2,034 research outputs found
Development of cancer biomarker assays from dna in various bodily fluids
Abstract
DNA from cancer cells can enter surrounding fluid after apoptosis or necrosis. This DNA can be identified by sampling and sequencing the fluid looking for the mutations that gave rise to the cancer, referred to as a liquid biopsy. We have developed several liquid biopsies for the purpose of diagnosis and treatment selection through the use of targeted PCR and high throughput sequencing. We used the SafeSeqS methodology, a molecular barcoding technology previously developed in this lab, to further reduce sequencing errors to aid us in finding these rare mutations. We developed assays that identified genetic mutations from saliva, blood plasma, and pancreatic cysts. We investigating head and neck squamous cell carcinoma (HNSCC) from the oral cavity, oropharynx, hypopharynx, and larynx in 93 patients using a combination of saliva and plasma. We first identified either the E7 gene of HPV 16 or a primary mutation in the tumor and then tried to detect their presence in saliva and plasma. We collected saliva from every patient, while we only had plasma samples from 43 patients. We found that saliva performed best in oral cavity cancers detecting 100% of those patients, while plasma performed similarly across all sites detecting 87% of HNSCC patients. We detected mutations in 96% of patients when both saliva and plasma were available. Pancreatic cyst fluid was used to aid clinicians in the classification of pancreatic cysts. We created an 8 gene panel to look for mutations as well as additional tests for loss of heterozygosity and aneuploidy. We used DNA from fluid captured through endoscopic aspiration as well as from surgically resected cysts. When combined with the typical clinical features we were able to accurately predict which cysts needed surgery with a sensitivity and specificity of 89% and 69% respectively. Each of these projects began as an attempt to aid clinicians in dealing with these various diseases. Our results illustrate that liquid biopsies can be developed into an effective tool for the fight against cancer
The eclipsing post-common envelope binary CSS21055: a white dwarf with a probable brown-dwarf companion
We report photometric observations of the eclipsing close binary CSS21055
(SDSS J141126+200911) that strongly suggest that the companion to the
carbon-oxygen white dwarf is a brown dwarf with a mass between 0.030 and 0.074
Msun. The measured orbital period is 121.73min and the totality of the eclipse
lasts 125s. If confirmed, CSS21055 would be the first detached eclipsing WD+BD
binary. Spectroscopy in the eclipse could provide information about the
companion's evolutionary state and atmospheric structure.Comment: 6 pages, 5 figure
L-selectin mediated leukocyte tethering in shear flow is controlled by multiple contacts and cytoskeletal anchorage facilitating fast rebinding events
L-selectin mediated tethers result in leukocyte rolling only above a
threshold in shear. Here we present biophysical modeling based on recently
published data from flow chamber experiments (Dwir et al., J. Cell Biol. 163:
649-659, 2003) which supports the interpretation that L-selectin mediated
tethers below the shear threshold correspond to single L-selectin carbohydrate
bonds dissociating on the time scale of milliseconds, whereas L-selectin
mediated tethers above the shear threshold are stabilized by multiple bonds and
fast rebinding of broken bonds, resulting in tether lifetimes on the timescale
of seconds. Our calculations for cluster dissociation suggest that
the single molecule rebinding rate is of the order of Hz. A similar
estimate results if increased tether dissociation for tail-truncated L-selectin
mutants above the shear threshold is modeled as diffusive escape of single
receptors from the rebinding region due to increased mobility. Using computer
simulations, we show that our model yields first order dissociation kinetics
and exponential dependence of tether dissociation rates on shear stress. Our
results suggest that multiple contacts, cytoskeletal anchorage of L-selectin
and local rebinding of ligand play important roles in L-selectin tether
stabilization and progression of tethers into persistent rolling on endothelial
surfaces.Comment: 9 pages, Revtex, 4 Postscript figures include
Bulk spectral function sum rule in QCD-like theories with a holographic dual
We derive the sum rule for the spectral function of the stress-energy tensor
in the bulk (uniform dilatation) channel in a general class of strongly coupled
field theories. This class includes theories holographically dual to a theory
of gravity coupled to a single scalar field, representing the operator of the
scale anomaly. In the limit when the operator becomes marginal, the sum rule
coincides with that in QCD. Using the holographic model, we verify explicitly
the cancellation between large and small frequency contributions to the
spectral integral required to satisfy the sum rule in such QCD-like theories.Comment: 16 pages, 2 figure
From lean production to Industrie 4.0: More autonomy for employees?
The article examines the relationship between lean production and Industrie 4.0 focusing on the question of autonomy in the work process. In contrast to the claim made by official Industrie 4.0 concepts that the autonomy of the employees would increase, we see in the current implementation projects a tendency towards greater standardization and control of work. This is in continuity with concepts of lean production, but neglects the participation-oriented elements of lean production such as teamwork and shop-floor-based improvement activities. Our argument is developed by analyzing practical examples from three relevant fields (digital assistance systems, data-based process management, modular assembly). The conclusions of this article also discuss the extent to which the concept of individual autonomy is suitable for the assessment of Industrie 4.0 concepts, given the high levels of interdependence already achieved in production processes
Conditions for Factorizable Output From a Beam splitter
A beam splitter is one of the most important devices in an optics laboratory
because of its handiness and versatility; equivalent devices are found in
various quantum systems to couple two subsystems or to interfere them. While it
is normal that two independent input fields are superposed at the beam splitter
to give correlated outputs, identical Gaussian states interfere there to
produce totally independent output fields. We prove that Gaussian states with
same the variance are the only states which bring about factorizable output
fields.Comment: 6 pages, published in PR
Induction of apoptosis in human cancer cells by targeting mitochondria with gold nanoparticles
A major challenge in designing cancer therapies is the induction of cancer cell apoptosis, although activation of intrinsic apoptotic pathways by targeting gold nanoparticles to mitochondria is promising. We report an in vitro procedure targeting mitochondria with conjugated gold nanoparticles and investigating effects on apoptosis induction in the human breast cancer cell line Jimt-1. Gold nanoparticles were conjugated to a variant of turbo green fluorescent protein (mitoTGFP) harbouring an amino-terminal mitochondrial localization signal. Au nanoparticle conjugates were further complexed with cationic maltotriose-modified poly(propylene imine) third generation dendrimers. Fluorescence and transmission electron microscopy revealed that Au nanoparticle conjugates were directed to mitochondria upon transfection, causing partial rupture of the outer mitochondrial membrane, triggering cell death. The ability to target Au nanoparticles into mitochondria of breast cancer cells and induce apoptosis reveals an alternative application of Au nanoparticles in photothermal therapy of cancer
Разработка системы электропитания малого космического аппарата
Объектом исследования является системы электропитания малого космического аппарата.
Целью ВКР является проектирование системы электропитания малого космического аппарата (МКА) для дистанционного зондирования Земли.
В результате исследования определены: характеристики малых космических аппаратов; структура системы электроснабжения; проведен расчет элементов схем; рассмотрены производственная и экологическая безопасность проекта; рассчитаны затраты на проектирование.The object of study is the power supply system of a small spacecraft.
The aim of the WRC is to design a power system for a small spacecraft (MCA) for remote sensing of the Earth.
The study identified: characteristics of small spacecraft; power system structure; Calculation of circuit elements; considered industrial and environmental safety of the project; Design costs are calculated
Aharonov-Bohm cages in two-dimensional structures
We present an extreme localization mechanism induced by a magnetic field for
tight-binding electrons in two-dimensional structures. This spectacular
phenomenon is investigated for a large class of tilings (periodic,
quasiperiodic, or random). We are led to introduce the Aharonov-Bohm cages
defined as the set of sites eventually visited by a wavepacket that can, for
particular values of the magnetic flux, be bounded. We finally discuss the
quantum dynamics which exhibits an original pulsating behaviour.Comment: 4 pages Latex, 3 eps figures, 1 ps figur
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