217 research outputs found

    Enhancement mode double top gated MOS nanostructures with tunable lateral geometry

    Full text link
    We present measurements of silicon (Si) metal-oxide-semiconductor (MOS) nanostructures that are fabricated using a process that facilitates essentially arbitrary gate geometries. Stable Coulomb blockade behavior free from the effects of parasitic dot formation is exhibited in several MOS quantum dots with an open lateral quantum dot geometry. Decreases in mobility and increases in charge defect densities (i.e. interface traps and fixed oxide charge) are measured for critical process steps, and we correlate low disorder behavior with a quantitative defect density. This work provides quantitative guidance that has not been previously established about defect densities for which Si quantum dots do not exhibit parasitic dot formation. These devices make use of a double-layer gate stack in which many regions, including the critical gate oxide, were fabricated in a fully-qualified CMOS facility.Comment: 11 pages, 6 figures, 3 tables, accepted for publication in Phys. Rev.

    Vaccinia virus immunomodulator A46 : a lipid and protein-binding scaffold for sequestering host TIR-domain proteins

    Get PDF
    TS received Austrian Science Fund (FWF) grants P24038, W1221 and W1258. GAB is a member of Max F. Perutz Laboratories and the Vienna International PostDoctoral Program (VIPS). TKS is a holder of Wellcome Trust grant 097831. IU has Spanish Ministry of Economy and Competitiveness grant BIO2013-49604-EXP.Vaccinia virus interferes with early events of the activation pathway of the transcriptional factor NF-kB by binding to numerous host TIR-domain containing adaptor proteins. We have previously determined the X-ray structure of the A46 C-terminal domain; however, the structure and function of the A46 N-terminal domain and its relationship to the C-terminal domain have remained unclear. Here, we biophysically characterize residues 1-83 of the N-terminal domain of A46 and present the X-ray structure at 1.55 Å. Crystallographic phases were obtained by a recently developed ab initio method entitled ARCIMBOLDO_BORGES that employs tertiary structure libraries extracted from the Protein Data Bank; data analysis revealed an all β-sheet structure. This is the first such structure solved by this method which should be applicable to any protein composed entirely of β-sheets. The A46(1-83) structure itself is a β-sandwich containing a co-purified molecule of myristic acid inside a hydrophobic pocket and represents a previously unknown lipid-binding fold. Mass spectrometry analysis confirmed the presence of long-chain fatty acids in both N-terminal and full-length A46; mutation of the hydrophobic pocket reduced the lipid content. Using a combination of high resolution X-ray structures of the N-and C-terminal domains and SAXS analysis of full-length protein A46(1-240), we present here a structural model of A46 in a tetrameric assembly. Integrating affinity measurements and structural data, we propose how A46 simultaneously interferes with several TIR-domain containing proteins to inhibit NF-κB activation and postulate that A46 employs a bipartite binding arrangement to sequester the host immune adaptors TRAM and MyD88.Publisher PDFPeer reviewe

    Phase-rectified signal averaging method to predict perinatal outcome in infants with very preterm fetal growth restriction- a secondary analysis of TRUFFLE-trial

    Get PDF
    BACKGROUND: Phase-rectified signal averaging, an innovative signal processing technique, can be used to investigate quasi-periodic oscillations in noisy, nonstationary signals that are obtained from fetal heart rate. Phase-rectified signal averaging is currently the best method to predict survival after myocardial infarction in adult cardiology. Application of this method to fetal medicine has established significantly better identification than with short-term variation by computerized cardiotocography of growth-restricted fetuses. OBJECTIVE: The aim of this study was to determine the longitudinal progression of phase-rectified signal averaging indices in severely growth-restricted human fetuses and the prognostic accuracy of the technique in relation to perinatal and neurologic outcome. STUDY DESIGN: Raw data from cardiotocography monitoring of 279 human fetuses were obtained from 8 centers that took part in the multicenter European “TRUFFLE” trial on optimal timing of delivery in fetal growth restriction. Average acceleration and deceleration capacities were calculated by phase-rectified signal averaging to establish progression from 5 days to 1 day before delivery and were compared with short-term variation progression. The receiver operating characteristic curves of average acceleration and deceleration capacities and short-term variation were calculated and compared between techniques for short- and intermediate-term outcome. RESULTS: Average acceleration and deceleration capacities and short-term variation showed a progressive decrease in their diagnostic indices of fetal health from the first examination 5 days before delivery to 1 day before delivery. However, this decrease was significant 3 days before delivery for average acceleration and deceleration capacities, but 2 days before delivery for short-term variation. Compared with analysis of changes in short-term variation, analysis of (delta) average acceleration and deceleration capacities better predicted values of Apgar scores <7 and antenatal death (area under the curve for prediction of antenatal death: delta average acceleration capacity, 0.62 [confidence interval, 0.19–1.0]; delta short-term variation, 0.54 [confidence interval, 0.13–0.97]; P=.006; area under the curve for prediction Apgar <7: average deceleration capacity <24 hours before delivery, 0.64 [confidence interval, 0.52–0.76]; short-term variation <24 hours before delivery, 0.53 [confidence interval, 0.40–0.65]; P=.015). Neither phase-rectified signal averaging indices nor short-term variation showed predictive power for developmental disability at 2 years of age (Bayley developmental quotient, <95 or <85). CONCLUSIONS: The phase-rectified signal averaging method seems to be at least as good as short-term variation to monitor progressive deterioration of severely growth-restricted fetuses. Our findings suggest that for short-term outcomes such as Apgar score, phase-rectified signal averaging indices could be an even better test than short-term variation. Overall, our findings confirm the possible value of prospective trials based on phase-rectified signal averaging indices of autonomic nervous system of severely growth-restricted fetuses

    Identifying Critical Non-Catalytic Residues that Modulate Protein Kinase A Activity

    Get PDF
    Distal interactions between discrete elements of an enzyme are critical for communication and ultimately for regulation. However, identifying the components of such interactions has remained elusive due to the delicate nature of these contacts. Protein kinases are a prime example of an enzyme with multiple regulatory sites that are spatially separate, yet communicate extensively for tight regulation of activity. Kinase misregulation has been directly linked to a variety of cancers, underscoring the necessity for understanding intramolecular kinase regulation.A genetic screen was developed to identify suppressor mutations that restored catalytic activity in vivo from two kinase-dead Protein Kinase A mutants in S. cerevisiae. The residues defined by the suppressors provide new insights into kinase regulation. Many of the acquired mutations were distal to the nucleotide binding pocket, highlighting the relationship of spatially dispersed residues in regulation.The suppressor residues provide new insights into kinase regulation, including allosteric effects on catalytic elements and altered protein-protein interactions. The suppressor mutations identified in this study also share overlap with mutations identified from an identical screen in the yeast PKA homolog Tpk2, demonstrating functional conservation for some residues. Some mutations were independently isolated several times at the same sites. These sites are in agreement with sites previously identified from multiple cancer data sets as areas where acquired somatic mutations led to cancer progression and drug resistance. This method provides a valuable tool for identifying residues involved in kinase activity and for studying kinase misregulation in disease states

    The TRUFFLE study; fetal monitoring indications for delivery in 310 IUGR infants with 2 year's outcome delivered before 32 weeks of gestation.

    Get PDF
    OBJECTIVE: In the TRUFFLE study on outcome of early fetal growth restriction women were allocated to three timing of delivery plans according to antenatal monitoring strategies based on reduced computerized cardiotocographic heart rate short term variation (c-CTG STV) , early Ductus Venosus (DV p95) or late DV (DV noA) changes. However, many infants were per protocol delivered because of 'safety net' criteria, or for maternal indications, or 'other fetal indications' or after 32 weeks of gestation when the protocol was not applied anymore. It was the objective of the present post-hoc sub-analysis to investigate the indications for delivery in relation to outcome at 2 years in infants delivered before 32 weeks, to come to a further refinement of management proposals. METHODS: we included all 310 cases of the TRUFFLE study with known outcome at 2 years corrected age and 7 perinatal and infant deaths, apart from 7 cases with an inevitable death. Data were analyzed according to the randomization allocation and specified for the intervention indication. RESULTS: overall only 32% of fetuses born alive were delivered according to the specified monitoring parameter for indication for delivery. 38% were delivered because of safety net criteria, 15% because of other fetal reasons and 15% because of maternal reasons. In the c-CTG arm 51% of infants were delivered because of reduced STV. In the DV p95 arm 34% were delivered because of an abnormal DV and in the DV no A wave arm only 10% of cases were delivered accordingly. The majority of fetuses in the DV arms delivered for safety net criteria were delivered because of spontaneous decelerations. Two year's intact survival was highest in the combined DV arms as compared to the c-CTG arm (p = 0.05 when life born, p = 0.21 including fetal death), with no difference between the DV arms. Poorer outcome in the c-CTG arm was restricted to fetuses delivered because of decelerations in the safety net subgroup. Infants delivered because of maternal reasons had the highest birth weight and a non-significant higher intact survival. CONCLUSIONS: In this sub-analysis of fetuses delivered before 32 weeks the majority of infants were delivered for other reasons than according to the allocated CTG or DV monitoring strategy. Since in the DV arms CTG criteria were used as safety net criteria, but in the c-CTG arms no DV safety net criteria were applied, we speculate that the slightly poorer outcome in the CTG arm might be explained by absence of DV data. Optimal timing of delivery of the early IUGR fetus may therefore best be achieved by monitoring them longitudinally with DV and CTG monitoring

    Accuracy of detecting residual disease after neoadjuvant chemoradiotherapy for esophageal squamous cell carcinoma (preSINO trial): A prospective multicenter diagnostic cohort study

    Get PDF
    Background: After neoadjuvant chemoradiotherapy (nCRT) for esophageal cancer, high pathologically complete response (pCR) rates are being achieved especially in patients with squamous cell carcinoma (SCC). An active surveillance strategy has been proposed for SCC patients with clinically complete response (cCR) after nCRT. To justify omitting surgical resection, patients with residual disease should be accurately identified. The aim of this study is to assess the accuracy of response evaluations after nCRT based on the preSANO trial, including positron emission tomography with computed tomography (PET-CT), endoscopy with bite-on-bite biopsies and endoscopic ultrasonography (EUS) with fine-needle aspiration (FNA) in patients with potentially curable esophageal SCC. Methods: Operable esophageal SCC patients who are planned to undergo nCRT according to the CROSS regimen and are planned to undergo surgery will be recruited from four Asian centers. Four to 6 weeks after completion of nCRT, patients will undergo a first clinical response evaluation (CRE-1) consisting of endoscopy with bite-on-bite biopsies. In patients without histological evidence of residual tumor (i.e. without positive biopsies), surgery will be postponed another 6 weeks. A second clinical response evaluation (CRE-2) will be performed 10-12 weeks after completion of nCRT, consisting of PET-CT, endoscopy with bite-on-bite biopsies and EUS with FNA. Immediately after CRE-2 all patients without evidence of distant metastases will undergo esophagectomy. Results of CRE-1 and CRE-2 as well as results of the three single diagnostic modalities will be correlated to pathological response in the resection specimen (gold standard) for calculation of sensitivity, specificity, negative predictive value and positive predictive value. Discussion: If the current study shows that major locoregional residual disease (> 10% residual carcinoma or any residual nodal disease) can be accurately (i.e. with sensitivity of 80.5%) detected in patients with esophageal SCC, a prospective trial will be conducted comparing active surveillance with standard esophagectomy in patients with a clinically complete response after nCRT (SINO trial). Trial registration: The preSINO trial has been registered at ClinicalTrials.gov as NCT03937362 (May 3, 2019)

    The burden of neglected tropical diseases in Ethiopia, and opportunities for integrated control and elimination

    Get PDF
    Background: Neglected tropical diseases (NTDs) are a group of chronic parasitic diseases and related conditions that are the most common diseases among the 2·7 billion people globally living on less than US$2 per day. In response to the growing challenge of NTDs, Ethiopia is preparing to launch a NTD Master Plan. The purpose of this review is to underscore the burden of NTDs in Ethiopia, highlight the state of current interventions, and suggest ways forward. Results: This review indicates that NTDs are significant public health problems in Ethiopia. From the analysis reported here, Ethiopia stands out for having the largest number of NTD cases following Nigeria and the Democratic Republic of Congo. Ethiopia is estimated to have the highest burden of trachoma, podoconiosis and cutaneous leishmaniasis in sub-Saharan Africa (SSA), the second highest burden in terms of ascariasis, leprosy and visceral leishmaniasis, and the third highest burden of hookworm. Infections such as schistosomiasis, trichuriasis, lymphatic filariasis and rabies are also common. A third of Ethiopians are infected with ascariasis, one quarter is infected with trichuriasis and one in eight Ethiopians lives with hookworm or is infected with trachoma. However, despite these high burdens of infection, the control of most NTDs in Ethiopia is in its infancy. In terms of NTD control achievements, Ethiopia reached the leprosy elimination target of 1 case/10,000 population in 1999. No cases of human African trypanosomiasis have been reported since 1984. Guinea worm eradication is in its final phase. The Onchocerciasis Control Program has been making steady progress since 2001. A national blindness survey was conducted in 2006 and the trachoma program has kicked off in some regions. Lymphatic Filariasis, podoconiosis and rabies mapping are underway. Conclusion: Ethiopia bears a significant burden of NTDs compared to other SSA countries. To achieve success in integrated control of NTDs, integrated mapping, rapid scale up of interventions and operational research into co implementation of intervention packages will be crucial

    Rotational IMRT techniques compared to fixed gantry IMRT and Tomotherapy: multi-institutional planning study for head-and-neck cases

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Recent developments enable to deliver rotational IMRT with standard C-arm gantry based linear accelerators. This upcoming treatment technique was benchmarked in a multi-center treatment planning study against static gantry IMRT and rotational IMRT based on a ring gantry for a complex parotid gland sparing head-and-neck technique.</p> <p>Methods</p> <p>Treatment plans were created for 10 patients with head-and-neck tumours (oropharynx, hypopharynx, larynx) using the following treatment planning systems (TPS) for rotational IMRT: Monaco (ELEKTA VMAT solution), Eclipse (Varian RapidArc solution) and HiArt for the helical tomotherapy (Tomotherapy). Planning of static gantry IMRT was performed with KonRad, Pinnacle and Panther DAO based on step&shoot IMRT delivery and Eclipse for sliding window IMRT. The prescribed doses for the high dose PTVs were 65.1Gy or 60.9Gy and for the low dose PTVs 55.8Gy or 52.5Gy dependend on resection status. Plan evaluation was based on target coverage, conformity and homogeneity, DVHs of OARs and the volume of normal tissue receiving more than 5Gy (V<sub>5Gy</sub>). Additionally, the cumulative monitor units (MUs) and treatment times of the different technologies were compared. All evaluation parameters were averaged over all 10 patients for each technique and planning modality.</p> <p>Results</p> <p>Depending on IMRT technique and TPS, the mean CI values of all patients ranged from 1.17 to 2.82; and mean HI values varied from 0.05 to 0.10. The mean values of the median doses of the spared parotid were 26.5Gy for RapidArc and 23Gy for VMAT, 14.1Gy for Tomo. For fixed gantry techniques 21Gy was achieved for step&shoot+KonRad, 17.0Gy for step&shoot+Panther DAO, 23.3Gy for step&shoot+Pinnacle and 18.6Gy for sliding window.</p> <p>V<sub>5Gy </sub>values were lowest for the sliding window IMRT technique (3499 ccm) and largest for RapidArc (5480 ccm). The lowest mean MU value of 408 was achieved by Panther DAO, compared to 1140 for sliding window IMRT.</p> <p>Conclusions</p> <p>All IMRT delivery technologies with their associated TPS provide plans with satisfying target coverage while at the same time respecting the defined OAR criteria. Sliding window IMRT, RapidArc and Tomo techniques resulted in better target dose homogeneity compared to VMAT and step&shoot IMRT. Rotational IMRT based on C-arm linacs and Tomotherapy seem to be advantageous with respect to OAR sparing and treatment delivery efficiency, at the cost of higher dose delivered to normal tissues. The overall treatment plan quality using Tomo seems to be better than the other TPS technology combinations.</p
    corecore