140 research outputs found

    Pancreatic metastasis from gastric carcinoma: a case report

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    BACKGROUND: The pancreas is a rare but occasionally favored target for metastasis. Metastatic lesions in the pancreas have been described for various primary cancers, such as carcinomas of the lung, the breast, renal cell carcinoma and sarcomas. CASE PRESENTATION: We report the case of a 60-year old female with a mass in the pancreatic head four years after partial gastrectomy for gastric adenocarcinoma. The patient underwent a pancreatoduodenectomy. Pathological examination revealed metastases of the primary gastric carcinoma within the pancreatic head and in regional lymph nodes. CONCLUSIONS: Pancreatic tumors in patients with a history of non-pancreatic malignancy should always be considered to be a putative metastatic lesion at an unusual site. If the pancreas can be identified as the only site of spread, radical resection may prolong survival

    A torsion balance as a weak-force testbed for novel optical inertial sensors

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    Torsion balances (TBs) are versatile instruments known for their ability to measure tiny forces and accelerations with high precision. We are currently commissioning a new TB facility to support the development and testing of novel optical inertial sensor units for future gravity-related space missions. Here, we report on the status of our apparatus and present first sensitivity curves that demonstrate acceleration and torque sensitivities of 5 ⋅ 10 − 11 m s − 2 and 1 ⋅ 10 − 12 N m H z − 1 at frequencies around 4 m H z , respectively. Capacitive sensors and optical levers measure the dynamics of the system with a displacement sensitivity of down to 9 ⋅ 10 − 10 m H z − 1 for the former and 2 ⋅ 10 − 11 m H z − 1 for the latter. Combining the readout of the suspended inertial member (IM) with environmental sensor signals, the system is characterized, and limiting noise sources are identified. We find that, in particular, the coupling of ambient seismic motion is limiting over a broad frequency range and show that due to its high susceptibility to ground motion, our TB is also a promising platform for exploring ground motion sensing in multiple degrees of freedom. Future upgrades will focus on mitigating seismic noise by controlling the torsion fiber suspension point using piezoelectric actuators and the integration of precision interferometric readout of the IM. These improvements will further increase the sensitivity towards the thermal noise limit which constrains the performance to 1 ⋅ 10 − 13 m s − 2 H z − 1 at 4 m H z

    On the behavior of micro-spheres in a hydrogen pellet target

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    A pellet target produces micro-spheres of different materials, which are used as an internal target for nuclear and particle physics studies. We will describe the pellet hydrogen behavior by means of fluid dynamics and thermodynamics. In particular one aim is to theoretically understand the cooling effect in order to find an effective method to optimize the working conditions of a pellet target. During the droplet formation the evaporative cooling is best described by a multi-droplet diffusion-controlled model, while in vacuum, the evaporation follows the (revised) Hertz-Knudsen formula. Experimental observations compared with calculations clearly indicated the presence of supercooling, the effect of which is discussed as well.Comment: 22 pages, 8 figures (of which two are significantly compressed for easier download

    An Integrated System for 3D Hip Joint Reconstruction from 2D X-rays: A Preliminary Validation Study

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    The acquisition of conventional X-ray radiographs remains the standard imaging procedure for the diagnosis of hip-related problems. However, recent studies demonstrated the benefit of using three-dimensional (3D) surface models in the clinical routine. 3D surface models of the hip joint are useful for assessing the dynamic range of motion in order to identify possible pathologies such as femoroacetabular impingement. In this paper, we present an integrated system which consists of X-ray radiograph calibration and subsequent 2D/3D hip joint reconstruction for diagnosis and planning of hip-related problems. A mobile phantom with two different sizes of fiducials was developed for X-ray radiograph calibration, which can be robustly detected within the images. On the basis of the calibrated X-ray images, a 3D reconstruction method of the acetabulum was developed and applied together with existing techniques to reconstruct a 3D surface model of the hip joint. X-ray radiographs of dry cadaveric hip bones and one cadaveric specimen with soft tissue were used to prove the robustness of the developed fiducial detection algorithm. Computed tomography scans of the cadaveric bones were used to validate the accuracy of the integrated system. The fiducial detection sensitivity was in the same range for both sizes of fiducials. While the detection sensitivity was 97.96% for the large fiducials, it was 97.62% for the small fiducials. The acetabulum and the proximal femur were reconstructed with a mean surface distance error of 1.06 and 1.01mm, respectively. The results for fiducial detection sensitivity and 3D surface reconstruction demonstrated the capability of the integrated system for 3D hip joint reconstruction from 2D calibrated X-ray radiograph

    Effects of a video game intervention on symptoms, training motivation, and visuo-spatial memory in depression

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    BackgroundPeople with Major Depressive Disorder (MDD) often experience reduced affect, mood, and cognitive impairments such as memory problems. Although there are various treatments for MDD, many of them do not address the cognitive deficits associated with the disorder. Playing 3D video games has been found to improve cognitive functioning in healthy people, but it is not clear how they may affect depressed mood and motivation in people with MDD. The aim of this study was to investigate whether a six-week video game intervention leads to improvements in depressed mood, training motivation, and visuo-spatial (working) memory functions in patients with MDD.MethodsA total of 46 clinically depressed individuals were randomly assigned to one of three groups: an experimental “3D video gaming” group (n = 14) which played a video game, an active control group (n = 16) which trained with a computer program “CogPack,” and a treatment-as-usual group (n = 16) which received a standard clinical treatment including psychotherapy and/or pharmacotherapy. Participants performed a neuropsychological assessment, including self-report questionnaires asking for depressive symptoms, training motivation, and visuo-spatial (working) memory functions before and after the training intervention.ResultsRegarding depressive symptoms, a significant decrease in the proportion of participants who showed clinical levels of depressive symptoms as measured by the Beck Depression Inventory was only found in the 3D video gaming group. Additionally, mean motivational levels of performing the training were significantly higher in the 3D video gaming group when compared with the active control group. Moreover, whereas the 3D Video Gaming group only significantly improved on one visuo-spatial memory test, the active control group improved in all visuo-spatial memory functions. The 3D video gaming group did not perform significantly better than the CogPack group, and the TAU group.ConclusionBesides a standalone cognitive training, the current findings suggest that cognitive trainings using a video game have potential to increase subjective well-being, show higher levels of training motivation, and lead to improvements in visuo-spatial (working) memory functions in MDD. However, given the mixed and unblinded nature of this study, the results should be interpreted with caution. Further research with larger samples and follow-up measurements is needed

    Separation of atomic and molecular ions by ion mobility with an RF carpet

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    Gas-filled stopping cells are used at accelerator laboratories for the thermalization of high-energy radioactive ion beams. Common challenges of many stopping cells are a high molecular background of extracted ions and limitations of extraction efficiency due to space-charge effects. At the FRS Ion Catcher at GSI, a new technique for removal of ionized molecules prior to their extraction out of the stopping cell has been developed. This technique utilizes the RF carpet for the separation of atomic ions from molecular contaminant ions through their difference in ion mobility. Results from the successful implementation and test during an experiment with a 600~MeV/u 124^{124}Xe primary beam are presented. Suppression of molecular contaminants by three orders of magnitude has been demonstrated. Essentially background-free measurement conditions with less than 1 %1~\% of background events within a mass-to-charge range of 25 u/e have been achieved. The technique can also be used to reduce the space-charge effects at the extraction nozzle and in the downstream beamline, thus ensuring high efficiency of ion transport and highly-accurate measurements under space-charge-free conditions.Comment: 8 pages, 4 figure

    Altered interaction of physiological activity and behavior affects risky decision-making in ADHD

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    BackgroundAdult attention-deficit/hyperactivity disorder (ADHD) is often associated with risky decision-making behavior. However, current research studies are often limited by the ability to adequately reflect daily behavior in a laboratory setting. Over the lifespan impairments in cognitive functions appear to improve, whereas affective functions become more severe. We assume that risk behavior in ADHD arises predominantly from deficits in affective processes. This study will therefore aim to investigate whether a dysfunction in affective pathways causes an abnormal risky decision-making (DM) behavior in adult ADHD.MethodsTwenty-eight participants with ADHD and twenty-eight healthy controls completed a battery of questionnaires regarding clinical symptoms, self-assessment of behavior and emotional competence. Furthermore, skin conductance responses were measured during the performance in a modified version of the Balloon Analogue Risk Task. A linear mixed-effects model analysis was used to analyze emotional arousal prior to a decision and after feedback display.ResultsResults showed higher emotional arousal in ADHD participants before decision-making (β = −0.12, SE = 0.05, t = −2.63, p < 0.001) and after feedback display (β = −0.14, SE = 0.05, t = −2.66, p = 0.008). Although risky behavior was greater in HC than in ADHD, we found a significant interaction effect of group and anticipatory skin conductance responses regarding the response behavior (β = 107.17, SE = 41.91, t = 2.56, p = 0.011). Post hoc analyses revealed a positive correlation between anticipatory skin conductance responses and reaction time in HC, whereas this correlation was negative in ADHD. Self-assessment results were in line with the objective measurements.ConclusionWe found altered changes in physiological activity during a risky decision-making task. The results confirm the assumption of an aberrant relationship between bodily response and risky behavior in adult ADHD. However, further research is needed with respect to age and gender when considering physiological activities

    Low expression of aldehyde deyhdrogenase 1A1 (ALDH1A1) is a prognostic marker for poor survival in pancreatic cancer

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    <p>Abstract</p> <p>Background</p> <p>Aldehyde deyhdrogenase 1 (ALDH1) has been characterised as a cancer stem cell marker in different types of tumours. Additionally, it plays a pivotal role in gene regulation and endows tumour cells with augmented chemoresistance. Recently, ALDH1A1 has been described as a prognostic marker in a pancreatic cancer tissue microarray. The aim of this study was to reevaluate the expression of ALDH1A1 as a prognostic marker on whole-mount tissue sections.</p> <p>Methods</p> <p>Real-time-quantitative-PCR (qRT-PCR) and Western blotting were used to evaluate the expression profile of ALDH1A1 in seven pancreatic cancer cell lines and one non-malignant pancreatic cell line. Immunostaining against ALDH1A1 and Ki-67 was performed on paraffin-embedded samples from 97 patients with pancreatic cancer. The immunohistochemical results were correlated to histopathological and clinical data.</p> <p>Results</p> <p>qRT-PCR and Western blotting revealed a different expression pattern of ALDH1A1 in different malignant and non-malignant pancreatic cell lines. Immunohistochemical analysis demonstrated that ALDH1A1 was confined to the cellular cytoplasm and occurred in 72 cases (74%), whereas it was negative in 25 cases (26%). High expression of ALDH1A1 was significantly correlated to an increased proliferation rate (Spearman correlation, p = 0.01). Univariate and multivariate analyses showed that decreased expression of ALDH1A1 is an independent adverse prognostic factor for overall survival.</p> <p>Conclusions</p> <p>Immunonhistochemical analysis on whole-mount tissue slides revealed that ALDH1A1 is more abundantly expressed in pancreatic cancer than initially reported by a tissue microarray analysis. Moreover, high expression of ALDH1A1 correlated significantly with the proliferation of tumour cells. Intriguingly, this study is the first which identifies low expression of ALDH1A1 as an independent adverse prognostic marker for overall survival in pancreatic cancer.</p

    The population-based oncological health care study OVIS – recruitment of the patients and analysis of the non-participants

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    <p>Abstract</p> <p>Background</p> <p>The ageing of the population is expected to bring an enormous growth in demand for oncological health care. In order to anticipate and respond to future trends, cancer care needs to be critically evaluated. The present study explores the possibility of conducting representative and population-based research on cancer care on the basis of data drawn from the Cancer Registry.</p> <p>Methods</p> <p>A population-based state-wide cohort study (OVIS) has been carried out in Schleswig-Holstein, Germany. All patients with malignant melanoma, breast, or prostate cancer were identified in the Cancer Registry. Epidemiological data were obtained for all the patients and screened for study eligibility. A postal questionnaire requesting information on diagnosis, therapy, QoL and aftercare was sent to eligible patients.</p> <p>Results</p> <p>A total of 11,489 persons diagnosed with the cancer types of interest in the period from January 2002 to July 2004 were registered in the Cancer Registry. Of the 5,354 (47%) patients who gave consent for research, 4,285 (80% of consenters) completed the questionnaire. In terms of relevant epidemiological variables, participants with melanoma were not found to be different from non-participants with the same diagnosis. However, participants with breast or prostate cancer were slightly younger and had smaller tumours than patients who did not participate in our study.</p> <p>Conclusion</p> <p>Population-based cancer registry data proved to be an invaluable resource for both patient recruitment and non-participant analysis. It can help improve our understanding of the strength and nature of differences between participants and non-respondents. Despite minor differences observed in breast and prostate cancer, the OVIS-sample seems to represent the source population adequately.</p
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