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Extramammary Paget disease is a rare cutaneous malignancy that most commonly affects the genitals, perianal area, and axilla of elderly patients. Delays in care often lead to high levels of disease burden for patients. Thus, evidence-based recommendations are paramount in mitigating morbidity and mortality for this unique patient population. This 2-part continuing medical education series provides a complete picture of extramammary Paget disease. Part 2 of this continuing medical education series focuses on the complex management of extramammary Paget disease including surgical and noninvasive therapies, as well as novel approaches for advanced disease. [ABSTRACT FROM AUTHOR]

Extramammary Paget disease (EMPD) is a rare skin cancer of apocrine-rich skin that mimics common inflammatory and infectious dermatoses, leading to delays in diagnosis and increased patient morbidity. Better clinical recognition of this entity, multidisciplinary patient assessment, and deeper understanding of the underlying pathophysiology are essential to improve patient care and disease outcomes. It is important to distinguish primary intraepithelial/micro-invasive EMPD from invasive EMPD or cases with adenocarcinoma arising within EMPD. This 2-part continuing medical education series provides a complete picture of EMPD. Part 1 of this continuing medical education series reviews the epidemiology, oncogenesis, clinical and histopathologic presentation, workup, and prognosis of this rare cancer. [ABSTRACT FROM AUTHOR]

• An unexpected artefact for radiotherapy MRI preparation was found. • An external marker in the field of view can be reconstructed inside the patient. • 3D distortion correction displaces the original marker but not the artefact. • The probability is high with distance >2 mm, such as when using thermoplastic masks. MRI for radiotherapy planning requires spatial referencing using immobilization devices and markers. Clinical images of a difficult-to-interpret artifact are presented, resembling a metastasis, which occurs when combining CAIPIRINHA k-space-based parallel imaging (PI), 3D distortion correction, and external markers. A 3D variable flip angle Turbo Spin Echo sequence was used on a 1.5 T and 3 T MRI using flexible and head and neck coils. Two types of markers were tested: Liquimark LM1 and Spee-D-Mark. A silicone oil phantom was used that represents low signal intensity, such as gray matter. 3D Fourier transforms were also used to show the issue's origin. The markers can appear in an unexpected region of a patient, not in the same original or reconstructed slice nor in a rectilinear direction in a slice, especially when using CAIPIRINHA acceleration with 3D distortion correction. The probability of occurrence was respectively 13% and 80% for distances of <=2 mm and >2 mm between marker and patient, for example when using thermoplastic masks. Clinical cases are shown where this semi-randomly occurring artifact appears post contrast only, and thus can be interpreted as metastases. The artifact did not appear when using compressed sensing acceleration. Markers used for radiotherapy MRI application can introduce additional artifacts that can be interpreted as metastases. However, other high signal intensity structures on the surface of a patient, such as the ear, can lead to an equivalent error. [ABSTRACT FROM AUTHOR]

Copyright of Archives of Cardiovascular Diseases is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Archives of Cardiovascular Diseases is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Highlights • Logging of humid tropical forests affects seed dispersal, wood and carbon stocks. • Logging impacts decreased seed size and biomass but not species richness. • 30 years after logging, forest composition still differs from initial state. Abstract Tropical forests harbor the greatest terrestrial biodiversity and provide various ecosystem services. The increase of human activities on these forests, among which logging, makes the conservation of biodiversity and associated services strongly dependent on the sustainability of these activities. However the indicators commonly used to assess the impact of forest exploitation, namely species richness and biomass, provide a limited understanding of their sustainability. Here, we assessed the sustainability of common forest exploitation in the Guiana Shield studying the recovery of two ecosystem services i.e. carbon storage and wood stock, and an ecosystem function i.e. seed dispersal by animals. Specifically, we compared total and commercial biomass, as well as functional composition in seed size of animal-dispersed species in replicated forest plots before and 27 years after exploitation. Species richness is also studied to allow comparison. While species richness was not affected by forest exploitation, total and commercial biomass as well as seed size of animal-dispersed species decreased 27 years after exploitation, similarly to forests affected by hunting. These results show that ecosystem services and function likely did not recover even at the lowest intensity of forest exploitation studied, questioning the sustainability of the most common rotation-cycle duration applied in the tropics. [ABSTRACT FROM AUTHOR]

Copyright of Archives of Cardiovascular Diseases is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

• Agreement between Catalyst SGRT and Halcyon CBCT was evaluated. • Manual arc interruption for DIBH results in minor dose differences. • A bias between SGRT and CBCT positioning can occur for patients. • Details in combining fast CBCT with SGRT workflow are important. To evaluate the accuracy/agreement of a three-camera Catalyst Surface Guided Radiation Therapy (SGRT) system on a closed-gantry Halcyon for Free-Breathing (FB) and Deep Inspiration Breath Hold (DIBH) breast-only treatments. The SGRT positioning agreement with Halcyon couch and cone-beam computed tomography (CBCT) was evaluated on phantom and by evaluation of 2401 FB and 855 DIBH breast-only treatment sessions. The DIBH agreement was evaluated using a programmable moving support. Dose agreement was evaluated for manual SGRT-assisted beam interruption and Halcyon arc beam interruption. Geometrical phantom agreement was < 0.4 mm. Couch and SGRT agreement for an anthropomorphic phantom resulted in 95% limits of agreement in Right-Left/Feet-Head/Posterior-Anterior (RL/FH/PA) directions of respectively ± 0.4/0.8/0.5 mm and ± 1.1/1.1/0.6 mm in the virtual and real isocenter. FB-SGRT-assisted patient positioning compared to CBCT positioning resulted in RL/FH/PA systematic differences of −0.1/0.1/2.0 mm with standard deviations of 2.7/2.8/2.4 mm. This mean systematic difference had three origins: a) couch sag/isocenter difference of ≤ 0.5 mm. b) Average reconstructed FB-CBCT images do not visually represent the average respiratory position. c) CBCT-based positioning focused on the inner thoracic interface, which can introduce a mean positioning difference between SGRT and CBCT. Manual SGRT-assisted beam interruption and arc interruptions resulted in mean gamma passing rates > 97% (0.5%/0.5 mm) and mean absolute differences < 0.3%. Accuracy was comparable with breast-only C-arm SGRT techniques, with different tradeoffs. Depending on the patient's morphology, real-time tracking accuracy in the real isocenter can be reduced. This study demonstrates possible discordances between SGRT and CBCT positioning for breast. [ABSTRACT FROM AUTHOR]

Purpose The main focus of the current paper is the clinical implementation of a Monte Carlo based platform for treatment plan validation for Tomotherapy and Cyberknife, without adding additional tasks to the dosimetry department. Methods The Monte Carlo platform consists of C++ classes for the actual functionality and a web based GUI that allows accessing the system using a web browser. Calculations are based on BEAMnrc/DOSXYZnrc and/or GATE and are performed automatically after exporting the dicom data from the treatment planning system. For Cyberknife treatments of moving targets, the log files saved during the treatment (position of robot, internal fiducials and external markers) can be used in combination with the 4D planning CT to reconstruct the actually delivered dose. The Monte Carlo platform is also used for calculation on MRI images, using pseudo-CT conversion. Results For Tomotherapy treatments we obtain an excellent agreement (within 2%) for almost all cases. However, we have been able to detect a problem regarding the CT Hounsfield units definition of the Toshiba Large Bore CT when using a large reconstruction diameter. For Cyberknife treatments we obtain an excellent agreement with the Monte Carlo algorithm of the treatment planning system. For some extreme cases, when treating small lung lesions in low density lung tissue, small differences are obtained due to the different cut-off energy of the secondary electrons. Conclusions A Monte Carlo based treatment plan validation tool has successfully been implemented in clinical routine and is used to systematically validate all Cyberknife and Tomotherapy plans. [ABSTRACT FROM AUTHOR]

Summary Background & aims This retrospective study evaluated the impact of new organization during the moving to a new university pediatric hospital on the incidence of central catheter-related blood stream infections (CRBSIs) among children on long-term parenteral nutrition. Methods The study ran from April 2007 to March 2014, starting a year prior to reorganisation of the department of pediatric Hepato-Gastroenterology and Nutrition associated to moving the children to a new hospital in April 2008, and continuing for 6 years following the move. During this time, data from all children hospitalized in this department who received parenteral nutrition (PN) for more than 15 days were analysed. Results During this 7-years study, 183 children aged 4.6 ± 0.5 years received prolonged PN. Intestinal diseases were the main aetiologies (89%), primarily short bowel syndrome (18.4%), Hirschsprung disease and CIPO (13.5%) and inflammatory bowel disease (13.8%). The mean durations of hospitalization and of PN during hospitalization were, respectively, 70 ± 2.1 and 55.7 ± 3.6 days. During the study period, 151 CRBSIs occurred in 77 children (42% of all patients), i.e. 14.8 septic episodes/1000 PN days and 12.0 septic episodes/1000 CVC days. No patient died of a central venous catheter-related infection. However, following the move from the older hospital to the newer one, the rate of CRBSIs significantly doubled, from 3.9/1000 to 8.8/1000 CVC days (p = 0.02). During the following 4 years, the incidence of CRBSIs tended to increase between the 2nd and the 5th year after the move: 11.3 (p = NS); 21.4 (p = 0.01); 17.3 (p = NS), 20.3/1000 (p = NS) CVC days. We also observed that after evaluations by the Department of Infection Control, nurse training and stabilization of the nursing team, the incidence decreased significantly from 20.3 to 11.1/1000 CVC days during the 6th year after the move (p = 0.01). Conclusion Our results reveal the deleterious impact of the reorganization during the hospital moving on the CRBSI incidence rate, and the possible implication of inexperienced team of nurses. [ABSTRACT FROM AUTHOR]

We present an application of the industrial Constant-Work-In-Progress (ConWIP) principle to radiotherapy treatments: from Operations Research to application in practice. Radiotherapy involves a chain of preparation steps before treatment. The time periods between patient referral, initial Computed Tomography (CT) scan, and the treatment should always be as short as possible. This is important in order to not allow further tumor growth and to capture the correct patient anatomy for the treatment. Therefore, the high-in-demand limited machine capacity and scheduling of intermediate steps have to be balanced. Conventionally, the treatment machine calendar is consulted for an open spot and the preparation steps are scheduled around that appointment. Conventional radiotherapy treatment scheduling is efficient in a predictable and low variability environment. Yet it is very inefficient for stereotactic radiotherapy treatments, due to the presence of (a) large variability in preparation time, (b) variable In Room Time especially for liver and lung treatments, which becomes known only right before the treatment, and (c) a high rate of cancellations. The end result is a suboptimal capacity use and high stress load for all personnel. We present a different organization method, a hybrid ConWIP system utilizing standardized work: managing work-in-progress instead of scheduling all steps. Discrete Event Simulations were performed before implementation in order to test the hypothesis and obtain the optimal parameters. Treatment type distribution was as follows: lung (29%), liver (21%), intracranial (13%), head and neck (11%), prostate (7%) and 20% other localizations. Implementation of this ConWIP workflow was supported by workflow software (RT-Flow) combining workflow, prioritization and load balancing. This resulted in a 32% (24%–40%) (95% CI) increase in number of treatments for the CyberKnife ® installation with a negligible increase in time from CT to treatment and an improved stress load for personnel. [ABSTRACT FROM AUTHOR]

Copyright of Archives of Cardiovascular Diseases is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background. To date, for esophageal cancer (EC), the optimal timing of surgical procedures after neoadjuvant chemoradiation (nCRT) is not well defined. Data in rectal cancer suggest that a prolonged interval between treatment and operation may improve tumoral pathologic response, RO resection rate, and survival. The aims of this study were to evaluate whether delaying operation after nCRT in EC increases pathologic response and has an impact on oncologic outcome or postoperative course. Methods. A total of 257 consecutive EC patients (n = 161 squamous cell carcinomas and n = 96 adenocarcinomas) undergoing nCRT followed by operation between 1997 and 2011 were retrospectively analyzed by the use of prospectively collected data. The patients were divided into two groups according to the median delay between nCRT and operation (<7 weeks, n = 122; ≥7 weeks, n = 135). The impact of surgical delay on outcomes was studied through univariable and multivariable analyses. Results. The groups were comparable regarding patient and tumor characteristics (p ≥ 0.074). The ypT0 and RO resection rates were similar between the two groups, as were postoperative course, median survivals, and incidence and patterns of recurrence (p ≥ 0.332). Multivariable analysis failed to identify any impact of the surgical delay on the endpoints. Subgroup analysis according to the histologic type found similar results. Conclusions. After nCRT for EC, delaying operation does not affect the ypT0 rate, postoperative course, or oncologic outcome and cannot therefore be justified by these aims. [ABSTRACT FROM AUTHOR]

Paroxysmal or chronic atrial fibrillation (AF) is frequent in hypertrophic cardiomyopathy (HCM), occurring in more than 20%-25% of patients, and is often considered as an important turning point for the quality of life of these patients. Defining the risk of atrial fibrillation in hypertrophic cardiomyopathy patients is an important clinical and prognostic challenge. The aim of this study is to determine HCM-phenogroups with different risk of AF-occurrence at 5-year. We applied retrospectively the Bayesian method, which can analyze a large number of variables, to differentiate phenogroups of patients with different risks of AF and prognoses across a French prospective on-going hospital-based registry of adult HCM patients (REMY). Clinical and imaging data were prospectively recorded, and patients were followed for 5 years. A total of 1431 HCM patients were recruited, including 1275 analyzed in the present study after exclusion criteria. The population included 412 women, and 369 patients with obstructive HCM. AF-occurred in 167 (11.6 %) patients during the 5-year follow-up. Three phenogroups were defined according to their common clinical and echocardiographic-characteristics. Patients at the highest risk were oldest, more often female, with more frequent comorbidities, anteroposterior diameter of the left atrium was significantly greater, with diastolic dysfunction, outflow-tract obstruction and mitral valve abnormality, and presented higher pulmonary artery pressure and/or right ventricular dysfunction. These also had a higher risk of all-cause hospitalizations and death. Based on a clustering analysis, three phenogroups of HCM according to the risk of AF occurrence can be identified. It can indicate which patients should be more monitored and/or treated, particular to prevent the risk of stroke. [ABSTRACT FROM AUTHOR]

Abstract: Topical application of nicotinic acid results in erythema, and in some cases oedema of the skin, supporting a strong relationship between niacin sensitivity and prostaglandin D2. The aim of this study was to examine the inter-rater and intra-rater reliability of a 12-min niacin sensitivity test in healthy adults. Three raters assessed the skin reaction of 12 volunteers, over 3-min intervals across four niacin concentrations (0.1, 0.01, 0.001, and 0.0001), and over six sessions. Inter-rater reliability estimates ranged from 0.85 to 0.97 for the total niacin sensitivity score. Similar inter-rater reliability estimates were found for niacin sensitivity ratings by concentration and time. Intra-rater reliability estimates ranged from 0.63 to 0.93 for the total niacin sensitivity score. These data indicate that the 12-min topical niacin sensitivity test has excellent reliability. [Copyright &y& Elsevier]

Abstract: A phase I trial was initiated to establish the dose-limiting toxicities (DLTs) and the maximum tolerated dose (MTD) of chronomodulated 5-fluorouracil and cisplatin given concurrently with preoperative radiotherapy in patients with esophageal cancer. Patients with stage I or II esophageal cancer received preoperative radiation therapy (28–30 daily 1.8-Gy fractions for a total of 50.4 or 54Gy) and concurrent three fortnightly cycles of chronomodulated 5-fluorouracil (700–835mg/m2 per day, d1–d4, with peak delivery at 4.00 am) and cisplatin (50mg/m2, d1, with peak delivery at 4.00 pm) administered by a time-programmable pump. Ten patients were treated on this study. Two of six patients treated at the starting dose-level experienced acute DLTs (esophagitis, asthenia) which required de-escalation of 5-fluorouracil. Five patients out of ten experienced seven DLTs (severe esophagitis, asthenia, vomiting: 5/1/1) at any dose-level. The MTD was not assessed because the study was halted due to slow accrual. Finally, two patients deceased from an Acute Respiratory Distress Syndrome due to inadequate radiation therapy planning. Without definitively ruling out any possible impact of chronomodulation in that setting, our data reinforce the need of a better selection of patients aimed to be treated by CRT plus surgery. [Copyright &y& Elsevier]

Abstract: A solid-phase microextraction – coupled to a gas chromatography – ion trap tandem mass spectrometry (SPME–GC–MS/MS) method was developed for the quantitative determination in rainwater of 8 pesticides amongst the most used in France and 3 triazines metabolites. The main factors affecting the SPME process were studied. Using a 3mL sample, the method developed showed good linearity for concentrations ranging from 0.05 to 50μgL−1 with correlation coefficients between 0.997 and 0.9999 and relative standard deviations (% RSD) below 14%. The study of matrix effects showed that rainwater was too diluted to have any significant influence on the extraction efficiency. To validate the method, a field campaign was carried out on the rain events, which occurred in Strasbourg during a one-year period. The rain concentrations showed patterns of high pesticide concentrations during spring months, which were correlated to the spraying periods of most of these substances. [Copyright &y& Elsevier]

Abstract: Background.: Photodynamic therapy is an endoscopic treatment of early cancers based on the photosensitisation of neoplasms following the administration of a photosensitiser prior to laser light-induced tissue destruction. Aim.: To assess the results of photodynamic therapy using Photofrin® (Axcan Pharma Inc., Quebec, Canada) in patients with an early oesophageal cancer. Patients.: Twenty-four patients with early oesophageal cancer presenting as a not well-demarcated irregular dyschromic area of mucosa and unsuitable for any other treatment underwent photodynamic therapy. Results.: Seventy-five per cent were successfully treated; three of them recurred and two died from head and neck cancer. To date, 54% of patients are alive without recurrence; the average follow-up is 21 months. There were one oesophageal lethal perforation and six stenosis. Results of photodynamic therapy were limited in this series by three failures, three recurrences and three deaths from previous head and neck cancers. Conclusion.: This study provides some promising data for photodynamic therapy of oesophageal carcinomas in selected patients. It also emphasises the need for a best delivery device of laser light. [Copyright &y& Elsevier]

Hypertrophic cardiomyopathy (HCM) is considered to be the first cause of sudden death in young subjects, including competitive athletes, often in the absence of significant symptoms. However, most of these data come from tertiary centers and the clinical profile of these patients, as well as their management in real life in France, remain poorly understood. To evaluate the management of young adults with sarcomeric HCM and the predictive factors for major cardiac event (MCE), patients < 25 years included in the national HCM register "REMY" of the French Society of Cardiology from 2006 to 2018 were identified. At inclusion was calculated the European 5-year sudden cardiac death (SCD) score and identified the presence of the 5 major classical SCD risk factors (MRF). At follow-up, MCE [SCD or implantable cardioverter defibrillator (ICD) shock, sustained ventricular tachycardia (SVT), atrial fibrillation (AF), stroke, hospitalization for heart failure (HFH) or syncope] were notified. Among 61 included patients [20.5 ± 3(16–25) years, 16(26%) women], 92% were in NHYA class I/II, 18(30%) obstructive, 37(86%) showed MRI fibrosis, 6(12%) abnormal exercise blood pressure response, 25% a family history of SCD, 13(21%) had a prophylactic ICD. The score (4.8 ± 3.2%) was < 4% in 53% and ≥ 6% in 25% of patients. After 4.4 ± 2.2years, 15(25%) patients (7 women) presented 18 MCE: 3 SCD (17%), 5 SVT (28%), 5 AF and 1 stroke (33%), 1 HFH (5%), 3 unexplained syncopal episodes (17%); 10 patients received an ICD (4 in secondary prevention). 61% patients with score> 6% had an ICD. Female sex was predictive of MCE (P =.02), with a tendency for obstruction (P =.09), but not late gadolinium enhancement, prophylactic ICD or MRF. Thus, in young adults with HCM, MCE are common, especially in women, more often rhythmic. Prophylactic ICD is frequent, especially if the score exceeds 6%, but MCE are difficult to predict using the current criteria. [ABSTRACT FROM AUTHOR]

Introduction Data on the management of valvular heart disease is scarce in the Pacific, a region where rheumatic heart disease remains endemic. Methods Were included patients presenting to the single tertiary centre in New Caledonia and who underwent heart valve surgery for the first time (2005-2010). Clinical, echocardiographic, surgical data and outcomes were collected in 2013. We explored potential factors associated with major cardiovascular events as a composite endpoint. Results Among the 180 patients included, 95 (52.8%) were male; mean age was 48.2 years (±19.3). 124 (78.9%) were Pacific islanders, 122 (70.9%) presented in heart failure (70.9%) and 125 (69.4%) had rheumatic heart disease. 84 patients (46.7%) received a mechanical prosthetic valve. Median follow-up was 4.7 years (IQR 3.5-6.7). Early postoperative mortality rate was of 2.8%. The incidence of annual mortality was 31.75‰ (95% CI 19.77-43.72) (including 25.78‰ cardiovascular death; 95 CI 15.01-36.55). The annual incidences of stroke and severe bleeding were 38.23‰ (95% CI 24.07-52.39) and 36.54‰ (95% CI 22.49-50.58), respectively. We did not identify factors associated with outcomes according to the aetiology (rheumatic heart disease versus other) or the procedure (mechanical prosthetic valve versus other). Conclusion In the Pacific heart valve interventions are mainly performed in young patients with underlying rheumatic heart disease. Post-operative mortality is low but morbidity remains high [ABSTRACT FROM AUTHOR]

Introduction It is widely admitted that dose distributions obtained with protons are more conformal compared to photons. We investigate the role of protontherapy for those cases where it was not possible to fulfill OAR constraints with most advanced photon techniques and where the prescribed dose had to be decreased. This study investigates all cases where protontherapy provides a better OAR sparing compared to photons in general, but focuses only on the difficult cases as described above. Methods During 2015, all SRT/SBRT cases with CyberKnife and helical Tomotherapy where prescribed dose to target volumes had to be decreased to fulfill OAR dose constraints were listed. They were replanned with an IBA proton machine using the Pencil Beam Scanning technique on a RaySearch workstation, with the same PTV as photons. Range uncertainties were not taken into account, except while selecting the beam incidences. Results Among the 1310 SRT/SBRT and IMRT treatments, the plans that needed a decreased prescription dose can be classified in two categories: - When a serial organ is adjacent and limiting, as spinal cord for vertebra re-irradiation. - When a parallel organ received too much low doses when target volumes are too big, as for liver where 700 cm 3 must receive less than a threshold. For the first category, proton plans didn’t allow delivering the initial prescribed dose either. The penumbra of Pencil Beam Scanning (3 mm spot) is not sharper compared to SRT/SBRT plans. For the second category, consisting of 11 liver lesions and 6 lung lesions with mediastinal nodes, initial prescribed dose can always be delivered when using the PBS technique. Conclusions Over one year, we counted 17 patients where it was necessary to decrease prescribed dose when applying photon treatments and where protons plans showed that the prescribed dose can be delivered. This is especially the case for large volumes in lung or liver. [ABSTRACT FROM AUTHOR]

Gas chromatography/ion trap detector (GC/ITD) was used to detect atmospheric triazines and their degradation products in the gaseous and particulate phases. Because triazines and their metabolites are expected to be present at very low concentrations and enclosed in the complex atmospheric matrix, the analytical method used was both highly selective and sensitive. These two properties were obtained by associating chromatography with ion trap tandem mass spectrometry (GC/ITD (MS/MS)). To develop this method, a comparison between the two ionization modes (electron impact and positive-chemical-ionisation) in single-MS was first conducted to choose the parent ions of the five target analytes, i.e. atrazine, desethylatrazine, deisopropylatrazine, terbuthylazine and desethylterbuthylazine. Then, a MS/MS method was optimised by parameters such as the radio frequency storage level and the collision-induced dissociation excitation voltage. Finally, a last stepenabled the development of a calibrating program based on the quantification of daughter ions. With this analytical procedure, the detection limits varied between 0.8 and 15 pg m-3 depending on the compounds under study. This method was tested with success for four atmospheric samples collected in Strasbourg (France) in which four of the five target compounds were detected. [ABSTRACT FROM AUTHOR]

While using alternative aviation fuels represents a promising approach to reduce the industry’s impact on climate change and local air quality, the influence of these new fuels on the chemical composition of exhaust plumes, and, in particular, on aviation-produced aerosols must be assessed. This paper studies the influence of using alternative jet fuels on induced particles, including contrails, in a near field of an aircraft. A computational model with detailed microphysics taking into account the condensation of organic species, homogeneous freezing, and soot activation was used to study the effect of different fuels on the formation and evolution of particulate matter in the exhaust plume of an aircraft flying at cruise conditions. Three different fuels were considered and compared: conventional kerosene (Jet A-1); a pure alternative fuel (with similar properties as Fischer–Tropsch (FT) or hydro-processed esters and fatty acids (HEFA) fuels); and a blend consisting of a 50/50 mixture of kerosene and the mentioned alternative fuel. Several conclusions can be drawn when using pure alternative and blended fuels instead of standard kerosene. The contribution of soluble organic matter in the composition of mixed aerosols increased on average by 29% with Jet A-1 to 45% with a blended fuel. The reduction in soot particles favors the homogeneous freezing pathway and the ice crystals formed were larger and evidenced lower number densities. The background particles can no longer be neglected, since they can account for more than 50% of the particles after 5 s behind the nozzle exit. All these changes are expected to alter the optical properties of contrails. [ABSTRACT FROM AUTHOR]