151 research outputs found
Ultrafast photoinduced enhancement of nonlinear optical response in 15-atom gold clusters on indium tin oxide conducting film
We show that the third order optical nonlinearity of 15-atom gold clusters is
significantly enhanced when in contact with indium tin oxide (ITO) conducting
film. Open and close aperture z-scan experiments together with non-degenerate
pump-probe differential transmission experiments were done using 80 fs laser
pulses centered at 395 nm and 790 nm on gold clusters encased inside
cyclodextrin cavities. We show that two photon absorption coefficient is
enhanced by an order of magnitude as compared to that when the clusters are on
pristine glass plate. The enhancement for the nonlinear optical refraction
coefficient is ~3 times. The photo-induced excited state absorption using
pump-probe experiments at pump wavelength of 395 nm and probe at 790 nm also
show an enhancement by an order of magnitude. These results attributed to the
excited state energy transfer in the coupled gold cluster-ITO system are
different from the enhancement seen so far in charge donor-acceptor complexes
and nanoparticle-conjugate polymer composites.Comment: To appear in Optics Express (2013);
http://dx.doi.org/10.1364/OE.21.00848
Spreading Information in Complex Networks: An Overview and Some Modified Methods
The knowledge of node’s ability and importance in spreading information in a complex network is important for developing efficient methods either to decelerate spreading in the case of diseases or to accelerate spreading in the case of information flow, which would benefit the whole population. Some systems are highly affected by a small fraction of influential nodes. Number of fast and efficient spreaders in a network is much less compared to the number of ordinary members. Information about the influential spreaders is significant in the planning for the control of propagation of critical pieces of information in a social or information network. Identifying important members who act as the fastest and efficient spreaders is the focal theme of a large number of research papers. Researchers have identified approximately 10 different methods for this purpose. Degree centrality, closeness centrality, betweenness centrality, k‐core decomposition, mixed degree decomposition, improved k‐shell decomposition, etc., are some of these methods. In this expository article, we review all previous works done in the field of identifying potential spreaders in a network
Tissue-Specific Bioink from Xenogeneic Sources for 3D Bioprinting of Tissue Constructs
3D bioprinting brings new aspirations to the tissue engineering and regenerative medicine research community. However, despite its huge potential, its growth towards translation is severely impeded due to lack of suitable materials, technological barrier, and appropriate validation models. Recently, the use of decellularized extracellular matrices (dECM) from animal sources is gaining attention as printable bioink as it can provide a microenvironment close to the native tissue. Hence, it is worth exploring the use of xenogeneic dECM and its translation potential for human application. However, extensive studies on immunogenicity, safety-related issues, and animal welfare-related ethics are yet to be streamlined. In addition, the regulatory concerns need to be addressed with utmost priority in order to expedite the use of xenogeneic dECM bioink for 3D bioprinted implantable tissues for human welfare
Rewarded meta-pruning: Meta Learning with Rewards for Channel Pruning
Convolutional Neural Networks (CNNs) have a large number of parameters and
take significantly large hardware resources to compute, so edge devices
struggle to run high-level networks. This paper proposes a novel method to
reduce the parameters and FLOPs for computational efficiency in deep learning
models. We introduce accuracy and efficiency coefficients to control the
trade-off between the accuracy of the network and its computing efficiency. The
proposed Rewarded meta-pruning algorithm trains a network to generate weights
for a pruned model chosen based on the approximate parameters of the final
model by controlling the interactions using a reward function. The reward
function allows more control over the metrics of the final pruned model.
Extensive experiments demonstrate superior performances of the proposed method
over the state-of-the-art methods in pruning ResNet-50, MobileNetV1, and
MobileNetV2 networks
A study of the propagation of magnetoacoustic waves in small-scale magnetic fields using solar photospheric and chromospheric Dopplergrams: HMI/SDO and MAST observations
In this work, we present a study of the propagation of low-frequency
magneto-acoustic waves into the solar chromosphere within small-scale inclined
magnetic fields over a quiet-magnetic network region utilizing
near-simultaneous photospheric and chromospheric Dopplergrams obtained from the
HMI instrument onboard SDO spacecraft and the Multi-Application Solar Telescope
(MAST) operational at the Udaipur Solar Observatory, respectively. Acoustic
waves are stochastically excited inside the convection zone of the Sun and
intermittently interact with the background magnetic fields resulting into
episodic signals. In order to detect these episodic signals, we apply the
wavelet transform technique to the photospheric and chromospheric velocity
oscillations in magnetic network regions. The wavelet power spectrum over
photospheric and chromospheric velocity signals show a one-to-one
correspondence between the presence of power in the 2.5-4 mHz band. Further, we
notice that power in the 2.5-4 mHz band is not consistently present in the
chromospheric wavelet power spectrum despite its presence in the photospheric
wavelet power spectrum. This indicates that leakage of photospheric
oscillations (2.5-4 mHz band) into the higher atmosphere is not a continuous
process. The average phase and coherence spectra estimated from these
photospheric and chromospheric velocity oscillations illustrate the propagation
of photospheric oscillations (2.5-4 mHz) into the solar chromosphere along the
inclined magnetic fields. Additionally, chromospheric power maps estimated from
the MAST Dopplergrams also show the presence of high-frequency acoustic halos
around relatively high magnetic concentrations, depicting the refraction of
high-frequency fast mode waves around vA ~ vs layer in the solar atmosphere.Comment: 16 pages, 7 figures, Accepted for Publication in Journal of
Atmospheric and Solar-Terrestrial Physics (Special Issue of STP-15
Subchondral raft plate fixation for lateral tibial plateau fractures - A prospective study
Introduction: Tibial plateau fractures are often complex fractures that are difficult to stabilize. Subchondral raft technique is used to prevent depression and reduction loss using Kirschner wires, lag screws or locking screws with or without plates. The study aimed to assess the functional outcome of lateral tibial plateau fractures fixed with raft plate and the associated complications.
Materials and methods: A prospective observational study of 45 consecutive patients with depressed lateral tibial plateau fractures treated with raft plate were studied at a tertiary care centre for a period of one year. Patients were followed up for a minimum period of 6 months. The Lysholm Knee Scoring Scale (LKSS) was used to assess the functional outcomes.
Results: The mean age of the patients was 43.8 ± 10.54 years (range 18-60 years). Male- Female ratio was 2.75:1 (M=33, F=12). Proportion of type II Schatzker fractures was 44.4%. 35 patients (77.8%) sustained injury due to road traffic accident and the rest due to fall. Bone grafting was done in 18 patients (40%). Knee stiffness and flexion less than 95⁰ were noted in 5 patients (11.1%). Superficial wound infection was noted in 2 patients (4.4%). Knee pain was observed in 7 patients (15.6%).
Conclusion: Laterally placed raft plate with periarticular locking screws through it offers an excellent method of fixation of tibial plateau fractures, which preserves the anatomical joint line and the normal mechanical axis with minimal complications. Raft plating may obviate the need for dual plating in most of the tibial plateau fractures
A Context-Responsive LSTM based IoT Enabled E- Healthcare Monitoring System for Arrhythmia Detection
Detecting Arrhythmia, a life-threatening cardiac condition, in real-time is crucial for timely intervention and improved healthcare outcomes. Traditional manual methods for Arrhythmia detection using Electrocardiogram (ECG) signals are error-prone and resource-intensive. To address these limitations, this paper presents an automated system based on the Context Responsive Long Short-Term Memory (CR-LSTM) model for real-time Arrhythmia classification. The system leverages IoT technology to continuously monitor vital signs and effectively combines contextual information with temporal sensor data to accurately discern different types of Arrhythmias. The CR-LSTM model achieves an impressive accuracy of 99.72% in multiclass classification of Arrhythmias, making it a promising solution for dynamic healthcare settings and proactive personalized care
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