Continuous atmospheric in-situ measurements of the CH4/CO ratio at the Mt. Cimone station (Italy, 2165 m a.s.l.) and their possible use for estimating regional CH4 emissions.

Methane (CH4) is an important climate forcer, contributing about 17% of the total radiative forcing by long living greenhouse gases. The Po basin is one of the most polluted and densely populated areas in Europe representing an important source region for CH4. The aim of this work was to test an inter-species correlation approach to derive estimates of anthropogenic CH4 emissions for the period 2015-2019 from the Po basin by combining CO bottom-up inventory data and continuous CH4 and CO observations from a mountain site in the northern Italy. The tested methodology suggested lower emissions in respect to EDGAR (-17%) and the Italian National Inventory (-40%) for the Po basin. However, despite the two bottom-up inventories, the emissions derived from the atmospheric observations reported an increasing tendency from 2015 to 2019 for the CH4 emissions. A sensitivity study revealed that using different subsets of the atmospheric observations implied a difference of 26% in the CH4 emission estimates. The highest agreement with two bottom-up CH4 inventories (EDGAR and the Italian national inventory) were obtained when atmospheric data were strictly selected for periods representative of air mass transport from the Po basin. Our study identified various challenges when using this methodology as a benchmark to verify bottom-up CH4 inventories. Issues could be attributed to the annual aggregation of the proxies used to derive the emission amounts, to the CO bottom-up inventory used as input information and to the relatively high sensitivity of the results to the different subsets of the atmospheric observations. However, the use of different bottom-up inventories as input data for CO emissions can potentially provide information that should be carefully considered for the purpose of integrating CH4 bottom-up inventories.

Warming and redistribution of nitrogen inputs drive an increase in terrestrial nitrous oxide emission factor.

Anthropogenic nitrogen inputs cause major negative environmental impacts, including emissions of the important greenhouse gas N2O. Despite their importance, shifts in terrestrial N loss pathways driven by global change are highly uncertain. Here we present a coupled soil-atmosphere isotope model (IsoTONE) to quantify terrestrial N losses and N2O emission factors from 1850-2020. We find that N inputs from atmospheric deposition caused 51% of anthropogenic N2O emissions from soils in 2020. The mean effective global emission factor for N2O was 4.3 ± 0.3% in 2020 (weighted by N inputs), much higher than the surface area-weighted mean (1.1 ± 0.1%). Climate change and spatial redistribution of fertilisation N inputs have driven an increase in global emission factor over the past century, which accounts for 18% of the anthropogenic soil flux in 2020. Predicted increases in fertilisation in emerging economies will accelerate N2O-driven climate warming in coming decades, unless targeted mitigation measures are introduced.

Short-term effects of physiotherapy on ventilation inhomogeneity in cystic fibrosis patients with a wide range of lung disease severity.

BACKGROUND: Lung clearance index (LCI) is increasingly used as a study endpoint for therapeutic interventions in cystic fibrosis (CF) patients. We set out to assess the effect of chest physiotherapy on ventilation inhomogeneity in clinically stable patients with CF lung disease of varying severity. METHODS: In 29 CF patients (7.3-43.7 years) N2MBW (nitrogen multiple breath washout), plethysmography, and spirometry measurements were conducted, followed by 30 min of supervised PEP mask chest physiotherapy and repeated measurements 30 min after therapy. RESULTS: We observed a mean change in LCI after physiotherapy from 15.00 to 14.80 (range, -4.84 to 3.37; p=0.578). In seven patients, LCI decreased, and in ten patients, LCI increased by ≥1. For the whole group, statistically significant improvements were seen in Reff, FEV1, FVC, and MEF50. CONCLUSIONS: By opening up previously poorly ventilated lung regions, physiotherapy may either increase or decrease ventilation inhomogeneity; the short-term effect of physiotherapy on LCI appears to be unpredictable.

Molecular hydrogen (H2) emissions from gasoline and diesel vehicles.

This study assesses individual-vehicle molecular hydrogen (H2) emissions in exhaust gas from current gasoline and diesel vehicles measured on a chassis dynamometer. Absolute H2 emissions were found to be highest for motorcycles and scooters (141+/-38.6 mg km(-1)), approximately 5 times higher than for gasoline-powered automobiles (26.5+/-12.1 mg km(-1)). All diesel-powered vehicles emitted marginal amounts of H2 ( approximately 0.1 mg km(-1)). For automobiles, the highest emission factors were observed for sub-cycles subject to a cold-start (mean of 53.1+/-17.0 mg km(-1)). High speeds also caused elevated H2 emission factors for sub-cycles reaching at least 150 km h(-1) (mean of 40.4+/-7.1 mg km(-1)). We show that H2/CO ratios (mol mol(-1)) from gasoline-powered vehicles are variable (sub-cycle means of 0.44-5.69) and are typically higher (mean for automobiles 1.02, for 2-wheelers 0.59) than previous atmospheric ratios characteristic of traffic-influenced measurements. The lowest mean individual sub-cycle ratios, which correspond to high absolute emissions of both H2 and CO, were observed during cold starts (for automobiles 0.48, for 2-wheelers 0.44) and at high vehicle speeds (for automobiles 0.73, for 2-wheelers 0.45). This finding illustrates the importance of these conditions to observed H2/CO ratios in ambient air. Overall, 2-wheelers displayed lower H2/CO ratios (0.48-0.69) than those from gasoline-powered automobiles (0.75-3.18). This observation, along with the lower H2/CO ratios observed through studies without catalytic converters, suggests that less developed (e.g. 2-wheelers) and older vehicle technologies are largely responsible for the atmospheric H2/CO ratios reported in past literature.

Observations of long-lived anthropogenic halocarbons at the high-Alpine site of Jungfraujoch (Switzerland) for assessment of trends and European sources.

Anthropogenic halocarbons, such as chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), hydrofluorocarbons (HFCs), bromocarbons (halons) and long-lived chlorinated solvents have been measured continuously at the high-Alpine site of Jungfraujoch (Switzerland) since January 2000. Chloro- and bromo-containing halocarbons are responsible for the stratospheric ozone depletion and will be globally banned from usage within the next years. With the exception of the stable CFC-12 (CF2 Cl2), all major CFCs and chlorinated solvents show a negative trend in recent years in their background concentrations at Jungfraujoch. HCFCs, as their first-generation substitute, are still increasing with a few percent per year. However, the frequency and the strength of HCFCs pollution events, which are caused by regional European emissions, are already declining. This can be seen as a sign of the impending ban of these gases within the next years in Europe. On the other hand, HFCs as the second-generation substitutes, are increasing with relative rates of at least 10% per year (e.g. almost 5 ppt per year for HFC-134a). An allocation of European sources was attempted by combining measured concentrations with trajectories of air masses reaching the Jungfraujoch during pollution events. Potential source regions could be detected in Italy, France, Spain and Germany.

An evaluation of the current radiative forcing benefit of the Montreal Protocol at the high-Alpine site Jungfraujoch.

A combination of reconstructed histories, long-term time series and recent quasi-continuous observations of non-CO2 greenhouse gases at the high-Alpine site Jungfraujoch is used to assess their current global radiative forcing budget and the influence of regulations due to the Montreal Protocol on Substances that Deplete the Ozone Layer in terms of climate change. Extrapolated atmospheric greenhouse gases trends from 1989 assuming a business-as-usual scenario, i.e. no Montreal Protocol restriction, are presented and compared to the observations. The largest differences between hypothetical business-as-usual mixing ratios and current atmospheric observations over the last 16 years were found for chlorinated species, in particular methyl chloroform (CH3CCl3) at 167 to 203 ppt and chlorofluorocarbon-12 (CFC-12) at 121 to 254 ppt. These prevented increases were used to estimate the effects of their restrictions on the radiative forcing budget. The net direct effect due to the Montreal Protocol regulations reduces global warming and offsets about 14 to 30% of the positive greenhouse effect related to the major greenhouse gases CO2, CH4, N2O and also SF6, and about 12 to 22% of the hypothetical current radiative forcing increase without Montreal Protocol restrictions. Thus, the Montreal Protocol succeeded not only in reducing the atmospheric chlorine content in the atmosphere but also dampened global warming. Nevertheless, the Montreal Protocol controlled species still add to global warming.

Secondary organic aerosols from anthropogenic and biogenic precursors.

Secondary organic aerosol (SOA) formation from the photooxidation of an anthropogenic (1,3,5-trimethylbenzene) and a biogenic (alpha-pinene) precursor was investigated at the new PSI smog chamber. The chemistry of the gas phase was followed by proton transfer reaction mass spectrometry, while the aerosol chemistry was investigated with aerosol mass spectrometry, ion chromatography, laser desorption ionization mass spectrometry, and infrared spectroscopy, along with volatility and hygroscopicity studies. Evidence for oligomer formation for SOA from both precursors was given by an increasing abundance of compounds with a high molecular weight (up to 1000 Da) and by an increasing thermal stability with increasing aging time. The results were compared to data obtained from ambient aerosol samples, revealing a number of similar features.

Identification of polymers as major components of atmospheric organic aerosols.

Results from photooxidation of aromatic compounds in a reaction chamber show that a substantial fraction of the organic aerosol mass is composed of polymers. This polymerization results from reactions of carbonyls and their hydrates. After aging for more than 20 hours, about 50% of the particle mass consists of polymers with a molecular mass up to 1000 daltons. This results in a lower volatility of this secondary organic aerosol and a higher aerosol yield than a model using vapor pressures of individual organic species would predict.

[Does immunoscintigraphy improve early diagnosis of metastatic or recurrent cancer?]. / Verbessert die Immunszintigraphie die Frühdiagnostik des metastasierten oder rezidivierten Karzinoms?

In 42 patients with suspicion of recurrent colorectal cancer results of conventional diagnostic methods were compared to those of immunoscintigraphy. In 69% of all cases the intraoperative findings of a second-look operation served for validation, in 31% the follow-up was controlled. Localization of recurrent tumors was successful in 83% using conventional methods versus 57% by immunoscintigraphy. This procedure disappointed especially by a low sensitivity (23%) and low predictive parameters (pos.: 33%; neg.: 37%) in regard to diagnosis of extrahepatic tumors compared to results of conventional methods (77%), 94% respectively 79%). The quote of false positive results was surprisingly high in immunoscintigraphy (n = 12), 83% of these especially in localization of extrahepatic tumors. Therefore, the validity of immunoscintigraphy as an additive diagnostic tool for early detection of recurrent colorectal cancer must be regarded critically.

The value of immunoscintigraphy for the operative retreatment of colorectal cancer. Limitations of a new diagnostic method.

In 42 patients with suspected recurrent colorectal cancer, results of conventional diagnostic methods were compared with those of immunoscintigraphy. In 69% of all cases, the intraoperative findings of a second-look operation served for validation, whereas in 31% close follow-up was used. Recurrent tumors were successfully localized in 83% of patients by conventional methods, whereas immunoscintigraphy was expressive in 57% of cases. Immunoscintigraphy was disappointing especially because of its low sensitivity (23%) and low predictive value (positive, 33%; negative, 37%) with regard to successful diagnosis of extrahepatic tumors compared with the results of conventional methods (77% sensitivity; positive, 94%; negative, 79%). The rate of false-positive results was relatively high with immunoscintigraphy (n = 12), 83% of which were related to extrahepatic recurrent tumors. The value of immunoscintigraphy using an immunococktail of 131-J-labeled F(ab')2 fragments of monoclonal antibodies against CEA, with Ca 19-9 as an additional diagnostic tool for early detection of recurrent colorectal cancer, must therefore be viewed critically.

Technetium-99m labeled renal function and imaging agents: II. Clinical evaluation of 99mTc MAG3 (99mTc mercaptoacetylglycylglycylglycine).

First clinical results indicated that among all potential 99mTc-complexes the N3S-complex 99mTc MAG3 has the biokinetic properties most similar to o-I-hippurate (OIH). A simultaneous comparison of 99mTc MAG3 and 131I OIH was conducted in a series of 48 patients. Twelve out of 18 transplant patients received simultaneously both radiopharmaceuticals for follow-up scintigraphic studies during the early post-transplantation period. In all of these double tracer studies (n = 90) the renograms obtained with 99mTc MAG3 exhibited qualitatively the same curve-shapes, compared with OIH, in cases of acute graft rejection or acute tubular necrosis. In addition, both agents were administered simultaneously to 46 of these patients and the plasma clearance values were determined under steady state conditions. The clearance data of both radio-pharmaceuticals showed a very good correlation (r = 0.95; P less than or equal to 0.05). The 99mTc MAG3/131I OIH clearance ratio showed a mean value of 0.65. Due to the high plasma protein binding of 99mTc MAG3 it is assumed not to be filtered through the glomerular membrane. Therefore we introduce for the 99mTc MAG3 clearance the term "Tubular Extraction Rate (TER)". Due to the favourable physical characteristics of 99mTc, higher activities can be administered as compared to 131I OIH. This allows the simultaneous examination of the tubular function as well as the renal perfusion. Additionally the kidney morphology is imaged with much better resolution. It is concluded that from the clinical point of view 99mTc MAG3 is a favourable replacement for OIH not only for renal imaging but also for the quantitative determination of tubular function. The acceptance will depend on the quality and on the handling of a commercially available kit formulation.

Technetium-99m labeled renal function and imaging agents: I. Clinical evaluation of 99mTc CO2-DADS-A (99mTc N,N'-bis-(mercaptoacetyl)-2,3-diaminopropanoate).

Animal experiments and preliminary clinical results showed that the N2S2-complex 99mTc CO2-DADS-A, which was claimed to be a potential replacement for o-I-hippurate as a renal function agent, had a lower affinity for the tubular transport system than o-I-hippurate. In order to evaluate if this finding offered the possibility of detecting decreases in tubular function with more sensitivity, or at earlier times, 6 patients in the early post-transplantation period were subjected to 53 simultaneous scintigraphic investigations with 131I o-I-hippurate and 99mTc CO2-DADS-A. The comparison of the renograms obtained with the respective agents showed that in almost all cases of acute graft rejection only o-I-hippurate yielded the typical, diagnostically useful accumulation curve which results from its high retention in the kidney parenchyma. 99mTc CO2-DADS-A did not reveal this effect. Additionally the plasma clearance of each agent was measured simultaneously under steady state conditions in nine patients. Although it was reported that relative to o-I-hippurate the analog images obtained with 99mTc CO2-DADS-A gave higher kidney-to-background ratios and the amount excreted in the urine at 30 min was slightly less, the clearance values obtained for 99mTc CO2-DADS-A were on average only 36% of those for o-I-hippurate. It is concluded that 99mTc CO2-DADS-A is not suitable as a substitute for o-I-hippurate.

[Current role of immunoscintigraphy for surgical therapy of the recurrence of colorectal cancers]. / Zur derzeitigen Rolle der Immunszintigraphie für die operative Rezidivtherapie colorectaler Carcinome.

In patients with local recurrence or liver metastases from colorectal cancer the preoperative results of conventional diagnostic methods (sonography, computed tomography, x-ray, endoscopy) and immunoscintigraphy performed with 131I labeled CEA/Ca 19-9 antibodies were compared to intraoperative findings. Specificity of immunoscintigraphy in detecting liver metastases was higher compared to conventional diagnostic methods but its predictive reliability was disappointing, especially in regard to diagnosis of the number of liver metastases and detection of local recurrence or peritoneal seedings. Compared to all intraoperative findings a positive predictive value of 74% and a negative predictive value of 42% for immunoscintigraphy could be found as compared to 88% and 63%, respectively, for conventional diagnostic methods. So immunoscintigraphy in our experience cannot give more information beyond conventional diagnostic tools for indication or planning of operative strategy in the treatment of recurrent colorectal cancer.

[Uptake behavior of bone metastases of hypernephroma in the 99m Tc-MDP bone scintigram. A comparison with x-ray findings]. / Das Speicherverhalten von ossären Metastasen des Hypernephroms im 99mTc-MDP-Knochenszintigramm. Vergleich mit röntgenologischen Befunden.

Ninety-one radiologically confirmed osteolytic metastases in 30 patients with hypernephromas were studied with regard to their uptake of 99mTc-MDP and this was compared with the radiological findings. In 16% of the radiologically proven metastases, there was no correlation with their isotope uptake. Compared with other bone metastases whose isotope uptake has been studied and described in the literature, there appears to be a higher proportion of hypernephroma secondaries that do not show uptake of 99mTc-MDP.

[Computed tomography of primary pulmonary sarcomas]. / Computertomographie primärer pulmonaler Sarkome.

CT findings of 4 patients with primary pulmonary sarcomas are presented. In all cases there was a more than 5 cm large solid, circular configured, intrapulmonary growth without enlarged hilar and mediastinal lymph nodes and also without atelectasis.

[Computed tomographic and roentgenologic findings in bronchiolo-alveolar carcinoma of the lung]. / Computertomographische und röntgenologische Befunde beim bronchiolo-alveolären Karzinom der Lunge.

Eighteen patients with alveolar carcinomas (ten solitary, eight disseminated) were examined pre-operatively by CT and conventional radiography and the results were compared. The 'pleura fingers' and air bronchogram were shown by conventional tomography as often as by CT in the solitary cases. In the disseminated form, CT is superior by showing small foci in the opposite lung.

[Computed tomographic and roentgenologic evaluation of solitary pulmonary nodules]. / Computertomographische und röntgenologische Beurteilung solitärer Lungenrundherde.

One hundred patients with solitary intrapulmonary round lesions were examined by CT and conventional tomography in order to compare their value in reaching a diagnosis. Correct diagnosis as to whether the lesion was malignant was possible in 79% by tomography and in 84% by CT; the type of lesion was diagnosed correctly in 50% and 64% respectively. CT was superior to conventional radiography, particularly for the recognition of calcified tuberculomas. A density value was determined which, when exceeded, always indicated that the lesion was benign.

[Computed tomography in the differential diagnosis of inflammatory and neoplastic lung diseases]. / Der Beitrag der Computertomographie zur Differentialdiagnostik entzündlicher und neoplastischer Lungenerkrankungen.

Fourty patients suspected of having a bronchogenic carcinoma but who, in fact, had inflammatory pulmonary lesions were examined by computed tomography. The findings were compared with the CT appearances of 40 patients with bronchogenic carcinomas (20 of these underwent surgery). In 28 patients (70%) suspected of having a bronchogenic carcinoma, the CT findings indicated an inflammatory lesion. As might have been expected, there was no single CT criterion which is found only in inflammatory lesions. Chronic inflammatory processes and inflammatory pseudo-tumours (chronic pneumonias and tuberculosis) cannot be distinguished from malignant tumours by CT (12 out of 40 patients, 30%).