The growth of α-sexithiophene films on Ag(111) studied by means of PEEM with linearly polarized light

In this study, we used photo electron emission microscopy (PEEM) to investigate the growth of α-sexithiophene (α-6 T) on Ag(111) surfaces. The experiments were carried out with linearly polarized ultraviolet-light (Hg lamp with hν=4.9 eV) in order to probe the alignment of the molecules on the surface. In particular, we acquired images before, during, and after growth while changing the polarization in a stepwise manner. For the stationary states of the clean and the α-6 T covered surfaces, we monitored the local electron yield and the intensity of the ultraviolet C-light (100-280 nm) reflected from the whole sample using PEEM and a photodiode, respectively. Due to the high ionization potential (IP>5 eV), there is no direct photoelectron emission from the organic crystallites. However, the photoelectron emission of the metal/organic interface is influenced by anisotropic absorption of the incident light beam, since the adsorbed molecules act as dichroic filters with distinct orientations.

Per-operative hemodynamic instability in normotensive patients with incidentally discovered pheochromocytomas

CONTEXT

The per-operative hemodynamic behavior of normotensive incidentally discovered pheochromocytomas is poorly documented.

OBJECTIVE

To compare the per-operative hemodynamic instability and early postoperative outcome of normotensive pheochromocytomas, hypertensive pheochromocytomas, and benign non-pheochromocytoma adrenal incidentalomas (AIs).

DESIGN

Retrospective cohort treated in a single center.

PATIENTS AND METHODS

Fifty patients (10 normotensive pheochromocytomas, 24 hypertensive pheochromocytomas, and 16 AIs) were anesthetized and operated on by the same team, using laparoscopy in 78% of cases. Before surgery, 60% of normotensive and 95.8% of hypertensive pheochromocytomas received pretreatment with α-receptor or calcium channel blockers. All of the patients received the same intraoperative hemodynamic monitoring, including continuous direct intra-arterial pressure recording.

RESULTS

All the features of hemodynamic instability, with the exception of the diastolic pressure nadir and fluid volume requirements, differed between hypertensive pheochromocytomas and AIs. Conversely, all features of hemodynamic instability were similar in hypertensive and normotensive pheochromocytomas. More specifically, by comparison with AIs, normotensive pheochromocytomas displayed higher maximal systolic pressure; more hypertensive, severe hypertensive, and hypotensive episodes; and a higher minimal heart rate, and also required more interventions to treat undesirable blood pressure elevations. Postoperative complications, all of which were mild, were more frequent in hypertensive pheochromocytomas than in normotensive pheochromocytomas (P < .03).

CONCLUSIONS

Normotensive pheochromocytomas have roughly comparable per-operative hemodynamic instability to hypertensive pheochromocytomas and differ markedly from non-pheochromocytoma AIs. It is therefore crucial to identify normotensive pheochromocytomas among AIs when surgery is scheduled and to apply the standard of care for pheochromocytoma anesthesia.

Surgical management of haemorrhaging renal angiomyolipoma in pregnancy

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We report the case of a 25-week pregnant woman that had a ruptured AML.

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This is the first case of nephrectomy in late second trimester with the foetus left in-utero.

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We present a literature review of the management of bleeding AML in pregnancy.

Introduction

Renal angiomyolipoma (AML) is a benign mesenchymal tumour of the kidney with a tendency of aneurysm formation at risk of rupturing. Due to increased maternal circulation and hormonal influences, rupture risk is greater in pregnancy, often leading to a vascular emergency and premature delivery or termination.

Presentation of case

A 24-weeks pregnant woman (45 years old, G6P1) presented with haematuria and flank pain. CT showed AML with acute haemorrhage. The patient became haemodynamically unstable and underwent urgent embolisation and follow-on total radical nephrectomy with the foetus being left in-utero. This involved a multidisciplinary team (urologist, vascular surgeon, interventional radiologist and obstetrician). The procedure was uncomplicated and the pregnancy went to term with a healthy girl delivered at 38 weeks.

Discussion

The incidence of AML is 0.13% in the general population. 21 reports of haemorrhaging AML in pregnancy have been published in the last 35 years. Mean gestational age was 29.6 weeks. Eight were treated conservatively to term, one underwent exploratory laparotomy with evacuation of haematoma only, five were embolised, and seven were managed with nephrectomy. Of the nephrectomy subgroup, one was preceded by vaginal delivery and five underwent concurrent caesarean section (one with pre-op embolisation). There were two associated foetal deaths.

Conclusion

This case demonstrates that with a multidisciplinary approach, it is possible to successfully leave a foetus undelivered whilst performing a radical nephrectomy for a large bleeding AML in a woman carrying a late second trimester pregnancy.

Surface-modified CAU-10 MOF materials as humidity sensors: impedance spectroscopic study on water uptake

Variation of the surface polarity of metal–organic frameworks caused by functional groups influences complex impedance: polar groups cause variations in water uptake, leading to measurable shifts in impedance signal.

Learning rate and temperament in a high predation risk environment

Living in challenging environments can influence the behavior of animals in a number of ways. For instance, populations of prey fish that experience frequent, nonlethal interactions with predators have a high proportion of individuals that express greater reaction to risk and increased activity and exploration—collectively known as temperament traits. Temperament traits are often correlated, such that individuals that are risk-prone also tend to be active and explore more. Spatial learning, which requires the integration of many sensory cues, has also been shown to vary in fish exposed to different levels of predation threat. Fish from areas of low predation risk learn to solve spatial tasks faster than fish from high predation areas. However, it is not yet known whether simpler forms of learning, such as learning associations between two events, are similarly influenced. Simple forms of associative learning are likely to be affected by temperament because a willingness to approach and explore novel situations could provide animals with a learning advantage. However, it is possible that routine-forming and inflexible traits associated with risk-prone and increased exploratory behavior may act in the opposite way and make risk-prone individuals poorer at learning associations. To investigate this, we measured temperament in Panamanian bishop fish (Brachyrhaphis episcopi) sampled from a site known to contain many predators. The B. episcopi were then tested with an associative learning task. Within this population, fish that explored more were faster at learning a cue that predicted access to food, indicating a link between temperament and basic learning abilities.

Quinacridone on Ag(111): Hydrogen Bonding versus Chirality

Quinacridone (QA) has recently gained attention as an organic semiconductor with unexpectedly high performance in organic devices. The strong intermolecular connection via hydrogen bonds is expected to promote good structural order. When deposited on a substrate, another relevant factor comes into play, namely the 2D-chirality of the quinacridone molecules adsorbed on a surface. Scanning tunneling microscopy (STM) images of monolayer quinacridone on Ag(111) deposited at room temperature reveal the formation of quasi-one-dimensional rows of parallel quinacridone molecules. These rows are segmented into short stacks of a few molecules in which adjacent, flat-lying molecules of a single handedness are linked via hydrogen bonds. After annealing to a temperature of T = 550-570 K, which is close to the sublimation temperature of bulk quinacridone, the structure changes into a stacking of heterochiral quinacridone dimers with a markedly different intermolecular arrangement. Electron diffraction (LEED) and photoelectron emission microscopy (PEEM) data corroborate the STM findings. These results illustrate how the effects of hydrogen bonding and chirality can compete and give rise to very different (meta)stable structures of quinacridone on surfaces.

Imaging in Erdheim-Chester disease: classic features and new insights

Erdheim-Chester disease is a rare non-Langerhans cell histiocytosis. Osseous involvement is the most frequent feature with bilateral and symmetric osteosclerotic changes in long bone diaphyseal and metaphyseal regions, classically sparing epiphyses. 99mTc scintigraphy shows bilateral and symmetrical metaphysal and diaphyseal increased uptake in almost all the patients, even asymptomatic. Other classical features on CT-scan, very evocative of Erdheim-Chester disease, must be recognised: e.g. 'coated' aorta, 'hairy kidney' patterns. New imaging techniques such as MRI have led to a better description of cardiac and central nervous system involvements. Pachymeningitis and right atrium wall infiltration are new evocative images of this disease. Fluorodeoxyglucose Positron Emission Tomography in the diagnosis or prognosis assessment is still discussed. The objective of this review is to discuss the place of each imaging technique in Erdheim-Chester disease in 2013.

Dark field nanoparticle tracking analysis for size characterization of plasmonic and non-plasmonic particles

Dark field microscopy is a widely unknown method to measure the particle size distribution of diffusing nanoparticles by particle tracking. Here we demonstrate that by using the surface plasmonic resonance of Au nanoparticles, size differences of ca. 20 nm can be identified within the particle size distribution. For that purpose, we developed a software tool which helps to analyze color videos of diffusing nanoparticles retrieved from CCD or CMOS cameras. Polystyrene beads with a diameter of 100 and 200 nm were used to compare the results to those obtained with a well-established laser-based particle tracking system. The methodology will be discussed in the light of recent developments in the emerging field of optical nanoparticle tracking.

Single event time series analysis in a binary karst catchment evaluated using a groundwater model (Lurbach system, Austria)

The Lurbach karst system (Styria, Austria) is drained by two major springs and replenished by both autogenic recharge from the karst massif itself and a sinking stream that originates in low permeable schists (allogenic recharge). Detailed data from two events recorded during a tracer experiment in 2008 demonstrate that an overflow from one of the sub-catchments to the other is activated if the discharge of the main spring exceeds a certain threshold. Time series analysis (autocorrelation and cross-correlation) was applied to examine to what extent the various available methods support the identification of the transient inter-catchment flow observed in this binary karst system. As inter-catchment flow is found to be intermittent, the evaluation was focused on single events. In order to support the interpretation of the results from the time series analysis a simplified groundwater flow model was built using MODFLOW. The groundwater model is based on the current conceptual understanding of the karst system and represents a synthetic karst aquifer for which the same methods were applied. Using the wetting capability package of MODFLOW, the model simulated an overflow similar to what has been observed during the tracer experiment. Various intensities of allogenic recharge were employed to generate synthetic discharge data for the time series analysis. In addition, geometric and hydraulic properties of the karst system were varied in several model scenarios. This approach helps to identify effects of allogenic recharge and aquifer properties in the results from the time series analysis. Comparing the results from the time series analysis of the observed data with those of the synthetic data a good agreement was found. For instance, the cross-correlograms show similar patterns with respect to time lags and maximum cross-correlation coefficients if appropriate hydraulic parameters are assigned to the groundwater model. The comparable behaviors of the real and the synthetic system allow to deduce that similar aquifer properties are relevant in both systems. In particular, the heterogeneity of aquifer parameters appears to be a controlling factor. Moreover, the location of the overflow connecting the sub-catchments of the two springs is found to be of primary importance, regarding the occurrence of inter-catchment flow. This further supports our current understanding of an overflow zone located in the upper part of the Lurbach karst aquifer. Thus, time series analysis of single events can potentially be used to characterize transient inter-catchment flow behavior of karst systems.

Impact of constant storage temperatures and multiple warming cycles on the quality of stored red blood cells

BACKGROUND

Red blood cells (RBCs) are routinely stored in liquid state at temperatures below 6°C, and RBC unit core temperature should not exceed 10°C during transport. Since the critical temperature of 10°C was chosen mostly arbitrarily, this study investigated the effect of both constant temperature settings as well as multiple rewarming cycles on stored RBCs with respect to morphology, biochemical parameters and haemolysis.

MATERIALS AND METHODS

Buffy coat-depleted filtered RBCs were used as standard products. RBCs were stored at 1-6°C (reference group, n = 12), 13 and 22°C (test groups, n = 12 each) or stored at 1-6°C and warmed up five times to 10, 13, or 22°C for a period of 24 h each. Various biochemical parameters were measured weekly. RBCs were further investigated using electron microscopy.

RESULTS

Red blood cells stored constantly at 13 or 22°C showed stable haemolysis rates until day 28 and day 14, respectively. RBCs stored at 1-6°C with five warming-up periods to 10, 13 or 22°C each lasting 24 h (total 120 h) did not exceed the limit of the haemolysis rate at the end of storage. Differently shaped erythrocytes were found in all samples, but more crenate erythrocytes appeared after 42 days of storage independent of temperature profiles.

CONCLUSION

Red cells can be kept at constant temperatures above 6°C without apparent harmful effects at least until day 14, whereas multiple warming cycles for no longer than 24 h at 10, 13 or 22°C with subsequent cooling do not cause quality loss as assessed using the in vitro assays employed in this study.

Association of age and packed red blood cell transfusion to 1-year survival--an observational study of ICU patients

OBJECTIVES

To compare the 1-year survival for different age strata of intensive care unit (ICU) patients after receipt of packed red blood cell (PRBC) transfusions.

BACKGROUND

Despite guidelines documenting risks of PRBC transfusion and data showing that increasing age is associated with ICU mortality, little data exist on whether age alters the transfusion-related risk of decreased survival.

METHODS

We retrospectively examined data on 2393 consecutive male ICU patients admitted to a tertiary-care hospital from 2003 to 2009 in age strata: 21-50, 51-60, 61-70, 71-80 and >80 years. We calculated Cox regression models to determine the modifying effect of age on the impact of PRBC transfusion on 1-year survival by using interaction terms between receipt of transfusion and age strata, controlling for type of admission and Charlson co-morbidity indices. We also examined the distribution of admission haematocrit and whether transfusion rates differed by age strata.

RESULTS

All age strata experienced statistically similar risks of decreased 1-year survival after receipt of PRBC transfusions. However, patients age >80 were more likely than younger cohorts to have haematocrits of 25-30% at admission and were transfused at approximately twice the rate of each of the younger age strata.

DISCUSSION

We found no significant interaction between receipt of red cell transfusion and age, as variables, and survival at 1 year as an outcome.

FDG-PET/CT findings during immune reconstitution in an HIV-1 patient infected with visceral leishmaniasis

Visceral leishmaniasis can rarely be unmasked by immune reconstitution in human immunodeficiency virus (HIV)-1-infected patients. We report the first case of immune reconstitution associated with leishmaniasis in an HIV patient to be imaged with [(18)F]fluorodeoxyglucose positron emission tomography (FDG/PET), at both baseline and after therapy.

Laser Sintering of High Temperature Resistant Polymers with Carbon Black Additives

Selective laser sintering (SLS) experiments with polyetherketone (PEK) and polyetheretherketone (PEEK) powders are described. The absorption behaviour of the polymer powders has been investigated with respect to the content of carbon black as an IR-absorber in the range from 0.03 to 0.1 wt.%. Laser sintering process studies have been carried out at room temperature using a Q-switched Nd:YAG laser system. The sintering depths of single layer substrates have been determined according to the process parameters, such as laser power, scanning speed and hatch distance. These process parameters have been optimised with the goal of achieving good structural integrity of the substrate. The influence of melt viscosity has been determined by comparing PEEK powders of low and standard melt viscosity. Scanning electron micrographs show the morphology of the original polymer powders and the laser sintered specimens. On the basis of the experimental results a qualitative SLS mechanism is proposed to describe the energy transfer from the carbon black particles to the surrounding polymer powder.

Mechanism- and experience-based strategies to optimize treatment response to the capsaicin 8% cutaneous patch in patients with localized neuropathic pain

The capsaicin 8% cutaneous patch is an emergent new treatment option for patients with peripheral neuropathic pain. In randomized controlled clinical studies relevant pain relief for 12 weeks was achieved in about one third of patients following a single application. The first part of this paper is a review of the pathophysiology, pharmacology, and published clinical trials with the capsaicin 8% cutaneous patch. The second part reports on outcomes of an interdisciplinary expert workshop, where new treatment results of three major German pain centers were presented and reviewed with the objectives of obtaining responder rates for different pain syndromes, assessing maintenance of effect under real-life conditions, and giving recommendations for practical care. The 12 week responder rates with pain relief of ≥ 30% were comparable in patients with mononeuropathies (37.9%) and postherpetic neuralgia (38.8%). Similar responder rates were seen in a subgroup of patients with cervical spine radiculopathy and back pain (46.7%). In HIV-associated neuropathy the responder rates were high (47.8%) but lower in patients with other polyneuropathies (17.6%). Response rates were nearly identical after 1 week (46.6%) and 4 weeks (43.3) and dropped only slightly at 12 weeks (37.4%). In a subgroup of 54 patients who underwent a second treatment, efficacy was maintained. Response rates in patients with or without lidocaine pretreatment were comparable. Treatment with the capsaicin 8% cutaneous patch was generally safe and well tolerated. The workshop panel recommended further investigation of opportunities to improve the application procedure and to perform studies on the skin penetration and distribution of capsaicin. A modified quantitative sensory testing (QST) should be developed for clinical practice in order to better understand the correlation of sensory profiles and response to capsaicin treatment.

Therapy response evaluation with FDG-PET/CT in small cell lung cancer: a prognostic and comparison study of the PERCIST and EORTC criteria

Introduction: Small cell lung cancer (SCLC) is an aggressive form of lung cancer with poor prognosis. Adequate staging and therapeutic evaluation is necessary for therapy planning. Fluorodeoxyglucose (FDG)-positron emission tomography (PET)/computed tomography (CT) has been shown to be useful for staging and therapy response evaluation. The European Organization for Research and Treatment of Cancer (EORTC) and Positron Emission Tomography Response Criteria In Solid Tumors (PERCIST) criteria were compared in the evaluation of response assessment and prognostic factors were defined in a cohort of SCLC patients. Methods: Twenty-nine consecutive patients with SCLC were included in this study. Sixteen patients had extensive disease and 13 had limited disease. All patients had chemotherapy, 21 had thoracic radiotherapy. FDG-PET/CT scans were performed before and after therapy to evaluate treatment response. Metabolic responses were assessed using the EORTC criteria and PERCIST criteria. Univariate and multivariate analysis were performed using a Cox model to investigate the association between progression-free and overall survival time with a number of covariates. Results: There was perfect concordance between the EORTC and PERCIST criteria. Eight patients had a complete metabolic response (CMR), 9 had a partial metabolic response (PMR), 5 had stable metabolic disease (SMD) and 7 had progressive metabolic disease (PMD). Overall survival time in patients with CMR was significantly longer compared with patients who did not have CMR. The initial or delayed CMR and post-therapeutic standardized uptake value corrected for lean body mass were significantly associated with overall survival. Conclusion: CMR on post-therapeutic FDG-PET/CT in patients with SCLC is an important prognostic factor and may help decision making for therapeutic management.

[A new working shift model for anesthesiologists: an analysis 3 years after implementation]

OBJECTIVE

The aim of this study was to assess the efficacy, appropriateness and cost-effectiveness of a new working shift model for anesthesiologists complying with the European working time directive (EWTD) at the University Hospital of Tübingen (UKT), Germany 3 years after implementation

BACKGROUND

Applying the standards of the EWTD is challenging for university hospitals as doctors must comply with the challenge of combining patient care, research and teaching. So far there have been no data available for German university hospitals on how these requirements can be met. As the department of anesthesiology is also a service-providing department it is essential not to increase staffing costs with a new shift model.

METHODS

In 2007 a new working shift model for the department of anesthesiology was designed and introduced in 2008. Shift planning and documentation of working hours were implemented electronically. The calculated number of doctors to run this model was 87.6 full time equivalents (FTE). For 2009 and 2010 the compliance with the EWTD parameters was checked for 1) average weekly working time limit (AWWTL) and 2) compliance to the maximum daily working time limit of 10 h (10 h DWTL). Furthermore, staffing costs for doctors in 2010 were compared to 2007. To check for the time spent in patient care the period of anesthetic attendance (PAA) was chosen, i.e. the total time of patient contact by anesthesiology staff. Data were analyzed descriptively for AWWTL and for 10 h DWTL. FTE, staff costs and PAA were evaluated by one-way ANOVA.

RESULTS

The new shift model allowed 84.4 % of all doctors to comply with the individual AWWT limits of 54 h and 48 h in 2009 (81/96) and 76.0 % in 2010 (79/104). In 2009 61.5 % of anesthesiologists voted for opt-out (59/96) and 53.8 % did so in 2010 (56/104). The 10 h DWTL was respected by 84.0 % in 2009 and by 85.9 % in 2010. The mean number of anesthesiologists rose significantly from 78.4 FTE in 2007 to 82.5 FTE in 2009 and 84.6 FTE in 2010 (p < 0.001 for 2010 vs. 2007, p = 0.004 for 2009 vs. 2007 and was not significant for 2010 vs. 2009). Staff costs per FTE increased from 7,524.79 <euro>/month to 7,800.66 <euro>/month and 7,966.11 <euro>/month in 2007, 2009 and 2010, respectively with the differences being non-significant. The PAA increased significantly from a mean of 6,124 h/month in 2007 to 6,581 h/month in 2009 and 6,872 h/month in 2010 (p < 0.001 for 2010 vs. 2007, whereas 2009 vs. 2007 and 2010 vs. 2009 were not significant). Thus, labour costs increased from 96.59 <euro>/h PAA in 2007 to 98.53 <euro>/h in both 2009 and 2010, the differences being not significant.

CONCLUSIONS

The newly designed shift model allowed a fair compliance with the EWTD in respect to AWTL and 10 h DWTL, although the calculated number of doctors to run the shift model could not be met in 2009 and 2010. Violations of the 10 h DWT limits were stable in 2009 and 2010; however the number of doctors exceeding the AWWT limits appeared to increase. The compliance with opt-out decreased from 2009 to 2010 and a high proportion of AWWTL violations resulted from the group of non-opt-out voters. The staff costs per hour PAA after implementation of the new shift model did not differ significantly from the year before although staffing costs increased by 7.2 % between 2007 and 2010. Costs increased by 162,454 <euro>/year for all PAA hours in 2010. Further evaluation of staff satisfaction with the new shift models is needed and already under way.