Demonstrating Agreement between Radio and Fluorescence Measurements of the Depth of Maximum of Extensive Air Showers at the Pierre Auger Observatory

We show, for the first time, radio measurements of the depth of shower maximum (X_{max}) of air showers induced by cosmic rays that are compared to measurements of the established fluorescence method at the same location. Using measurements at the Pierre Auger Observatory we show full compatibility between our radio and the previously published fluorescence dataset, and between a subset of air showers observed simultaneously with both radio and fluorescence techniques, a measurement setup unique to the Pierre Auger Observatory. Furthermore, we show radio X_{max} resolution as a function of energy and demonstrate the ability to make competitive high-resolution X_{max} measurements with even a sparse radio array. With this, we show that the radio technique is capable of cosmic-ray mass composition studies, both at Auger and at other experiments.

[Radiation-induced cataract-an occult risk for urologists]

BACKGROUND

Radiation-induced cataracts represent a relevant risk to people occupationally exposed to radiation. The annual limit dose for the eye lens was reduced to 20 mSv per year by German legislation (radiation protect law StrlSchG 2017; 2013/59/Euratom) based on recommendation of International Commission on Radiation Protection (2011 ICRP) to avoid radiation-induced cataracts.

OBJECTIVES

Is there a risk of exceeding the annual limit dose for the eye lens in routine urological practice without special radiation protection for the head?

METHODS

As part of a prospective, monocentric dosimetry study, of 542 different urological, fluoroscopically guided interventions, the eye lens dose was determined using a forehead dosimeter (thermo-luminescence dosemeter TLD, Chipstrate) over a period of 5 months.

RESULTS

An average head dose of 0.05 mSv per intervention (max. 0.29 mSv) was found with an average dose area product of 485.33 Gy/cm². Significant influencing factors for a higher dose were a higher patient body mass index (BMI), a longer operation time, and a higher dose area product. The level of experience of the surgeon showed no significant influence.

DISCUSSION

With 400 procedures per year or an average of 2 procedures per working day, the critical annual limit value for the eye lenses or for the risk of radiation-induced cataract would be exceeded without special protective measures.

CONCLUSION

Consistently effective radiation protection of the eye lens is essential for daily work in uroradiological interventions. This may require further technical developments.

Limits to Gauge Coupling in the Dark Sector Set by the Nonobservation of Instanton-Induced Decay of Super-Heavy Dark Matter in the Pierre Auger Observatory Data

Instantons, which are nonperturbative solutions to Yang-Mills equations, provide a signal for the occurrence of quantum tunneling between distinct classes of vacua. They can give rise to decays of particles otherwise forbidden. Using data collected at the Pierre Auger Observatory, we search for signatures of such instanton-induced processes that would be suggestive of super-heavy particles decaying in the Galactic halo. These particles could have been produced during the post-inflationary epoch and match the relic abundance of dark matter inferred today. The nonobservation of the signatures searched for allows us to derive a bound on the reduced coupling constant of gauge interactions in the dark sector: α_{X}≲0.09, for 10^{9}≲M_{X}/GeV<10^{19}. Conversely, we obtain that, for instance, a reduced coupling constant α_{X}=0.09 excludes masses M_{X}≳3×10^{13}  GeV. In the context of dark matter production from gravitational interactions alone, we illustrate how these bounds are complementary to those obtained on the Hubble rate at the end of inflation from the nonobservation of tensor modes in the cosmological microwave background.

Measurement of the Fluctuations in the Number of Muons in Extensive Air Showers with the Pierre Auger Observatory

We present the first measurement of the fluctuations in the number of muons in extensive air showers produced by ultrahigh energy cosmic rays. We find that the measured fluctuations are in good agreement with predictions from air shower simulations. This observation provides new insights into the origin of the previously reported deficit of muons in air shower simulations and constrains models of hadronic interactions at ultrahigh energies. Our measurement is compatible with the muon deficit originating from small deviations in the predictions from hadronic interaction models of particle production that accumulate as the showers develop.

Older People Facing the Crisis of COVID-19: Between Fragility and Resilience

The health crisis we are facing is challenging seniors’ resources and capacities for adaptation and resilience. The PACOVID survey, set up a few days after containment, investigates their psychological and social experiences with regard to the COVID-19 crisis and to what extent these characteristics, representations and attitudes have an impact on health and mortality. A telephone survey is being carried out on 935 people already followed up in the framework of ongoing epidemiological studies. As we are writing this article, the interviews conducted during the containment have just ended. Even though we will have to wait for the analysis of the results to draw conclusions, words collected by the psychologists during the interviews already illustrate a great heterogeneity in the way older adults lived this experience: social isolation, anxiety, the importance of family and the difficulty of being deprived of it, but also remarkable coping skills and resilience capacities.

Cytokine levels in children and adults with wheezing and asthma show specific patterns of variability over time

Levels of cytokines are used for in-depth characterization of patients with asthma; however, the variability over time might be a critical confounder. To analyze the course of serum cytokines in children, adolescents and adults with asthma and in healthy controls and to propose statistical methods to control for seasonal effects. Of 532 screened subjects, 514 (91·5%) were included in the All Age Asthma Cohort (ALLIANCE). The cohort included 279 children with either recurrent wheezing bronchitis (more than two episodes) or doctor-diagnosed asthma, 75 healthy controls, 150 adult asthmatics and 31 adult healthy controls. Blood samples were collected and 25 μl serum was used for analysis with the Bio-Plex Pr human cytokine 27-Plex assay. Mean age, body mass index and gender in the three groups of wheezers, asthmatic children and adult asthmatics were comparable to healthy controls. Wheezers (34·5%), asthmatic children (78·7%) and adult asthmatics (62·8%) were significantly more often sensitized compared to controls (4·5, 22 and 22·6%, respectively). Considering the entire cohort, interleukin (IL)-1ra, IL-4, IL-9, IL-17, macrophage inflammatory protein (MIP)-1- α and tumor necrosis factor (TNF)- α showed seasonal variability, whereas IL-1β, IL-7, IL-8, IL-13, eotaxin, granulocyte colony-stimulating factor (G-CSF), interferon gamma-induced protein (IP)-10, MIP-1 β and platelet-derived growth factor (PDGF)-BB did not. Significant differences between wheezers/asthmatics and healthy controls were observed for IL-17 and PDGF-BB, which remained stable after adjustment for the seasonality of IL-17. Seasonality has a significant impact on serum cytokine levels in patients with asthma. Because endotyping has achieved clinical importance to guide individualized patient-tailored therapy, it is important to account for seasonal effects.

Features of the Energy Spectrum of Cosmic Rays above 2.5×10^{18} eV Using the Pierre Auger Observatory

We report a measurement of the energy spectrum of cosmic rays above 2.5×10^{18}  eV based on 215 030 events. New results are presented: at about 1.3×10^{19}  eV, the spectral index changes from 2.51±0.03(stat)±0.05(syst) to 3.05±0.05(stat)±0.10(syst), evolving to 5.1±0.3(stat)±0.1(syst) beyond 5×10^{19}  eV, while no significant dependence of spectral features on the declination is seen in the accessible range. These features of the spectrum can be reproduced in models with energy-dependent mass composition. The energy density in cosmic rays above 5×10^{18}  eV is [5.66±0.03(stat)±1.40(syst)]×10^{53}  erg Mpc^{-3}.

Testing Hadronic Interactions at Ultrahigh Energies with Air Showers Measured by the Pierre Auger Observatory

Ultrahigh energy cosmic ray air showers probe particle physics at energies beyond the reach of accelerators. Here we introduce a new method to test hadronic interaction models without relying on the absolute energy calibration, and apply it to events with primary energy 6-16 EeV (E_{CM}=110-170  TeV), whose longitudinal development and lateral distribution were simultaneously measured by the Pierre Auger Observatory. The average hadronic shower is 1.33±0.16 (1.61±0.21) times larger than predicted using the leading LHC-tuned models EPOS-LHC (QGSJetII-04), with a corresponding excess of muons.

Comparison of indirect CsI/a:Si and direct a: SE digital radiography: An assessment of contrast and detail visualization

Purpose: To assess and quantify the image quality at two dose levels for an amorphous Silicon (a:Si) Cesium Iodide (CsI) flat panel system compared with a direct amorphous Selenium (a:Se) digital radiography system.

Material and Methods: A contrast detectability test was performed employing the CDRAD-phantom at mAs-values leading to approximately equal phantom entrance doses of 41.4, 57.9, 75.1 and 120.8 µGy for the a:Se and 39.9, 58.4, 75.6 and 117.9 µGy for the CsI system. Images were presented to 4 independent observers. For quantitative comparison, the image quality figure (IQF) was calculated. Statistical analysis was performed using Pearson's correlation and the Wilcoxon test. A ROC-analysis was performed employing the TRG-phantom in a high- and a low-dose setting leading to entrance doses of 126.2 and 35 µGy for the direct, and 125.9 and 34.4 µGy for the indirect system. Statistical significance was evaluated using the Wilcoxon test

Results: The flat panel a:Si digital system provided superior results compared with the a:Se drum digital system with respect to low-dose settings for CDRAD-phantom and ROC-analysis, ensuring a better image quality with respect to contrast and detail detectability. Higher-dose settings provided similar results for both systems.

Conclusion: Image quality of a:Si flat panel digital radiography proved to be superior to a:Se drum digital radiography using low-dose settings. If the primary target is dose reduction indirect flat panel technology should be used.

Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy

We measure the energy emitted by extensive air showers in the form of radio emission in the frequency range from 30 to 80 MHz. Exploiting the accurate energy scale of the Pierre Auger Observatory, we obtain a radiation energy of 15.8±0.7(stat)±6.7(syst)  MeV for cosmic rays with an energy of 1 EeV arriving perpendicularly to a geomagnetic field of 0.24 G, scaling quadratically with the cosmic-ray energy. A comparison with predictions from state-of-the-art first-principles calculations shows agreement with our measurement. The radiation energy provides direct access to the calorimetric energy in the electromagnetic cascade of extensive air showers. Comparison with our result thus allows the direct calibration of any cosmic-ray radio detector against the well-established energy scale of the Pierre Auger Observatory.

Search for patterns by combining cosmic-ray energy and arrival directions at the Pierre Auger Observatory

Energy-dependent patterns in the arrival directions of cosmic rays are searched for using data of the Pierre Auger Observatory. We investigate local regions around the highest-energy cosmic rays with [Formula: see text] eV by analyzing cosmic rays with energies above [Formula: see text] eV arriving within an angular separation of approximately 15[Formula: see text]. We characterize the energy distributions inside these regions by two independent methods, one searching for angular dependence of energy-energy correlations and one searching for collimation of energy along the local system of principal axes of the energy distribution. No significant patterns are found with this analysis. The comparison of these measurements with astrophysical scenarios can therefore be used to obtain constraints on related model parameters such as strength of cosmic-ray deflection and density of point sources.

[Arterial and portal venous complications after HPB surgical procedures: Interdisciplinary management]

The surgical treatment of hepatopancreatobiliary (HPB) diseases requires complex operative procedures. Within the last decades the morbidity (36-50 %) and mortality (<5 %) of these procedures could be reduced; nonetheless, postoperative complications still occur in 41.2 % of cases. Compared with hepatobiliary procedures, pancreatic surgery shows an increased rate of complications. Postoperative bleeding has a major effect on the outcome and the incidence is 6.7 % after pancreatic surgery and 3.2 % after hepatobiliary surgery. The major causes of early postoperative hemorrhage are related to technical difficulties in surgery whereas late onset postoperative hemorrhage is linked to anastomosis insufficiency, formation of fistulae or abscesses due to vascular arrosion or formation of pseudoaneurysms. In many cases, delayed hemorrhage is preceded by a self-limiting sentinel bleeding. The treatment is dependent on the point in time, location and severity of the hemorrhage. The majority of early postoperative hemorrhages require surgical treatment. Late onset hemorrhage in hemodynamically stable patients is preferably treated by radiological interventions. After interventional hemostatic therapy 8.2 % of patients require secondary procedures. In the case of hemodynamic instability or development of sepsis, a relaparotomy is necessary. The treatment concept includes surgical or interventional remediation of the underlying cause of the hemorrhage. Other causes of postoperative morbidity and mortality are arterial and portal venous stenosis and thrombosis. Following liver resection, thrombosis of the portal vein occurs in 8.5-9.1 % and in 11.6 % following pancreatic resection with vascular involvement. Interventional surgical procedures or conservative treatment are suitable therapeutic options depending on the time of diagnosis and clinical symptoms. The risk of morbidity and mortality after HPB surgery can be reduced only in close interdisciplinary cooperation, which is particularly true for vascular complications.

A prospective Phase 2a pilot study investigating focal percutaneous irreversible electroporation (IRE) ablation by NanoKnife in patients with localised renal cell carcinoma (RCC) with delayed interval tumour resection (IRENE trial)

INTRODUCTION

Focal ablation therapy is playing an increasing role in oncology and may reduce the toxicity of current surgical treatments while achieving adequate oncological benefit. Irreversible electroporation (IRE) has been proposed to be tissue-selective with potential advantages compared with current thermal-ablation technologies or radiotherapy. The aim of this pilot trial is to determine the effectiveness and feasibility of focal percutaneous IRE in patients with localised renal cell cancer as a uro-oncological tumour model.

METHODS

Prospective, monocentric Phase 2a pilot study following current recommendations, including those of the International Working Group on Image-Guided Tumor Ablation. Twenty patients with kidney tumour (T1aN0M0) will be recruited. This sample permits an appropriate evaluation of the feasibility and effectiveness of image-guided percutaneous IRE ablation of locally confined kidney tumours as well as functional outcomes. Percutaneous biopsy for histopathology will be performed before IRE, with magnetic-resonance imaging one day before and 2, 7, 27 and 112 days after IRE; at 28 days after IRE the tumour region will be completely resected and analysed by ultra-thin-layer histology.

DISCUSSION

The IRENE study will investigate over a short-term observation period (by magnetic-resonance imaging, post-resection histology and assessment of technical feasibility) whether focal IRE, as a new ablation procedure for soft tissue, is feasible as a percutaneous, tissue-sparing method for complete ablation and cure of localised kidney tumours. Results from the kidney-tumour model can provide guidance for designing an effectiveness and feasibility trial to assess this new ablative technology, particularly in uro-oncology.

Assessment and monitoring of liver function by ¹³C-aminopyrine breath test after selective transarterial chemoembolisation of hepatocellular carcinoma

BACKGROUND

Liver function and tumor staging are essential parameters for selection of treatment modalities in patients with hepatocellular carcinoma (HCC). Transarterial chemoembolization (TACE) is associated with a risk of deterioration of liver function. In clinical routine hepatic function in patients with liver cirrhosis is assessed by the Child-Pugh-classification. Dynamic breath tests allow the assessment of the hepatic functional mass and have the potential to give more accurate information on hepatic function periinterventionally.

PATIENTS AND METHODS

A prospective clinical study was performed in 13 patients receiving a total of 18 TACE sessions. (13)C-aminopyrine breath test was performed the day before TACE, 2 days and 30 days after TACE and correlated with standard laboratory work-up of the patients.

RESULTS

Fourteen TACE sessions were performed in Child A liver cirrhosis, 4 in Child B cirrhosis. All patients presented with impaired aminopyrine metabolism at baseline. No significant changes in the (13)C aminopyrine breath test following TACE were observed. Two patients treated in Child A cirrhosis decompensated to Child B, one of them recovered. No further decompensation was observed in patients treated in Child B cirrhosis.

DISCUSSION AND CONCLUSION

Liver function assessment with (13)C-aminopyrine breath test and Child-Pugh-classification following TACE was discordant in a large proportion of patients. Whether a quantification of mitochondrial liver function in patients planned to undergo locoregional treatment of HCC in liver cirrhosis is helpful in the prediction of postprocedural liver decompensation needs to be addressed in larger prospective clinical trials.

[Differential Vascular Medical Management of Visceral Artery Aneurysms in a Single-Centre Consecutive Patient Cohort as Part of an Ongoing Disease-Specific Systematic Clinical Prospective Observational Study]

AIM, PATIENTS AND METHODS

By means of a systematic single-centre prospective observational study, spectrum (symptomatology, frequency) and diagnostics of the different visceral artery aneurysm sites as well as the postinterventional course of the various therapeutic options used according to local finding and patient's clinical status as well as risk factors were analysed to contrast the different procedures (conservative, image-guided radiological intervention, open vascular surgery) in consideration of their decision-making criteria and their early postinterventional outcome (on the basis of complication rate, peri-interventional morbidity and hospital lethality) including relevant references from the literature.

RESULTS

During a time period of 14 years, 22 patients (sex ratio: 12 males/10 females; mean age: 54.3 [range: 22-76] years) were registered. Most frequently, visceral artery aneurysms occurred in the splenic artery (50 %). The gastroduodenal artery, the hepatic artery and the right renal artery were affected in each with 13.6 % (n = 3/22), the superior mesenteric artery in 9.1 % (n = 2/22). The majority of patients (54.5 %) were treated with image-guided radiological intervention, whereas in 31.8 %, the patient underwent open vascular surgery and 13.6 % of cases were managed with "watchful waiting". While morbidity was 21.1 % (n = 4/19), overall lethality was 9.1 % (n = 2/22).

CONCLUSION

Decision-making for a specific therapeutic approach should be made (i) after adequate diagnostic measures (transabdominal ultrasound, MR angiography, duplex ultrasonography, CT-A/DSA if required), (ii) on an individual case-adapted base, (iii) in a vascular surgical centre, (iv) case-associated to the specific local finding (in particular, according to size/specific probability of rupture [cave: gravidity]) and (v) according to the individual risk profile using the whole spectrum of therapeutic options (conservative vs. interventional; image-guided radiological intervention [endovascular repair such as embolisation, stent or stent graft] vs. open vascular surgery [according to a step-up approach]; open vascular ligation vs. reconstruction after exclusion of the aneurysm) including sufficient quality assurance of the treatment results as well as control investigations (duplex ultrasonography; MR-A if required) in a specialised vascular surgical out-patient centre within appropriate time intervals.

Identification of predictive CT angiographic factors in the development of high-risk type 2 endoleaks after endovascular aneurysm repair in patients with infrarenal aortic aneurysms

PURPOSE

An extensive analysis of the value of computed tomography (CT) parameters as potential predictors of the clinical outcome of type 2 endoleaks after endovascular aortic aneurysm repair (EVAR).

MATERIALS AND METHODS

Initial CT scans of 130 patients with abdominal aortic aneurysms (AAAs) were retrospectively reviewed. On the basis of postoperative CT scans and angiographies, patients were stratified into a low-risk group (LRG; without or transient type 2 endoleak; n = 80) and a high-risk group (HRG, persistent type 2 endoleak or need for reintervention; n = 50). Statistical analysis comprised a univariate and multivariate analysis.

RESULTS

Anatomical, thrombus-specific, as well as aortic side branch parameters were assessed on the initial CT scan. Of all anatomical parameters, the diameter of the immediate infrarenal aorta was significantly different in the univariate analysis (LRG 22.4 ± 3.8 mm; HRG 23.6 ± 2.5 mm; p = 0.03). The investigation of the thrombus-specific parameters showed a trend towards statistical significance for the relative thrombus load (LRG 31.7 ± 18.0%; HRG 25.3 ± 17.5%; p = 0.09). Assessment of aortic side branches revealed only for the univariate analysis significant differences in the patency of the inferior mesenteric artery (LRG 71.3%; HRG 92.0%; p = 0.003) and their diameter (LRG 3.3 ± 0.7 mm; HRG 3.8 ± 0.9 mm; p = 0.004). In contrast, the number of lumbar arteries (LAs; LRG 2.7 ± 1.4; HRG 3.6 ± 1.2; univariate: p = 0.01; multivariate: p = 0.006) as well as their diameter (LRG 2.1 ± 0.4 mm; HRG 2.4 ± 0.4 mm; univariate: p < 0.001; multivariate: p = 0.006) were highly significantly associated with the development of type 2 endoleaks of the HRG.

CONCLUSION

The most important predictive factors for the development of high-risk type 2 endoleaks were mainly the number and the diameter of the LAs which perfused the AAA.

KEY POINTS

• This study is a very detailed and comprehensive analysis of the value of various CT parameters as potential predictors of the clinical outcome of type 2 endoleaks after EVAR. • Anatomical as well as thrombus-specific parameters were unsuitable as predictors. • The most important predictive factors were mainly the number and the diameter of the LAs which perfused the AAA.

Can early computed tomography angiography after endovascular aortic aneurysm repair predict the need for reintervention in patients with type II endoleak?

PURPOSE

This study was designed to identify parameters on CT angiography (CTA) of type II endoleaks following endovascular aortic aneurysm repair (EVAR) for abdominal aortic aneurysm (AAA), which can be used to predict the subsequent need for reinterventions.

METHODS

We retrospectively identified 62 patients with type II endoleak who underwent early CTA in mean 3.7 ± 1.9 days after EVAR. On the basis of follow-up examinations (mean follow-up period 911 days; range, 373-1,987 days), patients were stratified into two groups: those who did (n = 18) and those who did not (n = 44) require reintervention. CTA characteristics, such as AAA, endoleak, as well as nidus dimensions, patency of the inferior mesenteric artery, number of aortic branch vessels, and the pattern of endoleak appearance, were recorded and correlated with the clinical outcome.

RESULTS

Univariate and receiver operating characteristic curve regression analyses revealed significant differences between the two groups for the endoleak volume (surveillance group: 1391.6 ± 1427.9 mm(3); reintervention group: 3227.7 ± 2693.8 mm(3); cutoff value of 2,386 mm(3); p = 0.002), the endoleak diameter (13.6 ± 4.3 mm compared with 25.9 ± 9.6 mm; cutoff value of 19 mm; p < 0.0001), the number of aortic branch vessels (2.9 ± 1.2 compared with 4.2 ± 1.4 vessels; p = 0.001), as well as a "complex type" endoleak pattern (13.6 %, n = 6 compared with 44.4 %, n = 8; p = 0.02).

CONCLUSIONS

Early CTA can predict the future need for reintervention in patients with type II endoleak. Therefore, treatment decision should be based not only on aneurysm enlargement alone but also on other imaging characteristics.

[What does the visceral surgeon need to know about computed tomography in the diagnostic work-up of the acute abdomen?]

The acute abdomen is a very serious yet common condition of patients presenting in the emergency department. The clinical symptoms of patients with acute abdomen are often unspecific. The responsibility of the surgeon in charge is to differentiate acute life-threatening from less serious conditions with a high level of diagnostic accuracy in a minimal period of time. Imaging represents a cornerstone in the diagnostic work-up of patients with acute abdomen. Computed tomography (CT) is increasingly utilised to detect emergency conditions in patients with acute abdomen. In this review article we aim to elaborate the role of CT in the imaging strategy for acute abdomen in comparison to conventional radiography, ultrasonography and magnetic resonance imaging. In addition, relevant factors pertaining for the indication of CT such as exposure to ionising radiation and safety of iodinated contrast media are discussed.

Prospective Evaluation of the radiologist’s hand dose in CT-guided interventions

PURPOSE

Assessment of radiologist's hand dose in CT-guided interventions and determination of influencing factors.

MATERIALS AND METHODS

The following CT-guided interventions were included: Core biopsy, drainage, periradicular therapy, and celiac plexus neurolysis. The hand dose was measured with an immediately readable dosimeter, the EDD-30 (Unfors, Sweden). The default parameters for CT fluoroscopy were 120 kV, 90 mA and a 4 mm slice thickness. All interventions were performed on a 16-slice CT unit (Aquilion 16 Toshiba, Japan). The tumor size, degree of difficulty (1 - 3), level of experience and device parameters (mAs, dose-length product, scan time) were documented.

RESULTS

138 CT-guided interventions (biopsy n = 99, drainage n = 23, pain therapy n = 16) at different locations (lung n = 41, retroperitoneum n = 53, liver n = 25, spine n = 19) were included. The lesion size was 4 - 240 mm (median: 23 mm). The fluoroscopy time per intervention was 4.6 - 140.2 s (median: 24.2 s). The measured hand dose ranged from 0.001 - 3.02 mSv (median: 0.22 mSv). The median hand dose for lung puncture (n = 41) was slightly higher (median: 0.32 mSv, p = 0.01) compared to that for the liver, retroperitoneum and other. Besides physical influencing factors, the degree of difficulty (p = 0.001) and summed puncture depth (p = 0.004) correlated significantly with the hand dose.

CONCLUSION

The median hand dose for different CT-guided interventions was 0.22 mSv. Therefore, the annual hand dose limit would normally only be reached with about 2000 interventions.

[Irreversible electroporation: the new generation of local ablation techniques for renal cell carcinoma]

BACKGROUND

Local ablation techniques are a major focus of current developments in oncology. The primary aim is to retain organs and preserve organ functions without compromising the oncological outcome.

METHOD

Irreversible electroporation (IRE) is a novel ablation technique that involves the application of high-voltage pulses to induce cell apoptosis without causing thermal damage to the target tissue or adjacent structures.

AIM

First published in 2005 IRE is currently undergoing preclinical and clinical trials in several areas of oncology and the initial results have been promising. The IRE technique could be a significant development in ablation treatment for renal cell carcinoma (RCC) but decisive proof of its effectiveness for local RCC has not yet been provided. This study presents the results of preclinical and initial clinical trials which are discussed and compared with those of other ablation techniques in order to demonstrate the current value of IRE.

Measurement of the proton-air cross section at √s=57 TeV with the Pierre Auger Observatory

We report a measurement of the proton-air cross section for particle production at the center-of-mass energy per nucleon of 57 TeV. This is derived from the distribution of the depths of shower maxima observed with the Pierre Auger Observatory: systematic uncertainties are studied in detail. Analyzing the tail of the distribution of the shower maxima, a proton-air cross section of [505±22(stat)(-36)(+28)(syst)] mb is found.