Ubiquitous atmospheric production of organic acids mediated by cloud droplets.

Atmospheric acidity is increasingly determined by carbon dioxide and organic acids1-3. Among the latter, formic acid facilitates the nucleation of cloud droplets4 and contributes to the acidity of clouds and rainwater1,5. At present, chemistry-climate models greatly underestimate the atmospheric burden of formic acid, because key processes related to its sources and sinks remain poorly understood2,6-9. Here we present atmospheric chamber experiments that show that formaldehyde is efficiently converted to gaseous formic acid via a multiphase pathway that involves its hydrated form, methanediol. In warm cloud droplets, methanediol undergoes fast outgassing but slow dehydration. Using a chemistry-climate model, we estimate that the gas-phase oxidation of methanediol produces up to four times more formic acid than all other known chemical sources combined. Our findings reconcile model predictions and measurements of formic acid abundance. The additional formic acid burden increases atmospheric acidity by reducing the pH of clouds and rainwater by up to 0.3. The diol mechanism presented here probably applies to other aldehydes and may help to explain the high atmospheric levels of other organic acids that affect aerosol growth and cloud evolution.

Needle-like structures discovered on positively charged lightning branches.

Lightning is a dangerous yet poorly understood natural phenomenon. Lightning forms a network of plasma channels propagating away from the initiation point with both positively and negatively charged ends-called positive and negative leaders1. Negative leaders propagate in discrete steps, emitting copious radio pulses in the 30-300-megahertz frequency band2-8 that can be remotely sensed and imaged with high spatial and temporal resolution9-11. Positive leaders propagate more continuously and thus emit very little high-frequency radiation12. Radio emission from positive leaders has nevertheless been mapped13-15, and exhibits a pattern that is different from that of negative leaders11-13,16,17. Furthermore, it has been inferred that positive leaders can become transiently disconnected from negative leaders9,12,16,18-20, which may lead to current pulses that both reconnect positive leaders to negative leaders11,16,17,20-22 and cause multiple cloud-to-ground lightning events1. The disconnection process is thought to be due to negative differential resistance18, but this does not explain why the disconnections form primarily on positive leaders22, or why the current in cloud-to-ground lightning never goes to zero23. Indeed, it is still not understood how positive leaders emit radio-frequency radiation or why they behave differently from negative leaders. Here we report three-dimensional radio interferometric observations of lightning over the Netherlands with unprecedented spatiotemporal resolution. We find small plasma structures-which we call 'needles'-that are the dominant source of radio emission from the positive leaders. These structures appear to drain charge from the leader, and are probably the reason why positive leaders disconnect from negative ones, and why cloud-to-ground lightning connects to the ground multiple times.

Patient navigation for colorectal cancer screening in deprived areas: the COLONAV cluster randomized controlled trial.

BACKGROUND: The objective of this study was to assess the effectiveness of a Patient Navigation Intervention targeting deprived patients for Colo-Rectal Cancer (CRC) screening participation. METHODS: A cluster randomized controlled trial was conducted in 5 districts. Peer Lay Patient Navigators were recruited to operate in deprived areas. Eligible participants had to be between 50 and 74 years old, live in these deprived areas and receive an invitation to the nationally organized Colo-Rectal Cancer (CRC) screening during the study period. The theory-driven navigation intervention was deployed for 18 months. A population Health Intervention Research assessment method was used to assess effectiveness and context interaction. The primary criterion was screening participation at 12 months. RESULTS: Twenty-four thousand two hundred eighty-one individuals were included inside 40 clusters. The increase in participation in the intervention group was estimated at 23%, (ORa = 1.23, CI95% [1.07-1.41], p = 0.003). For the subgroup of individuals who participated, the time delay to participating was reduced by 26% (ORa = 0.74, CI95% [0.57-0.96], p = 0.021). Main factors modulating the effect of the intervention were: closeness of navigator profiles to the targeted population, navigators' abilities to adapt their modus operandi, and facilitating attachment structure. CONCLUSION: The ColoNav Intervention succeeded in demonstrating its effectiveness, for CRC screening. Patient Navigation should be disseminate with broader health promotion goals in order to achieve equity in health care. TRIAL REGISTRATION: clinicaltrials.gov NCT02369757 24/02/2015.

Hemidiaphragmatic paralysis following ultrasound-guided anterior vs. posterior suprascapular nerve block: a double-blind, randomised control trial.

Interscalene brachial plexus block provides analgesia for shoulder surgery but is associated with hemidiaphragmatic paralysis. Before considering a combined suprascapular and axillary nerve block as an alternative to interscalene brachial plexus block, evaluation of the incidence of diaphragmatic dysfunction according to the approach to the suprascapular nerve is necessary. We randomly allocated 84 patients undergoing arthroscopic shoulder surgery to an anterior or a posterior approach to the suprascapular nerve block combined with an axillary nerve block using 10 ml ropivacaine 0.375% for each nerve. The primary outcome was the incidence of hemidiaphragmatic paralysis diagnosed by ultrasound. Secondary outcomes included: characterisation of the hemidiaphragmatic paralysis over time; numeric rating scale pain scores; oral morphine equivalent consumption; and patient satisfaction. The incidence of hemidiaphragmatic paralysis was 40% (n = 17) vs. 2% (n = 1) in the anterior and posterior groups, respectively (p < 0.001). In one third of patients with hemidiaphragmatic paralysis, it persisted beyond the eighth hour. The median (interquartile range [range]) oral morphine equivalent consumption was significantly higher in the posterior approach when compared with the anterior approach, whether in the recovery area (20 [5-31 (0-60)] mg vs. 7.5 [0-14 (0-52)] mg, respectively; p = 0.004) or during the first 24 h (82 [61-127 (12-360) mg] vs. 58 [30-86 (0-160)] mg, respectively; p = 0.01). Patient satisfaction was comparable between groups (p = 0.6). Compared with the anterior approach, diaphragmatic function is best preserved with the posterior needle approach to the suprascapular nerve block.

ColoNav: patient navigation for colorectal cancer screening in deprived areas - Study protocol.

BACKGROUND: The mass colorectal cancer screening program was implemented in 2008 in France, targeting 16 million French people aged between 50 and 74. The current adhesion is insufficient and the participation rate is even lower among the underserved population, increasing health inequalities within our health care system. Patient Navigation programs have proved their efficiency to promote the access to cancer screening and diagnosis. METHODS/DESIGN: The purpose of the study is to assess the implementation of a patient navigation intervention that has been described in another cultural environment and another health care system. The main objective of the program is to increase the colorectal cancer screening participation rate among the deprived population through the intervention of a navigator to promote the Fecal Occult Blood Test (FOBT) and complementary exams. We performed a multisite cluster randomized controlled trial, with three groups (one experimental group and two control groups) for 18 months. DISCUSSION: The study attempts to give a better understanding of the adhesion barriers to colorectal cancer screening among underserved populations. If this project is cost-effective, it could create a dynamic based on peer approaches that could be developed for other cancer screening programs and other chronic diseases. TRIAL REGISTRATION: NCT02369757.

The value of navigation-guided rTMS for the treatment of depression: an illustrative case.

Repetitive transcranial magnetic stimulation (rTMS) of the prefrontal cortex has been thought to have great potential to treat refractory depression since the first studies published ten years ago. However, one of the potential limitations of rTMS is the poor definition of the localization of the prefrontal cortical target, which is based on a rather simplistic anatomical approach, i.e., 5cm anterior to the primary motor cortical representation of the hand. This "standard procedure" does not take into consideration interindividual variations in brain morphology. We report the case of a 40-year-old woman who underwent two weeks of 10Hz-rTMS for the treatment of a major, drug-resistant depressive episode. The rTMS target was determined with the "standard procedure" for the first week and with a dedicated navigation system as the left Brodmann area 46 for the second week. The clinical assessment of antidepressant effects was performed before and after each week of stimulation. Following the first week of stimulation, the patient improved, in particular regarding speech production. Using the navigation system, the location of the target stimulated during the first week was found to correspond to Broca's area, and not to the prefrontal area as intended. Antidepressant effects were more marked after the second week of navigated rTMS. In the present case, the prefrontal target was situated 8.3cm anterior to hand motor cortex. This illustrates that the "standard procedure" may inaccurately target the prefrontal cortex, although resulting in antidepressant-like effects. The use of navigation systems should limit the variability of the results reported so far in the treatment of depression by rTMS.

Study of the efficacy of 18 sun filters authorized in European Union tested in vitro.

In this work, the authors study the influence of filter concentration on the SPF in a topical product measured in vitro. Firstly, the method was adapted by determining that a mass of 15 mg of product must be applied on the PMMA (polymethylmethacrylate) plate in order to have the best correlation with results obtained in vivo. By using the highest concentration allowed by European legislation, the following ranking was drawn up in ascending order of efficacy: 3-Benzylidene camphor (1.66) < oxybenzone (3.01) < octylsalicylate (3.12) < PABA (3.36) < polysilicone 15 (3.64) < methylene bis-benzotriazolyl tetramethylbutylphenol (3.68) < PEG25 PABA (3.81) < benzophenone-4 (3.85) < 4-methylbenzylidene camphor (4.22) < homosalate (4.33) < octyltriazone (7.80) < phenylbenzimidazole sulfonic acid (8.31) < octyldimethyl PABA (8.71) < octocrylene (10.41) < octylmethoxycinnamate (10.42) < diethylhexylbutamidotriazone (12.58)

Marked long-term decline in ambient CO mixing ratio in SE England, 1997-2014: evidence of policy success in improving air quality.

Atmospheric CO at Egham in SE England has shown a marked and progressive decline since 1997, following adoption of strict controls on emissions. The Egham site is uniquely positioned to allow both assessment and comparison of 'clean Atlantic background' air and CO-enriched air downwind from the London conurbation. The decline is strongest (approximately 50 ppb per year) in the 1997-2003 period but continues post 2003. A 'local CO increment' can be identified as the residual after subtraction of contemporary background Atlantic CO mixing ratios from measured values at Egham. This increment, which is primarily from regional sources (during anticyclonic or northerly winds) or from the European continent (with easterly air mass origins), has significant seasonality, but overall has declined steadily since 1997. On many days of the year CO measured at Egham is now not far above Atlantic background levels measured at Mace Head (Ireland). The results are consistent with MOPITT satellite observations and 'bottom-up' inventory results. Comparison with urban and regional background CO mixing ratios in Hong Kong demonstrates the importance of regional, as opposed to local reduction of CO emission. The Egham record implies that controls on emissions subsequent to legislation have been extremely successful in the UK.

[Characterisation of D(-)glyceric acid from Nocardia caviae (author's transl)]. / Caracterisation de l'acide D(-)glycerique dans un glycolipide de Nocardia caviae

A glycolipid was found in a strain of Nocardia caviae. It consists of glucose, myristic, palmitic and stearic acids and a polyhydroxylated acid. The structure of this hydroxyacid was demonstrated by the identification of the product glycerol after LiA1H4 reduction of the glycolipid methyl ester and subsequent hydrolysis, by comparison of the infrared spectra of the hydroxyacid and glyceric acid, by gas chromatography of acetylated methyl and ethyl esters of the polyhydroxylated acid and of standard glyceric acid and by mass spectrometry of the diacetylated methyl ester. The hydroxyacid from the glycolipid is D(-)glyceric acid, a compound rarely found amongst natural products.

Synthesis and psychoanaleptic properties of new compounds structurally related to diphenhydramine.

A new series of benzhydryloxyalkylpiperazines carrying a trivalent function has been synthesized and studied for its effects on the central nervous system. Most of the compounds exhibit unexpected nonamphetaminic psychoanaleptic properties. The structure-activity studies revealed the importance of the nature and the position of the substituents on the phenyl rings. However, no significant correlation between atropinic or antihistaminic effects and psychoanaleptic properties was observed.

Revised structure of mycosubtilin, a peptidolipid antibiotic from Bacillus subtilis.

The structure of mycosubtilin, a peptidolipid antibiotic from Bacillus subtilis, was revised by FAB mass spectrometry, 2D NMR spectrometry and also by Edman degradation of the peptide resulting from the N-bromosuccinimide reaction. Four homologous beta-amino acid components were identified by capillary gas chromatography. The cyclopeptide mycosubtilin consists of seven alpha-amino acids in an LDDLLDL sequence closed by a beta-amino acid linkage similar to that found in other antibiotics of the iturin group.

Structures of bacillomycin D and bacillomycin L peptidolipid antibiotics from Bacillus subtilis.

The complete structures of bacillomycin D and bacillomycin L were revised by FAB mass spectrometry and by Edman degradation of the derivatives resulting from the N-bromosuccinimide reaction. The homologous components of both series of antibiotics were separated by HPLC and the beta-amino acids were identified by capillary gas chromatography.

Comparison of lipid composition in two types of human putrefactive liquid.

The decomposition of a human cadaver was stopped after solidification of putrefactive liquid during a GIS Burial experiment. Knowledge of this phenomenon is necessary to optimize burial conditions and to decrease cemetery congestion. In this preliminary study, we devised a method using thin-layer chromatography and gas chromatography to compare different putrefactive liquids. A comparison of lipid composition among two cadavers revealed a decrease in the decomposition rate of the cadaver that had the gelled putrefactive liquid. Essentially, fatty acids were observed in two types of extracts. The difference was quantitative: there was a higher amount of fatty acids in the gelled sample than in the standard liquid, suggesting a decrease of decomposition rate in the gelled extract. A large quantity of oleate salts may be favourable for solidification. In addition, an isomer of oleic acid (elaidic acid) could be present which may have a determining factor in the phenomenon of gelled putrefaction. A large amount of stearic acid was present in the gelled extract and may be involved in solidification. This method was efficient for comparing the lipid composition of different putrefactive liquids and may be used for a large-scale study. This is the first report concerning methods to determine the lipid composition of human decomposition liquids after 4 years postmortem.

[Analysis of hematopoietic growth factor prescriptions in 19 french cancer centers]. / Analyse de la prescription de facteurs de croissance hématopoïétique dans 19 centres anticancéreux français. Groupe de pharmaciens de la Fédération nationale des centres de lutte contre le cancer.

Medical prescription of hematopoietic growth factors (HGF) was analysed in 19 anticancer french centers during 2 months. About 4% of anticancer chemotherapeutic cycles prescribed during this period were supported by HGF prescription. The mean duration of treatment was 8 days. Among the 755 collected prescriptions, two tumor localizations represented about 50% of the prescriptions: malignant non Hodgkin lymphomas and breast cancer. The other main localizations concerned adult or pediatric soft tissue sarcomas (18%), testicular cancer (7%) and gynecologic tumors (6%). The prescription for primary prophylaxis for febrile neutropenia remains the main use of HGF (44%). The respect of the guidelines established by the F|d|ration nationale des centres de lutte contre le cancer was analyzed. Overall, 66% of the prescriptions were in adequation with these guidelines. Whereas the consommation of HGF decreased in the 19 considered institutions, it did not reach a plateau and could decrease in institutions which are awaked to the international and national recommendations.