Charge-state resolved laser acceleration of gold ions to beyond 7 MeV/u.

In the past years, the interest in the laser-driven acceleration of heavy ions in the mass range of [Formula: see text] has been increasing due to promising application ideas like the fission-fusion nuclear reaction mechanism, aiming at the production of neutron-rich isotopes relevant for the astrophysical r-process nucleosynthesis. In this paper, we report on the laser acceleration of gold ions to beyond 7 MeV/u, exceeding for the first time an important prerequisite for this nuclear reaction scheme. Moreover, the gold ion charge states have been detected with an unprecedented resolution, which enables the separation of individual charge states up to 4 MeV/u. The recorded charge-state distributions show a remarkable dependency on the target foil thickness and differ from simulations, lacking a straight-forward explanation by the established ionization models.

Distributed acoustic sensing of microseismic sources and wave propagation in glaciated terrain.

Records of Alpine microseismicity are a powerful tool to study landscape-shaping processes and warn against hazardous mass movements. Unfortunately, seismic sensor coverage in Alpine regions is typically insufficient. Here we show that distributed acoustic sensing (DAS) bridges critical observational gaps of seismogenic processes in Alpine terrain. Dynamic strain measurements in a 1 km long fiber optic cable on a glacier surface produce high-quality seismograms related to glacier flow and nearby rock falls. The nearly 500 cable channels precisely locate a series of glacier stick-slip events (within 20-40 m) and reveal seismic phases from which thickness and material properties of the glacier and its bed can be derived. As seismic measurements can be acquired with fiber optic cables that are easy to transport, install and couple to the ground, our study demonstrates the potential of DAS technology for seismic monitoring of glacier dynamics and natural hazards.

[Right-sided or left-sided donor nephrectomy-is this really relevant?] / Rechts- oder linksseitige Donornephrektomie ­ ist das wirklich relevant?

BACKGROUND: In the context of living donation, the protection of the donor and the outcome are very important aspects. However, the side selection of the donor nephrectomy is also decisive. In this work, the basics of side selection and the question of whether there are differences regarding the left-sided or right-sided donor nephrectomy are considered. MATERIALS AND METHODS: Living kidney donation data of our center between December 2004 and July 2019 were evaluated in terms of withdrawal side, complications and outcome, as well as the current literature in PubMed. Finally, the results from our center are compared with the current literature. RESULTS: During the investigation period, 152 live donations were carried out in our center. In these cases 66 patients had a left-sided and in 86 cases a right-sided donor nephrectomy. One transplant vein thrombosis occurred in each group. Complications and outcome were similar for the recipient in both groups. It was noticed in the current literature that generally more left-sided donor nephrectomies are performed, most likely due to the preference of the surgeon. Although a low significantly increased risk of transplant vein thrombosis after right-sided donor nephrectomy is described, all authors agree that right-sided donor nephrectomy is a safe procedure with good outcome. CONCLUSIONS: Our own results and the current literature show that the right-sided donor nephrectomy is a safe procedure with only a slightly increased risk of complications compared to the left side and therefore can be recommended. It is clearly safe for the donor and organ, with an equivalent outcome for the recipient. The results are also dependent on the experience of the surgeon.

Single-center study: The diagnostic performance of contrast-enhanced ultrasound (CEUS) for assessing focal splenic lesions compared to CT and MRI.

BACKGROUND: Frequently focal splenic lesions (FSL) - cysts, hemangioma, hamartoma, metastases or infarction amongst others - are incidentally found within the scope of the sonographic examination of the abdomen. By using native B-mode and Color Doppler the underlying entity often is not elucidated. Thus, more elaborate imaging modalities like CT and MRI scans with their associated risks are used to clarify the entity of FSL. PURPOSE: The aim of the present retrospective single-center study is to evaluate the diagnostic performance of CEUS examination for assessing splenic focal lesions by comparison with findings from CT and MRI scans. MATERIALS AND METHODS: Between 2010-2018 46 patients were included in the study. All patients underwent native B-mode, Color Doppler and CEUS after given informed consent. The applied contrast agent was a second-generation blood pool agent (SonoVue®, Bracco, Milan, Italy). CEUS examinations were performed and interpreted by a single experienced radiologist (EFSUMB Level 3). RESULTS: All patients were examined without occurrence of any side effects. In total, 53 FSL were investigated (9% traumatic vs. 91% non-traumatic). Compared to CT, CEUS showed a sensitivity, specificity, PPV, NPV of 100% for assessing infarction, hematoma, hamartoma, cystic and malignant lesions. In comparison with MRI, CEUS presented a sensitivity, specificity, PPV, NPV of 100% for evaluating pseudolesions, hemangioma, hamartoma, cystic and malignant lesions. CONCLUSION: With an excellent safety profile CEUS shows an equipollent diagnostic performance for differentiating FSL compared to CT and MRI scans.

The use of contrast-enhanced ultrasound (CEUS) for the diagnostic evaluation of hepatic echinococcosis.

BACKGROUND: Hepatic echinococcosis (HE) is a zoonosis and depicts a rare but potentially lethal disease caused by larval infestation of E. multilocularis (alveolar echinococcosis, AE) and E. granulosus (cystic echinocococcosis, CE). In many countries, HE is a critical public health problem. Clinically, HE patients initially are often asymptomatic for years. Depending on the echinococcal manifestations patients can later develop unspecific symptoms as fatigue, abdominal pain and may present with elevated transaminases, jaundice and hepatomegaly. The combination of grey scale ultrasound and serological tests has been the gold standard for the screening and diagnosis of HE. Besides MRI, CT and FDG-PET scans, safe and directly accessible contrast-enhanced ultrasound (CEUS) may easily help to indirectly describe perilesional inflammation. Upon diagnosis of HE, an appropriate therapeutical strategy should be evaluated in a multidisciplinary way. OBJECTIVE: The aim of the present retrospective monocenter study is to assess the diagnostic performance of CEUS examination in the evaluation of hepatic echinococcal manifestation by comparison with CT, MRI, FDG-PET scans and histopathology. METHODS: Out of 36 patients with echinococcal disease (16 patients with E. multilocularis infection, 12 patients with E. granulosus infection and 8 patient with unspecified Echinococcus infection) 8 HE patients (4 patients with E. multilocularis, 2 patients with E. granulosus and 2 patients with unspecified echinococcal liver disease) were included in this study on whom CEUS was performed between 2008-2016. The applied contrast agent was a second-generation blood pool agent (SonoVue ®, Bracco, Milan, Italy). CEUS examinations were performed and interpreted by a single experienced radiologist with more than 15 years of experience. RESULTS: All patients were examined without occurrence of any side effects. In all 4 AE patients, contrast enhancement could be detected by means of CEUS and was confirmed by MRI or PET-CT scan. In the remaining 4 patients (CE and unspecified echinococcosis), doppler ultrasonography, CEUS and corresponding CT or MRI scans could not detect any hypervascularization of the lesions of interest. The histopathological analysis did not reveal any viable parasite material. CEUS showed a sensitivity of 100% and a specificity of 100% compared to MRI, CT or FDG-PET-CT. CONCLUSIONS: CEUS depicts a safe method for the evaluation of echinococcal liver disease. In addition to serological tests and grey scale ultrasound, CEUS imaging could be integrated as an easily accessible tool helping to describe hypervascularization as a sonomorphological correlate for active perilesional inflammation of echinococcal manifestations. CEUS may further help to differentiate between CE and AE and also to evaluate treatment outcome.

A novel approach to electron data background treatment in an online wide-angle spectrometer for laser-accelerated ion and electron bunches.

Laser-based ion acceleration is driven by electrical fields emerging when target electrons absorb laser energy and consecutively leave the target material. A direct correlation between these electrons and the accelerated ions is thus to be expected and predicted by theoretical models. We report on a modified wide-angle spectrometer, allowing the simultaneous characterization of angularly resolved energy distributions of both ions and electrons. Equipped with online pixel detectors, the RadEye1 detectors, the investigation of this correlation gets attainable on a single shot basis. In addition to first insights, we present a novel approach for reliably extracting the primary electron energy distribution from the interfering secondary radiation background. This proves vitally important for quantitative extraction of average electron energies (temperatures) and emitted total charge.

Isolated proton bunch acceleration by a petawatt laser pulse.

Often, the interpretation of experiments concerning the manipulation of the energy distribution of laser-accelerated ion bunches is complicated by the multitude of competing dynamic processes simultaneously contributing to recorded ion signals. Here we demonstrate experimentally the acceleration of a clean proton bunch. This was achieved with a microscopic and three-dimensionally confined near critical density plasma, which evolves from a 1 µm diameter plastic sphere, which is levitated and positioned with micrometer precision in the focus of a Petawatt laser pulse. The emitted proton bunch is reproducibly observed with central energies between 20 and 40 MeV and narrow energy spread (down to 25%) showing almost no low-energetic background. Together with three-dimensional particle-in-cell simulations we track the complete acceleration process, evidencing the transition from organized acceleration to Coulomb repulsion. This reveals limitations of current high power lasers and viable paths to optimize laser-driven ion sources.

Impact of indication-shift of primary and adjuvant chemo radiation in advanced laryngeal and hypopharyngeal squamous cell carcinoma.

Based on level I evidence, postoperative platinum-based radiochemotherapy (PORCT) is the recommended standard of care in defined risk situations after resection of squamous cell carcinomas of the larynx and hypopharynx (LHSCC). The value of the addition of chemotherapy to adjuvant radiation in intermediate and high risk situations other than extracapsular spread or R1-/R2 resection is still debated. From 1993 to 2009, 555 patients (median follow-up: 24.4 months) with advanced LHSCC (UICC stages III-IVB) were treated in a curative intent. Patient data were continuously documented in the county of Leipzig cancer registry and were retrospectively analyzed as mono institutional survey. PORCT was introduced into the standard procedures in 2004, but also applied before in selected cases. Based on this paradigm shift, the patient population was divided into two comparative groups treated before and after 2004. 361 patients were treated before 2004. 43.8 % received primary surgery (OP) + postoperative radiotherapy (PORT) and 20.2 % OP + PORCT. 194 patients were treated after 2004: 21.1 % received OP + PORT and 35.6 % OP + PORCT. Regarding the PORCT groups, 20.6 % received cisplatin plus 5FU before 2004 which shifted to 59.4 % after 2004. The 3-year tumor-specific-survival rate of the whole cohort was improved from 47 to 60 % (p = 0.006). The subgroup treated with OP + PORT or PORCT improved from 56.1 to 68.5 % (p = 0.028). Localization proved to be a significant and independent factor. Only patients with advanced laryngeal cancer had significant improved survival (p < 0.01), while the improvement for hypopharyngeal cancer patients was not significant (p < 0.2). After 2004, there was a slight increase (+10.2 %) of primary radiochemotherapy (pRCT) due to stronger selection if R0 > 5 mm-resectability is unlikely. Standardised use of PORCT and pRCT considering clear indications showed to be significantly involved in improved survival in advanced LHSCC.

Thermophobicity of liquids: heats of transport in mixtures as pure component properties--the case of arbitrary concentration.

We have measured Soret coefficients of a large number of binary mixtures of 23 different organic solvents. The present analysis is based on 77 equimolar mixtures and strongly supports the thermophobicity concept previously developed for the heats of transport of originally 10 different substances [S. Hartmann, G. Wittko, W. Köhler, K. I. Morozov, K. Albers, and G. Sadowski, Phys. Rev. Lett. 109, 065901 (2012)]. Among the investigated compounds, cis-decalin is the most thermophobic, hexane the most thermophilic one. In addition to the equimolar mixtures, we have also analyzed the composition dependence of the Soret coefficients and the heats of transport for 22 selected binary mixtures. Both the interpretation of the heats of transport in equimolar mixtures as pure component thermophobicities and the composition dependence of the Soret coefficient can be understood on the basis of the thermodiffusion theory developed by Morozov [Phys. Rev. E 79, 031204 (2009)], according to which the composition dependence is determined by the excess volume of mixing.

Assessment of spleen stiffness using acoustic radiation force impulse imaging (ARFI): definition of examination standards and impact of breathing maneuvers.

PURPOSE: Spleen elastography is a promising method for the characterization of portal hypertension in cirrhotic individuals. However, standardized examination procedures for spleen stiffness measurement have not been defined yet. We analyzed the distribution characteristics of spleen shear-wave velocity (ARFI) and assessed the influence of the respiratory position on spleen stiffness measured by ARFI. MATERIALS AND METHODS: 25 healthy probands and 25 patients with Child A liver cirrhosis were prospectively characterized with conventional ultrasound, transient elastography, liver ARFI, and underwent spleen ARFI in two respiratory positions: breath hold after expiration (exp) and deep inspiration (insp). For each position 20 single measurements were performed. The distribution of spleen ARFI values was analyzed for normality and the appropriate number of measurements for spleen stiffness estimation was investigated. RESULTS: Spleen ARFI results were normally distributed in > 95 % of cases. Performing 20 instead of 10 single measurements resulted in < 5 % deviation from the mean value after 20 measurements in the majority of cases. Cirrhotic patients had a higher spleen stiffness compared to healthy probands (exp: 3.25 ±â€Š0.58 vs. 2.46 ±â€Š0.35 m/s; p < 0.001). Deep inspiration caused an overall increase in spleen stiffness in both groups: probands 2.46 ± 0.35 m/s (exp) vs. 2.66 ±â€Š0.36 m/s (insp), p = 0.01; cirrhotics 3.25 ±â€Š0.58 m/s (exp) vs. 3.46 ±â€Š0.38 m/s (insp), p = 0.03. However, cases with high spleen stiffness values (exp) show decreasing ARFI values in deep inspiration. CONCLUSION: ARFI values of the spleen are normally distributed and the mean of 10 valid measurements can be used as a representative value. Deep inspiration significantly modulates spleen stiffness. Therefore, the respiratory position needs careful standardization.

Safety of intralesional cidofovir in patients with recurrent respiratory papillomatosis: an international retrospective study on 635 RRP patients.

Intralesional use of cidofovir (Vistide(®)) has been one of the mainstays of adjuvant therapy in patients with recurrent respiratory papillomatosis (RRP) since 1998. In 2011, a communication provided by the producer of cidofovir addressed very serious side effects concerning its off-label use. As this was a general warning, it was inconclusive whether this would account for its use in RRP. The aim of this study is to determine whether nephrotoxic, neutropenic, or oncogenic side effects have occurred after intralesional use of cidofovir in patients with RRP. Update of recent developments in RRP, a multicentre questionnaire and a multicentre retrospective chart review. Sixteen hospitals from eleven countries worldwide submitted records of 635 RRP patients, of whom 275 were treated with cidofovir. RRP patients received a median of three intralesional injections (interquartile range 2-6). There were no statistical differences in occurrence of neutropenia or renal dysfunction before and after cidofovir. There was no statistical difference in occurrence of upper airway and tracheal malignancies between the cidofovir and the non-cidofovir group. In this retrospective patient chart review, no clinical evidence was found for more long-term nephrotoxicity, neutropenia or laryngeal malignancies after the administration of intralesional cidofovir in RRP patients.

Attosecond double-slit experiment.

A new scheme for a double-slit experiment in the time domain is presented. Phase-stabilized few-cycle laser pulses open one to two windows (slits) of attosecond duration for photoionization. Fringes in the angle-resolved energy spectrum of varying visibility depending on the degree of which-way information are measured. A situation in which one and the same electron encounters a single and a double slit at the same time is observed. The investigation of the fringes makes possible interferometry on the attosecond time scale. From the number of visible fringes, for example, one derives that the slits are extended over about 500 as.

Intragastric acidity during treatment with esomeprazole 40 mg twice daily or pantoprazole 40 mg twice daily--a randomized, two-way crossover study.

BACKGROUND: Patients with severe or complicated reflux disease may require higher than standard doses of a proton pump inhibitor for sufficient acid suppression. AIM: To test the hypothesis that esomeprazole 40 mg twice daily is superior to pantoprazole 40 mg twice daily in lowering intragastric acidity. METHODS: In a randomized, single-blinded, two-way crossover study, healthy subjects received esomeprazole 40 mg twice daily or pantoprazole 40 mg twice daily orally for five consecutive days. Continuous ambulatory 24-h intragastric pH was recorded on day 5 of each treatment. RESULTS: Thirty subjects were analysed. Esomeprazole provided significantly higher intragastric pH-values over the 24-h period [median intragastric pH 6.4 for esomeprazole and 5.1 for pantoprazole (P < 0.00005)]. Intragastric pH > 4 was maintained for 21.1 h with esomeprazole and 16.8 h with pantoprazole (P < 0.0001). An intragastric pH > 4 for more than 16 h was achieved in 96.7 and 56.7% of subjects, respectively (P = 0.0002). During night-time the proportion of time with intragastric pH > 4 was 85.4% with esomeprazole and 63.6% with pantoprazole (P = 0.0001). Nocturnal acid break through occurred less frequently on esomeprazole. CONCLUSIONS: Esomeprazole 40 mg twice daily provides better and more consistent intragastric acid control than pantoprazole 40 mg twice daily.

Gouy phase shift for few-cycle laser pulses.

We measured for the first time the influence of the Gouy effect on focused few-cycle laser pulses. The carrier-envelope phase is shown to undergo a smooth variation over a few Rayleigh distances. This result is of critical importance for any application of ultrashort laser pulses, including high-harmonic and attosecond pulse generation, as well as phase-dependent effects.

Nonsequential double ionization at the single-optical-cycle limit.

We report differential measurements of Ar++ ion momentum distributions from nonsequential double ionization in phase-stabilized few-cycle laser pulses. The distributions depend strongly on the carrier-envelope (CE) phase. Via control over the CE phase one is able to direct the nonsequential double-ionization dynamics. Data analysis through a classical model calculation reveals that the influence of the optical phase enters via (i) the cycle dependent electric field ionization rate, (ii) the electron recollision time, and (iii) the accessible phase space for inelastic collisions. Our model indicates that the combination of these effects allows a look into single cycle dynamics already for few-cycle pulses.

Measurement of the phase of few-cycle laser pulses.

For the shortest pulses generated to date, the amplitude of the electromagnetic wave changes almost as rapidly as the field oscillates. The temporal variation of the field, which directly governs strong-field interactions, therefore depends on whether the maximum of the pulse amplitude coincides with that of the wave cycle or not, i.e., on the phase of the field with respect to the pulse envelope. It is demonstrated that the direction of electron emission from photoionized atoms can be controlled by varying the phase of the field, providing for the first time a tool for its accurate determination. Directing fast electron emission to the right or to the left with the light phase constitutes a new kind of coherent control.

[Surgery of varicose veins. Late results in relation to vessel morphology]. / Chirurgie der Krampfadern. Spätergebnisse in Abhängigkeit von der Gefässmorphologie.

A survey of the literature on the long-term results of surgical treatment for varicose veins is given. The recurrence of varicose veins after operative treatment is shown to result from inadequate surgical technique and other causes. Vascular-morphological data indicating possible deterioration of long-term results if not considered sufficiently are presented. The main requirements for good long-term results are (1) adequate diagnosis and (2) meticulous surgical technique.

[Entrapment and cystic degeneration of the adventitia as a cause of occlusion of the popliteal artery]. / Entrapment und cystische Adventitia-Degeneration als Ursache für Verschlüsse der Arteria poplitea.

The entrapment syndrome and the cystic adventitial degeneration of the popliteal artery are diseases affecting relative young patients. Four cases of entrapment and one case of cystic degeneration are demonstrated. In one patient also an entrapment of the popliteal vein is demonstrated. In all patients the outcome of vascular reconstruction was good. For the entrapment syndrome the posterior approach is prefered.

Laser initiated spark development in an air gap.

Spark development is studied by 20-nsec image converter photography. A diffuse and transparent prechannel bridges the gap from the top of the metal vapor jet, which has counterelectrode potential. The prechannel cuts off the development of the cone shaped jet with increasing gap voltage. The final breakdown is initiated by a z-axis, laser induced filament, which expands into the prechannel volume within less, similar10 nsec. This interval represents the final high current thermalization phase of the breakdown. Thermal expansion of the initial spark channel (Braginskii) follows.