The model entirely relies on the chronology of these successive events of the metastatic cascade. The simulation calculations were performed for two embedded growth models to describe the Gompertzian like growth behaviour of tumours. The initial training of the models was carried out using an analytical solution for the size distribution of metastases of a hepatocellular carcinoma. We then show the applicability of our models to clinical data from the Munich Cancer Registry. Growth and dissemination characteristics of metastatic cells originating from cells in the primary breast cancer can be modelled thus showing its ability to perform systematic analyses relevant for clinical breast cancer research and treatment. In particular, our calculations show that generally metastases formation has already been initiated before the primary can be detected clinically.A simple and fast computational model to describe the dynamics of tumour growth and metastasis formation is presented. The model is based on the calculation of successive generations of tumour cells and enables one to describe biologically important entities like tumour volume, time point of 1 The second ones are complex mathematical analyses of continuum models on the base of differential equations. A good overview of these approaches can be found in the articles of Ward and King . Accordingly the part (1-F) will be eliminated from the blood system. In our model only the small fraction λc/λenv of these cells will each colonise and develop metastases. The mean time point can be calculated by integrating the distribution function of such an exponential decay. The other group of cells, cells that just enter the circulation are subject to a different treatment. The process of creation and immediate elimination during the same time step TG has to be accounted for. Number of surviving cells as well as mean time point and number of colonizing cells can be calculated by the combination of both the distribution function for dissemination into the blood stream and function for subsequent colonization of the stroma. Especially when the time scales for the life cycle Tenv in the environment respective the generation time TG differs significantly, this approach is necessary to calculate a more precise time of 1st metastasis formation.In continuation of the generation model with the time steps TG and in total at time n·TG. Following the same strategy and by the use of recursion techniques the development in time of per TG released metastatic cells and the process of secondary respective multiple metastases formation from metastases was calculated. If not indicated otherwise the further calculation is performed under the assumption, that metastases grow with the same speed and to the same maximal tumour size as the primary tumour.From the computational point of view simply a loop over N generations was generated, where each cycle generates the cell size of the primary tumour, number of disseminated cells in the blood or lymphatic vessels and the number of metastatic cells per Tα. The parameter γ is simply the colonization coefficient and α stands for the fractal dimension of blood vessels infiltrating the tumour. In principle α denotes the fraction of tumour cells which participate in metastasis formation. For example α = 2/3 reflects a superficial angiogenesis of the tumour and dissemination occurs then notably only from the surface.In the following we will demonstrate the features of our straightforward strategy using the widely used Gompertzian growth function given by g(x)=μ⋅x⋅log(b/x). The parameter b is the asymptotic maximal reachable cell or tumour size and μ is the growth constant. Integration gives a tumour size of G(t) = b(1-exp(-μ∙t)). For metastasis formation a rate of the following form was taken by IKS: β(x) = γ·xD can be calculated to TD = -1/μ∙log(1-log(2)/log(b). In our model only the fraction d leads to further tumour growth, this simply translates to TG = TD⋅log(2.d)/log(2) = log(2.d)/λG. To realize the Gompertzian like bending behaviour two different models were used. In the 1st model - the Metabolic Stagnation model (MS-model) - a per generation variation of TG with log(b)/log(b/x) was taken, where x denotes the tumour size before starting a new generation of tumour cells. In the 2nd model, a continuous decreasing of the doubling rate was assumed; the numbers can be calculated by a fit to a given Gompertzian growth. With the constraint a + d + m = 1 this reduction is compensated by a successive increasing of the number of apoptotic cells. This approach lets the generation time constant over the entire live cycle of the tumour and will be referenced to as the model of Generation Dependent Rates (GDR-model). Our approach takes the biology of the cell cycle into account and represents an approximation of the Gompertzian growth. Especially the S-shaped bending in the saturation region of the growth curve is not perfectly reproduced. An over-estimate of the tumour volume of up to 10% depending on the weights during the fit procedure remains for the GDR-model. The MS-model fits marginally better, but possesses the same tendency. Figure st time on CT-images 432 days after primary diagnosis, are available. The values which we adopted from IKS were the cell size b = 7.3⋅1010 cells and μ=0.00286 day-1, which leads to an initial doubling time TD of 9.8 days. As aforementioned in the 1st simulation step of our model of successive generations of tumour cells three concurrent processes are considered: doubling, apoptosis and dissemination respective migration into the next compartment. The branching ratio for cell doubling d to the combined term of apoptosis and migration a + m was set to 2:1. This somewhat arbitrary choice has the advantage of both, smaller simulation time steps TG because of the relation TG = TD⋅log(2.d)/log(2) and the possibility of a variation of the rate for migration in a wide range with respect to the constraint a + d + m = 1. Dissemination from the primary occurs at a calculated ratio of m = 2.49⋅10-6 to get the identical number of metastases as given by IKS for day 432 after diagnosis at a colony size of ~4.6⋅107 cells. In the 2nd simulation step the disseminated and potential metastatic cells will be followed up. The ratio for elimination by the immune system respective successful colonisation was taken to 10-4 at a mean lifetime of the tumour cells in the bloodstream of 1 day. Tumour growth and the different simulation steps of the developing cascade are shown for the MS-model. The tumour growth function is in return underlayed with a fit of the Gompertzian growth with b = 7.321⋅1010 cells and μ=0.00296 day-1. The full blue line shows the number of per generation colonizing cells with the characteristic maximum at the time, when the variation of the Gompertz function has its maximum d/dt[dG/dt] = 0. The green asterisk stands for the cumulative numbers of 1st order colonies.From the above given equation for G(t) the initial characteristic doubling time Trd order metastases is plotted for both models. In the original article  = 0. Since the dissemination step is coupled to mitosis this corresponds to the time-point when maximal metastases formation occurs. The probability for metastases formation is for small maximal cell sizes b in the percentage level and increases to 1 at around b = 109 cells. It is obvious that the MS-model would be able to describe a tumour entity which shows an extreme early but low rate of metastasis formation. In particular, in the next section we will argue that the MS-model is a suitable candidate to describe a subgroup of breast cancer data. The monotonous decreasing data points above 109 cells and the range b ≫ 5⋅107 cells for the GDR-model can be fitted with f(b) = −γ/μ⋅log(1-log(β)/log(b)); a functional relation which is already known in a similar form from the combination of μ with TD. The parameter γ is simply a scaling factor and β depends both on μ or TD and the dissemination characteristics Vm. For the GDR-model the comparison of the three graphs of TD = 10 days but with different rates or dissemination characteristics emphasize again that a common asymptotic value for T1stM will be reached if small tumour sizes are considered. Different to the MS-model, the GDR-model T1stM does not correspond to the maximum of the variation of the Gompertzian growth. If the follow up time is sufficiently long, metastases formation will occur even if the primary does not change its size any longer as it has reached its maximum size. In contrast to the MS-model where metastases start early and with low rate the metastases in the GDR model will colonize relative late but more frequent. This metastatic pattern reflects the fundamental differences between the two models. On one hand we assume a continuous prolongation of the tumour generation time TG. This involves a naturally ageing of the cells with slower and slower running processes but with a regular and balanced sequence in mitosis and apoptosis. On the other hand we have highly active tumour cells; TG remains constant but everything run with a high and lethal error rate. The fraction for doubling and apoptosis are shifted against each other which results in the decreasing tumour growth. Both models find their analogy in the biology of cells. It is known that a misbalance of anabolic and metabolic processes, reduced concentrations of enzymes or a failure in signal transduction is jointly responsible for an ageing of cells. Inadequate repair mechanism or missing stop signals in time during G0-phase of mitosis on the other hand leads to a slightly increasing of unformed and later apoptotic cells.In the upper part of Figure 3 μm3. To investigate whether our results depend crucial on this estimate, calculations were done with different quotients of the volume of a primary and a metastatic cell; the results are summarized in Table 7 cells, if primary and metastatic cells are equal in volume, or 1⋅108 cells, if a metastatic cell has only half of the volume of a primary tumour cell. In Figure 10 cells in the asymptotic region and dissemination proportional to V2/3 as used in Figures 12-7 day-1 for the GDR-model than those used for the hepatocellular carcinoma in the IKS model. The red markers and lines in Figure st diagnosis for pT2 category. The blue lines and symbols represent the calculated probabilities for tumours of 60 mm in diameter, which only corresponds to the mean size of a pT4 tumour and not to the mean age information as given by the Munich Cancer Registry. Nevertheless, for reasons of simplicity in the further context we will speak of pT4-stage tumours.After having adjusted our mathematical model to the IKS data, we wanted to expand its application to the breast cancer data from the Munich Cancer Registry (MCR) ,8. We fo2/3 and V1/3, the lower part shows the results for the GDR-model, again with a V2/3 and V1/3 dependency. For both models a variation of the growth characteristics with an artificially slewed down growth behaviour of the metastatic cells are calculated and included in the plots. For the GDR-model this growth behaviour was achieved by starting the metastatic growth process with the doubling rate of the time step the malignant cell has being disseminated. Taking the same generation time TG and error rate for mitosis as for the primary tumour, a reduced initial doubling rate consequently leads to a reduced maximal colony size of the metastases. The modified growth function for the MS-model was achieved by starting the metastatic growth just with the prolonged TG of the generation the cell was disseminated. The ageing process is inherited. These colonies will reach the same maximal size as the primary but need for this growth significantly more time. Figure 1/3 for the MS-model or even lower ones for the GDR-model are needed for the dissemination step, in order to achieve partly congruence between the clinical breast cancer data and our calculated probabilities.In the upper part of Figure 1/3 should be taken into account to describe the low clinical probabilities for metastasis formation or the growth characteristics of metastatic cells should be different from that of the primordial stem cell initiating the primary tumour. Our models with the artificially reduced growth functions of the cells within metastases apparently come into the range of the clinical data. Due to the reduced maximal colony size in the variation of the GDR-model metastases do not become large enough to be clinically detectable and the probability for the presence of metastases at stage pT2 is around 3%. At pT4 the probability falls below 10% where 21% was given for the MCR data. This indicates that the reduced growth as chosen for the GDR model somewhat underestimate the real growth characteristics. Anyhow it clearly demonstrates that a similar mechanism would be helpful to reproduce the data. More favourable is the situation for the MS-model. Metastases that colonize distant organs at a later stage of malignant progression grow much slower than the primary tumour initially did. They remain hidden for a long time (“dormancy”). Under these assumptions we achieve a fair accordance with the data from the cancer registry, both pT2 and pT4-stage probabilities are reproduced. The complete data set is summarized in Table 11, 1.25⋅1012 cells] of the maximal reachable tumour size.Tumours of pT1 stage are in diameter just 3 times larger than our current clinical detection limit. To detect metastases of nearly equal size as the primary tumour indicates that the metastasis initiating cell must have been disseminated extremely early during tumour progression and even more importantly at a considerable rate of spread. Consequently the numbers of metastases will then increase nearly exponentially. Some mouse models  suggest We have verified that a variation of the single cell size of both, primary and metastatic cells in the same direction do not lead to any noteworthy shift in the probabilities of metastasis formation. This is mainly due to the normalization at pT1-stage. To show that our method is in general insensitive to the exact size of a tumour cell calculations where the quotient of metastatic and primary cell diameter varies by a factor ±2 are also given. Small systematic effects can only be seen for the standard growth behaviour of the metastatic cells. A reduction of the metastatic single cell size to half volume results in a relative 5-10% higher probability for primary metastasis formation at the pT2-stage. This is a direct consequence of the reduced visibility during the normalisation procedure to 1.1% at pT1-stage. On the other hand, doubling of the primary single cell size leads to a smoother bending of the tumour growth curve with a reduced growth rate. The increase in metastasis formation between pT1 and pT2 will therefore also be reduced. Again a 5-10% effect relative to the standard values can be seen.12 cells) needs to reach the pT1 stage is single cell size dependent 49.4 month for cells of 2⋅103 μm3 in volume, respective 54.9 month for 103 μm3 cells. The mean time for the 1st malignant cell to colonize into the stroma of the target organ lay around 23 month for the V-dependency and 28 and 45–53 months for the surface and diameter dependencies, respectively. All time distributions have a full width at half maximum of around 70%. These findings indicate that at least in half of the patients metastasis formation has taken place before the primary tumour became visible. The relative survival after 15 years with an over all metastasis formation rate was calculated to 77.6% for pT1 and 24.1% for pT4 [1/3 dependency for dissemination would best have the ability to explain the data if a reduction of metastases due to radio- or chemotherapy is incorporated.In the following we will focus on those models in which metastases grow like the primary tumour. The time a primary tumour of the considered size (101/3 dependency for the further observed low numbers at pT2 and pT4 stages should be able to cover the whole range of growth and metastasis pattern. Additional and more detailed clinical data are however necessary before definite statements can be made.We proposed a simple model of metastasis formation based on successive series of generations of tumour cells. With relative low computational power our model enables a fast insight into the growth and spreading behaviour of malignant tumours. The modelling itself is independent from the specific growth characteristics of a particular tumour. Here we concentrate on the Gompertzian growth and developed models rooted in the biological behaviour of malignant cells to describe such a growth function. Inside our framework we have demonstrated which mandatory implications can be deduced from the occurrence of metastases at a definite time. Especially the calculations based upon clinical data support the hypothesis that formation of metastases is a continuous and extreme early event during malignant progression. Our results are in good accordance with the analytical solution of Iwata et al. , who calA novel approach to simulate tumour growth and metastasis formation is presented. Within the framework of our model growth and dissemination characteristics of metastatic cells originating from cells in the primary tumour can be modelled. We adopted our model to clinical breast cancer data thus showing its ability to perform systematic analyses relevant for clinical breast cancer research and treatment. In particular, our calculations using these clinical data show that generally metastases formation has already been happened before the primary tumour can be detected with current clinical methods.IKS = The authors Iwata, Kawasaki and Shigesada; MS = Metabolic stagnation; GDR = Generation dependent rates; MCR = Munich Cancer Registry; pT1,pT2,pT3,pT4 = histopathological TNM classification of malignant tumours.The authors declare that they have no competing interests.VH did the writing of the programme for the calculations and wrote the first version of the manuscript. VH and US contributed and participated equally in the design of the general outline of the work. US helped in finalising and editing of the final version of the manuscript. Both authors read and approved the final manuscript.


Therefore, novel treatment options are urgently needed. Hyaluronan (HA) is a polysaccharide present in the matrix of human oesophageal squamous cell carcinoma (ESCC). Importantly, in vitro ESCC cells critically depend on HA synthesis to maintain the proliferative phenotype. The aim of the present study is (1) to study HA-synthase (HAS) expression and regulation in human ESCC, and (2) to translate the mRNA expression was investigated in human ESCC biopsies by semiquantitative real-time RT PCR. Furthermore, human ESCC were xenografted into NMRI nu/nu mice. The effects on tumour progression and morphology of 4-methylumbelliferone (4-MU), an inhibitor of HA-synthesis, and of lentiviral knock down of HA-synthase 3 (HAS3), the main HAS isoform in the human ESCC tissues and the human ESCC cell line used in this study, were determined. Tumour progression was monitored by calliper measurements and by flat-panel detector volume computed tomography (fpVCT). HA content, cellular composition and proliferation (Ki67) were determined histologically.in vitro. During the course of seven weeks, 4-MU inhibited progression of xenograft tumours. Interestingly, remodelling of the tumour into a more differentiated phenotype and inhibition of cell proliferation were observed. Lentiviral knockdown of HAS3 in human ESCC cells prior to xenografting mimicked all effects of 4-MU treatment suggesting that hyaluronan produced by ESCC is accountable for major changes in tumour environment in vivo.mRNA of HAS isoform 3 (HAS3) was upregulated in human ESCC biopsies and HAS3 mRNA was positively correlated to expression of the epidermal growth factor (EGF) receptor. EGF was also proven to be a strong inductor of HAS3 mRNA expression Systemic inhibition of HA-synthesis and knockdown of tumour cell HAS3 cause decreased ESCC progression accompanied by tumour stroma remodelling and may therefore be used in novel approaches to ESCC therapy. Oesophageal cancer is the sixth leading cause of cancer deaths worldwide . The morHyaluronan (HA) is an unbranched high molecular weight polysaccharide that is composed of D-glucuronic acid beta(1-3)-D-N-acetyl-glucosamine beta1-4). HA is produced by three isoforms of the hyaluronan synthase family (HAS1-3), which are located at the plasma membrane and extrude the growing HA polymer into the extracellular space . HA is p, breast HA activates membrane receptors such as the receptor of HA-mediated motility (RHAMM) and CD44 to induce signalling and specific cellular responses. Both CD44 and RHAMM have been implicated in tumour cell biology and tumour progression .An HA-rich matrix is important for a variety of aspects of tumour pathobiology including anchorage-independent growth, migration, angiogenesis, suppression of apoptosis ,16 and mThe HA matrix of oesophageal carcinoma may contain novel targets for therapeutic approaches such as the HAS-isoforms, hyaluronidases and HA-receptors. Furthermore, the role of individual HAS enzymes and the factors that regulate HAS expression in oesophageal cancer have not been defined. In addition, the relative importance of stromal versus tumour cell HAS expression has not been addressed experimentally in any cancer yet, which is due to the fact that HAS2 deficient mice are lethal and HAS1 and HAS3 deficient mice are not available to the scientific community .in vivo. Furthermore changes in tumour morphology and distribution of HA and HA receptors, following either systemic HA inhibition by 4-MU or inhibition of tumour HA production by lentiviral knockdown of HAS3, were examined. This approach may help to define and specify the molecular targets and to explore the therapeutic promises of pharmacologic HAS inhibition in ESCC.Previously it was demonstrated in ESCC cell lines that HA-synthesis mediated by HAS3, and to a lesser extent by HAS2, is required for the malignant cell phenotype characterised by filopodial plasma membrane extensions and high proliferative activity . KnockdoUnless otherwise stated, all reagents were obtained from Sigma-Aldrich, Munich, Germany. Erlotinib was bought from LC Laboratories, Woburn. MA, USA. Cetuximab is a product of Merck Serono, Darmstadt, Germany.2 and 95% humidified air.OSC1 cells were a gift from M. Sarbia  and wereTissue samples from oesophageal squamous cell carcinomas  and normal oesophageal mucosa (n = 13) were collected from patients undergoing radical en bloc oesophagectomy at Düsseldorf University Hospital. The tissues were snap-frozen in liquid nitrogen immediately after resection and stored in liquid nitrogen until use. Written informed consent was obtained from all patients. The collection of the fresh tumour samples was approved by the ethics committee of the Heinrich Heine University Düsseldorf. Tumour stage and grading were classified by routine histopathologic assessment according to the UICC  Classification for Malignant Tumours; the pathologists performing the assessment were unaware of the experimental data.in vitro. The tumours were initiated by the subcutaneous injection of 106 OSC1 cells into both flanks, and the mice were monitored after xenografting for 47 days in the 4-MU group and 65 days in the shHAS3 group, respectively. The mice were treated with 4-MU, which was pelleted into the chow, at a daily dose of 250 mg per mouse. Treatment started two days before xenografting. Biopsies for immunostaining and molecular studies were taken after sacrifice of the animals at the end of the experiment. The animal experiments were approved by the local animal facility and the Landesamt für Natur, Umwelt und Verbraucherschutz, NRW.NMRI nu/nu mice were used for subcutaneous tumour formation experiments after xenografting of OSC1 cells with or without previous lentiviral transduction ®) was injected intravenously, mice were subjected to fpVCT, a nonclinical volume CT prototype , as described previously  method. The primer sequences of the genes of interest are given in Table The PCR reactions were performed according to standard procedures with the SYBR Green PCR Master Mix (Applied Biosystems). Relative expression levels were compared by using real-time PCR with the 2The ESCC cell line, OSC1, was used for xenografting and was maintained as described  in monolt test as appropriate. Data are presented as means ± SEM. Statistical significance was assigned at the level of p < 0.05.Statistical analysis of mRNA levels in biopsy samples was performed by using the nonparametric Mann-Whitney test and the Spearman correlation analysis. All other datasets were analyzed either by ANOVA and the Bonferroni post hoc test or by Student's in vitro experiments and for the xenograft model. In addition, only HAS3 expression was significantly higher in ESCC than in normal mucosal tissue whereas there was no significant increase regarding HAS1 and HAS2 (data not shown). This result was true over all studied samples  as well as for the T = 1  and the T = 2-4  subgroups according to TNM classification (defining tumour size (T), lymph node involvement (N) and existence of metastases (M))  Figure . Further) Figure . Interes) Figure .A xenograft tumour model was established by subcutaneously injecting the human ESCC line OSC1 into the flanks of NMRI nu/nu mice. The mice were given oral doses of the small molecule HAS inhibitor 4-MU starting 2 days before injection for the whole experimental period. During the first 47 days after xenografting calliper measurements showed that treatment with 4-MU strongly inhibited the time course of tumour progression Figure . At the Treatment with 4-MU not only was associated with decreased tumour size but also caused remarkable alterations in tumour morphology. Histopathological examination of tumour specimens from control mice showed that OSC1-derived xenograft tumours were poorly differentiated, with numerous loosely cohesive tumour cells Figure , left. IHAS3 is the major isoform in human ESCC as determined by real time RT-PCR and was correlated to EGFR expression, perhaps pointing to the functional importance of HAS3 in ESCC. Because the systemic application of 4-MU inhibits HA synthesis in both tumour cells and stromal fibroblasts independently of the involved HAS isoforms, the relative contribution and functional significance of HA derived specifically from tumour cell associated HAS3 was addressed. Transduction with shHAS3 lentivirus caused marked knockdown of HAS3 mRNA and protein expression  is overexpressed in 40% to 90% of ESCC tumours and overexpression of EGFR is associated with a poor prognosis ,43. As wOn the other hand, HA has been shown to contribute to the EGFR pathway via HA-CD44 interaction. HA-CD44 complexes colocalize and potentially transactivate the EGF receptor leading to phosphorylation of ERK1 and ERK2 in glioblastoma cell lines  and to iin vivo growth of human oesophageal xenograft tumours. Specifically, it is proposed that ESCC tumour cells overexpress HAS3 in an EGFR dependent manner and that this overexpression supports a dedifferentiated proliferative tumour cell phenotype. Therefore, pharmacologic inhibition of HA synthesis may provide a novel therapeutic target for ESCC.In summary the present data extend the results from cell culture experiments  to in viThe authors declare that they have no competing interests.ST planned and carried out the cell culture and lentiviral experiments, supervised the animal studies and wrote the manuscript. TF carried out and supervised the animal experiments. EP performed the histological staining and analysed them. GD designed primers and performed real time PCR experiments. KJ and CD carried out the animal vCT experiments. FA analysed the vCT experiments and did counselling. KP, WTK, NHS acquired the human oesophageal cancer samples, performed staging and did counselling. RCS provided the RHAMM antibody and participated in the planning of the experiments. BH participated in the design of the study and did counselling regarding growth factors. JWF designed and coordinated the study and drafted the manuscript. All authors read and approved the final manuscript.


Inappropriate prescribing of intravenous (IV) fluid, particularly 0.9% sodium chloride, causes post-operative complications. Fluid prescription is often left to junior medical staff and is frequently poorly managed. One reason for poor intravenous fluid prescribing practices could be inadequate coverage of this topic in the textbooks that are used.We formulated a comprehensive set of topics, related to important common clinical situations involving IV fluid therapy,  to assess the adequacy of textbooks in common use. We assessed 29 medical textbooks widely available to students in the UK, scoring the presence of information provided by each book on each of the topics. The scores indicated how fully the topics were considered: not at all, partly, and adequately. No attempt was made to judge the quality of the information, because there is no consensus on these topics.The maximum score that a book could achieve was 52. Three of the topics we chose were not considered by any of the books. Discounting these topics as “too esoteric”, the maximum possible score became 46. One textbook gained a score of 45, but the general score was poor . In particular, coverage of routine postoperative management was inadequate.Textbooks for undergraduates cover the topic of intravenous therapy badly, which may partly explain the poor knowledge and performance of junior doctors in this important field. Systematic revision of current textbooks might improve knowledge and practice by junior doctors. Careful definition of the remit and content of textbooks should be applied more widely to ensure quality and “fitness for purpose”, and avoid omission of vital knowledge. Some practical aspects of medical education in the UK appear to be deficient. For example, a questionnaire study of 710 consultant surgeons in the UK, on intravenous fluid prescribing showed that only 16% felt that trainee doctors had been adequately trained in prescribing intravenous fluids, and only 30% of them judged that patients after surgery received appropriate water and electrolyte therapy-5. Fluid“Tomorrow’s Doctors”, published by the General Medical Council, sets a Fluid and electrolyte requirements for a standard adultFluid balance, including losses and gains in a healthy adultElectrolyte composition of different body fluidsAre the routes of perioperative fluid loss describedSystemic Inflammatory ResponseIncreased ADH secretionType of surgery and specific effects on fluid balance.Evaporation during a laparotomyNormal physiological changes seen in a post-operative patientHow is blood volume assessed in the routine postoperative patientSigns and symptoms of blood loss in the patient after surgeryHow are perioperative losses assessedSigns of fluid overload in the patient after surgerySigns of inadequate circulating volume in a patient after surgeryDoes the book describe how to assess the adequacy of therapyDoes the book describe intraoperative fluid managementSuitable fluid regiment for 1 day or three days fastingReason and evidence for a particular choice of fluidsFluid resuscitation in a patient with GI lossesFluid resuscitation in a patient with blood lossFluid resuscitation in a patient who is septicContents of:5% GlucoseSalineHartmanns/Sodium LactateGelofusine (different formulations)Human albumin solutionBefore we started our survey, we used an iterative checklist to draw up a formal set of topics that we considered would give sufficient information to allow an adequate clinical assessment and an appropriate IV fluid prescription in a variety of common clinical settings Table . These iWe did not seek ethical approval for the study. With the help of our medical library staff, we compiled lists of undergraduate medical textbooks on surgery, general medicine and critical care, from university libraries and medical publishers in the UK. From these lists we selected 29 textbooks published between 2002 and 2010. We chose all the books that were likely to be used for guidance on fluid balance and IV fluid prescription by medical students in the final years of their course  then surveyed each book separately to find any information on each topic in this working definition of necessary content. The book was searched using chapter headings and index, using the following phrases, separately and in combination: fluid management; perioperative fluid; intraoperative fluid; postoperative fluid; fluid balance; fluid maintenance; maintenance fluids; fluid therapy, intravenous fluids, dehydration, hypovolaemia, losses, abnormal losses, haemorrhage, oedema, fluid overload, sodium chloride, Hartmann’s solution, Sodium lactate, lactated Ringer, balanced salt solution, albumin, colloid, and Gelofusine.quality of the information, because this was considered to be too subjective to be precisely scored: the score related solely to the extent of the coverage. To assess the reliability of this review, an experienced academic anaesthetist (GBD) independently re-scored 20% of textbooks. For the duplicate assessments by the two book assessors, the Spearman coefficient of Rank concordance was 1.0 (P = 0.0167).The amount of information that could be found was categorised either as not found, adequately covered, or good coverage. No attempt was made to judge the http://explore.bl.uk/primo_library/libweb/action/search.do).Because larger books can cover topics more fully, we also considered the number of pages in each book  had provided information on a specific topic sufficiently, then the number of marks attributed to that topic could be 58. The range of marks allocated to each topic ranged from 0 to 21, with a median of 14 , equivalent to 24, (15–36)%. These medians and ranges, excluding the three “unanswered” topics, indicate that the other topics had a symmetrical range of severity. The average score (14.3) of all the topics was poor, and few of the topics were answered adequately by all the books . Books with less than 350 pages generally got very poor marks , although two, with less than 200 pages, came second and fifth best, with marks of 29 and 23 (63 and 50%). The marks given to each book for each question are shown in Additional fileThe topics on the identification of hypovolaemia and the resuscitation of a patient with blood loss were well covered, with 26 marks allocated out of a maximum of 58 marks possible if all the books had provided a full coverage of the topic. In contrast, the topics that were badly covered were body fluid composition, routes of loss, perioperative loss, and suitable regimens for a patient not taking oral intake for 1 or 3 days. There was a weak relationship between the number of pages and the mark that the book was given  were any better or worse than newly published books. In addition, recognising the patients. If coreIn 2008, consensus guidelines were developed to help doctors prescribe IV fluids in a wide range of clinical settings. The British Consensus Guidelines on Intravenous Fluid Therapy for Adult Surgical Patients (GIFTASUP) recommend appropriate IV fluid prescribing in the pre-operative and postoperative period. Recent prospective surveys, using historical controls, suggested that guidelines and instruction on fluid management could improve outcome,18. TeacKnowledge of the basic facts of fluid therapy is not in itself sufficient. Considering his Pyramid model for clinical assessment, Miller argued “it may be reasonable to assume that either action or performance implies achievement of the more basic elements of the triangle”. AlthougIn – service teaching programmes for trainee doctors have been set up to counter the problem of inadequate knowledge. HoweverThe authors declare that they have no competing interests.AGMTP developed the research idea and the study plan, collected and scored the books, and wrote the first draft of the text. S P-B assisted with the data presentation and contributed to the writing of the final text. GBD conceived the research idea, assisted with the book collection, reviewed a sample of the books, collated and analysed the data, and wrote the final text. All authors are responsible for the final text. All authors read and approved the final manuscript.The pre-publication history for this paper can be accessed here:http://www.biomedcentral.com/1472-6920/14/35/prepubMarks given to each book for each question.Click here for file


Raf mutant malignancies, its utility as a suppressor of hyperactive MAPK signaling in the absence of mutated Raf or Ras, is an area of ongoing research. MAPK activation is associated with loss of ERα expression and hormonal resistance in numerous malignancies. Herein, we demonstrate that MEKi induces a feedback response that results in ERα overexpression, phosphorylation and transcriptional activation of ER-regulated genes. Mechanistically, MEKi-mediated ERα overexpression is largely independent of erbB2 and AKT feedback activation, but is ERK-dependent. We subsequently exploit this phenomenon therapeutically by combining the ER-antagonist, fulvestrant with MEKi. This results in synergistic suppression of tumor growth, in vitro and potentiation of single agent activity in vivo in nude mice bearing xenografts. Thus, we demonstrate that exploiting adaptive feedback after MEKi can be used to sensitize ERα-positive tumors to hormonal therapy, and propose that this strategy may have broader clinical utility in ERα-positive ovarian carcinoma.While the clinical benefit of MEK inhibitor (MEKi)-based therapy is well established in  Epithelial ovarian cancer (EOC), the most common type of ovarian cancer, is the fifth leading cause of female cancer mortality in the United States. Of the estimated 21,990 cases that occurred in 2011, more than two-thirds will die from the disease due to innate, or acquired drug resistance Ras or Raf, , which is thought to promote neoplastic transformation from low grade ovarian tumors to invasive type I disease The Mitogen-Activated Protein Kinase (MAPK) signaling pathway is a major regulator of cell proliferation, survival and differentiation. Hyperactivation of this pathway occurs in EOC via gain of function mutations in It is known that signaling networks such as MAPK interact with hormonal mediators, such as estrogen receptor alpha (ERα) in a non-genomic, estrogen (ES)-independent manner in hormonally-dependent malignancies The response rate to anti-estrogen therapies (AET) in clinical trials for patients with recurrent ovarian cancer ranges from 8%–17%, irrespective of ERα status Ras retards cell growth by causing cell cycle arrest and/or apoptosis, and in vivo models have demonstrated varying degrees of response to MEK inhibitors (MEKi) in tumor models Ras-mutant malignancies, such as type I ovarian cancer, constitute a tumor class with unmet clinical need. Several MEKi’s are being developed in multiple cancer trials . Given the interactions between MAPK signaling and ERα in ovarian cancer, we hypothesized that deregulation of MAPK modulates the intrinsic activity of ERα, and contributes to endocrine resistance in EOC. Thus, inhibition of the pathway using a selective MEKi may sensitize defined cohorts of ovarian cancer patients with ERα-positive disease to anti-estrogen therapy.Blocking oncogenic 2. All cell lines were cultured in medium supplemented with 10% fetal bovine serum (FBS), and cells with less than eight passages were used for all experiments. Antibodies used were from Cell Signaling Technologies except ERα . For cell culture experiments, all inhibitors used were formulated in 100% DMSO. The MEKi, PD0325901, was obtained from Pfizer; fulvestrant was purchased from Sigma for cell-based experiments and pharmacy-grade drug was used for animal experiments; the protein Kinase B (AKT) inhibitor, MK-2206 was purchased from Chemietek; the pan-erbB inhibitor lapatinib was obtained from the developmental therapeutics program, NCI, and the Ribosomal S6 Kinase (RSK) inhibitor BI-D1780 was purchased from Enzo Life Sciences.Cells were purchased from American Type Culture Collection (ATCC), or the NCI tumor repository and cultured in RPMI 1640 at 37°C in a humidified incubator with 5% COhttp://pga.mgh.harvard.edu/primerbank/), except for the ESR1 gene (accession NM_000125.3), for which primers were designed according to the sequence 5′–CCTGGGACTGCACTTGCT –3′and reverse 5′-CACAGCCCGAGGTTAGAGG-3′. Target gene expression was normalized to cyclophilin b, and data presented as fold-change relative to vehicle-only control.Total RNA was extracted from cells  and cDNA synthesized  and used for quantitative RT-PCR to determine the expression of genes of interest. Sequences for all primers utilized were obtained from primerbank  without replenishing media or drug. For combination studies, cells were treated with fulvestrant at a fixed dose of 200 nM, dilutions of MEKi, and the combination of both (using a fixed dose of fulvestrant combined with dilutions of MEKi at a range of doses encompassing the IC50). The nature of the drug interaction was evaluated using the Bliss additivity model C = (EA+EB) – (EA×EB). EA and EB are fractional inhibition of growth (relative to vehicle-only control) for drug A (fulvestrant), and drug B (MEKi) at specific concentrations. EC is the expected fractional inhibition that predicts an additive interaction between A and B (combined fulvestrant and MEKi). If the experimentally measured fractional inhibition is greater than EC, the combination is greater than additive (synergistic). If the experimentally measured fractional inhibition is less than Ec, the combination is predicted to be antagonistic. Bliss additivity is the preferred method for analyzing drug interactions when one (or more) components are cytostatic (do not have a dose-response).Doubling times were determined by counting cells at various stages of confluence using a coulter counter, and calculating doubling time (h) according to the formula, t*ln(2)/ln(A/Ao), where A is the cell number at time t; Ao is the initial cell number. The effect of drugs on cell proliferation was determined using the Sulforhodamine B (SRB) assay 118 and ERα167.Cells were treated with the indicated concentrations of drugs for the periods defined, and cell extracts obtained by solubilization in Tris-SDS denaturing lysis buffer. Extracts were resolved on SDS-PAGE gels, transferred to nitrocellulose and probed with relevant antibodies. For immunoprecipitation studies, drug treated SKOV3 cells were lysed in RIPA buffer, and 1 mg protein immunoprecipitated overnight with 4 µg of ERα antibody, followed by 2 hours incubation with 40λ protein A/G plus-agarose beads. Immunoprecipitated complexes were released from beads by boiling in Laemmli sample buffer and resolved on 7.5% acrylamide gels. Proteins immobilized onto nitrocellulose were immunoblotted for total ERα, ERαTo simulate estrogen deprivation conditions, SKOV3 cells were grown in phenol-free RPMI containing 10% charcoal stripped fetal bovine serum and treated with 1 µM MEKi for 24 hours. Adherent and nonadherent cells were harvested, fixed in 70% ethanol, permeabilized with 0.1% Triton X-100 and stained with 10 µg/ml propidium iodide (Sigma) in a PBS solution containing 1 µg/ml RNase A. Cell cycle acquisition and analysis was performed using the Becton Dickinson FACScan and Flowjo software, gating to remove debris and cellular aggregates.All mice used in this study were maintained in the Einstein Animal Facility. This Institutional Animal Welfare Assurance (A3312-01) is fully accredited by the Association for the Assessment and Accreditation of Laboratory Animal Care (AAALAC), February 22, 1983. All animals received humane care as per the Animal Welfare Act and the NIH “Guide for the Care and Use of Laboratory Animals”. Experimental protocols were reviewed and approved by the Einstein Institutional Animal Care and Use Committee, (Protocol No. 20100612), and all studies were performed according to the methods approved in this protocol.6 cells per animal. MEKi was formulated as described previously 3 (n = 5 per treatment group) were treated with either MEKi or fulvestrant alone, or the combination, whereby drugs were given concurrently (MEKi daily and fulvestrant on days 1 and 4). Control mice received vehicle alone. Mice were weighed twice weekly, and tumor dimensions also measured twice per week, and used to calculate tumor volume that was expressed relative to initial tumor volume. Mice were orally gavaged with saline to relieve transient hyperkeratosis and diarrhea that occurred in the combination-treated group.The human ovarian cancer xenograft model, SKOV3 was established in nude mice as described previously In a panel ovarian cancer cell lines, SKOV3 was the only ERα expressing cell line among the five tested . TreatmeTo determine the dependence of cellular proliferation on estrogen, we cultured the ovarian cell lines in phenol red-free, charcoal-stripped media; and quantified this effect on cell cycle distribution and cell proliferation . Estroge50 of the cell lines to MEKi are summarized in B-Raf mutant and are hypersensitive to MEKi, consistent with previously published studies Since MAPK is known to regulate nongenomic ERα signaling T202/Y204) and Ras-mediated feedback (apparent as increased phosphorylation of MEKS271/221) was observed in all cell lines, even those with high intrinsic MAPK activity , we immuno-precipitated total ERα from MEKi-treated SKOV3 cells. ERαS118 is a known phosphorylation site for activation by ES, which subsequently promotes nuclear localization of ERα, and recruitment of coactivators and promotors for transactivation of target genes. ERαS118 can also be activated in a ligand (ES)-independent manner by MAPK, GSK-3, IKKα, CDK7, and mTOR/p70S6K S118 was observed relative to both total ERα and IgG  by 24 h after MEKi-treatment, coincided with the onset of ERα overexpression, suggesting a relationship between proliferative arrest and altered expression and activity of ERα.We next determined the effect of ERα receptor inhibition (using the antagonist fulvestrant) on erbB feedback by MEKi . Doses oSKOV3 cells were treated with the pan-erbB inhibitor lapatinib to further explore the potential role of erbB/EGFR in mediating changes in ERα after MEKi treatment. Since lapatinib acts upstream of MAPK and PI3K, and has the potential to suppress both pathways, it may also increase ERα expression in the same manner as MEKi. As shown in Similar to ER, activated ERK can participate in cytoplasmic, non-genomic signaling via activation of RSK. Since RSK has been shown to directly regulate ER via phosphorylation on S167, we probed the involvement of the cytoplasmic ERK-RSK pathway in mediating ERα overexpression in response to MEKi, using the specific inhibitor RSK inhibitor, BI-D1780 (RSKi). RSKi specificity is evident from the suppression of its downstream effectors, AKT and GSK3, as described To exploit the phenomena of ERα overexpression, we evaluated the efficacy of MEKi in combination with the ER receptor antagonist, fulvestrant, in the ERα-positive cancer cell lines (SKOV3 and Ishikawa). A2780, an ERα-negative ovarian carcinoma cell line, was used as a negative control. Fulvestrant alone mildly increased the proliferation of SKOV3 cells; however, the combination of fulvestrant and MEKi negated this, and potentiated sensitivity to MEKi , Fig. S33. Similar to what we observed in cell culture, fulvestrant alone increased tumor growth, while MEKi alone had weak activity; however the combination of both potently suppressed tumor growth. This effect was sustained for three weeks post dosing, when animals in other groups had to be euthanized due to tumor burden. The mean tumor volume of the combination treatment was statistically significantly smaller than either single agent alone by 18 days post-treatment . Moreover, the combination regimen was well tolerated. Noted toxicities including hyperkeratosis and diarrhea were resolved with topical antibiotic application and oral hydration, respectively. Thus, these data strongly support a role for combined MEKi and fulvestrant therapy as a promising regimen with impressive anti-tumor efficacy in an ERα-positive EOC tumor model.The combination of fulvestrant and MEKi was evaluated in nude mice bearing SKOV3 xenografts . The meain vitro, and has promising anti-tumor efficacy in vivo, in ERα positive ovarian cancer. Furthermore, we demonstrate that MEKi-mediated overexpression of ERα is due to ERK suppression. The precise mechanism by which this occurs is likely to be multifactorial; however it does not appear to be mediated by feedback signaling that activates RTK, and AKT. Thus, the ability of MEKi  to increase the expression of ERα can be therapeutically exploited to render cancer cells sensitive to endocrine therapy, irrespective of their response to MEKi alone.In this proof of concept study, we have shown that the combination of MEKi and fulvestrant has synergistic activity Although fulvestrant is largely perceived to be an ER-antagonist, it has recently emerged that at high doses it can act as a partial agonist in some cell types, and promotes shuttling of the ER to the plasma membrane, resulting in complex formation with the IGF-1-receptor (IGF-1-R) Raf mutant tumors.There is increasing appreciation for non-genomic signaling as a major driver of tumorigenesis, as discussed above in the case of ER-signaling. This model also applies to MAPK signaling as recently illustrated in the clinical evaluation of the B-Raf inhibitor, PLX4032, whereby clinical responses were associated with 80% dephosphorylation of cytoplasmic, but not nuclear ERK Ras and Raf mutations , suppressed the growth of ERα-positive SKOV3 cells by two-fold, but had minimal effect on ERα -negative A2780 cells. Titration of estradiol (E2) back into growth media reversed the phenomenon and was dose-independent. PF = Phenol free media containing charcoal-absorbed serum. RPMI = Regular media containing 10% fetal bovine serum.(PPT)Click here for additional data file.Figure S2Over-expression of ERα by MEKi in the ERα positive endometrial carcinoma cell line, Ishikawa. Cells were treated for 24 hours with MEKi.(PPTX)Click here for additional data file.Figure S3Dose-response curves generated from SRB-based proliferation assays  for single-agent MEKi, fulvestrant and the combination of both, demonstrating potentiation (greater than additive/synergistic cytotoxicity). Cells were treated according to the experimental details described in (PPTX)Click here for additional data file.Figure S4MEKi-mediated effects on ERα are RSK-independent in SKOV3 cells.(PPTX)Click here for additional data file.Figure S5The Effect of fulvestrant and MEKi  on ES-regulated gene expression in SKOV3 cells after treatment for 24 h. Refer to materials and methods for experimental details.(PPTX)Click here for additional data file.Table S1Sensitivity of Human Ovarian Carcinoma Cell Lines to MEKi.(PPT)Click here for additional data file.


Brain-computer interface-based communication plays an important role in brain-computer interface (BCI) applications; electronic mail is one of the most common communication tools. In this study, we propose a hybrid BCI-based mail client that implements electronic mail communication by means of real-time classification of multimodal features extracted from scalp electroencephalography (EEG). With this BCI mail client, users can receive, read, write, and attach files to their mail. Using a BCI mouse that utilizes hybrid brain signals, that is, motor imagery and P300 potential, the user can select and activate the function keys and links on the mail client graphical user interface (GUI). An adaptive P300 speller is employed for text input. The system has been tested with 6 subjects, and the experimental results validate the efficacy of the proposed method. Millions of patients suffer from motor disabilities, including amyotrophic lateral sclerosis (ALS), brainstem stroke, cerebral palys, or spinal cord injuries, that are referred, as locked-in syndrome (LIS). The maintenance of communication ability is an essential factor for improving the quality of life for this group of people, but these patients are often severely or totally paralyzed and can produce few signals for communicating with other people. Brain-computer interfaces (BCIs) directly translate brain activities recorded on the scalp into control commands by bypassing the normal neuromuscular pathways, thus enabling users with motor disabilities to convey their thoughts and intentions to the external world , 2. SignAn important application for BCIs is communication , and eleHybrid BCIs, which use more than one brain signal or one brain signal and a different type of input to detect users' intentions, have attracted much attention in recent years . StudiesIn this paper, we propose a BCI mail client as a novel application of the hybrid BCI. The control of this mail client is based on a BCI mouse consisting of two-dimensional cursor movement, target selection, and an adaptive P300 speller. Users are able to receive, read, write, reply to, and forward mails; they can attach files by moving the BCI mouse to the buttons or links on the mail client GUI and activating them. In particular, the horizontal movement of the mouse is controlled by mu/beta rhythm, the vertical movement of the mouse is controlled by P300 potential, and the target selection or click is controlled by a combination of the detection of P300 waves presented on one of the stop buttons and/or an idle state of mu/beta rhythm when the mouse is on a target . Furthermore, with an adaptive P300 speller, users can input the text content of a piece of mail.This paper is organized as follows. The system paradigm, mouse control methodology and adaptive P300 detection are discussed in Scalp EEG signals are recorded with a SynAmps2 amplifier using the 32-channel Quik-Cap  at a sampling rate of 250 Hz and band-pass filtered between 0.05 and 40 Hz. Two channels, “HEOG” and “VEOG,” representing eye movements are excluded for signal processing. The remaining 30 channels are used without further channel selection and are shown in The graphical user interface (GUI) is presented in The user controls the vertical movement of the mouse; that is, he/she moves the mouse up or down, by paying attention to one of the three “UP”/“DOWN” buttons. Meanwhile, the horizontal movement of the mouse is controlled by the user's motor imagery. Specifically, the user moves the mouse toward the right by imaging the movement of his/her right hand and vice versa for the left . Once thReceiving: users move the mouse to the “Receive” button and select it. New incoming mails are then received  is indicated by a translucent box that is placed on top of the target and becomes visible only when the mouse reaches it see . When a The vertical and horizontal movements of the mouse are controlled by P300 and motor imagery, respectively. We briefly describe this method here, and additional details can be found in .c(k) of the kth update is determined by P300 detection. That is, if P300 potential is detected at one of the three “UP” buttons, c(k) is set to 1 and the mouse moves upward. If P300 potential is detected at one of the three “DOWN” buttons, c(k) is set to −1, and the mouse moves down. If P300 potential is detected at one of the two “STOP” buttons, c(k) is set to 0, and the mouse has no vertical movement. If no P300 potential is detected at any button, c(k) keeps its value, and the direction of vertical movement of the mouse does not change. For details of the P300 detection algorithm, readers can refer to  with a step 0.05. Detection accuracy and information transfer rate (ITR) [θ0 in the set {0,0.05,0.10,…, 1.0}. The formulation of ITR is as follows:N is the number of characters (50 here), P denotes the detection accuracy, and M represents the number of decisions that are made per minute. Then, the value of θ0, which provides the highest ITR with an accuracy above 90% of the highest accuracy, is chosen as the θ0 that is used in the online spelling. Accordingly, θ0 is set between 0.2 and 0.3 in this paper.According to the offline analysis, we have found that if te (ITR)  are calcSix subjects, aged from 23 to 30, participated in the online experiment. Two datasets were collected from each subject earlier to set the parameters of the three models as below. For Dataset I, each subject attended a P300 calibration session of 20 trials with the GUI of the P300 speller see . SpecifiThe subject first activated the mail client from the predefined home page see  using thAfter the mail client was opened, the subject moved the mouse toward the “Receive” button and selected it. Once the receiving procedure finished, the mail client returned to the “Inbox.” The subject moved the mouse and opened the latest piece of mail.The subject replied to the writer by moving the mouse to and selecting the “Reply” button after reading the mail.The subject selected the “Add attachment” button to attach a file.In the file list view shown in The subject selected the “Content” box for text input. The system switched to the P300 speller interface see .The subject input mail content, for example, a simple sentence, with the P300 speller.After inputting text, the subject selected the “Back” button of the GUI of the speller to return to the previous interface. The subject moved the mouse to and selected the “Send” button to send this mail.In the online experiment, each of the six subjects was requested to receive mails and reply to the latest mail with an attachment, using the hybrid BCI-mail client to complete all these tasks. Specifically, the task for each subject contained the following 9 sequential operations.Once these nine operations were completed, the mail client returned to the main menu for the next trial. The entire procedure is illustrated in To acquire a more complete evaluation of this BCI mail client, subjective workload and satisfaction were assessed with NASA Task Load Index (NASA-TLX) questionnaires  followinIn the online experiment, the task including multiple mouse operations and text input was quite complicated. Using this comprehensive task, we assessed the BCI mail client. Our results show that most of the functions for mail communication were available in the BCI mail client. Most of the subjects could finish a trial within 450 seconds with only a small number of mistakes, and all of the subjects were able to complete this complex task within an acceptable period of time. The workload evaluation further showed that this BCI mail client was acceptable to the subjects.For comparison, all of the subjects performed the identical task using their hands as usual. The average time across all of the subjects was 57 seconds for a trial. It took these subjects a relatively long time to complete the trial using our hybrid BCI mail client for three reasons. First, extra selection operations were required to correct the selection of an unintended target. Second, text inputting was time consuming. Third, switching between mouse operation mode and text-spelling mode, which was also performed through target selection, costed additional time.To confirm that both the P300 and motor imagery were functioning properly in our system, we further analyzed these EEG features as we have in our previous studies –17. By aax and bx in model (θ in our P300 detection algorithm, as in [Note that simultaneously executing the dual tasks of the P300 and motor imagery may deteriorate the performance of P300 or motor imagery for many subjects because both tasks require attention. The solution to this problem was twofold in our study. First, we set the parameters in model  as in Sem, as in . The priAlthough our experimental results show that this BCI mail client is capable of providing basic email communication, our system needs to be improved and extended in the future. First, the mail client itself can be extended to include several other functions, such as accessibility to a contact list and the outbox. Second, the algorithms for detecting P300 potential and motor imageries can be further optimized to reduce the execution time for each task. Third, in addition to the P300 potential and motor imagery, other modalities, such as SSVEP, may be incorporated into our system for more functions and better performance. Finally, it will be of great interest to verify whether this system works for paralyzed subjects.This study presents a hybrid BCI-based mail client as a real-world application of BCIs. Common functions of a mail client, including receiving, reading, writing mails, and attaching files, are implemented in this system. The mail client is based on a hybrid BCI mouse. The BCI mouse control, including 2D movement control and target selection, is implemented using the P300 potential and motor imagery-related mu/beta rhythm. The user operates the mail client using the BCI mouse to select function keys. Furthermore, an adaptive P300 speller is incorporated for text input. Experimental results show that users have access to basic mail communication through this BCI mail client.


The aim of this study was to observe the effects of Endostar (recombinant human endostatin) and radiotherapy, singly or in combination, on blood flow in mouse tumour tissue using ultrasound imaging. The ultrasound contrast agent, SonoVue, was used for the contrast-enhanced ultrasound examinations. SonoLiver software was used to analyse dynamic vascular patterns (DVPs) in the contrast process. Blood perfusion data were collected and statistical analysis was performed for data processing. Results were presented as DVP curves and quantitative parameters. Quantitative parameters showed statistically significant (P<0.05) differences in peak strength, rise time, time to peak and mean transit time among the various treatment groups. Changes in tumour blood perfusion were quantified by the assessment of contrast-enhanced ultrasound parameters. The results indirectly reflected the degree of change in angiogenesis in the tumour following experimental intervention. Ultrasound contrast imaging effectively showed the extent of the changes in vascularity and flow state. Therefore, contrast-enhanced ultrasound is suitable for use as an indicator of blood flow changes in an experimental model. A previous study demonstrated that Endostar (recombinant human endostatin) improves the efficacy of radiotherapy in cell and animal experiments . EndostaIn the present study, the method of visualisation was contrast-enhanced ultrasonography. Intravenous injections of SonoVue, a second-generation contrast agent comprising microbubbles of sulfur hexafluoride, are widely used for abdominal and superficial organ tumour imaging . The advThe mechanical index (MI) of the ultrasound contrast agent used in the present study is <0.15, which is lower than that of microbubbles. Therefore, the energy of the ultrasound waves when reflected not only achieves continuous harmonic imaging but also reduces the disturbance of harmonics from the surrounding normal tissue . PerfusiIn total, 192 specific pathogen-free female C57BL/6 mice weighing 17–20 g were used. Four of the mice had Lewis lung cancer. The diameter of the lump in the left forelimb armpit was ~1.5 cm. The mice were reared in the Experimental Animal Center of Renmin Hospital of Wuhan University . The study was carried out in strict accordance with the recommendations of the Guide for the Care and Use of Laboratory Animals of the National Institutes of Health (8th edition). The animal use protocol was reviewed and approved by the Institutional Animal Care and Use Committee of Wuhan University.3. The mice were randomly divided into four groups as follows: Blank control (control), Endostar (ES), radiotherapy (RT) and Endostar combined with radiotherapy (ES + RT). For the control group, each mouse was administered a subcutaneous injection of 0.2 ml saline for 14 days. For the ES group, each mouse was administered a subcutaneous injection of 0.2 ml Endostar  for 14 days. Each mouse in the RT group was subjected to 6 MeV electron irradiation with a radiation dose of 2 Gy/day for five consecutive days  for a total dose of 10 Gy. In the ES + RT group, each mouse was administered a subcutaneous injection of 0.2 ml Endostar for 14 days and concomitantly received radiotherapy from day 1 to day 5 of the 14 days.Lewis tumour-bearing mice were sacrificed by cervical dislocation on a sterile bench. Mouse tumour homogenate was stripped and cut into pieces. The living cell suspension was used for subcutaneous inoculation of the tumour. The C57BL/6 mice were subcutaneously inoculated to provide a tumour volume of 80 mmContrast video was stored in DICOM format and SonoLiver CAP software version 1.0  was used for quantitative analysis. Three regions of interest (ROI) were painted in the contrast images. Boundary, lesion and reference ROIs were coloured blue, green and yellow, respectively. The areas of depth of the lesion and reference ROIs were equal. Enhanced level differences were shown by the dynamic vascular pattern (DVP) curves and quantitative parameters. The DVP curves reflected the change process of enhancement level difference with time between the tumour and the surrounding normal tissue.SPSS version 17.0 statistics software  was used to analyse the data. Measurement data are expressed as mean ± SD. Single-factor analysis of variance was selected as the statistical method. P<0.05 was considered to indicate a statistically significant difference.Two-dimensional ultrasonic observations of the internal mouse tumour region showed hypoechoic and heterogeneous changes. A clear boundary interval was observed in the normal tissue around the tumour . Tumour SonoLiver quantitative analysis software was used to reconstruct a dynamic vascular model based on the parameters of the level of difference between the tumour and the surrounding normal tissue. Each point on the DVP curve reflects the change in the level of difference with time of the enhancement between the tumour and the surrounding normal tissue. DVP curves have an automatic correction function, as they employ motion compensation to reduce or eliminate the artefacts caused by the movement of the probe.Based on the relationship between the opening of the curve and trending of the DVP curve and the X axis, the DVP curve of the focus area was divided into three types: Regression, not subsidised and negative, which accounted for 63.41, 36.59 and 0%, respectively .Quantitative parameters differed among the groups for peak strength, rise time, the time to peak and the mean transit time of perfusion. The differences of peak strength, rise time, time to peak and the mean transit time of perfusion in the ES+RT group and control group were statistically significant P<0.05; .Since the late 20th century, worldwide studies have achieved effective, quantitative blood flow imaging of experimental canine myocardium through the application of ultrasound with the analysis of parameters from microbubble refilling curves . The preContrast-enhanced ultrasound showed that all mice exhibited malignant tumour-specific ultrasonographic filling, which manifests as mixed masses . The mixThe present study used ultrasound contrast imaging to determine DVP parameters. The greyscale changes of contrast-enhanced ultrasound were transformed into colour changes and displayed in a quantitative curve form. The DVP curve provided accurate results of quantitative analysis; therefore, the results were more objective. The enhancement pattern was associated with the distribution of the microvasculature of the tumour. As the microvessel density differed among the groups, enhancement was observed at different times.Ultrasound contrast agents are a type of blood pool contrast agent that enable the observation of the microcirculation . The resThe vascular characteristics of malignant tumours are unique . IncreasFollowing the administration of antiangiogenic drugs, changes in vascular morphology and improved perfusion are the key points of observation. In early animal experiments, it was observed that the tumour inhibition rate in mice treated with Endostar and radiotherapy was significantly higher compared with that in the single-factor treatment groups. Moreover, the inhibitory effect on angiogenesis was the most pronounced –19. HoweIn the present study, the DVP curves of the treatment groups varied according to different morphological changes. According to existing literature , this rein vivo. This effective method may provide more quantitative perfusion information to aid treatment selection.Analysis of the average tumour microvessel density and microvessel count are alternative methods for evaluating tumour neovascularisation. However, these methods do not accurately reflect the efficacy of antiangiogenic therapy. Ultrasound contrast imaging accurately evaluates blood flow velocity, blood volume and blood flow parameters by mathematical models. A comparative analysis of the parameters indirectly reflects the blood flow and perfusion changes in tumours The present study aimed to explore the effects of an antiangiogenic therapy on tumour tissue perfusion using a low MI harmonic grey-scale contrast-enhanced method. The study produced clear images. The results enable the quantitative study of perfusion in tumour vessels and generally reflect the overall changes to the tumour during the treatment process. The study also describes an imaging method that may be used to provide information about angiogenesis and the therapeutic effects of antiangiogenic drugs .Further comparison and analysis of the results with those from transmission electron microscopy and confocal microscopy are warranted, which are likely to improve understanding of the treatment effect following treatment with radiotherapy combined with antiangiogenic drugs.


In the Funding section, the NIH grant number contained an error. The correct grant number is: R01GM081388.


An objective method for determining the location of the cancer with respect to peritoneal reflection would be helpful to decide the treatment modality for rectal cancer. This study was designed to evaluate the accuracy and usefulness of rectal MRI to determine spatial relations between the peritoneal reflection and rectal cancer and to compare these with operative findings.Patients that underwent a rectal cancer operation after a rectal MRI check between November 2008 and June 2010 were considered for the study. The patients that received preoperative concurrent chemoradiation or trans-anal local excision were excluded.Fifty-four patients constituted the study cohort. By comparing surgical and radiologic findings, the accuracy for predicting tumour location in relation to the peritoneal reflection by rectal MRI in all patients was 90.7%. In terms of tumour location in relation to peritoneal reflection, the accuracy of rectal MRI was 93.5% in patients with a tumour located above the peritoneal reflection, 90.0% in patients with a tumour located on the peritoneal reflection, and 84.6% in patients with a tumour located below the peritoneal reflection (p=0.061). When the cohort was subdivided by gender, body mass index (BMI), operative findings, or tumour size, no significant difference was observed among subgroups.Rectal MRI could be a useful tool for evaluating the relation between rectal cancer and peritoneal reflection especially when tumour size is less than 8cm. Rectal MRI can provide information regarding the location of rectal cancer in relation to the peritoneal reflection for treatment planning purposes. Thus, neoadjuvant therapy could be determined based on preoperative clinical staging status, but it has not been determined which parts of rectal tumours should be included in such as staging system. Some authors have suggested that considerations of height from the anal verge might have beneficial on the radiotherapy of rectal tumors.et al. concluded that tumour location in relation to the peritoneal reflection is a prognostic factor in rectal cancer.The peritoneal reflection is a landmark used for evaluating the rectum anteriorly, and divides the rectum into two parts, that is, the intraperitoneal and extraperitoneal regions, which are referred to considerations of the venous and lymphatic drainage systems of the rectum.Reported distances from the anal verge to the peritoneal reflection are highly variable.Many reports have been issued on the role of magnetic resonance imaging (MRI) in rectal cancer in terms of determining circumferential margins or perirectal nodal statuses.Of the patients that underwent surgery for rectal cancer after a preoperative work-up  at the Colorectal Cancer Center, Konkuk University Medical Center between November 2008 and June 2010, 54 patients that did not receive preoperative concurrent chemoradiation or trans-anal local excision were included in the present study.Rectal MRI images were reviewed by radiologists , on axial, sagittal, and coronal scans of T2-weighted images without clinical information. The peritoneal reflection appears as a low-signal-intensity linear structure that extends over the surface of the bladder and can be traced posteriorly to its point of attachment onto the rectumOperative findings were recorded by a colorectal surgeon (DYH), who performed all surgeries. Intraoperative tumour levels were described by the surgeon as above, on, or below the peritoneal reflection, and as anterior, posterior, lateral, or circumferential. Tumour sizes were determined pathologically and tumours were staged according to the TNM staging system. Distances from the anal verge to lower tumour borders were determined by digital rectal examination and by sigmoidoscopy.2), the normal BMI group (≥20 and <25 kg/m2), and the high BMI group (≥25 kg/m2).Body mass index (BMI) was calculated using weight (kg) divided by height (m) squared, and was divided into three groups; the low BMI group ’ version 14.0 for Windows . Pearson’s chi-square test was used to compare locational accuracies between subgroups, and The 54 study subjects  had a mean age of 62.2 years. All were diagnosed with adenocarcinoma and low anterior resection was performed in 49 (90.7%) and abdominoperineal resection in 5 (9.3%). TNM tumour stage was 0 in 2 patients (3.7%), I in 11 patients (20.4%), II in 17 patients (31.5%), III in 22 patients (40.7%), and IV in 2 patients (3.7%). Mean tumour size was 4.8 cm. Patients’ characteristics are summarized in p=0.092); for BMI, accuracies were 88.0%, 91.6 %, and 86.3% in the low, normal, and high BMI subgroups, respectively (p=0.528).The accuracy of predicting tumour location relative to the peritoneal reflection by rectal MRI using surgical findings as the standard in all 54 patients was 90.7% . No signp=0.061). When tumours were classified by 2 cm increments in size, accuracies were 88.9% for a tumour size of 0–1.9 cm, 91.7% for 2.0–3.9cm, 93.3% for 4.0–5.9 cm, 100% for 6.0–7.9 cm, and 57.1% for 8.0–10.0 cm (p=0.394), indicating that accuracy increased with tumour size until tumours exceeded 8 cm.The accuracy of rectal MRI was 93.5% in patients with a tumour located above the peritoneal reflection, 90.0% in patients with a tumour located on the peritoneal reflection, and 84.6% in patients with tumour located below the peritoneal reflection , the overall accuracy of rectal MRI was 44.4%. No significant difference was observed between gender, BMI, operative findings, and tumour size subgroups. Overall, tumour directions were predicted less accurately than tumour locations .When considering treatment options for rectal cancer, preoperative evaluations are important, because decisions regarding surgery and preoperative concurrent chemoradiotherapy are dependent on tumour location, mesorectal fascia involvement, and nodal status.For descriptive purposes, the rectum is divided into three parts, that is, the upper, mid, and lower thirds. The upper third is covered by peritoneum anteriorly and laterally, whereas the middle third is covered only anteriorly, and the lower third is devoid of peritoneum.For this reason, most articles on rectal cancer define the upper rectum as 10 to 15cm from the anal verge, the mid third as 5 to 10 cm, and the lower third as < 5cm, although one author defined the upper third as 12 to 16cm from the anal verge.et al. used trans-endorectal ultrasound (TRUS) to evaluate tumour locations with respect to the peritoneal reflection.Accordingly, we considered that the peritoneal reflection might be of use as a landmark to determine the location of the rectal subdivision for rectal cancer management. Some authors have evaluated the use of the peritoneal reflection as an anatomic landmark in rectal cancer patients. Gerdes On rectal MR images, the peritoneal reflection appears as low-signal intensity linear structure at the junction between the rectum and the posterior aspect of the bladder in males or the vagina in females . In the In the present study, the accuracy of determining tumour direction was not high as 44.4%, probably because natural rectal folds make the interpretation of direction difficult, although near the peritoneal reflection, the accuracy of tumour direction determination was rather high. However, as tumour size increased, it became more difficult to determine tumour direction. Nevertheless, the peritoneal reflection could be used to determine directions accurately for small size tumours less than 4 cm.et al. suggested that treatment outcomes for rectal cancer located 10 to 15cm above the anal verge are similar to those of sigmoid colon cancer.5In a Dutch study, it was suggested that upper third rectal cancer be treated like colon cancerIn conclusions, we believe that subdivision of the rectum by rectal MRI based on the location of the peritoneal reflection is more objective and anatomical than previously described methods, and that the more accurate information obtained regarding anatomic relations between rectal tumours and the peritoneal reflection aids treatment planning.


This study was also supported by a grant from the Perm Territory Government, Russian Federation . The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript." A funding organization was incorrectly omitted from the Funding Statement. The Funding Statement should read: "1/2012; Wezimann711458, Grant of The Ministry of Education and Science of Perm Krai, Russian Federation entitled “International Research Groups of Scientists (IRG)” URL:


Enhanced Recovery (ER) after Surgery (or Fast Track) is a bundle of ‘best evidence based practices’ delivered by a multi-professional health care team, with the intention of helping patients recover faster after surgery . ProfessThe National Programme has evolved into the Enhanced Recovery Partnership (ERP), and the most recent guide published by the ERP includes evidence of widespread adoption of ER in the NHS in England and achievement of stated goals i.e. reduced length of hospital stay after surgery resulting in more operations being performed despite fewer bed days, no increase in readmissions and high levels of patient satisfaction . PeriopeThe ERP thought it was timely to produce a consensus statement from the National Clinical Leads and Specialist Advisors within the specific context of Enhanced Recovery and, for the purpose of widespread dissemination, the general principles and key recommendations outlined in the latest guide are reiterated in this article . Of noteFor further details see latest ERP guide .· Maintain good pre-operative hydration.· Give carbohydrate drinks.· Avoid bowel preparation.· Use fluid management technologies to deliver individualised goal directed fluid therapy.· Avoid crystalloid excess . ‘Maintenance’ fluid, if utilised, should be limited to less than 2 ml/kg/hr including any drug infusions. The use of isotonic balanced electrolyte solution (e.g. Hartmann’s) will minimise hyperchloraemic acidosis.· Avoid post-operative i.v. fluids when it is possible.· Always ask the question; ‘what are we giving fluids for?:Maintenance fluid?Push early drinking and eating;Replacement fluid?Consider oral before i.v. and consider ‘prescribing’ oral fluidsResuscitation fluids?Use Goal Directed Fluid TherapyThe Enhanced Recovery Partnership recommends the development of local guidelines and algorithms for fluid management and regular audit of compliance, in line with national guidelines, NICE recommendations and the Innovation, Health and Wealth Review (2011)[ew (2011),8.· Patients core temperature is normal (circa 37°C).· No evidence of hypovolaemia, tissue hypoperfusion or hypoxia.· No evidence of hypervolaemia or excess fluid .· Hb ≫ 7 g/dl.· No clinically significant coagulopathy.· Minimal use of vasopressors.Predictors of poor outcome include: greater age, higher ASA status, high blood loss, longer than expected surgery, evidence of hypovolaemia or hypoperfusion , greater use of vasopressors, high volumes of i.v. fluids , positive fluid balance (≫ 2 litres positive on day of surgery) -18.In an individual patient, failure to achieve these aims should prompt a review of the need for ongoing care in a higher care environment . If audit of a group of patients shows that these aims were not achieved, this suggests that the delivery of care should be reviewed.The Enhanced Recovery Partnership recommends the use of intra-operative fluid management technologies to enhance treatment with the aim of avoiding both hypovolaemia and fluid excess. This should be decided on a case-by-case basis adhering to local guidelines in the context of NICE recommendations, national guidelines and the Innovation, Health and Wealth Review[th Review,8.Indicators of central hypovolaemia include:· Blood loss or fluid loss· Tachycardia· Hypotension· Cool peripheries· Low CVP· Low cardiac output· Reduced stroke volume· Pulse pressure variation (during IPPV)· Pre-load responsiveness· Low central venous O2 saturation· Raised blood lactateCentral hypovolaemia should respond to volume therapy (i.e. a fluid bolus) -18.The Enhanced Recovery Partnership recommends that all Anaesthetists caring for patients undergoing intermediate or major surgery should have cardiac output measuring technologies immediately available and be trained to use them.The use of intra-operative fluid management technologies are recommended from the outset in the following types of cases:· Major surgery with a 30 day mortality rate of ≫ 1%.· Major surgery with and anticipated blood loss of greater than 500 ml.· Major intra-abdominal surgery.· Intermediate surgery  in high risk patients .· Unexpected blood loss and/or fluid loss requiring ≫ 2 litres of fluid replacement.· Patients with ongoing evidence of hypovolaemia and or tissue hypoperfusion (e.g. persistent lactic acidosis).Perceived lack of resources is not a viable excuse. NICE have concluded that we can’t afford NOT to use intra-operative fluid management technologies where indicated . Practit“…The case for adopting the CardioQ-ODM in the NHS,…is supported by the evidence…The CardioQ-ODM should be considered for use in patients undergoing major or high-risk surgery or other surgical patients in whom a clinician would consider using invasive cardiovascular monitoring. This will include patients undergoing major or high-risk surgery or high-risk patients undergoing intermediate-risk surgery.”[surgery.”“In patients undergoing some forms of orthopaedic and abdominal surgery, intraoperative treatment with intravenous fluid to achieve an optimal value of stroke volume should be used where possible as this may reduce postoperative complication rates and duration of hospital stay.”[al stay.”“Individualised goal-directed fluid therapy…When intravenous fluid is given, the benefits of maintaining circulatory filling and organ perfusion must be weighed against the risk of excess fluid accumulation in the lungs causing hypoxia, and, in the gut, causing nausea and delayed return of gut motility (ileus).When there is not enough fluid in the bloodstream, the stroke volume falls – that is, there is a fall in the volume of blood ejected by the heart each heartbeat….In a typical regime enough colloid is given to maintain the stroke volume, but no more. This allows circulatory volume and organ perfusion to be maintained with the minimum of administered fluid, which minimises fluid accumulation in the tissues.”[tissues.”The Enhanced Recovery Partnership recommends the regular audit of practice and outcomes benchmarked against national data for surgical procedures.This should ideally include:· 30 and 90 day mortality rate .· Length of hospital stay.· Same day admission rate.· Readmission rate.· Patient reported outcomes.Each author contributed equally to this consensus statement. All authors read and approved the final manuscript.


The paper presents the effects of fluid flow on the static and dynamic properties of carbon nanotubes that convey a viscous fluid. The mathematical model is based on the modified couple stress theory. The effects of various fluid parameters and boundary conditions on the pull-in voltages are investigated in detail. The applicability of the proposed system as nanovalves or nanosensors in nanoscale fluidic systems is elaborated. The results confirm that the nanoscale system studied in this paper can be properly applied for these purposes. Nanotechnology can be defined as the science of manipulating materials on an atomic or molecular scale . Hence, One of the most important types of theses multidisciplinary fields are nano-electromechanical systems (NEMS). They include aspects of mechanical engineering, electrical engineering and some basic sciences. In general, NEMS are nanostructures such as beams, shells, plates, tubes or other similar structures, which are sensed or actuated by using electrical mechanisms. They can be applied as nanoswitches, nanocapacitors, nanotransistors and computer storage media. These systems have been studied by using both theoretical and experimental techniques. Of course, the former is more extensive, probably because of the higher costs of experimentation and less elaborated fabrication technologies for nanotechnology. Thus, numerical simulations that include discrete and continuum modeling techniques are conducted more often. In spite of the higher accuracy of discrete modeling approaches such as molecular dynamics, it is rarely applied in scrutinizing NEMS because of their limitation in analyzing the complicated behaviors of such systems –12. HencAmong the various materials and structures made from different metallic and non-metallic materials, carbon nanomaterials play a special role. For instance, carbon nanotubes (CNTs) possess extraordinary chemical, physical, mechanical and electrical properties. Thus, since their discovery in 1991 by Iijima , they haKe et al. further developed the studies of Dequence et al. by presenting two papers regarding CNT-based NEMS –17. The Potential applications of CNTs range from nanoelectronic devices to nanofluidic systems –26. GaseBecause of the potential application of CNTs to convey fluids, it is obvious that the effects of fluid flow on the mechanical behaviors of CNTs should be scrutinized by including them in the governing equations of fluid dynamics. The papers on NEMS mentioned above and also similar research only studied different aspects of the mechanical behavior of the nanostructures under electrostatic actuation but without considering fluids passing through them. Of course, the mechanical behavior of CNTs that convey fluids without electrostatic actuation was studied before. To our knowledge, Yoon et al. were the first to study the flutter instability that results from fluid flow in CNTs . They prDespite some studies concerning the effects of fluid flow on the static and dynamic behavior of CNTs, the control of the flow was not investigated in detail. Only a limited number of papers reported rudimentary conceptual designs of CNTs as nanovalves –29. It i60 molecule and simulated it by using molecular dynamics [60 molecule could block it inside the CNT. In spite of invaluable ideas behind the designs presented in [Solares et al. designed a nanomechanical fluid control valve based on functionalized silicon cantilevers and modeled it by using molecular dynamics . A settldynamics . It was ented in –29, theiElectrostatically actuated CNTs have various potential applications. For example, in the static actuation, they could be used as nanovalves. It is shown in In this paper, the effects of a fluid flow on the static and dynamic pull-in instabilities of the CNTs with cantilever and doubly clamped boundary conditions are investigated. The pull-in voltages of the CNTs for various fluid parameters including fluid viscosity, velocity, pressure and mass ratio (fluid mass/CNT mass) are scrutinized. A brief discussion on the buckling loads, vibrational behaviors and natural frequencies of the CNTs is presented.G0 (state 1 in V is applied between the CNT as the positive electrode and the graphene sheets as the negative electrode (ground plate). This voltage and cooperated with the interatomic forces between the electrodes lead to deflection of the CNT towards the ground plate (state 2 in w = w(x), corresponds to the applied voltage up to the point at which the elasticity of the CNT can no longer compensate the forces that result from the applied voltage and the interatomic forces. Then, the CNT suddenly drops on the ground plate. This phenomenon is called pull-in instability and the corresponding voltage is the pull-in voltage. If the behavior is static, the pull-in will be static. In the case of dynamic motion, the pull-in will be a dynamic pull-in. Details are to be discussed in the following sections.As shown in The most appropriate, and perhaps the only, method to effectively actuate CNTs at the nanoscale is the electrostatic actuation technique. The described external force in Another application of the system is its utilization for feedback control. A control strategy should have some control parameters that an algorithm adjusts in order to control the system. Passing viscous fluids through the CNT with different fluid characteristics can provide a platform for controlling the electromechanical behaviors of the CNT under electrostatic actuation by imposing changes in the stiffness and damping ratios, as will be studied in the paper.All mathematical formulae and expressions that are used in this study can be found in v* = L/t* and the parameters of fluid flow of The length and chirality of the CNT considered in this paper are 50 nm and , respectively. Based on the chirality, the diameter of the CNT is considered to be about 1.4 nm. The effects of different dimensions on the pull-in behavior of CNTs were studied in our previous papers. In this research, we investigate the effects of fluid flow on the static and dynamic pull-in instabilities of the CNTs with cantilever and doubly clamped boundary conditions by using MCST. The dynamic behavior of the cantilever and doubly clamped CNTs are illustrated in Since, the fluid flow influences both stiffness and damping properties of the CNT, it can be applied as a proper tool for controlling and positioning purposes. By using different parameters of the fluid flow, one can control the behaviors of the CNT for a special goal. In the following section the effects of the mentioned parameters on the static and dynamic pull-in voltages of the CNTs that convey fluids are given.low = 1 mPa·s and μlow = 1 mPa·s, and the scaling of the pull-in voltages is done corresponding to these values.In this section, the effects of changes in the parameters of the fluid flow on the static and dynamic pull-in voltages of the CNT are investigated and the results of classical elasticity theory (CET) and MCST are compared. The outcomes are presented for both cantilever and doubly clamped boundary conditions. Some of the mentioned parameters do not affect the pull-in voltages. The fluid parameters are the same as presented in The effects of changes in the mass ratio on the static and dynamic pull-in voltages of the CNT are studied in A variation of the mass ratio does not affect the dynamic pull-in behavior of the cantilevered CNTs and only shows little effect on the dynamic pull-in voltages of the doubly clamped ones. The mass ratio increment decreases the dynamic pull-in voltages of the CNTs with doubly clamped boundary conditions.Furthermore, our simulations reveal that a variation of the flow pressure does not, at least in the considered range of the parameters, affect the pull-in voltages of the CNTs. This can be attributed to this fact that a pressure variation does not impose remarkable changes on the stiffness of the system with the properties and dimensions considered here. In fact, the effects are so small that they can be neglected. In order to have a system sensitive to the fluid pressure, one would need to weaken the nanostructure by using larger lengths or smaller diameters of the CNT.In this paper, the applicability of the electrostatically actuated CNTs that convey fluids as nanosensors or nanoactuators was investigated. The model of an Euler–Bernoulli beam was applied in modeling the CNT by using MCST and the effects of the fluid flow were formulated by using the Navier–Stokes equations. The effects of fluid flow on the static and dynamic pull-in voltages of the CNTs under cantilever and doubly clamped boundary conditions were studied in detail. Certain flow parameters, i.e., fluid velocity, viscosity, mass and temperature were varied and the effects were scrutinized. The results showed various trends in the static and dynamic pull-in voltages of the CNTs. For example, an increase of fluid velocity increased the pull-in voltages of the cantilevered CNTs, whereas it decreased the pull-in voltages of the doubly clamped CNTs. All of the variations were justified in detail. In addition, the results revealed that the proposed system can be applied properly for the purposes mentioned above. The fluid flow through the CNT can be applied as control parameters for a desired behavior of the CNT by changing the stiffness and the damping of the system.The Supporting Information features the comprehensive presentation of the mathematical formulae and expressions that are used in this study.File 1Mathematical formulae.