Systematic Scan Research Articles

1086. Impact of Systematic Thoraco-Abdomino-Pelvic CT Scan on the Diagnosis of Infective Endocarditis

BackgroundThe incidence of embolic events (EE) is high in patients with infective endocarditis (IE). EE influence patient management in different settings because they are minor criteria in the Duke classification and may lead to changes medical therapy or surgical strategy. If current guidelines suggest that systematic thoraco-abdominopelvic CT scan (TAP-CT) may be helpful, reliable data are lacking. The main objective of this study was to describe how systematic TAP-CT affects the diagnosis of patients with IE. Secondary objectives were to assess the impact of the TAP-CT on the management of patients with IE and the incidence of contrast-induced acute kidney injury (CI-AKI).MethodsIn this multicenter cohort study between January 2013 and July 2016, we included consecutive patients who had definite or possible acute IE according to the Duke-modified criteria, and after validation by the endocarditis teams. The main exclusion criterion was the absence of TAP-CT scan. We compared the Duke classification diagnosis data and treatment data (medical and/or surgical) regarding the presence or the absence of EE on the CT and investigated the tolerance of this examination as well.ResultsOf the 522 patients included in this study, 217 (41.6%) had one or more EE on the TAP-CT. The two major Duke modified criteria were found in 397 patients (76,1%) and 457 patients (87,6%) had a definite endocarditis. On the basis of TAP-CT results in asymptomatic patients, diagnostic classification was upgraded from possible endocarditis to definite endocarditis for only four cases which represent 0.8% of the population. The presence of EE on CT did not modify the duration of antibiotic treatment (P = 0.55) and the decision of surgical treatment (P = 0.39). Specific treatment of the EE was necessary in 42 patients (8.0%) but only nine of these EE (1.9%) were asymptomatic. CI-AKI was observed in 78 patients (14.9%).ConclusionThe CT-scan findings slightly affected diagnosis of IE. The impact on the therapeutic management is low and the incidence of CI-AKI should not be underestimated. Additional studies are needed to assess whether CT-scan improves patient outcomes, leads to unnecessary procedures and increased costs.Disclosures All authors: No reported disclosures.

VHE γ-ray discovery and multi-wavelength study of the blazar 1ES 2322-409

A hotspot at a position compatible with the BL Lac object 1ES 2322-409 was serendipitously detected with H.E.S.S. during observations performed in 2004 and 2006 on the blazar PKS 2316-423. Additional data on 1ES 2322-409 were taken in 2011 and 2012, leading to a total live-time of 22.3h. Point-like very-high-energy (VHE; E>100GeV) $\gamma$-ray emission is detected from a source centred on the 1ES 2322-409 position, with an excess of 116.7 events at a significance of 6.0$\sigma$. The average VHE $\gamma$-ray spectrum is well described with a power law with a photon index $\Gamma=3.40\pm0.66_{\text{stat}}\pm0.20_{\text{sys}}$ and an integral flux $\Phi(E>200GeV) = (3.11\pm0.71_{\rm stat}\pm0.62_{\rm sys})\times10^{-12} cm^{-2} s^{-1}$, which corresponds to 1.1$\%$ of the Crab nebula flux above 200 GeV. Multi-wavelength data obtained with Fermi LAT, Swift XRT and UVOT, RXTE PCA, ATOM, and additional data from WISE, GROND and Catalina, are also used to characterise the broad-band non-thermal emission of 1ES 2322-409. The multi-wavelength behaviour indicates day-scale variability. Swift UVOT and XRT data show strong variability at longer scales. A spectral energy distribution (SED) is built from contemporaneous observations obtained around a high state identified in Swift data. A modelling of the SED is performed with a stationary homogeneous one-zone synchrotron-self-Compton (SSC) leptonic model. The redshift of the source being unknown, two plausible values were tested for the modelling. A systematic scan of the model parameters space is performed, resulting in a well-constrained combination of values providing a good description of the broad-band behaviour of 1ES 2322-409.

Postoperative collections after liver surgery: predictors, and long-term outcomes

Introduction: Postoperative collection (PC) can occur after liver surgery (LS), but little is know on their impact on short and long-term outcomes. The aim of this study was to analyze factors predicting the occurrence of PC, the need of drainage and their impact on oncologic outcomes. Methods: . This prospective, single-center, cohort-study included all patients undergoing LS from 2008 to 2017. A systematic postoperative CT scan was realized on day7. The primary outcome was to determine variables associated with PC, defined as the presence of a fluid collection, and infected in case of positive bacterial culture. Secondary outcomes were to determine factors predicting drainage requirement, and the impact of infected PC on 5-y overall (OS) survival. Results: We included 254 patients: 45% (n=114) experienced PC. In the multivariate analysis, variables associated to PC occurrence were BMI (25-30=OR1.56(95%IC:0.78,3.13), 30-35=OR1.99(95%IC:0.67,5.89) p=0.002) and surgical resection (anatomic=reference, nonanatomic=OR1.22(95%IC:0.52,2.85), combined=OR2.09(95%IC:0.72,6.07), p=0.014). In the PC subgroup (n=114), variables predicting drainage requirement were antibiotic use OR14.01(95%CI:1.25,157 p= 0.015) and C-reactive protein (CRP) OR1.02(95%CI:1,1.05 p=0.043). The AUROC (0.71, 95%CI:0.59,0.83 p=0.002) found 152 mg/L as the optimal CRP cutoff value associated with PC drainage. In the malignant disease subgroup with PC (n=96), we observed lower 5-y OS among patients with infected vs non-infected PC (33% vs 56%, Log-Rank=0.03). Conclusions: In this cohort study we observed how nonanatomic or combined LS and BMI are associated to PC after LS, and those with CRP higher than 152 mg/L may require drainage. Moreover, the presence of an infected PC negatively impact 5-y OS.

Novel HDAC5-interacting motifs of Tbx3 are essential for the suppression of E-cadherin expression and for the promotion of metastasis in hepatocellular carcinoma

Tbx3, a transcriptional repressor, is essential in the organogenesis of vertebrates, stem cell self-renewal and differentiation, and the carcinogenesis of multiple tumor types. However, the mechanism by which Tbx3 participates in the metastasis of hepatocellular carcinoma (HCC) remains largely unknown. In this study, we show that Tbx3 was dramatically upregulated in clinical HCC samples and that elevated expression of Tbx3 promoted cancer progression. To determine the underlying mechanism, systematic glycine scan mutagenesis and deletion assays were performed. We identified two critical motifs, 585LFSYPYT591 and 604HRH606, that contribute to the repression of transcriptional activity. These motifs are also essential for Tbx3 to promote cell migration and metastasis both in vitro and in vivo via the suppression of E-cadherin expression. More importantly, Tbx3 directly interacts with HDAC5 via these motifs, and an HDAC inhibitor blocks Tbx3-mediated cell migration and the downregulation of E-cadherin in HCC. As Tbx3 is involved in the carcinogenesis of multiple types of human cancers, our findings suggest an important target for anti-cancer drug development.

The involvement of Canadian physicians in promoting and providing unproven and unapproved stem cell interventions

BackgroundDirect to consumer offerings of unproven stem cell interventions (SCIs) is a pressing scientific and policy issue. According to media reports, providers of SCIs have emerged in Canada. This study provides the first systematic scan of Canadian providers and associated trends and claims.MethodsThe study sample consisted of 15 websites retrieved from a Google™ keyword search. The websites were assessed by a rater using a peer-reviewed coding frame that queried treatment location, stem cell offerings, treatment claims, supporting evidence, and legal and regulatory compliance. A second rater reviewed a subset of the websites for purposes of inter-rater reliability. Disagreements between raters were resolved by consensus. Data collected by the raters was analyzed in SPSS.ResultsPhysicians are the dominant treatment providers in Canada. Providers operate in urban and semi-urban areas in the most populous provinces. SCIs provided are mainly autologous adult stem cells for multiple conditions including musculoskeletal disorders, spinal cord injury (SCI) and diabetes. Efficacy and benefits of treatment are prominently and positively portrayed, while risks are not mentioned or portrayed as trivial. Regulatory concerns are not discussed.ConclusionsThe involvement of physicians in promoting and providing unproven and unapproved SCIs raises significant ethical, legal and regulatory concerns. Treatment claims and trends appear to contravene applicable professional standards, statutory obligations, and consumer protection laws. While the number of providers observed is still marginal, urgent and proactive regulatory response is needed to prevent proliferation of a potentially exploitative and harmful market for unproven SCIs in Canada.

Enhanced ion acceleration in transition from opaque to transparent plasmas

Using particle-in-cell simulations, we investigate ion acceleration in the interaction of high intensity lasers with plasmas which transition from opaque to transparent during the interaction process. We show that the highest ion energies are achieved when the laser traverses the target around the peak intensity and re-heats the electron population responsible for the plasma expansion, enhancing the corresponding sheath electric field. This process can lead to an increase of up to 2x in ion energy when compared with the standard Target Normal Sheath Acceleration in opaque targets under the same laser conditions. A theoretical model is developed to predict the optimal target areal density as a function of laser intensity and pulse duration. A systematic parametric scan for a wide range of target densities and thicknesses is performed in 1D, 2D and 3D and shown consistent with the theory and with recent experimental results. These results open the way for a better optimization of the ion energy in future laser–solid experiments.

Characterization of a medium-sized washer-gun for an axisymmetric mirror.

A new medium-sized washer gun is developed for a plasma start-up in a fully axisymmetric mirror. The gun is positioned at the east end of the Keda Mirror with AXisymmetricity facility and operated in the pulsed mode with an arc discharging time of 1.2 ms and a typical arc current of 8.5 kA with 1.5 kV discharge voltage. To optimize the operation, a systematic scan of the neutral pressure, the arc voltage, the bias voltage on a mesh grid 6 cm in front of the gun and an end electrode located on the west end of mirror, and the mirror ratio was performed. The streaming plasma was measured with triple probes in the three mirror cells and a diamagnetic loop in the central cell. Floating potential measurements suggest that the plasma could be divided into streaming and mirror-confined plasmas. The floating potential for the streaming plasma is negative, with an electric field pointing inwards. The mirror-confined plasma has a typical lifetime of 0.5 ms.

Simulation design for forthcoming high quality plasma wakefield acceleration experiment in linear regime at SPARC_LAB

In the context of plasma wakefield acceleration beam driven, we exploit a high density charge trailing bunch whose self-fields act by mitigating the energy spread increase via beam loading compensation, together with bunch self-contain operated by the self-consistent transverse field. The work, that will be experimentally tested in the SPARC_LAB test facility, consists of a parametric scan that allows to find optimized parameters in order to preserve the high quality of the trailing bunch over the entire centimeters acceleration length, with a final energy spread increase of 0.1% and an emittance increase of 5nm. The stability of trailing bunch parameters after acceleration is tested employing a systematic scan of the parameters of the bunches at the injection. The results show that the energy spread increase keeps lower than 1% and the emittance increase is lower than 0.02 mm mrad in all the simulations performed. The energy jitter is of the order of 5%.

Structure and chemistry of interfaces between ceria and yttria-stabilized zirconia studied by analytical STEM

Epitaxial undoped and Gd2O3-doped ceria films were grown by pulsed laser deposition on (1 1 1) faced Y2O3-stabilized zirconia (YSZ). Highly localized cerium reduction at the film-substrate interfaces is revealed by atomically resolved valence EELS mapping using Cs aberration-corrected scanning transmission electron microscopy. The chemical profiles reveal interdiffusion of Ce, (Gd), Y, Zr, forming an intermixing zone at the interface 7–9 (1 1 1) lattice planes wide. In its vicinity, the fraction of Ce3+ raises gradually over 6–8 lattice planes from zero in the bulk ceria to ≈100% in one single plane at the interface. Beyond this plane the Ce3+ fraction drops sharply within the YSZ substrate. In the vicinity of the interface systematic scan deflections are observed during EELS line scans. The advancing electron probe experiences a retarding force at the ceria side, and an accelerating force at the YSZ side, irrespective of the scan direction. This behavior is suggestive of coulombic interactions between the electron probe and a charged interface. This is interpreted as an indication of the presence of a space-charge situation at the YSZ/ceria interface, resulting from an excess negative charge at the ceria side (due to Ce3+cations) and an excess positive charge at the YSZ side (due to oxygen vacancies).

Rational use of systematic postoperative CT scans after neurosurgical craniotomy.

The aim of this retrospective study was to evaluate the relevance of a systematic postoperative CT scan after neurosurgical craniotomy and to identify predictive factors of complications. This retrospective analysis included all the patients at our institution who benefited from a cerebral postoperative CT scan within 24 hours post-craniotomy. Patient characteristics and neuroimaging abnormalities were recorded. Predictive factors were identified using a recursive partitioning analysis. A total of 633 patients were included. Of these, 17.9% of patients suffered from postoperative complications and 7.4% of them required a new surgery. The decision for reoperation was based on the neurological deterioration and the CT scan, but never on the CT scan alone. The mortality rate was 1.1%. The risk to be reoperated was correlated to the occurrence of a new postoperative neurological deficit (P<0.001, HR=4.60) and in situ hemorrhage (P<0.001, HR=4.19). The risk of postoperative hematoma was correlated to the supratentorial location versus infratentorial (P=0.027, HR=2.50). With clinical factors, such as location and etiology of the lesion, schedule type of surgery, and the age of patients, we proposed six classes with the risk to present with hemorrhage or midline shift on postoperative CT scans. The post-craniotomy CT scan did not impact patient management as an independent decisional tool. We identified several variables associated with the risk of clinical modification that can impact the decision to reoperate and allow establishment of a risk score. This score could be an interesting tool in order to reduce the systematic use of CT scans in the post-surgical period but has to be validated in a prospective study.

Comparing the fractal basins of attraction in the Hill problem with oblateness and radiation

The basins of convergence, associated with the roots (attractors) of a complex equation, are revealed in the Hill problem with oblateness and radiation, using a large variety of numerical methods. Three cases are investigated, regarding the values of the oblateness and radiation. In all cases, a systematic and thorough scan of the complex plane is performed in order to determine the basins of attraction of the several iterative schemes. The correlations between the attracting domains and the corresponding required number of iterations are also illustrated and discussed. Our numerical analysis strongly suggests that the basins of convergence, with the highly fractal basin boundaries, produce extraordinary and beautiful formations on the complex plane.

Key aromatic/hydrophobic amino acids controlling a cross-amyloid peptide interaction versus amyloid self-assembly

The interaction of the intrinsically disordered polypeptide islet amyloid polypeptide (IAPP), which is associated with type 2 diabetes (T2D), with the Alzheimer's disease amyloid-β (Aβ) peptide modulates their self-assembly into amyloid fibrils and may link the pathogeneses of these two cell-degenerative diseases. However, the molecular determinants of this interaction remain elusive. Using a systematic alanine scan approach, fluorescence spectroscopy, and other biophysical methods, including heterocomplex pulldown assays, far-UV CD spectroscopy, the thioflavin T binding assay, transmission EM, and molecular dynamics simulations, here we identified single aromatic/hydrophobic residues within the amyloid core IAPP region as hot spots or key residues of its cross-interaction with Aβ40(42) peptide. Importantly, we also find that none of these residues in isolation plays a key role in IAPP self-assembly, whereas simultaneous substitution of four aromatic/hydrophobic residues with Ala dramatically impairs both IAPP self-assembly and hetero-assembly with Aβ40(42). Furthermore, our experiments yielded several novel IAPP analogs, whose sequences are highly similar to that of IAPP but have distinct amyloid self- or cross-interaction potentials. The identified similarities and major differences controlling IAPP cross-peptide interaction with Aβ40(42) versus its amyloid self-assembly offer a molecular basis for understanding the underlying mechanisms. We propose that these insights will aid in designing intervention strategies and novel IAPP analogs for the management of type 2 diabetes, Alzheimer's disease, or other diseases related to IAPP dysfunction or cross-amyloid interactions.

Enhanced understanding of non-axisymmetric intrinsic and controlled field impacts in tokamaks

An extensive study of intrinsic and controlled non-axisymmetric field (δB) impacts in KSTAR has enhanced the understanding about non-axisymmetric field physics and its implications, in particular, on resonant magnetic perturbation (RMP) physics and power threshold (Pth) for L–H transition. The n = 1 intrinsic non-axisymmetric field in KSTAR was measured to remain as low as δB/B0 ~ 4 × 10−5 even at high-beta plasmas (βN ~ 2), which corresponds to approximately 20% below the targeted ITER tolerance level. As for the RMP edge-localized-modes (ELM) control, robust n = 1 RMP ELM-crash-suppression has been not only sustained for more than ~90 τE, but also confirmed to be compatible with rotating RMP. An optimal window of radial position of lower X-point (i.e. Rx = m) proved to be quite critical to reach full n = 1 RMP-driven ELM-crash-suppression, while a constraint of the safety factor could be relaxed (q95 = 5 0.25). A more encouraging finding was that even when Rx cannot be positioned in the optimal window, another systematic scan in the vicinity of the previously optimal Rx allows for a new optimal window with relatively small variations of plasma parameters. Also, we have addressed the importance of optimal phasing (i.e. toroidal phase difference between adjacent rows) for n = 1 RMP-driven ELM control, consistent with an ideal plasma response modeling which could predict phasing-dependent ELM suppression windows. In support of ITER RMP study, intentionally misaligned RMPs have been found to be quite effective during ELM-mitigation stage in lowering the peaks of divertor heat flux, as well as in broadening the ‘wet’ areas. Besides, a systematic survey of Pth dependence on non-axisymmetric field has revealed the potential limit of the merit of low intrinsic non-axisymmetry. Considering that the ITER RMP coils are composed of 3-rows, just like in KSTAR, further 3D physics study in KSTAR is expected to help us minimize the uncertainties of the ITER RMP coils, as well as establish an optimal 3D configuration for ITER and future reactors.

Accuracy of B-scan ultrasonography in acute fundus obscuring vitreous hemorrhage using a standardized scanning protocol and a dedicated ophthalmic ultrasonographer

PurposeTo assess the accuracy of B-scan ultrasound (U/S) in diagnosing cases of acute fundus obscuring vitreous hemorrhage (FOVH) using a standardized scan protocol and dedicated ophthalmic ultrasonographer.MethodsConsecutive patients presenting with acute FOVH of unknown cause, between January 2013 and December 2014, were prospectively recruited. Patients underwent a scan performed by a dedicated ultrasonographer, utilizing a systematic scan sequence and using an ocular specific U/S device. The U/S findings were compared to the findings during vitrectomy or after spontaneous hemorrhage clearance.ResultsFifty-eight eyes (58 patients) were included. An underlying rhegmatogenous retinal detachment (RRD) and retinal tears without RRD were reported in nine and 14 patients, respectively. Nineteen of these patients underwent vitrectomy, and the other four underwent laser retinopexy or cryopexy alone. An additional six patients with suspected but uncertain retinal tears underwent vitrectomy, during which tears were confirmed in three, two had retinal vessel avulsions, and one had retinal new vessels. There was “complete” agreement between the B-scan findings and clinical findings in 78% of patients, “partial” agreement in 19%, and agreement was not tested in 3%. When the agreement was “partial”, the disagreements did not affect patient management. The sensitivity was 100% for the detection of RRD, and for the detection of new retinal tears in patients without retinal detachment.ConclusionB-scan U/S scan was highly sensitive in identifying the pathology in acute FOVH. Our results show an improvement from previously reported results, likely related to the standardized scan protocol and dedicated ophthalmic ultrasonographer.

Using a Vibrotactile Seat for Facilitating the Handover of Control during Automated Driving

Studies have found that drivers tend to neglect their surrounding traffic during automated driving. This may lead to a late and inefficient resumption of control in case of handover of the driving task to the driver. The authors evaluated the effectiveness of a vibrotactile seat displaying spatial information regarding vehicles approaching from behind to enhance the driver preparedness to the handover of control. A simulator experiment, involving 26 participants, showed that when drivers were required to regain control of the vehicle, having a vibrotactile seat improved speed and efficiency of reactions in scenarios requiring lane changing immediately following a handover. In addition, eye-tracking analysis showed that the participants had more systematic scan patterns of the mirrors in the first two seconds following the transition of control request. Interestingly, this effect exists in-spite of the finding that during automated driving mode, having a vibrotactile display led to fewer glances at the road.

Substituted cysteine accessibility method (SCAM) analysis of the transport domain of human concentrative nucleoside transporter 3 (hCNT3) and other family members reveals features of structural and functional importance

The human SLC28 family of concentrative nucleoside transporter (CNT) proteins has three members: hCNT1, hCNT2, and hCNT3. Na+-coupled hCNT1 and hCNT2 transport pyrimidine and purine nucleosides, respectively, whereas hCNT3 transports both pyrimidine and purine nucleosides utilizing Na+ and/or H+ electrochemical gradients. Escherichia coli CNT family member NupC resembles hCNT1 in permeant selectivity but is H+-coupled. Using heterologous expression in Xenopus oocytes and the engineered cysteine-less hCNT3 protein hCNT3(C−), substituted cysteine accessibility method analysis with the membrane-impermeant thiol reactive reagent p-chloromercuribenzene sulfonate was performed on the transport domain (interfacial helix 2, hairpin 1, putative transmembrane domain (TM) 7, and TM8), as well as TM9 of the scaffold domain of the protein. This systematic scan of the entire C-terminal half of hCNT3(C−) together with parallel studies of the transport domain of wild-type hCNT1 and the corresponding TMs of cysteine-less NupC(C−) yielded results that validate the newly developed structural homology model of CNT membrane architecture for human CNTs, revealed extended conformationally mobile regions within transport-domain TMs, identified pore-lining residues of functional importance, and provided evidence of an emerging novel elevator-type mechanism of transporter function.

Early liver metastases in resectable periampullary cancer: Incidence and risk factors

PurposeThe aim of the present study was to estimate the incidence of very early hepatic metastases (HMs) (<6 months) and their imaging patterns after cephalic duodenopancreatectomy (CDP) for periampullary carcinoma (excluding duodenal carcinoma) and to identify their associated risk factors. MethodsFrom January 2003 to June 2016, all patients who underwent surgical treatment for periampullary carcinoma by CDP at our institution and with adequate pre- and postoperative CT scans were included. Univariate and multivariate logistic regressions were performed to determine factors associated with very early HM and recurrence. ResultsOf the 132 patients included retrospectively, 27 (20.5%) patients developed HMs. The mean time to diagnosis of HM was 103.9±55.2days. HMs were multiple in 81.4% of cases and bilobar in 59.3% of cases; their mean maximum size was 16.7±12.7mm.In univariate logistic analysis, lymphovascular emboli were significantly associated with HM (p=0.02). No independent risk factors for HM were found in multivariate analysis. In multivariate logistic analysis, two independent risk factors were identified for the occurrence of early recurrence: tumor size >23mm on preoperative CT scan (OR: 3.3; 95% CI: [1.2–9.3]; p=0.02) and tumor differentiation (poor vs. good: OR 15.5; 95 CI [1.5–158.3]; moderate vs. good: OR: 17.1; 95% CI: [1.9–154.4]; p=0.04). ConclusionsNearly one in five patients developed HM after CDP within 6 months with a highly consistent pattern. A thorough preoperative assessment, combining CT scan and MRI with a delay of less than three weeks before surgery, appears essential. A routine systematic postoperative CT scan at 8 weeks is also required prior to initiating adjuvant chemotherapy.The type of surgical intervention does not seem to be a risk factor, although the risk of HM occurrence appears to be related to the lymphovascular invasion of the tumor and maybe its degree of differentiation, elements not assessable by imaging.

First-trimester screening for fetal structural and chromosomal anomalies by detailed early anomaly scan

Objectives To assess the performance of first trimester ultrasound screening for fetal structural and chromosomal anomalies based on a detailed anomaly and nuchal translucency (NT) scan at 11–13+6weeks' gestation. Methods A prospective cohort study was conducted at Nanjing Drum Tower Hospital. Fetuses with a crown-rump length (CRL) between 45 mm and 84 mm scanned during December 2015 to March 2016 were enrolled in this study. After a detailed first-trimester anomaly scan followed the protocol of systematic standardized scan plans, fetuses with congenital abnormalities were screened out. Second trimester ultrasound screening and postnatal examination were performed for further examination of fetal anomalies. Cytogenetic analysis was performed on the fetuses with informed consent. Results (1) A total of 1 154 fetuses were enrolled in this study and among them, 36 (3.1%) cases of fetal abnormalities were diagnosed through prenatal examination (35 cases) and postnatal examination (one case). (2) Twenty-one (58.3%) out of the 36 cases with structural and chromosomal anomalies were screened out by using the first-trimester scan, including eight cases of congenital cardiac defect (two cases of atrioventricular septal defect, one case of tricuspid atresia, one case of tetralogy of tetralogy, one case of right ventricle aneurysms and one cases of hypoplastic left heart syndrome combined with cystic hygroma with one case combined with polydactyly), four cases of central nervous system anomaly (three cases of exencephaly and one case of anencephaly combined with double outlet right ventricle), two cases of cleft palate/lip with one case combined with double outlet right ventricle, two cases of exomphalos, one case of amniotic band syndrome, one case of spinal bifida combined with megacystis, one case of umbilical cyst, one case of polydactyly and one case of cystic hygroma. One case of twin pregnancy chose selective fetocide to the fetus with exencephaly and 16 cases terminated pregnancy. The other four cases were confirmed by second trimester ultrasound screening and postnatal examination. Fourteen (38.9%, 14/36) new cases of structural and chromosomal anomalies were detected by the second-trimester scan, six of which terminated the pregnancies and the rest were confirmed at term. One (2.8%, 1/36) case of polydactyly was detected postnatally. (3) Chromosomal microarray analysis was performed on 28 cases, seven of which were identified as having chromosomal abnormalities including five cases detected in the first trimester and two cases detected in the second trimester. (4) Out of the 20 fetuses with abnormal NT in early trimester, which accounted for 1.7% of all enrolled fetuses, nine were indentified with major structural or chromosomal abnormalies, a quarter of all abnormal fetus. Conclusions Detailed anomaly scan and NT scan in the first-trimester can increase the detection rate of fetal structural and chromosomal anomalies as compared with the traditional NT scan and provide earlier detection of severe fetal abnormalities as compared with second trimester anomaly scan. Key words: Pregnancy trimester, first; Ultrasonography, penatal; Congenital anormalities; Chromosome aberrations

Effect of rotation zero-crossing on single-fluid plasma response to three-dimensional magnetic perturbations

In order to understand the effect of rotation on the response of a plasma to three-dimensional magnetic perturbations, we perform a systematic scan of the zero-crossing of the rotation profile in a DIII-D ITER-similar shape equilibrium using linear, time-independent modeling with the M3D-C1 extended magnetohydrodynamics code. We confirm that the local resonant magnetic field generally increases as the rotation decreases at a rational surface. Multiple peaks in the resonant field are observed near rational surfaces, however, and the maximum resonant field does not always correspond to zero rotation at the surface. Furthermore, we show that non-resonant current can be driven at zero-crossings not aligned with rational surfaces if there is sufficient shear in the rotation profile there, leading to amplification of near-resonant Fourier harmonics of the perturbed magnetic field and a decrease in the far-off-resonant harmonics. The quasilinear electromagnetic torque induced by this non-resonant plasma response provides drive to flatten the rotation, possibly allowing for increased transport in the pedestal by the destabilization of turbulent modes. In addition, this torque acts to drive the rotation zero-crossing to dynamically stable points near rational surfaces, which would allow for increased resonant penetration. By one or both of these mechanisms, this torque may play an important role in bifurcations into suppression of edge-localized modes. Finally, we discuss how these changes to the plasma response could be detected by tokamak diagnostics. In particular, we show that the changes to the resonant field discussed here have a significant impact on the external perturbed magnetic field, which should be observable by magnetic sensors on the high-field side of tokamaks but not on the low-field side. In addition, TRIP3D-MAFOT simulations show that none of the changes to the plasma response described here substantially affects the divertor footprint structure.

Nonlinear effects associated with fast magnetosonic waves and turbulent magnetic amplification in laboratory and astrophysical plasmas

This paper presents the spatio-temporal evolution of magnetic field due to the nonlinear coupling between fast magnetosonic wave (FMSW) and low frequency slow Alfven wave (SAW). The dynamical equations of finite frequency FMSW and SAW in the presence of ponderomotive force of FMSW (pump wave) has been presented. Numerical simulation has been carried out for the nonlinear coupled equations of finite frequency FMSW and SAW. A systematic scan of the nonlinear behavior/evolution of the pump FMSW has been done for one of the set of parameters chosen in this paper, using the coupled dynamical equations. Filamentation of fast magnetosonic wave has been considered to be responsible for the magnetic turbulence during the laser plasma interaction. The results show that the formation and growth of localized structures depend on the background magnetic field but the order of amplification does not get affected by the magnitude of the background magnetic field. In this paper, we have shown the relevance of our model for two different parameters used in laboratory and astrophysical phenomenon. We have used one set of parameters pertaining to experimental observations in the study of fast ignition of laser fusion and hence studied the turbulent structures in stellar environment. The other set corresponds to the study of magnetic field amplification in the clumpy medium surrounding the supernova remnant Cassiopeia A. The results indicate considerable randomness in the spatial structure of the magnetic field profile in both the cases and gives a sufficient indication of turbulence. The turbulent spectra have been studied and the break point has been found around k which is consistent with the observations in both the cases. The nonlinear wave-wave interaction presented in this paper may be important in understanding the turbulence in the laboratory as well as the astrophysical phenomenon.This paper presents the spatio-temporal evolution of magnetic field due to the nonlinear coupling between fast magnetosonic wave (FMSW) and low frequency slow Alfven wave (SAW). The dynamical equations of finite frequency FMSW and SAW in the presence of ponderomotive force of FMSW (pump wave) has been presented. Numerical simulation has been carried out for the nonlinear coupled equations of finite frequency FMSW and SAW. A systematic scan of the nonlinear behavior/evolution of the pump FMSW has been done for one of the set of parameters chosen in this paper, using the coupled dynamical equations. Filamentation of fast magnetosonic wave has been considered to be responsible for the magnetic turbulence during the laser plasma interaction. The results show that the formation and growth of localized structures depend on the background magnetic field but the order of amplification does not get affected by the magnitude of the background magnetic field. In this paper, we have shown the relevance of our model f...