194 research outputs found
Ultra fast miniaturized real-time PCR: 40 cycles in less than six minutes
We have designed, fabricated and tested a real-time PCR chip capable of conducting one thermal cycle in 8.5 s. This corresponds to 40 cycles of PCR in 5 min and 40 s. The PCR system was made of silicon micromachined into the shape of a cantilever terminated with a disc. The thin film heater and a temperature sensor were placed on the disc perimeter. Due to the system's thermal constant of 0.27 s, we have achieved a heating rate of 175°C s−1 and a cooling rate of −125°C s−1. A PCR sample encapsulated with mineral oil was dispensed onto a glass cover slip placed on the silicon disc. The PCR cycle time was then determined by heat transfer through the glass, which took only 0.5 s. A real-time PCR sample with a volume of 100 nl was tested using a FAM probe. As the single PCR device occupied an area of only a few square millimeters, devices could be combined into a parallel system to increase throughput
Evidence for an interaction between the Galactic Center clouds M0.10-0.08 and M0.11-0.11
We present high-resolution (~2-3"; ~0.1 pc) radio observations of the
Galactic center cloud M0.10-0.08 using the Very Large Array at K and Ka band
(~25 and 36 GHz). The M0.10-0.08 cloud is located in a complex environment near
the Galactic center Radio Arc and the adjacent M0.11-0.11 molecular cloud. From
our data, M0.10-0.08 appears to be a compact molecular cloud (~3 pc) that
contains multiple compact molecular cores (5+; <0.4 pc). In this study we
detect a total of 15 molecular transitions in M0.10-0.08 from the following
molecules: NH3, HC3N, CH3OH, HC5N, CH3CN, and OCS. We have identified more than
sixty 36 GHz CH3OH masers in M0.10-0.08 with brightness temperatures above 400
K and 31 maser candidates with temperatures between 100-400 K. We conduct a
kinematic analysis of the gas using NH3 and detect multiple velocity components
towards this region of the Galactic center. The bulk of the gas in this region
has a velocity of 51.5 km/s (M0.10-0.08) with a lower velocity wing at 37.6
km/s. We also detect a relatively faint velocity component at 10.6 km/s that we
attribute to being an extension of the M0.11-0.11 cloud. Analysis of the gas
kinematics, combined with past X-ray fluorescence observations, suggests
M0.10-0.08 and M0.11-0.11 are located in the same vicinity of the Galactic
center and could be physically interacting.Comment: Accepted for publication in the Astrophysical Journa
Robust Optimal Trajectory Planning under Uncertain Winds and Convective Risk
The existence of significant uncertainties in the models and systems required for trajectory prediction represent a major challenge for Trajectory-Based Operations concept. Weather can be considered as one of the most relevant sources of uncertainty. Understanding and managing the impact of these uncertainties is necessary in order to increase the predictability of the ATM system. We present preliminary results on robust trajectory planning in which weather is assumed to be the unique source of uncertainty. State-of-the-art forecasts from Ensemble Prediction Systems are used as input data for the wind field and to calculate convective risk. The term convective area is defined here as an area within which individual convective storms may develop, i.e., a necessary (though not sufficient) condition. An ad-hoc robustoptimal control methodology is presented. A set of Pareto-optimal trajectories is obtained for different preferences between predictability, convective risk and average efficiency.This work has been partially supported by project TBO-MET project (https://tbometh2020.com/), which has received funding from the SESAR JU under grant agreementNo 699294 under European Union’s Horizon 2020 research and innovation programme
Techno-Economic Feasibility Study of Renewable Power Systems for a Small-Scale Plasma-Assisted Nitric Acid Plant in Africa
Characterization of Uncultivable Bat Influenza Virus Using a Replicative Synthetic Virus
Bats harbor many viruses, which are periodically transmitted to humans resulting in outbreaks of disease (e.g., Ebola, SARSCoV). Recently, influenza virus-like sequences were identified in bats; however, the viruses could not be cultured. This discovery aroused great interest in understanding the evolutionary history and pandemic potential of bat-influenza. Using synthetic genomics, we were unable to rescue the wild type bat virus, but could rescue a modified bat-influenza virus that had the HA and NA coding regions replaced with those of A/PR/8/1934 (H1N1). This modified bat-influenza virus replicated efficiently in vitro and in mice, resulting in severe disease. Additional studies using a bat-influenza virus that had the HA and NA of A/swine/Texas/4199-2/1998 (H3N2) showed that the PR8 HA and NA contributed to the pathogenicity in mice. Unlike
other influenza viruses, engineering truncations hypothesized to reduce interferon antagonism into the NS1 protein didn’t attenuate bat-influenza. In contrast, substitution of a putative virulence mutation from the bat-influenza PB2 significantly attenuated the virus in mice and introduction of a putative virulence mutation increased its pathogenicity. Mini-genome replication studies and virus reassortment experiments demonstrated that bat-influenza has very limited genetic and protein compatibility with Type A or Type B influenza viruses, yet it readily reassorts with another divergent bat-influenza
virus, suggesting that the bat-influenza lineage may represent a new Genus/Species within the Orthomyxoviridae family. Collectively, our data indicate that the bat-influenza viruses recently identified are authentic viruses that pose little, if any, pandemic threat to humans; however, they provide new insights into the evolution and basic biology of influenza viruses
Salvage radiotherapy for recurrent hypopharyngeal and laryngeal squamous cell carcinoma (SCC) after first-line treatment with surgery alone: a 10-year single-centre experience
Purpose: Salvage surgery of recurrent hypopharyngeal and laryngeal squamous cell carcinoma (SCC) results in limited local control and survival rates. As a result of recent technological progress, radiotherapy (RT) has become a valuable, potentially curative therapeutic option. Thus, we aimed to determine prognostic factors for survival outcome in order to optimize patient selection for salvage radiotherapy after failure of first-line treatment with surgery alone in this special patient cohort.
Methods: Seventy-five patients (85% male, median age of 64 years) underwent salvage RT in a secondary setting for recurrent hypopharyngeal or laryngeal SCC after prior surgery alone between 2007 and 2017. On average, patients were treated with one prior surgery (range 1–4 surgeries). Median time between surgery and salvage RT was 7 months (range 1–47 months) for initially advanced tumors (T3/4, N+, extracapsular spread) and 18 months (range 5–333 months) for initially early stage tumors. The majority of patients received concomitant chemotherapy (n = 48; 64%) or other kind of systemic treatment concurrent to radiotherapy (n = 10; 13%).
Results: Median follow-up was 41 months (range 3–120 months). Overall, fifteen patients were diagnosed with local failure (all were in-field) at last follow-up (20%). Median time to recurrence was 35 months (range 3–120 months) and 3-year local progression-free survival (LPFS) was 75%, respectively. Dose-escalated RT with 70.4 Gy applied in 2.1 Gy or 2.2 Gy fractions corresponding an EQD2 > 70 Gy (p = 0.032) and the use of concomitant cisplatin weekly chemotherapy (p = 0.006) had a significant positive impact on LPFS. 3-year OS and DPFS were 76 and 85%, respectively. No toxicity-related deaths occurred. Reported grade >  3 side effects were rare (n = 4/70, 6%).
Conclusion: Salvage radiotherapy resulted in excellent local control rates while radiation dose and the use of cisplatin weekly chemotherapy were identified as prognostic factors for LPFS. Nevertheless, patient selection for curative salvage treatment remains challenging
A multifunctional human monoclonal neutralizing antibody that targets a unique conserved epitope on influenza HA
The high rate of antigenic drift in seasonal influenza viruses necessitates frequent changes in vaccine composition. Recent seasonal H3 vaccines do not protect against swine-origin H3N2 variant (H3N2v) strains that recently have caused severe human infections. Here, we report a human VH1-69 gene-encoded monoclonal antibody (mAb) designated H3v-47 that exhibits potent cross-reactive neutralization activity against human and swine H3N2 viruses that circulated since 1989. The crystal structure and electron microscopy reconstruction of H3v-47 Fab with the H3N2v hemagglutinin (HA) identify a unique epitope spanning the vestigial esterase and receptor-binding subdomains that is distinct from that of any known neutralizing antibody for influenza A H3 viruses. MAb H3v-47 functions largely by blocking viral egress from infected cells. Interestingly, H3v-47 also engages Fcγ receptor and mediates antibody dependent cellular cytotoxicity (ADCC). This newly identified conserved epitope can be used in design of novel immunogens for development of broadly protective H3 vaccines
Entry into a New Class of Potent Proteasome Inhibitors Having High Antiproliferative Activity by Structure- Based Design
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