high. This finding is based on SEAC(exp 4)RS observations of NO(x) and its oxidation products, surface network observations of nitrate wet deposition fluxes, and OMI satellite observations of tropospheric NO2 columns. Our results indicate that NEI NO(x) emissions from mobile and industrial sources must be reduced by 30-60%, dependent on the assumption of the contribution by soil NO(x) emissions. Upper-tropospheric NO2 from lightning makes a large contribution to satellite observations of tropospheric NO2 that must be accounted for when using these data to estimate surface NO(x) emissions. We find that only half of isoprene oxidation proceeds by the high-NO(x) pathway to produce ozone; this fraction is only moderately sensitive to changes in NO(x) emissions because isoprene and NO(x) emissions are spatially segregated. GEOS-Chem with reduced NO(x) emissions provides an unbiased simulation of ozone observations from the aircraft and reproduces the observed ozone production efficiency in the boundary layer as derived from a regression of ozone and NO(x) oxidation products. However, the model is still biased high by 6 plus or minus 14 ppb relative to observed surface ozone in the Southeast US. Ozonesondes launched during midday hours show a 7 ppb ozone decrease from 1.5 km to the surface that GEOS-Chem does not capture. This bias may reflect a combination of excessive vertical mixing and net ozone production in the model boundary layer.
Calcific aortic valve stenosis (CAVS) is a major health problem facing aging societies. The identification of osteoblast-like and osteoclast-like cells in human tissue has led to a major paradigm ...shift in the field. CAVS was thought to be a passive, degenerative process, whereas now the progression of calcification in CAVS is considered to be actively regulated. Mechanistic studies examining the contributions of true ectopic osteogenesis, nonosseous calcification, and ectopic osteoblast-like cells (that appear to function differently from skeletal osteoblasts) to valvular dysfunction have been facilitated by the development of mouse models of CAVS. Recent studies also suggest that valvular fibrosis, as well as calcification, may play an important role in restricting cusp movement, and CAVS may be more appropriately viewed as a fibrocalcific disease. High-resolution echocardiography and magnetic resonance imaging have emerged as useful tools for testing the efficacy of pharmacological and genetic interventions in vivo. Key studies in humans and animals are reviewed that have shaped current paradigms in the field of CAVS, and suggest promising future areas for research.
Monoclonal antibodies (mAbs) targeting the immune checkpoint anti-programmed cell death protein 1 (aPD-1) have demonstrated impressive benefits for the treatment of some cancers; however, these drugs ...are not always effective, and we still have a limited understanding of the mechanisms that contribute to their efficacy or lack thereof. We used in vivo imaging to uncover the fate and activity of aPD-1 mAbs in real time and at subcellular resolution in mice. We show that aPD-1 mAbs effectively bind PD-1
tumor-infiltrating CD8
T cells at early time points after administration. However, this engagement is transient, and aPD-1 mAbs are captured within minutes from the T cell surface by PD-1
tumor-associated macrophages. We further show that macrophage accrual of aPD-1 mAbs depends both on the drug's Fc domain glycan and on Fcγ receptors (FcγRs) expressed by host myeloid cells and extend these findings to the human setting. Finally, we demonstrate that in vivo blockade of FcγRs before aPD-1 mAb administration substantially prolongs aPD-1 mAb binding to tumor-infiltrating CD8
T cells and enhances immunotherapy-induced tumor regression in mice. These investigations yield insight into aPD-1 target engagement in vivo and identify specific Fc/FcγR interactions that can be modulated to improve checkpoint blockade therapy.
As wearable fitness devices have gained commercial acceptance, interest in real-time monitoring of an individual’s physiological status using noninvasive techniques has grown. Microneedles have been ...proposed as a minimally invasive technique for sampling the dermal interstitial fluid (ISF) for clinical monitoring and diagnosis, but little is known about its composition. In this study, a novel microneedle array was used to collect dermal ISF from three healthy human donors and compared with matching serum and plasma samples. Using a shotgun quantitative proteomic approach, 407 proteins were quantified with at least one unique peptide, and of those, 135 proteins were differently expressed at least 2-fold. Collectively, these proteins tended to originate from the cytoplasm, membrane bound vesicles, and extracellular vesicular exosomes. Proteomic analysis confirmed previously published work that indicates that ISF is highly similar to both plasma and serum. In this study, less than one percent of proteins were uniquely identified in ISF. Taken together, ISF could serve as a minimally invasive alternative for blood-derived fluids with potential for real-time monitoring applications.
Summary Background Afatinib, an irreversible ErbB-family blocker, has shown preclinical activity when tested in EGFR mutant models with mutations that confer resistance to EGFR tyrosine-kinase ...inhibitors. We aimed to assess its efficacy in patients with advanced lung adenocarcinoma with previous treatment failure on EGFR tyrosine-kinase inhibitors. Methods In this phase 2b/3 trial, we enrolled patients with stage IIIB or IV adenocarcinoma and an Eastern Cooperative Oncology Group performance (ECOG) performance score of 0–2 who had received one or two previous chemotherapy regimens and had disease progression after at least 12 weeks of treatment with erlotinib or gefitinib. We used a computer-generated sequence to randomly allocate patients (2:1) to either afatinib (50 mg per day) or placebo; all patients received best supportive care. Randomisation was done in blocks of three and was stratified by sex and baseline ECOG performance status (0–1 vs 2). Investigators, patients, and the trial sponsor were masked to treatment assignment. The primary endpoint was overall survival (from date of randomisation to death), analysed on an intention-to-treat basis. This study is registered with ClinicalTrials.gov , number NCT00656136. Findings Between May 26, 2008, and Sept 21, 2009, we identified 697 patients, 585 of whom were randomly allocated to treatment (390 to afatinib, 195 to placebo). Median overall survival was 10·8 months (95% CI 10·0–12·0) in the afatinib group and 12·0 months (10·2–14·3) in the placebo group (hazard ratio 1·08, 95% CI 0·86–1·35; p=0·74). Median progression-free survival was longer in the afatinib group (3·3 months, 95% CI 2·79–4·40) than it was in the placebo group (1·1 months, 0·95–1·68; hazard ratio 0·38, 95% CI 0·31–0·48; p<0·0001). No complete responses to treatment were noted; 29 (7%) patients had a partial response in the afatinib group, as did one patient in the placebo group. Subsequent cancer treatment was given to 257 (68%) patients in the afatinib group and 153 (79%) patients in the placebo group. The most common adverse events in the afatinib group were diarrhoea (339 87% of 390 patients; 66 17% were grade 3) and rash or acne (305 78% patients; 56 14% were grade 3). These events occurred less often in the placebo group (18 9% of 195 patients had diarrhoea; 31 16% had rash or acne), all being grade 1 or 2. Drug-related serious adverse events occurred in 39 (10%) patients in the afatinib group and one (<1%) patient in the placebo group. We recorded two possibly treatment-related deaths in the afatinib group. Interpretation Although we recorded no benefit in terms of overall survival with afatinib (which might have been affected by cancer treatments given after progression in both groups), our findings for progression-free survival and response to treatment suggest that afatinib could be of some benefit to patients with advanced lung adenocarcinoma who have failed at least 12 weeks of previous EGFR tyrosine-kinase inhibitor treatment. Funding Boehringer Ingelheim Inc.
Ion exchange membranes are widely used to selectively transport ions in various electrochemical devices. Hydroxide exchange membranes (HEMs) are promising to couple with lower cost platinum-free ...electrocatalysts used in alkaline conditions, but are not stable enough in strong alkaline solutions. Herein, we present a Cu2+-crosslinked chitosan (chitosan-Cu) material as a stable and high-performance HEM. The Cu2+ ions are coordinated with the amino and hydroxyl groups of chitosan to crosslink the chitosan chains, forming hexagonal nanochannels (~1 nm in diameter) that can accommodate water diffusion and facilitate fast ion transport, with a high hydroxide conductivity of 67 mS cm−1 at room temperature. The Cu2+ coordination also enhances the mechanical strength of the membrane, reduces its permeability and, most importantly, improves its stability in alkaline solution (only 5% conductivity loss at 80 °C after 1,000 h). These advantages make chitosan-Cu an outstanding HEM, which we demonstrate in a direct methanol fuel cell that exhibits a high power density of 305 mW cm−2. The design principle of the chitosan-Cu HEM, in which ion transport channels are generated in the polymer through metal-crosslinking of polar functional groups, could inspire the synthesis of many ion exchange membranes for ion transport, ion sieving, ion filtration and more.A Cu2+-crosslinked chitosan material with unique 1 nm hexagonal nanochannels is synthesized and applied as a high-performance and alkaline-stable hydroxide exchange membrane.
A method for the decarboxylative macrocyclization of peptides bearing N‐terminal Michael acceptors has been developed. This synthetic method enables the efficient synthesis of cyclic peptides ...containing γ‐amino acids and is tolerant of functionalities present in both natural and non‐proteinogenic amino acids. Linear precursors ranging from 3 to 15 amino acids cyclize effectively under this photoredox method. To demonstrate the preparative utility of this method in the context of bioactive molecules, we synthesized COR‐005, a somatostatin analogue that is currently in clinical trials.
Oh, take me back to the start: A method for the decarboxylative macrocyclization of peptides bearing N‐terminal Michael acceptors was developed. This photoredox method enables efficient synthesis of cyclic peptides containing γ‐amino acids and is tolerant of functionalities present in natural amino acids. Linear precursors ranging from 3 to 15 amino acids can be effectively cyclized by using this method.
Dysregulation of Antioxidant Mechanisms Contributes to Increased Oxidative Stress in Calcific Aortic Valvular Stenosis in Humans Jordan D. Miller, Yi Chu, Robert M. Brooks, Wayne E. Richenbacher, ...Ricardo Peña-Silva, Donald D. Heistad Oxidative stress plays an important role in development of atherosclerotic lesions. We report that superoxide and H2 O2 levels are increased in calcified and peri-calcified regions of stenotic aortic valves and are associated with increases in myofibroblast activation and pro-osteogenic gene expression. In striking contrast to atherosclerotic plaques, increases in oxidative stress in aortic valves are not due to increases in nicotinamide adenine dinucleotide phosphate oxidase activity but seem to be due to reductions in antioxidant defense mechanisms and increases in uncoupling of nitric oxide synthase. We propose that oxidative stress might play an important role in driving calcification in aortic valve stenosis.
Summary Background Afatinib is an irreversible ErbB-family blocker with preclinical activity in non-small-cell lung cancer (NSCLC) with EGFR mutations. We aimed to assess the efficacy of afatinib in ...patients with lung adenocarcinoma and EGFR mutations. Methods In this phase 2 study, we enrolled patients from 30 centres in Taiwan and the USA with lung adenocarcinoma (stage IIIb with pleural effusion or stage IV) with EGFR mutations, who had no more than one previous chemotherapy regimen for advanced disease, an Eastern Cooperative Oncology Group performance status of 0–2, and no previous treatment with EGFR tyrosine-kinase inhibitors. We tested two afatinib starting doses: 50 mg daily and subsequently 40 mg daily, introduced to establish whether tolerability could be improved with retention of anti-tumour activity. The primary endpoint was the proportion of patients with a confirmed objective response (complete response or partial response), on the basis of Response Evaluation Criteria in Solid Tumors 1.0 (independent review). This study is registered with ClinicalTrials.gov , number NCT00525148. Findings 129 patients were treated with afatinib, 99 with a starting dose of 50 mg and 30 with a starting dose of 40 mg. 79 (61%) of 129 patients had an objective response (two complete responses, 77 partial responses). 70 (66%) of the 106 patients with the two common activating EGFR mutations (deletion 19 or L858R) had an objective response, as did nine (39%) of 23 patients with less common mutations. Similar proportions of patients had an objective response when analysed by starting dose (18 60% of 30 patients at 40 mg vs 61 62% of 99 patients at 50 mg). Of the two most common adverse events (diarrhoea and rash or acne), grade 3 events were more common in patients receiving a 50 mg starting dose (22 22% of 99 patients for diarrhoea and 28 28% of 99 patients for rash or acne) than they were in those receiving a 40 mg starting dose (two 7% of 30 patients for both diarrhoea and rash or acne); possibly treatment-related serious adverse events were also less common in patients receiving a 40 mg starting dose (two of 30 patients vs 14 of 99 patients). We recorded one possibly drug-related death (interstitial lung disease). Interpretation Afatinib shows activity in the treatment of patients with advanced lung adenocarcinoma with EGFR mutations, especially in patients with deletion 19 or L858R mutations. The efficacy of afatinib 40 mg should be compared with chemotherapy or other EGFR tyrosine-kinase inhibitors in EGFR-mutation-positive NSCLC. Funding Boehringer Ingelheim Inc.
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