247 research outputs found
In-Situ Defect Detection in Laser Powder Bed Fusion by Using Thermography and Optical Tomography—Comparison to Computed Tomography
Among additive manufacturing (AM) technologies, the laser powder bed fusion (L-PBF) is one of the most important technologies to produce metallic components. The layer-wise build-up of components and the complex process conditions increase the probability of the occurrence of defects. However, due to the iterative nature of its manufacturing process and in contrast to conventional manufacturing technologies such as casting, L-PBF offers unique opportunities for in-situ monitoring. In this study, two cameras were successfully tested simultaneously as a machine manufacturer independent process monitoring setup: a high-frequency infrared camera and a camera for long time exposure, working in the visible and infrared spectrum and equipped with a near infrared filter. An AISI 316L stainless steel specimen with integrated artificial defects has been monitored during the build. The acquired camera data was compared to data obtained by computed tomography. A promising and easy to use examination method for data analysis was developed and correlations between measured signals and defects were identified. Moreover, sources of possible data misinterpretation were specified. Lastly, attempts for automatic data analysis by data integration are presented
Cooperative learning and the implications for gifted students
In today\u27s educational community, several buzz words surface dally ln the layperson\u27s journals. Some of the terms are curriculum-based measurement (taking basal texts and devising a measurement tool to evaluate one school district\u27s students\u3e, global education (taking into consideration the need to address skills which will enable students to fit into the world marketplace), whole-language (incorporating all language arts skills along with the chosen reading texts or stories into the total curriculum), grouping (placing students in homogeneous groups to teach them a skill), and cooperative learning. The last term is not new, however. It has been present for many years, but it seems to be enjoying a resurgence in the contemporary classroom. With the new stress on banning ability grouping, cooperative learning ls viewed as a way to fill this void
Assessment of preoperative accelerated radiotherapy and chemotherapy in stage IIIa (N2) non-small-cell lung cancer
AbstractForty patients with N2 non-small-cell lung cancer (stage IIIA), as determined by mediastinoscopy, were entered into a preoperative neoadjuvant study of chemotherapy (platinum, 5-fluorouracil, vinblastine) and accelerated radiotherapy (150 cGy twice per day for 7 days) for two cycles. Surgical resection was then performed and followed up with an additional cycle of chemotherapy and radiotherapy. All patients completed preoperative therapy. A major clinical response was seen in 87% of patients. Thirty-five patients underwent resection (one preoperative death, one refused operation, one had deterioration of pulmonary function, and two had pleural metastases). Operative mortality rate was 5.7% (2/35). Sixty percent of patients had no complications. Major complications included pulmonary emboli (three), pneumonia (two), and myocardial infarction (one). Downstaging was seen in 46% of patients, with two patients (5.7%) having no evidence of tumor in the specimen, five patients having sterilization of all lymph nodes, and nine patients having sterilization of mediastinal nodes but positive N1 nodes. Median survival of 40 patients was 28 months, with a projected 5-year survival of 43%. Patients with downstaged disease had statistically significant improved survival compared with patients whose disease was not downstaged. (J THORAC CARDIOVASC SURG 1996;111:123-33
Solar System Processes Underlying Planetary Formation, Geodynamics, and the Georeactor
Only three processes, operant during the formation of the Solar System, are
responsible for the diversity of matter in the Solar System and are directly
responsible for planetary internal-structures, including planetocentric nuclear
fission reactors, and for dynamical processes, including and especially,
geodynamics. These processes are: (i) Low-pressure, low-temperature
condensation from solar matter in the remote reaches of the Solar System or in
the interstellar medium; (ii) High-pressure, high-temperature condensation from
solar matter associated with planetary-formation by raining out from the
interiors of giant-gaseous protoplanets, and; (iii) Stripping of the primordial
volatile components from the inner portion of the Solar System by super-intense
solar wind associated with T-Tauri phase mass-ejections, presumably during the
thermonuclear ignition of the Sun. As described herein, these processes lead
logically, in a causally related manner, to a coherent vision of planetary
formation with profound implications including, but not limited to, (a) Earth
formation as a giant gaseous Jupiter-like planet with vast amounts of stored
energy of protoplanetary compression in its rock-plus-alloy kernel; (b) Removal
of approximately 300 Earth-masses of primordial gases from the Earth, which
began Earth's decompression process, making available the stored energy of
protoplanetary compression for driving geodynamic processes, which I have
described by the new whole-Earth decompression dynamics and which is
responsible for emplacing heat at the mantle-crust-interface at the base of the
crust through the process I have described, called mantle decompression
thermal-tsunami; and, (c)Uranium accumulations at the planetary centers capable
of self-sustained nuclear fission chain reactions.Comment: Invited paper for the Special Issue of Earth, Moon and Planets
entitled Neutrino Geophysics Added final corrections for publicatio
Characterization of AKT independent effects of the synthetic AKT inhibitors SH-5 and SH-6 using an integrated approach combining transcriptomic profiling and signaling pathway perturbations
<p>Abstract</p> <p>Background</p> <p>Signal transduction processes mediated by phosphatidyl inositol phosphates affect a broad range of cellular processes such as cell cycle progression, migration and cell survival. The protein kinase AKT is one of the major effectors in this signaling network. Chronic AKT activation contributes to oncogenic transformation and tumor development. Therefore, analogs of phosphatidyl inositol phosphates (PIAs) were designed as new small drugs to block AKT activity for cancer treatment. Here we characterize the biological effects of the PIAs SH-5 and SH-6 in colorectal cancer cell lines.</p> <p>Methods</p> <p>Serum-starved or serum-supplemented human colorectal cancer cell lines SW480, HT29 and HCT116 were exposed to SH-5 and SH-6. AKT activation was determined by western blotting. Cell viability was assessed using a colorimetric XTT-based assay, apoptosis and cell cycle changes were monitored by FACS analysis. The dynamics of cell morphology alterations was evaluated by confocal and time-lapse microscopy. Transcriptional changes due to inhibitor treatment were analyzed using Affymetrix HG-U133A microarrays and RT-PCR.</p> <p>Results</p> <p>While the PIAs clearly reduce AKT phosphorylation in serum starved cells, we did not observe a significant reduction under serum supplemented conditions, giving us the opportunity to analyze AKT independent effects of these compounds. Both inhibitors induce broadly the same morphological alterations, in particular changes in cell shape and formation of intracellular vesicles. Moreover, we observed the induction of binucleated cells specifically in the SW480 cell line. Gene expression analysis revealed transcriptional alterations, which are mostly cell line specific. In accordance to the phenotype we found a gene group associated with mitosis and spindle organization down regulated in SW480 cells, but not in the other cell lines. A bioinformatics analysis using the Connectivity Map linked the gene expression pattern of the inhibitor treated SW480 cells to PKC signaling. Using confocal laser scanning microscopy and time lapse recording we identified a specific defect in the last step of the cytokinesis as responsible for the binucleation.</p> <p>Conclusions</p> <p>The PIAs SH-5 and SH-6 impinge on additional cellular targets apart from AKT in colorectal cancer cells. The effects are mostly cell line specific and have an influence at the outcome of the treatment. In view of potential clinical trials it will be necessary to take these diverse effects into consideration to optimize patient treatment.</p
Activity-Dependent Shedding of the NMDA Receptor Glycine Binding Site by Matrix Metalloproteinase 3: A PUTATIVE Mechanism of Postsynaptic Plasticity
Functional and structural alterations of clustered postsynaptic ligand gated ion channels in neuronal cells are thought to contribute to synaptic plasticity and memory formation in the human brain. Here, we describe a novel molecular mechanism for structural alterations of NR1 subunits of the NMDA receptor. In cultured rat spinal cord neurons, chronic NMDA receptor stimulation induces disappearance of extracellular epitopes of NMDA receptor NR1 subunits, which was prevented by inhibiting matrix metalloproteinases (MMPs). Immunoblotting revealed the digestion of solubilized NR1 subunits by MMP-3 and identified a fragment of about 60 kDa as MMPs-activity-dependent cleavage product of the NR1 subunit in cultured neurons. The expression of MMP-3 in the spinal cord culture was shown by immunoblotting and immunofluorescence microscopy. Recombinant NR1 glycine binding protein was used to identify MMP-3 cleavage sites within the extracellular S1 and S2-domains. N-terminal sequencing and site-directed mutagenesis revealed S542 and L790 as two putative major MMP-3 cleavage sites of the NR1 subunit. In conclusion, our data indicate that MMPs, and in particular MMP-3, are involved in the activity dependent alteration of NMDA receptor structure at postsynaptic membrane specializations in the CNS
Overhaul and Installation of the ICARUS-T600 Liquid Argon TPC Electronics for the FNAL Short Baseline Neutrino Program
The ICARUS T600 liquid argon (LAr) time projection chamber (TPC) underwent a
major overhaul at CERN in 2016-2017 to prepare for the operation at FNAL in the
Short Baseline Neutrino (SBN) program. This included a major upgrade of the
photo-multiplier system and of the TPC wire read-out electronics. The full TPC
wire read-out electronics together with the new wire biasing and
interconnection scheme are described. The design of a new signal feed-through
flange is also a fundamental piece of this overhaul whose major feature is the
integration of all electronics components onto the signal flange. Initial
functionality tests of the full TPC electronics chain installed in the T600
detector at FNAL are also described
First measurement of quasi-elastic baryon production in muon anti-neutrino interactions in the MicroBooNE detector
We present the first measurement of the cross section of Cabibbo-suppressed
baryon production, using data collected with the MicroBooNE detector
when exposed to the neutrinos from the Main Injector beam at the Fermi National
Accelerator Laboratory. The data analyzed correspond to
protons on target of neutrino mode running and protons on
target of anti-neutrino mode running. An automated selection is combined with
hand scanning, with the former identifying five candidate production
events when the signal was unblinded, consistent with the GENIE prediction of
events. Several scanners were employed, selecting between three
and five events, compared with a prediction from a blinded Monte Carlo
simulation study of events. Restricting the phase space to only
include baryons that decay above MicroBooNE's detection thresholds,
we obtain a flux averaged cross section of
cmAr, where statistical and systematic uncertainties are combined
First demonstration of timing resolution in the MicroBooNE liquid argon time projection chamber
MicroBooNE is a neutrino experiment located in the Booster Neutrino Beamline
(BNB) at Fermilab, which collected data from 2015 to 2021. MicroBooNE's liquid
argon time projection chamber (LArTPC) is accompanied by a photon detection
system consisting of 32 photomultiplier tubes used to measure the argon
scintillation light and determine the timing of neutrino interactions. Analysis
techniques combining light signals and reconstructed tracks are applied to
achieve a neutrino interaction time resolution of .
The result obtained allows MicroBooNE to access the ns neutrino pulse structure
of the BNB for the first time. The timing resolution achieved will enable
significant enhancement of cosmic background rejection for all neutrino
analyses. Furthermore, the ns timing resolution opens new avenues to search for
long-lived-particles such as heavy neutral leptons in MicroBooNE, as well as in
future large LArTPC experiments, namely the SBN program and DUNE
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