Evaluation of a

We report on an evaluation of an optical clock that uses the ^{2}S_{1/2}→^{2}D_{5/2} transition of a single ^{88}Sr^{+} ion as the reference. In contrast to previous work, we estimate the effective temperature of the blackbody radiation that shifts the reference transition directly during operation from the corresponding frequency shift and the well-characterized sensitivity to thermal radiation. We measure the clock output frequency against an independent ^{171}Yb^{+} ion clock, based on the ^{2}S_{1/2}(F=0)→^{2}F_{7/2}(F=3) electric octupole (E3) transition, and determine the frequency ratio with a total fractional uncertainty of 2.3×10^{-17}. Relying on a previous measurement of the ^{171}Yb^{+} (E3) clock frequency, we find the absolute frequency of the ^{88}Sr^{+} clock transition to be 444 779 044 095 485.277(59) Hz. Our result reduces the uncertainty by a factor of 3 compared with the previously most accurate measurement and may help to resolve so far inconsistent determinations of this value. We also show that for three simultaneously interrogated ^{88}Sr^{+} ions, the increased number causes the expected improvement of the short-term frequency instability of the optical clock without degrading its systematic uncertainty.

Assessment of the microvasculature in poppers maculopathy.

PURPOSE: To investigate a possible microvascular component of poppers maculopathy (PMP) using optical coherence tomography angiography (OCTA). METHODS: Twelve patients suffering from poppers maculopathy were included. Health records, optical coherence tomography (OCT), and OCTA data was gathered and compared to a healthy control group (HC). PMP lesion type was determined by manifestation in OCT. OCTA-based evaluation of retinal vascular plexus and choriocapillaris (CC) was executed. Vessel density (VD) and vessel length density (VLD) in superficial and deep capillary plexus (SCP, DCP), as well as flow deficits (FD), within the foveal avascular zone (FAZ) in CC were assessed. RESULTS: Median age of PMP patients was 40 (min 24; max 64) years, all male. Eleven patients presented with ellipsoid zone-type lesions; one patient showed a vitelliform-type lesion. No qualitative microvascular changes between PMP patients and HC were identified. Quantitative values for VD and VLD of SCP and DCP did not differ in between the two groups. The analysis of FDs in CC showed no deviation from PMP patients to HC. CONCLUSIONS: No vascular anomalies in qualitative and quantitative analysis in OCTA were detected in PMP patients. The constitution of the CC within FAZ of PMP patients does not differ from HC when assessed as FD.

Development of a sensor and measurement platform for water quality observations: design, sensor integration, 3D printing, and open-source hardware.

A measurement and development platform for collecting water quality data (the WaterWatcher) was developed. The platform includes sensors to measure turbidity, total dissolved solids (TDS), and water temperature as variables that are often collected to assess water quality. The design is extensible for research and monitoring purposes, and all the design files are provided under open-source permissive licenses for further development. System design and operation are discussed for illustrative purposes. A block diagram indicates elements of mechanical, electrical, and software design for this system. The mechanical assembly used to house circuit boards and sensors is designed using 3D printing for rapid prototyping. The electronic circuit board acts as a carrier for an Arduino 32-bit microcontroller board and an associated cellular module along with a GPS for geolocation of water quality measurements. The cellular module permits data transfer for Internet of Things (IoT) functionality. System operation is set up using a command line interface (CLI) and C + + code that allows for calibration coefficients and human-readable transfer functions to be defined so that sensor voltages are related to physical quantities. Data are cached on a secure digital (SD) card for backup. The circuit was calibrated, and system operation assessed by deployment on an urban reservoir. Biogeochemical cycles were identified in the collected data using spectrogram and semivariogram analyses to validate system operation. As a system with hardware and software released under an open source license, the WaterWatcher platform reduces the time and effort required to build and deploy low-cost water quality measurement sensors and provides an example of the basic hardware design that can be used for measurements of water quality.

Assessment of stormwater discharge contamination and toxicity for a cold-climate urban landscape.

Background: Stormwater is water resulting from precipitation events and snowmelt running off the urban landscape, collecting in storm sewers, and typically being released into receiving water bodies through outfalls with minimal to no treatment. Despite a growing body of evidence observing its deleterious pollution impacts, stormwater management and treatment in cold climates remains limited, partly due to a lack of quality and loading data and modeling parameters. This study examines the quality of stormwater discharging during the summer season in a cold-climate, semi-arid Canadian city (Saskatoon, Saskatchewan). Results: Seven stormwater outfalls with mixed-land-use urban catchments > 100 km2 were sampled for four summer (June-August 2019) storm events and analyzed for a suite of quality parameters, including total suspended solids (TSS), chemical oxygen demand (COD), dissolved organic carbon (DOC), metals, and targeted polyaromatic hydrocarbons (PAHs). In addition, assessment of stormwater toxicity was done using the two toxicity assays Raphidocelis subcapitata (algae) and Vibrio fischeri (bacteria). Notable single-event, single-outfall contaminant pulses included of arsenic (420 µg/L), cadmium (16.4 µg/L), zinc (924 µg/L), fluorene (4.95 µg/L), benzo[a]pyrene (0.949 µg/L), pyrene (0.934 µg/L), phenanthrene (1.39 µg/L), and anthracene (1.40 µg/L). The IC50 in both R. subcapitata and V. fischeri was observed, if at all, above expected toxicity thresholds for individual contaminant species. Principal component analysis (PCA) showed no clear trends for individual sampling sites or sampling dates. In contrast, parameters were correlated with each other in groups including DOC, COD, TSS, and reduced algal toxicity; and total dissolved solids (TDS), sum of metals, and pH. Conclusions: In general, stormwater characteristics were similar to those of previous studies, with a bulk of contamination carried by the first volume of runoff, influenced by a combination of rainfall depth, antecedent dry period, land use, and activity within the catchment. Roads, highways, and industrial areas contribute the bulk of estimated contaminant loadings. More intensive sampling strategies are necessary to contextualize stormwater data in the context of contaminant and runoff volume peaks. Supplementary Information: The online version contains supplementary material available at 10.1186/s12302-022-00619-x.

Long-term passive wastewater surveillance of SARS-CoV-2 for seven university dormitories in comparison to municipal surveillance.

Wastewater-based surveillance (WBS) has been an effective tool for monitoring and understanding potential SARS-CoV-2 transmission across small and large-scale communities. In this study at the University of Saskatchewan, the assessment of SARS-CoV-2 was done over eight months during the 2021-2022 academic year. Wastewater samples were collected using passive samplers that were deployed in domestic sewer lines near adjacent campus residences and extracted for viral RNA, followed by Reverse Transcription quantitative Polymerase Chain Reaction (RT-qPCR). The results showed similar trends for SARS-CoV-2 detection frequencies and viral loads across university residences, the whole campus, and from related WBS at Saskatoon Wastewater Treatment Plant. The maximum daily detection frequency for seven dormitories considered was about 75 %, while maximum daily case numbers for the residences and campus-wide were about 11 and 75 people, respectively. In addition, self-reported rates of infection on campus peaked during similar time frames as increases in viral load were detected at the Saskatoon wastewater treatment plant. These similarities indicate the usefulness and cost-effectiveness of monitoring the spread of COVID-19 in small-scale communities using WBS.

Morphological clues to wet granular pile stability.

When a granular material such as sand is mixed with a certain amount of liquid, the surface tension of the latter bestows considerable stiffness to the material, which enables, for example, sand castles to be sculpted. The geometry of the liquid interface within the granular pile is of extraordinary complexity and strongly varies with the liquid content. Surprisingly, the mechanical properties of the pile are largely independent of the amount of liquid over a wide range. We resolve this puzzle with the help of X-ray microtomography, showing that the remarkable insensitivity of the mechanical properties to the liquid content is due to the particular organization of the liquid in the pile into open structures. For spherical grains, a simple geometric rule is established, which relates the macroscopic properties to the internal liquid morphologies. We present evidence that this concept is also valid for systems with non-spherical grains. Hence, our results provide new insight towards understanding the complex physics of a large variety of wet granular systems including land slides, as well as mixing and agglomeration problems.

Terbutaline-induced desensitization of human lymphocyte beta 2-adrenoceptors. Accelerated restoration of beta-adrenoceptor responsiveness by prednisone and ketotifen.

We investigated, in 36 healthy volunteers, the effects of prednisone and ketotifen on recovery of lymphocyte beta 2-adrenoceptor density (determined by (-)-125iodocyanopindolol binding) and responsiveness (assessed by lymphocyte cyclic AMP [cAMP] responses to 10 microM (-)-isoprenaline) after desensitization by the beta 2-agonist terbutaline. Terbutaline (3 X 5 mg/d) decreased lymphocyte beta 2-adrenoceptor density by approximately 40-50%; concomitantly, lymphocyte cAMP responses to 10 microM (-)-isoprenaline were significantly reduced. After withdrawal of terbutaline beta 2-adrenoceptor, density and responsiveness gradually increased, reaching predrug levels after 4 d. Prednisone (1 X 100 mg orally) accelerated beta 2-adrenoceptor recovery; only 8-10 h after administration of the steroid beta 2-adrenoceptor density and cAMP responses to (-)-isoprenaline had reached values not significantly different from pretreatment levels. Similar effects were obtained with ketotifen (2 mg; thereafter 2 X 1 mg/d for 4 d): 24 h after application of the drug beta 2-adrenoceptor density and cAMP responses to (-)-isoprenaline had reached pretreatment levels. Furthermore, ketotifen simultaneously applied with terbutaline completely prevented terbutaline-induced decrease in lymphocyte beta 2-adrenoceptor density and responsiveness. Prednisone (1 X 100 mg orally) or ketotifen (2 mg; thereafter 2 X 1 mg/d for 2 d) had no significant influence on lymphocyte beta 2-adrenoceptor density in healthy volunteers not pretreated with terbutaline, but shifted the ratio high-to-low affinity state of the lymphocyte beta 2-adrenoceptor toward high affinity state. We conclude that glucocorticoids as well as ketotifen can accelerate recovery of density and responsiveness of lymphocyte beta 2-adrenoceptors desensitized by long-term treatment with beta 2-agonists. Such an effect may have clinical implications for preventing tachyphylaxis of asthmatic patients against therapy with beta 2-agonists.

Fipronil and two of its transformation products in water and European eel from the river Elbe.

Fipronil is an insecticide which, based on its mode of action, is intended to be predominantly toxic towards insects. Fipronil bioaccumulates and some of its transformation products were reported to be similar or even more stable in the environment and to show an enhanced toxicity against non-target organisms compared to the parent compound. The current study investigated the occurrence of Fipronil and two of its transformation products, Fipronil-desulfinyl and Fipronil-sulfone, in water as well as muscle and liver samples of eels from the river Elbe (Germany). In water samples total concentrations of FIP, FIP-d and FIP-s ranged between 0.5-1.6ngL(-1) with FIP being the main component in all water samples followed by FIP-s and FIP-d. In contrast, FIP-s was the main component in muscle and liver tissues of eels with concentrations of 4.05±3.73ngg(-1) ww and 19.91±9.96ngg(-1) ww, respectively. Using a physiologically based toxicokinetic (PBTK) model for moderately hydrophobic organic chemicals, the different distributions of FIP, FIP-d and FIP-s in water and related tissue samples could be attributed to metabolic processes of eels. The measured concentrations in water of all analytes and their fractional distribution did not reflect the assumed seasonal application of FIP and it seems that the water was constantly contaminated with FIP, FIP-d and FIP-s.

Arrest stress of uniformly sheared wet granular matter.

We conduct extensive independent numerical experiments considering frictionless disks without internal degrees of freedom (rotation, etc.) in two dimensions. We report here that for a large range of the packing fractions below random-close packing, all components of the stress tensor of wet granular materials remain finite in the limit of zero shear rate. This is direct evidence for a fluid-to-solid arrest transition. The offset value of the shear stress characterizes plastic deformation of the arrested state which corresponds to dynamic yield stress of the system. Based on an analytical line of argument, we propose that the mean number of capillary bridges per particle, ν, follows a nontrivial dependence on the packing fraction, ϕ, and the capillary energy, ɛ. Most noticeably, we show that ν is a generic and universal quantity which does not depend on the driving protocol. Using this universal quantity, we calculate the arrest stress, σ(a), analytically based on a balance of the energy injection rate due to the external force driving the flow and the dissipation rate accounting for the rupture of capillary bridges. The resulting prediction of σ(a) is a nonlinear function of the packing fraction, ϕ, and the capillary energy, ɛ. This formula provides an excellent, parameter-free prediction of the numerical data. Corrections to the theory for small and large packing fractions are connected to the emergence of shear bands and of contributions to the stress from repulsive particle interactions, respectively.

Selective labelling of beta 1-adrenoceptors in rabbit lung membranes by (-)[3H]bisoprolol.

The binding properties of a newly developed, highly selective beta 1-adrenoceptor antagonist radioligand, (-)[3H]bisoprolol (EMD 33512) were investigated in rabbit lung membranes containing a mixture of 80% beta 1-and 20% beta 2-adrenoceptors. The binding of (-)[3H]bisoprolol at 25 degrees C was saturable, of high affinity (KD = 4.7 +/- 0.6 nM, N = 4), rapid and readily reversible. The maximal number of (-)[3H]bisoprolol binding sites (244 +/- 31 fmol bound/mg protein, N = 4), however, was only 80% of the number of sites labelled by the non-selective beta-adrenoceptor radioligand (-)[125I]iodocyanopindolol (299 +/- 36 fmol bound/mg protein, N = 4). beta-Adrenoceptor antagonists (non-selective: propranolol, alprenolol; beta 1-selective: metoprolol, practolol, bisoprolol; beta 2-selective: ICI 118,551) inhibited (-)[3H]bisoprolol binding with monophasic displacement curves and pseudo-Hill coefficients of 1.0 indicating that in rabbit lung membranes (-)[3H]bisoprolol labels a homogeneous class of beta-adrenoceptors. Agonists inhibited binding with an order of potency: (-)-isoprenaline greater than (-)-noradrenaline = (-)-adrenaline, which is a typical one for beta 1-adrenoceptors. It is concluded that in rabbit lung membranes (-)[3H]bisoprolol selectively labels beta 1-adrenoceptors. (-)[3H]Bisoprolol therefore seems to be a suitable ligand for direct determination of the properties of beta 1-adrenoceptors in those tissues where both beta-adrenoceptor subtypes coexist.

Beta-adrenoceptor antagonists (non-selective as well as beta 1-selective) with partial agonistic activity decrease beta 2-adrenoceptor density in human lymphocytes. Evidence for a beta 2-agonistic component of the partial agonistic activity.

In the present study the effects of pindolol [non-selective beta-adrenoceptor antagonist with strong partial agonistic activity (PAA)] on beta 2-adrenoceptor density in lymphocytes (assessed by (-)-[125I]iodocyanopindolol (ICYP) binding) were compared with those of the beta 1-selective antagonists celiprolol (with PAA) and bisoprolol (no PAA) in normotensive young volunteers to get further insights into the nature of PAA. Administration of pindolol (2 X 5 mg/day) caused an about 25% decrease in lymphocyte beta 2-adrenoceptor density after 2 days; during treatment beta 2-adrenoceptor density declined further (maximum decrease after 7 days: 50%). After withdrawal of pindolol lymphocyte beta 2-adrenoceptor density recovered very slowly being still after 4 days significantly reduced, although no pindolol was detectable in plasma after 36 h. The KD-values for ICYP, however, did not change during or after pindolol treatment. The decrease in lymphocyte beta 2-adrenoceptor density induced by pindolol could be completely prevented by simultaneous administration of propranolol (3 X 40 mg/day) indicating that the PAA of pindolol is the cause of its beta-adrenoceptor decreasing effect. Administration of the non-selective beta-adrenoceptor antagonist bopindolol (1 X 2 mg/day) with PAA caused decreases in lymphocyte beta 2-adrenoceptor density (maximum decrease after 7 days: 40%); concomitantly the 10 mumol/l (-)-isoprenaline evoked increases in the intracellular level of lymphocyte cyclic AMP were attenuated to a similar extent indicating that the beta-adrenoceptor antagonist-induced decrease in beta-adrenoceptor density is accompanied by a loss in beta-adrenoceptor function.(ABSTRACT TRUNCATED AT 250 WORDS)

[Characterization of hepatic tumors with contrast-enhanced ultrasound and digital grey-scale analysis]. / Charakterisierung von Lebertumoren durch kontrastverstärkte Sonographie und digitale Graustufenbestimmung.

PURPOSE: The characterization of different liver tumors is of therapeutic and prognostic relevance and has been the purpose of several studies. Although ultrasound offers the opportunity to detect hepatic tumors without ionizing radiation, its previous techniques did not lead toward a definitive differentiation of different tumor entities. The purpose of this study was the clinical evaluation of contrast enhanced ultrasound followed by quantitative digital analysis in patients with focal hepatic tumors. MATERIALS AND METHODS: In a prospective study, 50 patients (18 females, 32 males, age 28 to 83 years, mean age 59.4 years) with liver tumors previously detected by CT (n = 47) or MRI (n = 3) were examined by ultrasound of the upper abdomen using conventional technique and phase inversion technique after intravenous application of sulfur-based contrast enhancer SonoVue. At scheduled intervals after application of the contrast enhancer, a digital image was stored and the characteristic signal course of each lesion determined semiquantitatively. The gold standard was either resection (n = 17), percutaneous needle biopsy (n = 19) or the clinical course (n = 14). RESULTS: While the percentage of tumors correctly characterized by CT/MRI amounted to 78 %, the percentage increased from 60 % using conventional ultrasound to 86 % using contrast enhanced ultrasound including grey-scale analysis. Typical graphs were achieved for different tumor entities on digital grey-scale analysis. The optimal intervals for the differentiation of particular entities were 20 and 100 seconds after injection. CONCLUSION: Quantification of contrast enhanced ultrasound is an addition to the previous diagnostic procedure in hepatic tumors. It offers the possibility of an investigator-independent characterization of lesions and should be evaluated in further studies.

[Accuracy of the CT-estimated weight of the right hepatic lobe prior to living related liver donation (LRLD) for predicting the intraoperatively measured weight of the graft]. / Voraussagegenauigkeit der präoperativen CT-gestützten Gewichtsbestimmung des rechten Leberlappens bezüglich des intraoperativen Transplantatgewichts bei Leberlappen-Lebendspendern.

PURPOSE: Due to the shortage of cadaver donors, living related liver donation (LRLD) has emerged as an alternative to cadaver donation. The expected graft weight is one of the main determinants for donor selection. This study investigates the accuracy of preoperatively performed CT-volumetry to predict the actual weight of the right liver lobe graft. MATERIALS AND METHODS: In a prospective study the weight of the right hepatic lobe was calculated by volumetric analysis based on CT in 33 patients (21 females, 12 males, mean age 42.1 years, median age 41 years) prior to living related liver donation. Graft weight was calculated as the product of CT-based graft volume and 1.00 g/ml (the approximated density of healthy liver parenchyma). The calculated weight was compared with the intraoperatively measured weight of the harvested right hepatic lobe. The difference was used to determine a correction factor for estimating the actual graft weight. RESULTS: Based on the assumption of a parenchymal density of 1.00 g/ml, the preoperatively estimated graft weight (mean 980 g +/- 168 g) deviated +33 % from the intraoperatively measured right hepatic lobe weight (mean 749 g +/- 170 g). By reducing the preoperatively predicted weight of the right hepatic lobe with a correction factor of 0.75, the actual graft weight can be calculated. CONCLUSION: Preoperative estimation of the weight of the right hepatic lobe based on CT of living related liver donors predicts the weight of the right lobe graft with sufficient accuracy by applying a single correction factor. Intraoperative fluid loss (i.e., blood, bile) from the harvested liver as well as variations in parenchymal density may contribute to the observed preoperative overestimation of the actual graft volume by CT-based volumetry.

Refractive state of aphakic and pseudophakic eyes of dogs.

Streak retinoscopy was performed by 5 ophthalmologists on 256 eyes (191 dogs) to determine their postoperative refractive state after cataract extraction. Aphakic and pseudophakic eyes that had been implanted with 1 of 5 intraocular lenses (IOL) with dioptric powers ranging from +14.5 to +38 diopters (D) were studied. By use of ANOVA, breed and body type of dog and individual performing refraction were found to have no detectable effect on final refractive state. Mean refractive state of aphakic eyes was +14.4 +/- 2.10 D. Mean refractive state for different IOL powers was as follows: +14.5 D IOL = +11.54 +/- 1.18 D (n = 13); +30 D IOL = +5.15 +/- 1.18 D (n = 105); +34.0 D IOL = +3.5 D (n = 1); +36 D IOL = +2.34 +/- 0.73 D 9 (n = 61); and +38 D IOL = +1.41 +/- 0.56 D (n = 28). Residual hyperopia ranged from +0.5 D to +2.5 D with +38 D IOL, and no eyes were myopic (overcorrected) by use of any of the IOL studied. Linear regression analysis of refractive state on IOL power for all dogs predicted that dioptric strength of +41.53 D was necessary to best approximate emmetropia for the population as a whole. Body type of the dog had only slight effect (< 1.0 D) on predicted optimal IOL power. Further linear regression analysis of the 7 breeds studied predicted variations from +39.62 to +43.14 D in IOL powers necessary to approximate emmetropia.(ABSTRACT TRUNCATED AT 250 WORDS)

A novel microwave applicator for tailoring the energy input for hydrothermal synthesis of zeolites.

A new applicator system for microwave heating of aqueous solutions for the hydrothermal synthesis of zeolite crystals has been developed and experimentally characterized. It is based on a short-ended coaxial waveguide with the solution being inserted as a lossy dielectric. The electrical and thermal design of the autoclave has been optimized by numerical simulations of the E-field and of the temperature distribution respectively. Different reference temperature profiles--a homogeneous and a gradient one--could be established within the zeolite solution and were held constant over time. From temperature measurements at various positions in the solution the two reference profiles could be verified. Temperature differences of less than 15 degrees C have been measured within the homogeneous autoclave whereas differences up to 55 degrees C have been found in the gradient autoclave. In the first synthesis experiments using this applicator zeolite crystals of the zeolite A and VPI-5-type could be successfully crystallized.

Mapping the 3D distribution of CdSe nanocrystals in highly oriented and nanostructured hybrid P3HT-CdSe films grown by directional epitaxial crystallization.

Highly oriented and nanostructured hybrid thin films made of regioregular poly(3-hexylthiophene) and colloidal CdSe nanocrystals are prepared by a zone melting method using epitaxial growth on 1,3,5-trichlorobenzene oriented crystals. The structure of the films has been analyzed by X-ray diffraction using synchrotron radiation, electron diffraction and 3D electron tomography to afford a multi-scale structural and morphological description of the highly structured hybrid films. A quantitative analysis of the reconstructed volumes based on electron tomography is used to establish a 3D map of the distribution of the CdSe nanocrystals in the bulk of the films. In particular, the influence of the P3HT-CdSe ratio on the 3D structure of the hybrid layers has been analyzed. In all cases, a bi-layer structure was observed. It is made of a first layer of pure oriented semi-crystalline P3HT grown epitaxially on the TCB substrate and a second P3HT layer containing CdSe nanocrystals uniformly distributed in the amorphous interlamellar zones of the polymer. The thickness of the P3HT layer containing CdSe nanoparticles increases gradually with increasing content of NCs in the films. A growth model is proposed to explain this original transversal organization of CdSe NCs in the oriented matrix of P3HT.

Sentinel Lymph Node Biopsy in Patients with Breast Cancer: Comparison of Peritumoral and Periareolar Injection.

Introduction: Intradermal periareolar injection technique for sentinel lymph node biopsy (SLNB) may offer an advantage by including multifocal breast cancer as an additional indication. In May 2008 we changed our standard procedure from peritumoral (PT) to periareolar (PA) injection. We compared the results for corresponding periods before and after the change in procedure. Material and Method: A total of 117 patients (pts.) were investigated the year after we changed our technique; a total of 152 pts were investigated in the reference period 2007. We investigated the identification rates for sentinel lymph nodes (SLN) identified scintigraphically and surgically as well as the rates of metastatic involvement (LN). Results: After PT injection, scintigraphic detection of SLN failed in 5/152 pts., and in a further 10 pts. SLN was not found at surgery. In 7 of 15 pts. in whom SLN was not detected, histology demonstrated nodal involvement. Metastases were found in the SLN of 28 of 137 pts. with successful detection of SLN; no other lymph nodes were affected in 21 of these pts. (75.0 % of pts. with positive SLN detection). With PA injection at least one SLN could always be detected using scintigraphy; only 2/117 SLN could not be found intraoperatively. Metastasis was found in SLN in 34/115 pts.; in 19/34 pts., metastatic involvement was limited to the SLN with no other lymph nodes involved (55.9 % of pts. with positive detection of SLN). Discussion: The detection rate for SLN was significantly higher using PA injection (98.3 % vs. 90.1 %). As axillary dissection was not done in SLN-negative patients, rates of false-negative detection cannot be determined. PA injection not only results in better detection rates, it also offers the advantage that the technique can be performed correctly regardless of tumour localisation.

Fluidization of wet granulates under shear.

Small amounts of a wetting liquid render sand a stiff and moldable material. The cohesive forces between the sand grains are caused by capillary bridges at the points of contact. Due to the finite strength of these bridges wet sand undergoes a transition from an arrested (i.e., solidified) to a fluidized state under an externally applied shear force. The transition between these two dynamic states is studied in a MD-type simulation of a two-dimensional assembly of bidisperse frictionless disks under the action of a cosine force profile. In addition to soft core repulsion the disks interact through a hysteretic and short ranged attractive force modeling the effect of the capillary bridges. In this model the transition between the fluidized and the arrested state is discontinuous and hysteretic. The parameter dependence of the critical force for solidification is modeled by combining theoretical arguments with a detailed numerical exploration of the transition. We address a range of densities from slightly below close packing until slightly above densities where the system approaches a shear-banded state. Differences and similarities of the transition in wet granulates to the jamming transition are also addressed.