16,303 research outputs found
DNA Logic-A novel approach to semiconductor based genetics
In the coming years, genetic test results will be increasingly used as indicators that
influence medical decision-making. With chronic disease on the rise and the
continuing global spread of infectious disease, novel instruments able to detect
relevant mutations in a point-of-care setting are being developed to facilitate this
increased demand in personalized health care. However, diagnosis for such demand
often requires laboratory facilities and skilled personnel, meaning that diagnostic tests
are restricted by time and access. This thesis presents a novel configuration for Ion
sensitive Field Effect Transistors (ISFETs) to be used as a threshold detector during
nucleic acid base pairs match. ISFET-based inverters are used as reaction threshold
detectors to convey the chemical reaction level to a logic output once a threshold has
been reached. Using this method, novel DNA logic functions are derived for
nucleotides allowing local digital computations.
The thesis also presents business models that enable such technology to be utilised in
point of care applications, and experiment as results and business models given for an
HIV point of care example are proposed
Mass-spectrometric investigation of reaction of oxygen atoms with methane
Mass spectrometric investigation of oxygen atoms reacting with methan
Secure Communications in Millimeter Wave Ad Hoc Networks
Wireless networks with directional antennas, like millimeter wave (mmWave)
networks, have enhanced security. For a large-scale mmWave ad hoc network in
which eavesdroppers are randomly located, however, eavesdroppers can still
intercept the confidential messages, since they may reside in the signal beam.
This paper explores the potential of physical layer security in mmWave ad hoc
networks. Specifically, we characterize the impact of mmWave channel
characteristics, random blockages, and antenna gains on the secrecy
performance. For the special case of uniform linear array (ULA), a tractable
approach is proposed to evaluate the average achievable secrecy rate. We also
characterize the impact of artificial noise in such networks. Our results
reveal that in the low transmit powerregime, the use of low mmWave frequency
achieves better secrecy performance, and when increasing transmit power, a
transition from low mmWave frequency to high mmWave frequency is demanded for
obtaining a higher secrecy rate. More antennas at the transmitting nodes are
needed to decrease the antenna gain obtained by the eavesdroppers when using
ULA. Eavesdroppers can intercept more information by using a wide beam pattern.
Furthermore, the use of artificial noise may be ineffective for enhancing the
secrecy rate.Comment: Accepted by IEEE Transactions on Wireless Communication
Interaction Between Ion Beams and Plasmas
Stability limits for ion acoustic waves due to interaction between low energy cesium ion beam and thermal cesium plasm
A New Look at Physical Layer Security, Caching, and Wireless Energy Harvesting for Heterogeneous Ultra-dense Networks
Heterogeneous ultra-dense networks enable ultra-high data rates and ultra-low
latency through the use of dense sub-6 GHz and millimeter wave (mmWave) small
cells with different antenna configurations. Existing work has widely studied
spectral and energy efficiency in such networks and shown that high spectral
and energy efficiency can be achieved. This article investigates the benefits
of heterogeneous ultra-dense network architecture from the perspectives of
three promising technologies, i.e., physical layer security, caching, and
wireless energy harvesting, and provides enthusiastic outlook towards
application of these technologies in heterogeneous ultra-dense networks. Based
on the rationale of each technology, opportunities and challenges are
identified to advance the research in this emerging network.Comment: Accepted to appear in IEEE Communications Magazin
Derivation of linearized transfer functions for switching-mode regulations. Phase A: Current step-up and voltage step-up converters
Small-signal models are derived for the power stage of the voltage step-up (boost) and the current step-up (buck) converters. The modeling covers operation in both the continuous-mmf mode and the discontinuous-mmf mode. The power stage in the regulated current step-up converter on board the Dynamics Explorer Satellite is used as an example to illustrate the procedures in obtaining the small-signal functions characterizing a regulated converter
Electroproduction of the d* dibaryon
The unpolarized cross section for the electroproduction of the isoscalar
di-delta dibaryon is calculated for deuteron target using a
simple picture of elastic electron-baryon scattering from the and the components of the deuteron. The calculated
differential cross section at the electron lab energy of 1 GeV has the value of
about 0.24 (0.05) nb/sr at the lab angle of 10 (30) for the
Bonn B potential when the dibaryon mass is taken to be 2.1 GeV. The cross
section decreases rapidly with increasing dibaryon mass. A large calculated
width of 40 MeV for combined with a small
experimental upper bound of 0.08 MeV for the decay width appears to have
excluded any low-mass model containing a significant admixture of the
configuration.Comment: 11 journal-style pages, 8 figure
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RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are.Abstract
Chronic Pancreatitis Progressing to Duodenal Obstruction in the Absence of Classic Symptoms
We report the case of a 34-year-old alcoholic who was initially seen in March 1985 because of acute pancreatitis. A mass was demonstrated in the head of the pancreas. Serial sonogram and computed tomography scans over 4 1/2 years revealed progressive encroachment of the duodenum without symptoms attributable to obstruction. In 1989, three separate endoscopies with multiple biopsies showed chronic inflammation and strictures. Hypotonic duodenography confirmed stricture and obstructed duodenum. Surgical intervention is being considered. Duodenal obstruction secondary to chronic pancreatitis is rare. It may proceed subclinically for several years independent of continued alcohol use. Only when obstruction became severe in our patient did the classic symptoms of postprandial nausea, emesis, and weight loss become manifest. Obstructive jaundice from chronic pancreatitis due to stricture in the pancreatic portion of the common bile duct is uncommon
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