2,334 research outputs found
Q-enhanced fold-and-bond MEMS inductors
This work presents a novel coil fabrication technology
to enhance quality factor (Q factor) of microfabricated inductors
for implanted medical wireless sensing and data/power transfer
applications. Using parylene as a flexible thin-film device
substrate, a post-microfabrication substrate folding-and-bonding
method is developed to effectively increase the metal thickness of
the surface-micromachined inductors, resulting in their lower
self-resistance so their higher quality factor. One-fold-and-bond
coils are successfully demonstrated as an example to verify the
feasibility of the fabrication technology with measurement results
in good agreements with device simulation. Depending on target
specifications, multiple substrate folding-and-bonding can be
extensively implemented to facilitate further improved electrical
characteristics of the coils from single fabrication batch. Such Q-enhanced
inductors can be broadly utilized with great potentials
in flexible integrated wireless devices/systems for intraocular
prostheses and other biomedical implants
Description of local dilatancy and local rotation of granular assemblies by microstretch modeling
AbstractThis study investigates the microstretch continuum modeling of granular assemblies while accounting for both the dilatant and rotational degrees of freedom of a macroelement. By introducing the solid volume fraction and the gyration radius of a granular system, the balance equations of the microstretch continuum are transformed into a new formulation of evolution equations comprising six variables: the solid volume fraction, the gyration radius, the velocity field, the averaged angular velocity, the rate of gyration radius, and the internal energy. The bulk microinertia density, the averaged angular velocity, and the microgyration tensor at a macroscopic point are obtained in terms of discrete physical quantities. The bulk part and the rotational part of the microgyration tensor are proposed as the two indices to measure the local dilatancy and local rotation of granular assemblies. It is demonstrated in the numerical simulation that the two indices can be used to identify the shear band evolution in a granular system under a biaxial compression
An Automatic Indirect Immunofluorescence Cell Segmentation System
Indirect immunofluorescence (IIF) with HEp-2 cells has been used for the detection of antinuclear autoantibodies (ANA) in systemic autoimmune diseases. The ANA testing allows us to scan a broad range of autoantibody entities and to describe them by distinct fluorescence patterns. Automatic inspection for fluorescence patterns in an IIF image can assist physicians, without relevant experience, in making correct diagnosis. How to segment the cells from an IIF image is essential in developing an automatic inspection system for ANA testing. This paper focuses on the cell detection and segmentation; an efficient method is proposed for automatically detecting the cells with fluorescence pattern in an IIF image. Cell culture is a process in which cells grow under control. Cell counting technology plays an important role in measuring the cell density in a culture tank. Moreover, assessing medium suitability, determining population doubling times, and monitoring cell growth in cultures all require a means of quantifying cell population. The proposed method also can be used to count the cells from an image taken under a fluorescence microscope
An Effective Clustering Approach to Stock Market Prediction
In this paper, we propose an effective clustering method, HRK (Hierarchical agglomerative and Recursive K-means clustering), to predict the short-term stock price movements after the release of financial reports. The proposed method consists of three phases. First, we convert each financial report into a feature vector and use the hierarchical agglomerative clustering method to divide the converted feature vectors into clusters. Second, for each cluster, we recursively apply the K-means clustering method to partition each cluster into sub-clusters so that most feature vectors in each sub-cluster belong to the same class. Then, for each sub-cluster, we choose its centroid as the representative feature vector. Finally, we employ the representative feature vectors to predict the stock price movements. The experimental results show the proposed method outperforms SVM in terms of accuracy and average profits
DEXON: A Highly Scalable, Decentralized DAG-Based Consensus Algorithm
A blockchain system is a replicated state machine that must be fault
tolerant. When designing a blockchain system, there is usually a trade-off
between decentralization, scalability, and security. In this paper, we propose
a novel blockchain system, DEXON, which achieves high scalability while
remaining decentralized and robust in the real-world environment. We have two
main contributions. First, we present a highly scalable sharding framework for
blockchain. This framework takes an arbitrary number of single chains and
transforms them into the \textit{blocklattice} data structure, enabling
\textit{high scalability} and \textit{low transaction confirmation latency}
with asymptotically optimal communication overhead. Second, we propose a
single-chain protocol based on our novel verifiable random function and a new
Byzantine agreement that achieves high decentralization and low latency
Contralateral effects by unilateral eccentric versus concentric resistance training
Purpose: Unilateral resistance training increases muscle strength of the contralateral homologous muscle by the cross-education effect. Muscle damage induced by second eccentric exercise bout is attenuated, even when it is performed by the contralateral limb. The present study compared the effects of unilateral eccentric training (ET) and concentric training (CT) of the elbow flexors (EF) on maximal voluntary isometric contraction (MVC) strength and muscle damage of the contralateral untrained EF.
Methods: Young men were placed into ET, CT, ipsilateral repeated bout (IL-RB), and contralateral repeated bout (CL-RB) groups (n = 12 per group). The ET and CT groups performed unilateral EF training consisting of five sets of six eccentric and concentric contractions, respectively, once a week for 5 wk by increasing the intensity from 10% to 100% of MVC, followed by 30 maximal eccentric contractions (30MaxEC) of the opposite EF 1 wk later. The IL-RB group performed two bouts of 30MaxEC separated by 2 wk using the nondominant arm, and CL-RB group performed two bouts of 30MaxEC with a different arm for each bout in 1-wk apart.
Results: The MVC increased (P \u3c 0.05) greater for the trained (19% ± 8%) and untrained (11% ± 5%) arms in ET when compared with those in CT (10% ± 6%, 5% ± 2%). The magnitude of changes in muscle damage markers was reduced by 71% ± 19% after the second than the first bout for IL-RB group, and by 48% ± 21% for CL-RB group. Eccentric training and CT attenuated the magnitude by 58% ± 25% and 13% ± 13%, respectively, and the protective effect of ET was greater (P \u3c 0.05) than CL-RB, but smaller (P \u3c 0.05) than IL-RB.
Conclusions: These results showed that cross-education effect was stronger for ET than CT, and progressive ET produced greater contralateral muscle damage protective effect than a single eccentric exercise bout
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Efficient Prodrug Activator Gene Therapy by Retroviral Replicating Vectors Prolongs Survival in an Immune-Competent Intracerebral Glioma Model.
Prodrug activator gene therapy mediated by murine leukemia virus (MLV)-based retroviral replicating vectors (RRV) was previously shown to be highly effective in killing glioma cells both in culture and in vivo. To avoid receptor interference and enable dual vector co-infection with MLV-RRV, we have developed another RRV based on gibbon ape leukemia virus (GALV) that also shows robust replicative spread in a wide variety of tumor cells. We evaluated the potential of GALV-based RRV as a cancer therapeutic agent by incorporating yeast cytosine deaminase (CD) and E. coli nitroreductase (NTR) prodrug activator genes into the vector. The expression of CD and NTR genes from GALV-RRV achieved highly efficient delivery of these prodrug activator genes to RG-2 glioma cells, resulting in enhanced cytotoxicity after administering their respective prodrugs 5-fluorocytosine and CB1954 in vitro. In an immune-competent intracerebral RG-2 glioma model, GALV-mediated CD and NTR gene therapy both significantly suppressed tumor growth with CB1954 administration after a single injection of vector supernatant. However, NTR showed greater potency than CD, with control animals receiving GALV-NTR vector alone (i.e., without CB1954 prodrug) showing extensive tumor growth with a median survival time of 17.5 days, while animals receiving GALV-NTR and CB1954 showed significantly prolonged survival with a median survival time of 30 days. In conclusion, GALV-RRV enabled high-efficiency gene transfer and persistent expression of NTR, resulting in efficient cell killing, suppression of tumor growth, and prolonged survival upon CB1954 administration. This validates the use of therapeutic strategies employing this prodrug activator gene to arm GALV-RRV, and opens the door to the possibility of future combination gene therapy with CD-armed MLV-RRV, as the latter vector is currently being evaluated in clinical trials
The role of cytochrome c oxidase subunit Va in non-small cell lung carcinoma cells: association with migration, invasion and prediction of distant metastasis
BACKGROUND: Lung cancer is one of the most lethal malignancies worldwide, but useful biomarkers of lung cancer are still insufficient. The aim of this study is to identify some membrane-bound protein(s) associated with migration and invasion in human non-small cell lung cancer (NSCLC) cells. METHODS: We classified four NSCLC cell lines into high and low migration/invasion groups by Transwell and Matrigel assays. Using two-dimensional gel electrophoresis and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), we identified 10 membrane-associated proteins being significantly overexpressed in the high migration/invasion group. The expression of the target protein in the four NSCLC cell lines was then confirmed by reverse transcription polymerase chain reaction (RT-PCR), western blot and immunostaining. RNA interference technique was applied to observe the influence of the target protein on migration and invasion. Gelatin zymography was also performed to evaluate the activities of matrix metalloproteinase (MMP)-2 and MMP-9. Expression condition of the target protein on surgical specimens was further examined by immunohistochemical staining and the clinicopathologic data were analyzed. RESULTS: We identified a mitochondria-bound protein cytochrome c oxidase subunit Va (COX Va) because of its abundant presence found exclusively in tumorous areas. We also demonstrated that migration and invasion of NSCLC cells decreased substantially after knocking down COX Va by siRNA. Meanwhile, we found a positive correlation between COX Va expression, Bcl-2 expression and activities of MMP-2 and MMP-9 in NSCLC cells. Immunohistochemical staining of surgically resected lung adenocarcinomas in 250 consecutive patients revealed that strong COX Va expression was found in 54.8% (137/250) of patients and correlated positively with the status of lymph node metastasis (P = 0.032). Furthermore, strong COX Va expression was associated with the presence of distant metastasis (P = 0.033). CONCLUSIONS: Our current study showed that COX Va may play a role in migration and invasion of NSCLC cells and can be used as a biomarker to predict aggressiveness of NSCLC
Hepatocellular carcinoma detected by regular surveillance: Does timely confirmation of diagnosis matter?
AbstractBackgroundAlthough current guidelines recommended surveillance of hepatocellular carcinoma, prognosis in patients undergoing enhanced follow-up has yet to be evaluated.AimsExamine outcomes of hepatocellular carcinoma diagnosed during enhanced follow-up.MethodsDuring 2010–2012, 194 patients underwent ultrasonography surveillance were diagnosed with hepatocellular carcinoma and divided into: (A) immediate diagnosis (N=105, 54.1%) after positive ultrasonography, (B) enhanced follow-up: (N=38, 19.6%) for initial negative recall procedures, (C) late call back: (N=28, 14.4%) recall procedures were deferred after positive ultrasonography, and (D) beyond ultrasonography: (N=23, 11.9%) surveillance ultrasonography had been negative.ResultsMedian time from positive ultrasonography to confirmation of hepatocellular carcinoma were 9.5 months (2–67) in the Group B and 6.5 months (3–44) in the Group C. Stage distribution and 3-year survival rates were similar amongst all Groups. Surveillance intervals longer than 6 months were associated with the non-curative stage (3.7% vs. 12.5%, p=0.04). Nine (4.6%) patients underwent surveillance were diagnosed as Barcelona-Clinic Liver Cancer stage C.ConclusionEnhanced follow-up by current guidelines is appropriate that treatment can be deferred until a definite diagnosis. Despite optimal surveillance interval and recall policies, few non-curative stage diagnoses seemed inevitable under current standard of care
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