[Outcomes following the triage of patients for urological cancer and non-cancer surgery during Covid-19 pandemic peak]. / Évaluation des mesures de triages de la première vague pandémique Covid-19 pour sélectionner les patients à opérer pour cancers et urgences urologiques.

INTRODUCTION: Faced with the first wave of Covid-19 pandemic, guidelines for surgical triage were developed to free up healthcare resources. The aim of our study was to assess clinical characteristics and surgical outcomes of triaged patients during the first Covid-19 crisis. METHOD: We conducted a cohort-controlled, non-randomized, study in a University Hospital of south-eastern France. Data were collected prospectively from consecutive patients after triage during the period from March 15th to May 1st and compared with control data from outside pandemic period. Primary endpoint was intensive care unit (ICU) admissions for surgery-related complications. Rates of surgery-specific death, postponed operations, positive PCR testing and Clavien-Dindo complications and data from cancer and non- cancer subgroups were assessed. RESULTS: After triage, 96 of 142 elective surgeries were postponed. Altogether, 71 patients, median age 68 y.o (IQR: 56-75 y.o), sex ratio M/F of 4/1, had surgery, among whom, 48 (68%) had uro-oncological surgery. No patients developed Covid-19 pneumonia in the post-surgery period. Three (4%) were admitted to the ICU, one of whom died from multi-organ failure due to septic shock caused by klebsiella pneumonia following a delay in treatment. Three Covid-19 RT-PCR were done and all were negative. There was no difference in mortality rates or ICU admission rates between control and Covid- era patients. CONCLUSIONS: Surgery after triage during the first Covid-19 pandemic was not associated with worse short-term outcomes. Urological cancers could be operated on safely in our context but delays in care for aggressive genitourinary diseases could be life threatening. LEVEL OF EVIDENCE: 3.

Photocatalytic abatement results from a model street canyon.

During the European Life+ project PhotoPAQ (Demonstration of Photocatalytic remediation Processes on Air Quality), photocatalytic remediation of nitrogen oxides (NOx), ozone (O3), volatile organic compounds (VOCs), and airborne particles on photocatalytic cementitious coating materials was studied in an artificial street canyon setup by comparing with a colocated nonactive reference canyon of the same dimension (5 × 5 × 53 m). Although the photocatalytic material showed reasonably high activity in laboratory studies, no significant reduction of NOx, O3, and VOCs and no impact on particle mass, size distribution, and chemical composition were observed in the field campaign. When comparing nighttime and daytime correlation plots of the two canyons, an average upper limit NOx remediation of ≤2% was derived. This result is consistent only with three recent field studies on photocatalytic NOx remediation in the urban atmosphere, whereas much higher reductions were obtained in most other field investigations. Reasons for the controversial results are discussed, and a more consistent picture of the quantitative remediation is obtained after extrapolation of the results from the various field campaigns to realistic main urban street canyon conditions.

Construction of a photocatalytic de-polluting field site in the Leopold II tunnel in Brussels.

Within the framework of the European Life+-funded project PhotoPAQ (Demonstration of Photocatalytic remediation Processes on Air Quality), which was aimed at demonstrating the effectiveness of photocatalytic coating materials on a realistic scale, a photocatalytic de-polluting field site was set up in the Leopold II tunnel in Brussels, Belgium. For that purpose, photocatalytic cementitious materials were applied on the side walls and ceiling of selected test sections inside a one-way tunnel tube. This article presents the configuration of the test sections used and the preparation and implementation of the measuring campaigns inside the Leopold II tunnel. While emphasizing on how to implement measuring campaigns under such conditions, difficulties encountered during these extensive field campaigns are presented and discussed. This included the severe de-activation observed for the investigated material under the polluted tunnel conditions, which was revealed by additional laboratory experiments on photocatalytic samples that were exposed to tunnel air. Finally, recommendations for future applications of photocatalytic building materials inside tunnels are given.

A tunable diode laser absorption spectrometer for formaldehyde atmospheric measurements validated by simulation chamber instrumentation.

A tunable diode laser absorption spectrometer (TDLAS) for formaldehyde atmospheric measurements has been set up and validated through comparison experiments with a Fourier transform infrared spectrometer (FT-IR) in a simulation chamber. Formaldehyde was generated in situ in the chamber from reaction of ethene with ozone. Three HCHO ro-vibrational line intensities (at 2909.71, 2912.09 and 2914.46 cm(-1)) possibly used by TDLAS were calibrated by FT-IR spectra simultaneously recorded in the 1600-3200 cm(-1) domain during ethene ozonolysis, enabling the on-line deduction of the varying concentration for HCHO in formation. The experimental line intensities values inferred confirmed the calculated ones from the updated HITRAN database. In addition, the feasibility of stratospheric in situ HCHO measurements using the 2912.09 cm(-1) line was demonstrated. The TDLAS performances were also assessed, leading to a 2sigma detection limit of 88 ppt in volume mixing ratio with a response time of 60 sec at 30 Torr and 294 K for 112 m optical path. As part of this work, the room-temperature rate constant of this reaction and the HCHO formation yield were found to be in excellent agreement with the compiled literature data.

Kinetics and products of gas-phase reactions of ozone with methyl methacrylate, methyl acrylate, and ethyl acrylate.

The kinetics and products of the gas-phase reactions of ozone with methyl methacrylate, methyl acrylate, and ethyl acrylate have been investigated at 760 Torr total pressure of air and 294 +/- 2 K. The rate coefficients obtained (in cm(3) molecule(-1) s(-1) units) were as follows: k(methyl methacrylate) = (6.7 +/- 0.9) x 10(-18), k(methyl acrylate) = (0.95 +/- 0.07) x 10(-18), and k(ethyl acrylate) = (1.3 +/- 0.1) x 10(-18). In addition to formaldehyde being observed as a product of the three reactions, the other major reaction products were methyl pyruvate from reaction of ozone with methyl methacrylate, methyl glyoxylate from reaction of ozone with methyl acrylate, and ethyl glyoxylate from reaction of ozone with ethyl acrylate. Possible reaction mechanisms leading to the observed products are presented and discussed.

Gas phase reaction of allyl alcohol (2-propen-1-ol) with OH radicals and ozone.

The gas phase reactions of allyl alcohol with OH radicals and ozone have been investigated using different experimental systems. The rate coefficient for the OH reaction is reported in the temperature range 231-373 K, k(OH) = (5.7 +/- 0.2) x 10(-12) exp[(650 +/- 52)/T] cm3 molecule(-1) s(-1). This reaction is found to be pressure independent between 33 and 760 Torr. Rate coefficient (k(O3)) and gas phase products of the ozone reaction with allyl alcohol are reported at atmospheric pressure and 298 K. The obtained k(O3) = (1.8 +/- 0.2) x 10(-17) cm3 molecule(-1) s(-1) is in good agreement with the single measurement reported in the literature. The reaction of 03 with allyl alcohol is found to lead to the formation of formaldehyde and glycolaldehyde as the main products. Other products such as CH3OH, CO and CO2 have also been observed in low yield. Aerosol formation has been detected in the ozonolysis of allyl alcohol and its size distribution investigated.

Calculation of the vibrational properties of LiMgAs.

We have studied the vibrational properties of the filled tetrahedral semiconductor LiMgAs and its binary analog AlAs by using the plane-wave pseudopotential method within density functional theory. The calculated lattice constants for the studied compounds are in good agreement with previous theoretical and experimental results. The phonon dispersion curves and phonon density of states are calculated by using density functional perturbation theory. The sound speeds in different directions are quantitatively similar in LiMgAs and AlAs. The assignment of the zone center modes to the relative motion of the atoms shows that the lower optic modes are due to the Mg-As pair vibrations, while for the upper ones the Li-Mg pair dominates, which is attributed to the smaller Mg atom mass. The longitudinal interatomic force constant of Mg-As is about 66% higher than that of Li-As, showing the relatively high covalency of the former bond.

UV absorption cross-sections of a series of dimethylbenzaldehydes.

The ultraviolet absorption cross-sections of 2,4-, 2,5-, 2,6-, 3,4- and 3,5- dimethylbenzaldehydes are reported in the wavelength range 240-320 nm. The measurements were carried out in the temperature range 318-363 K using two different experimental systems (D 2 lamp-monochromator and D 2 lamp-diode array). The absorption spectra of the five aldehydes have been found to exhibit relatively high absorption cross-sections in the region of the tropospheric interest with maxima around 290 nm. This work provides the first UV cross-section measurements for these aromatic aldehydes. The obtained cross-section values enable us to estimate the tropospheric photolysis lifetimes of these compounds. The results suggest that photolysis could be an important removal process for these species in the troposphere.

The gas phase tropospheric removal of fluoroaldehydes (CxF2x+1CHO, x = 3, 4, 6).

The rate coefficient of the OH reaction with the perfluoroaldehydes C(3)F(7)CHO and C(4)F(9)CHO have been determined in the temperature range 252-373 K using the pulsed laser photolysis-laser induced fluorescence (PLP-LIF) method: k(C(3)F(7)CHO+OH) = (2.0 +/- 0.6) x 10(-12) exp[-(369 +/- 90)/T] and k(C(4)F(9)CHO+OH) = (2.0 +/- 0.5) x 10(-12) exp[-(356 +/- 70)/T] cm(3) molecule(-1) s(-1), corresponding to (5.8 +/- 0.6) x 10(-13) and (6.1 +/- 0.5) x 10(-13) cm(3) molecule(-1) s(-1), respectively, at 298 K. The UV absorption cross sections of these two aldehydes and CF(3)(CF(2))(5)CH(2)CHO have been measured over the range 230-390 nm at 298 K and also at 328 K for CF(3)(CF(2))(5)CH(2)CHO. The obtained results for C(3)F(7)CHO and C(4)F(9)CHO are in good agreement with two recent determinations but the maximum value of the absorption cross section for CF(3)(CF(2))(5)CH(2)CHO is over a factor of two lower than the single one recently published. The photolysis rates of C(3)F(7)CHO, C(4)F(9)CHO and CF(3)(CF(2))(5)CHO have been measured under sunlight conditions in the EUPHORE simulation chamber in Valencia (Spain) at the beginning of June. The photolysis rates were, respectively, J(obs) = (1.3 +/- 0.6) x 10(-5), (1.9 +/- 0.8) x 10(-5) and (0.6 +/- 0.3) x 10(-5) s(-1). From the J(obs) measurements and calculated photolysis rate J(calc), assuming a quantum yield of unity across the atmospheric range of absorption of the aldehydes, quantum yields J(obs)/J(calc) = (0.023 +/- 0.012), (0.029 +/- 0.015) and (0.046 +/- 0.028) were derived for the photodissociation of C(3)F(7)CHO, C(4)F(9)CHO and CF(3)(CF(2))(5)CHO, respectively. The atmospheric implication of the data obtained in this work is discussed. The main conclusion is that the major atmospheric removal pathway for fluoroaldehydes will be photolysis, which under low NO(x) conditions, may be a source of fluorinated carboxylic acids in the troposphere.

Trifluralin: photolysis under sunlight conditions and reaction with HO* radicals.

The gas phase atmospheric degradation of trifluralin (a widely used herbicide) has been investigated at the EUPHORE facility. Its photolysis has been studied under sunlight conditions and its reaction rate constant with HO() radicals was measured using the relative rate method. Using 1,3,5-trimethylbenzene as reference compound, the rate constant of HO() reaction with trifluralin was obtained to be [formula: see text] The mean photolysis rate measured under solar radiation was [formula: see text] . The photolysis of trifluralin was found to generate organic aerosols with a yield of (20 +/-10)%. The data obtained enabled us to discuss the atmospheric fate of trifluralin in the gas phase.

Reaction of Cl atoms with C6F13CH2OH, C6F13CHO, and C3F7CHO.

The Cl atom initiated oxidation of C(6)F(13)CH(2)OH, C(6)F(13)CHO, and C(3)F(7)CHO was investigated at 298 K and 1000 mbar pressure of air in a photoreactor using in situ Fourier transform infrared (FTIR) analysis. The rate coefficient for the reaction Cl + C(6)F(13)CH(2)OH (reaction 2) was measured using a relative method: k(2) = (6.5 +/- 0.8) x 10(-13) cm(3) molecule(-1) s(-1). C(6)F(13)CHO was detected as the major primary product, while CO and CF(2)O were found to be the major secondary products. A fitting procedure applied to the concentration-time profiles of C(6)F(13)CHO provided a production yield of (1.0 +/- 0.2) for this aldehyde in reaction 2, and the rate coefficient for the reaction Cl + C(6)F(13)CHO (reaction 4) was k(4) = (2.8 +/- 0.7) x 10(-12) cm(3) molecule(-1) s(-1). A high CO yield observed in the oxidation of C(6)F(13)CH(2)OH, (52 +/- 1)%, is attributed to the Cl atom initiated oxidation of C(6)F(13)CHO. High CO yields, (61 +/- 2)% and (85 +/- 5)%, were also measured in the Cl atom initiated oxidation of C(3)F(7)CHO in air and nitrogen, respectively. These high CO yields suggest the occurrence of a decomposition reaction of the perfluoroacyl, C(6)F(13)CO, and C(3)F(7)CO radicals to form CO which will compete with the combination reaction of these radicals with oxygen to form perfluoroacyl peroxy radicals in the presence of air. The latter radicals C(n)F(2)(n)(+1)CO(O)(2) (n = 6-12), through their reaction with HO(2) radicals, are currently considered as a possible source of persistent perfluorocarboxylic acids which have been detected in the environment. The consequences of the present results would be a reduction of the strength of this potential source of carboxylic acids in the atmosphere.

Atmospheric fate of dichlorvos: photolysis and OH-initiated oxidation studies.

The OH-initiated oxidation of dichlorvos (a widely used insecticide) has been investigated under atmospheric conditions at the large outdoor European photoreactor (EUPHORE) in Valencia, Spain. The rate constant of OH reaction with dichlorvos, k, was measured by using a conventional relative rate technique where 1,3,5-trimethylbenzene (TMB) and cyclohexane were taken as references. With the use of the rate constants of 5.67 x 10(-11) and of 6.97 x 10(-12) cm3 molecule(-1) s(-1) for the reactions OH + TMB and OH + cyclohexane, respectively, the resulting value of the OH reaction rate constant with dichlorvos was derived to be k = (2.6 +/- 0.3) x 10(-11) cm3 molecule(-1) s(-1). The tropospheric lifetime of dichlorvos with respect to reaction with OH radical has been estimated to be around 11 h. The major carbon-containing products observed for the OH reaction with dichlorvos in air under sunlight condition were phosgene and carbon monoxide. The formation of a very stable toxic primary product such as phosgene associated with the relatively short lifetime of dichlorvos may make the use of this pesticide even more toxic for humans when released into the atmosphere.

Photolysis and OH-Initiated oxidation of glycolaldehyde under atmospheric conditions.

The photolysis and OH-initiated oxidation of glycolaldehyde (HOCH(2)CHO), which are relevant atmospheric processes, have been investigated under different conditions using complementary methods in three different laboratories. The UV absorption cross sections of glycolaldehyde determined in two of the laboratories are in excellent agreement. The photolysis of glycolaldehyde in air has been investigated in a quartz cell with sunlamps and in the EUPHORE chamber irradiated by sunlight. The mean photolysis rate measured under solar radiation was (1.1 +/- 0.3) x 10(-5) s(-1) corresponding to a mean effective photolysis quantum yield of (1.3 +/- 0.3). The major products detected were HCHO and CO, whereas CH(3)OH was also observed with an initial yield around 10%. Evidence for OH production was found in both experiments using either OH scavenger or OH tracer species. Photolysis of glycolaldehyde was used as the OH source to measure the reaction rate constants of OH with a series of dienes by the relative method and to identify and quantify the oxidation products of the OH-initiated oxidation of 2-propanol. The different experiments suggest that OH is produced by the primary channel: HOCH(2)CHO + hnu --> OH + CH(2)CHO (1). The rate constant of the OH reaction with glycolaldehyde has been measured at 298 K using the relative method: k(glyc) = (1.2 +/- 0.3) x 10(-11) cm(3) molecule(-1) s(-1). The product study of the OH-initiated oxidation of glycolaldehyde in air has been performed using both a FEP bag and the EUPHORE chamber. HCHO was observed to be the major product with a primary yield of around 65%. Glyoxal (CHOCHO) was also observed in EUPHORE with a primary yield of (22 +/- 6)%. This yield corresponds to the branching ratio ( approximately 20%) of the H-atom abstraction channel from the CH(2) group in the OH + HOCH(2)CHO reaction, the major channel ( approximately 80%) being the H-atom abstraction from the carbonyl group. The data obtained in this work, especially the first determination of the photolysis rate of glycolaldehyde under atmospheric conditions, indicate that the OH reaction and photolysis can compete as tropospheric sinks for glycolaldehyde. Since glycolaldehyde is a significant oxidation product of isoprene whereas the photolysis of glycolaldehyde is a significant source of methanol, isoprene might contribute a few percent of the global budget of methanol.

The OH-initiated oxidation of hexylene glycol and diacetone alcohol.

The OH-initiated oxidation of two VOCs directly emitted to the atmosphere through their use as industrial solvents, hexylene glycol (HG, (CH3)2C(OH)CH2CH(OH)CH3) and diacetone alcohol (DA, (CH3)2C(OH)CH2C(O)CH3), has been studied in two photoreactors: a 140 L Teflon bag irradiated by lamps at CNRS-Orleans and the 200 m3 European photoreactor, EUPHORE, irradiated by sunlight. The rate constants for the reactions of HG and DA with OH radicals have been determined at (298 +/- 3) K using a relative rate method: k(HG) = (1.5 +/- 0.4) x 10(-11) and k(DA) = (3.6 +/- 0.6) x 10(-12) cm(3) molecule(-1) s(-1) and have been found in good agreement with estimations from structure-reactivity relationships. The study at Orleans and EUPHORE of the OH-initiated oxidation of hexylene glycol showed the formation of diacetone alcohol, acetone, and PAN as the principal products. The branching ratio of the H-atom abstraction from the > CH- group of HG has been estimated to be (47 +/- 4)% corresponding to the measured formation yield of DA. The formation yields of acetone and PAN lead to the determination of a lower limit of (33 +/- 7)% for the branching ratio of the H-atom abstraction of the -CH2- group of HG. For diacetone alcohol, studies at EUPHORE have shown negligible photolysis under atmospheric conditions (J < 5 x 10(-6) s(-1)) and the formation of acetone, PAN, HCHO, and CO in the OH-initiated oxidation experiments. The molar yield of acetone, close to 100%, corresponds to the branching ratio of the H-atom abstraction from the -CH2- group of DA. The present study has allowed the identification of the nature and the fate of the oxy radicals as intermediates in the oxidation mechanism of both HG and DA. The atmospheric implication of these results, especially the ozone formation potential of HG and DA, is discussed.

Rotational Analysis of the nu(7) Band in Furan (C(4)H(4)O).

We recorded and analyzed the absorption spectrum of the nu(7) fundamental band in furan, observed around 995 cm(-1). Fourier transform (FT) spectroscopy was used at ULB to record the spectrum under room-temperature conditions, at 0.01 cm(-1) instrumental resolution. Diode-laser (DL) spectroscopy in a supersonic jet was used to record some portions of the band at Lille, revealing the fine structure around the band center. Pure rotation (MMW) data in the upper state were also recorded at Lille. Some 5559 FT, 101 DL, and 23 MMW data were assigned in this work. We fitted, on one hand, the MMW and DL data together and, on the other hand, the MMW, DL, and FT data simultaneously using a weighted procedure, constraining the ground state constants to their value determined from the microwave data in the literature. The results from these fits are provided and the constants discussed. Ab initio calculations are also performed to provide a force field which is used to support the very strong increase with the vibrational excitation observed in the inertial defect determined from the experimental rotational constants. Copyright 1999 Academic Press.

Rotation-Vibration Constants for the nu1, nu22, nu24, nu22 + nu24, and Ground States in Pyrrole (12C4H5N).

We have recorded the infrared absorption spectrum of pyrrole at 0.005 cm-1 spectral resolution using a Fourier transform interferometer. The rotational analysis of the symmetric out-of-plane C-H bend 22(1)0 fundamental band at 722.132993(5) cm-1 was performed, allowing 6760 lines to be assigned. These lines were fitted simultaneously to literature data on nu1 [A. Mellouki, R. Georges, M. Herman, D. L. Snavely, and S. Leytner, Chem. Phys. 220, 311-322 (1997)] and microwave lines [G. Wlodarczak, L. Martinache, J. Demaison, and B. P. Van Eijck, J. Mol. Spectrosc. 127, 200-208 (1988)]. A set of rotation parameters was determined for the ground state in Ir and IIIr representations, together with vibration-rotation constants for the v1 = 1 and v22 = 1 vibrational states. The fine structure in the strongest of the hot bands in that range was highlighted by division, from the experimental data, of the spectrum of the 22(1)0 band, computed using the vibration-rotation parameters. The rotational assignment of 930 lines in the strongest hot band was performed. The 22(1)024(1)1 vibrational assignment is proposed, leading to x22,24 = 1.90 cm-1. The transition dipole matrix element for the 22(1)0 band is estimated to || || = 2 x 10(-4) D. Copyright 1999 Academic Press.

Kinetic Studies of OH Reactions with a Series of Methyl Esters.

Absolute rate constants have been measured for the gas-phase reactions of hydroxyl radicals with a series of methyl esters: methyl propionate (k 1), methyl butyrate (k 2), methyl valerate (k 3), and methyl caproate (k 4). Experiments were carried out using the pulsed laser photolysis-laser induced fluorescence technique over the temperature range 253-372 K. The obtained kinetic data were used to derive the following Arrhenius expressions: k 1 = (1.45 ± 0.42) × 10-12 exp[-(148 ± 86)/T]; k 2 = (0.96 ± 0.29) × 10-12 exp[(380 ± 91)/T]; k 3 = (1.37 ± 0.64) × 10-12 exp[(401 ± 142)/T]; k 4 = (2.46 ± 1.04) × 10-12 exp[(326 ± 130)/T] (in units of cm3 molecule-1 s-1). At room temperature, the rate constants obtained (in units of 10-12 cm3 molecule-1 s-1) were as follows: methyl propionate (0.83 ± 0.09); methyl butyrate (3.30 ± 0.25); methyl valerate (4.83 ± 0.55); methyl caproate (7.15 ± 0.70). Our results are compared with the previous determinations and discussed in terms of structure-activity relationships.

Kinetics of the OH Reaction with Methyl Chloroform and Its Atmospheric Implications.

The rate coefficients for the reaction of hydroxyl (OH) radicals with methyl chloroform (CH(3)CCI(3)) were measured between 243 and 379 kelvin with the pulsed photolysis-laserinduced fluorescence method. The measured rate coefficients at 298 and 277 kelvin were approximately 20 and approximately 15%, respectively, lower than earlier values. These results will increase the tropospheric OH concentrations derived from the CH(3)CCI(3) budget analysis by approximately 15%. The predicted atmospheric lifetimes of species whose main loss process is the reaction with OH in the troposphere will be lowered by 15% with consequent changes in their budgets, global warming potentials, and ozone depletion potentials.