2,428 research outputs found
Turbulence attenuation by large neutrally buoyant particles
Turbulence modulation by inertial-range-size, neutrally-buoyant particles is
investigated experimentally in a von K\'arm\'an flow. Increasing the particle
volume fraction , maintaining constant impellers Reynolds
number attenuates the fluid turbulence. The inertial-range energy transfer rate
decreases as , suggesting that only particles
located on a surface affect the flow. Small-scale turbulent properties, such as
structure functions or acceleration distribution, are unchanged. Finally,
measurements hint at the existence of a transition between two different
regimes occurring when the average distance between large particles is of the
order of the thickness of their boundary layers.Comment: 7 pages, 4 figure
Cell division: a source of active stress in cellular monolayers
We introduce the notion of cell division-induced activity and show that the
cell division generates extensile forces and drives dynamical patterns in cell
assemblies. Extending the hydrodynamic models of lyotropic active nematics we
describe turbulent-like velocity fields that are generated by the cell division
in a confluent monolayer of cells. We show that the experimentally measured
flow field of dividing Madin-Darby Canine Kidney (MDCK) cells is reproduced by
our modeling approach. Division-induced activity acts together with intrinsic
activity of the cells in extensile and contractile cell assemblies to change
the flow and director patterns and the density of topological defects. Finally
we model the evolution of the boundary of a cellular colony and compare the
fingering instabilities induced by cell division to experimental observations
on the expansion of MDCK cell cultures.Comment: Accepted Manuscript for Celebrating Soft Matter's 10th Anniversar
Evaluation of the ADVIA (R) Centaur (TM) TSH-3 assay
An analytical evaluation of the thyroid stimulating hormone (TSH-3) assay on the Sayer ADVIA(R) Centaur(TM) immunoassay system was performed. General analytical requirements (linearity, resistance to typical interferences, absence of a carry-over effect) were fulfilled and reproducibility was satisfactory. Inter-assay coefficient of variation (CV) of a human serum pool with a concentration of 0.014 mU/l was 22.3%; at concentrations between 0.26 and 83 mU/l CV was below 6%. Method comparison study demonstrated close agreement of TSH results compared to those obtained with the Roche Elecsys(R) 2010 TSH assay (ADVIA Centaur = 1.08 x Elecsys - 0.18 mU/l; r = 0.987; n = 324). Handling and practicability of the ADVIA Centaur system proved to be convenient with a very high sample throughput. We conclude that the ADVIA Centaur TSH-3 assay meets requirements for clinical use
Collision metastasis from prostate adenocarcinoma and pancreatic ductal adenocarcinoma to a lung nodule
Introduction
Prostate cancer and pancreatic cancer are often complex pathologies that affect millions of patients worldwide. However, the incidence of a distant collision metastasis of both malignancies remains a rare and often poorly documented incidence.
Case presentation
A 75-year-old male patient with past history of prostate cancer on maximal androgen blockade was recently diagnosed with pancreatic cancer for which he underwent radical surgical resection of pancreas with curative intent. A metastatic lung nodule was noted on surveillance CT imaging and, subsequently, biopsied. A diagnosis of collision metastasis from two distinct primary malignancies was histopathologically confirmed following immunohistochemical evaluation.
Conclusion
We report the first case of collision metastasis of prostate and pancreatic adenocarcinomata to a lung nodule to the best of our knowledge
A review on the clinical implementation of respiratory-gated radiation therapy
Respiratory-gated treatment techniques have been introduced into the radiation oncology practice to manage target or organ motions. This paper will review the implementation of this type of gated treatment technique where the respiratory cycle is determined using an external marker. The external marker device is placed on the abdominal region between the xyphoid process and the umbilicus of the patient. An infrared camera tracks the motion of the marker to generate a surrogate for the respiratory cycle. The relationship, if any, between the respiratory cycle and the movement of the target can be complex. The four-dimensional computed tomography (4DCT) scanner is used to identify this motion for those patients that meet three requirements for the successful implementation of respiratory-gated treatment technique for radiation therapy. These requirements are (a) the respiratory cycle must be periodic and maintained during treatment, (b) the movement of the target must be related to the respiratory cycle, and (c) the gating window can be set sufficiently large to minimise the overall treatment time or increase the duty cycle and yet small enough to be within the gate. If the respiratory-gated treatment technique is employed, the end-expiration image set is typically used for treatment planning purposes because this image set represents the phase of the respiratory cycle where the anatomical movement is often the least for the longest time. Contouring should account for tumour residual motion, setup uncertainty, and also allow for deviation from the expected respiratory cycle during treatment. Respiratory-gated intensity-modulated radiation therapy (IMRT) treatment plans must also be validated prior to treatment. Quality assurance should be performed to check for positional changes and the output in association with the motion-gated technique. To avoid potential treatment errors, radiation therapist (radiographer) should be regularly in-serviced and made aware of the need to invoke the gating feature when prescribed for selected patients
Characterization of food product innovation practices with reference to functional food product development in Singapore
Functional foods, being one of the major food categories of the global health and wellness market, are becoming a major focus of new product development (NPD) in the food industry. The development of functional foods is more complex than traditional food New Product Development (NPD), calling for a concerted effort from researchers and NPD experts to explore and understand the functional food product development (FFPD) process in more detail. The current research in this field has reported that there is a need to evolve from a traditional NPD approach, towards an integrative and innovative approach involving cooperative networks and techniques of commercialization. However, there is little practical evidence on how much progress has been made to date. Therefore, this research was designed to investigate the food product innovation process of food manufacturing in the Asia-Pacific region (Singapore) with reference to functional foods development. Results report on a comparative account of NPD practices between registered Singapore food companies that are doing some sort of functional food development (Group 1) and those that are not (Group 2). A significant difference (P<0.05) in the aims and mode of NPD between Group 1 and Group was observed. Further it was observed that food companies in Group 1 have significantly (P<0.05) more diverse external collaborations with broad aims to collaborate, in comparison with food companies in Group 2. This is a positive step toward developing an external resource base, which is essential in developing functional foods. This attitude should be encouraged in future innovation polices as being critical to value-added food product innovations in Singapore. Apart from these differences, food companies are still pursuing a traditional NPD approach (independent and closed NPD); with loose Intellectual Property protection practices irrespective of type of innovation activity. There is a need to create awareness among the stakeholders about the factors needed for developing unique and inimitable resources, and dynamic capabilities in food manufacturing
Assessment of patient satisfaction with the preoperative anaesthetic evaluation
Preoperative anaesthetic evaluation is important in the perioperative care. The aim of the study was to evaluate the level of satisfaction and factors affecting patient satisfaction in the preanaesthetic clinic (PAC). A total of 304 patients who attended PAC for preoperative evaluation were recruited into this study. A bilanguage validated Patient Satisfaction Survey in English and Bahasa Malaysia with total questions of 18 examining non-provider factors (NPF) (facilities and appropriateness of waiting time) and provider factors (PF) (doctor, counter services, nurses and supporting staff) were utilized. The survey form was graded in a strongly agree/ disagree five-point Likert scale format for patients’ level of satisfaction. Overall satisfaction of preoperative evaluation was reported as 98.7% with mean scores from doctor (4.49 + 0.60), counter service (4.48 + 0.61), support staff (4.47 + 0.62) and the NPF (4.40 + 0.62), respectively. All factors were found to be significantly correlated with the overall patients’ satisfaction (p<0.001) and waiting time shown to be the independent predictor affecting the level of satisfaction. Overall majority of the patients were satisfied with the preoperative evaluation provided at PAC and both non-provider and provider factors were shown to have a significant impact on patient satisfaction
Computer Simulation Study of the Phase Behavior and Structural Relaxation in a Gel-Former Modeled by Three Body Interactions
We report a computer simulation study of a model gel-former obtained by
modifying the three-body interactions of the Stillinger-Weber potential for
silicon. This modification reduces the average coordination number and
consequently shifts the liquid-gas phase coexistence curve to low densities,
thus facilitating the formation of gels without phase separation. At low
temperatures and densities, the structure of the system is characterized by the
presence of long linear chains interconnected by a small number of three
coordinated junctions at random locations. At small wave-vectors the static
structure factor shows a non-monotonic dependence on temperature, a behavior
which is due to the competition between the percolation transition of the
particles and the stiffening of the formed chains. We compare in detail the
relaxation dynamics of the system as obtained from molecular dynamics with the
one obtained from Monte Carlo dynamics. We find that the bond correlation
function displays stretched exponential behavior at moderately low temperatures
and densities, but exponential relaxation at low temperatures. The bond
lifetime shows an Arrhenius behavior, independent of the microscopic dynamics.
For the molecular dynamics at low temperatures, the mean squared displacement
and the (coherent and incoherent) intermediate scattering function display at
intermediate times a dynamics with ballistic character and we show that this
leads to compressed exponential relaxation. For the Monte Carlo dynamics we
find always an exponential or stretched exponential relaxation. Thus we
conclude that the compressed exponential relaxation observed in experiments is
due to the out-of-equilibrium dynamics
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This is the Piece that Everyone Here Has Come to Experience: The Challenges to Copyright of John Cage’s 4’33”
Framed within the broader context of law's engagement with modernism, this paper offers an argument in defence of copyright protection of John Cage's 4′33″ as a ‘musical work’ under the Copyright, Designs and Patents Act 1988. This argument approaches the issues involved analytically and contextually. In doing so, it draws on both legal and non-legal sources. Throughout the paper, the underlying question remains as to whether Cage's 4′33″ really is – or is not – a challenge to law (and to music)
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