932 research outputs found
An Integrative Remote Sensing Application of Stacked Autoencoder for Atmospheric Correction and Cyanobacteria Estimation Using Hyperspectral Imagery
Hyperspectral image sensing can be used to effectively detect the distribution of harmful cyanobacteria. To accomplish this, physical- and/or model-based simulations have been conducted to perform an atmospheric correction (AC) and an estimation of pigments, including phycocyanin (PC) and chlorophyll-a (Chl-a), in cyanobacteria. However, such simulations were undesirable in certain cases, due to the difficulty of representing dynamically changing aerosol and water vapor in the atmosphere and the optical complexity of inland water. Thus, this study was focused on the development of a deep neural network model for AC and cyanobacteria estimation, without considering the physical formulation. The stacked autoencoder (SAE) network was adopted for the feature extraction and dimensionality reduction of hyperspectral imagery. The artificial neural network (ANN) and support vector regression (SVR) were sequentially applied to achieve AC and estimate cyanobacteria concentrations (i.e., SAE-ANN and SAE-SVR). Further, the ANN and SVR models without SAE were compared with SAE-ANN and SAE-SVR models for the performance evaluations. In terms of AC performance, both SAE-ANN and SAE-SVR displayed reasonable accuracy with the Nash???Sutcliffe efficiency (NSE) > 0.7. For PC and Chl-a estimation, the SAE-ANN model showed the best performance, by yielding NSE values > 0.79 and > 0.77, respectively. SAE, with fine tuning operators, improved the accuracy of the original ANN and SVR estimations, in terms of both AC and cyanobacteria estimation. This is primarily attributed to the high-level feature extraction of SAE, which can represent the spatial features of cyanobacteria. Therefore, this study demonstrated that the deep neural network has a strong potential to realize an integrative remote sensing application
Results of Hepatic Resections at S. N. U. H.: A Ten-year Experience
The medical records of 399 patients who underwent hepatic resection between
January 1981 and December 1990 were reviewed. Information regarding the
results of hepatic resection in terms of operative indication, operative procedure, operative
morbidity and mortality, was abstracted. Until the end of 1990, a total of 402
hepatic resections were completed including 319 primary malignancies, 4 secondary
malignancies, 2 gallbladder carcinomas, 42 intrahepatic cholelithiasis, 35 benign
masses. Major hepatic resections were performed on 117 patients(29%). Of the 117
patients, 60(51%) had histologically proven liver cirrhosis. Minor hepatic resections
were performed on 285 patients (71%). Sepsis was the most frequent complication,
manifested primarily as wound infection(71 cases) or intra-abdominal infection(25
cases). Nonfatal hepatic failure occured in 9 patients with cirrhosis and 1 patient without
cirrhosis. There were 38 operative deaths among 402 hepatic resections, for an
overall operative mortality of 9.4 %. Twenty five of these patients died from hepatic failure
after operation, accounting for 66 % of the total operative mortality. There has
been an increasing frequency of hepatic resection during the last five years. Indications
for resection increased from 87 to 195 resections for hepatocellular carcinoma. The
cumulative data show a decrease in the complication rate and operative mortality. In
the recent period, nonlethal postoperative complications have occured in 135 of 286
patients (47%). The overall survival rates in 172 patients with hepatocellular carcinoma
excluding operative mortalities and palliative resections and reresections, were 71.0 %,
39.8%, 28.3% for 1, 3, and 5 years, respectively
Progress in Understanding and Sequencing the Genome of Brassica rapa
Brassica rapa, which is closely related to
Arabidopsis thaliana, is an important crop and a
model plant for studying genome evolution via
polyploidization. We report the current understanding of the
genome structure of B. rapa and efforts for the
whole-genome sequencing of the species. The tribe
Brassicaceae, which comprises ca. 240 species,
descended from a common hexaploid ancestor with a basic genome
similar to that of Arabidopsis. Chromosome
rearrangements, including fusions and/or fissions, resulted in
the present-day “diploid” Brassica
species with variation in chromosome number and phenotype.
Triplicated genomic segments of B. rapa are
collinear to those of A. thaliana with InDels.
The genome triplication has led to an approximately 1.7-fold
increase in the B. rapa gene number compared to
that of A. thaliana. Repetitive DNA of B.
rapa has also been extensively amplified and has
diverged from that of A. thaliana. For its
whole-genome sequencing, the Brassica rapa Genome
Sequencing Project (BrGSP) consortium has developed suitable
genomic resources and constructed genetic and physical maps.
Ten chromosomes of B. rapa are being allocated to
BrGSP consortium participants, and each chromosome will be
sequenced by a BAC-by-BAC approach. Genome sequencing of
B. rapa will offer a new perspective for plant
biology and evolution in the context of polyploidization
Carbon monoxide inhibits Fas activating antibody-induced apoptosis in endothelial cells
<p>Abstract</p> <p>Background</p> <p>The extrinsic apoptotic pathway initiates when a death ligand, such as the Fas ligand, interacts with its cell surface receptor (<it>ie</it>., Fas/CD95), forming a death-inducing signaling complex (DISC). The Fas-dependent apoptotic pathway has been implicated in several models of lung or vascular injury. Carbon monoxide, an enzymatic product of heme oxygenase-1, exerts antiapoptotic effects at low concentration <it>in vitro </it>and <it>in vivo</it>.</p> <p>Methods</p> <p>Using mouse lung endothelial cells (MLEC), we examined the antiapoptotic potential of carbon monoxide against apoptosis induced by the Fas/CD95-activating antibody (Jo2). Carbon monoxide was applied to cell cultures <it>in vitro</it>. The expression and/or activation of apoptosis-related proteins and signaling intermediates were determined using Western Immunoblot and co-immunoprecipitation assays. Cell death was monitored by lactate dehydrogenase (LDH) release assays. Statistical significance was determined by student T-test and a value of <it>P </it>< 0.05 was considered significant.</p> <p>Results</p> <p>Treatment of MLEC with Fas-activating antibody (Jo2) induced cell death associated with the formation of the DISC, and activation of caspases (-8, -9, and -3), as well as the pro-apoptotic Bcl-2 family protein Bax. Exposure of MLEC to carbon monoxide inhibited Jo2-induced cell death, which correlated with the inhibition of DISC formation, cleavage of caspases-8, -9, and -3, and Bax activation. Carbon monoxide inhibited the phosphorylation of the Fas-associated death domain-containing protein, as well as its association with the DISC. Furthermore, carbon monoxide induced the expression of the antiapoptotic protein FLIP and increased its association with the DISC.</p> <p>CO-dependent cytoprotection against Fas mediated apoptosis in MLEC depended in part on activation of ERK1/2-dependent signaling.</p> <p>Conclusions</p> <p>Carbon monoxide has been proposed as a potential therapy for lung and other diseases based in part on its antiapoptotic effects in endothelial cells. In vitro, carbon monoxide may inhibit both Fas/caspase-8 and Bax-dependent apoptotic signaling pathways induced by Fas-activating antibody in endothelial cells. Strategies to block Fas-dependent apoptotic pathways may be useful in development of therapies for lung or vascular disorders.</p
Approximation of most penetrating particle size for fibrous filters considering Cunningham slip correction factor
In the estimation of the aerosol single fiber efficiency using fibrous filters, there is a size range, where the particles penetrate most effectively through the fibrous collectors, and corresponding minimum single fiber efficiency. For small particles in which the diffusion mechanism is dominant, the Cunningham slip correction factor (Cc) affects the single fiber efficiency and the most penetrating particle size (MPPS). Therefore, for accurate estimation, Cc is essential to be considered. However, many previous studies have neglected this factor because of its complexity and the associated difficulty in deriving the appropriate parameterization particularly for the MPPS. In this study, the expression for the MPPS, and the corresponding expression for the minimum single fiber efficiency are analytically derived, and the effects of Cc are determined. In order to accommodate the slip factor for all particle-size ranges, Cc is simplified and modified. Overall, the obtained analytical expression for the MPPS is in a good agreement with the exact solution
Renal infarction resulting from traumatic renal artery dissection
Renal artery dissection may be caused by iatrogenic injury, trauma, underlying arterial diseases such as fibromuscular disease, atherosclerotic disease, or connective tissue disease. Radiological imaging may be helpful in detecting renal artery pathology, such as renal artery dissection. For patients with acute, isolated renal artery dissection, surgical treatment, endovascular management, or medical treatment have been considered effective measures to preserve renal function. We report a case of renal infarction that came about as a consequence of renal artery dissection
Highly sensitive colorimetric detection of allergies based on an immunoassay using peroxidase-mimicking nanozymes
Nanomaterials that exhibit enzyme-like characteristics, which are called nanozymes, have recently attracted significant attention due to their potential to overcome the intrinsic limitations of natural enzymes, such as low stability and relatively high cost for preparation and purification. In this study, we report a highly efficient colorimetric allergy detection system based on an immunoassay utilizing the peroxidase- mimicking activity of hierarchically structured platinum nanoparticles (H-Pt NPs). The H-Pt NPs had a diameter of 30 nm, and were synthesized by a seed-mediated growth method, which led to a significant amount of peroxidase-like activity. This activity mainly occurs because of the high catalytic power of the Pt element, and the fact that the H-Pt NPs have a large surface area available for catalytic events. The H-Pt NPs were conjugated to an antibody for the detection of immunoglobulin E (IgE) in the analytes; IgE is a representative marker for the diagnosis of allergies. They were then successfully integrated into a conventionally used allergy diagnostic test, the ImmunoCAP diagnostic test, as a replacement for natural signaling enzymes. Using this strategy, total and specific IgE levels were detected within 5 min at room temperature, with high specificity and sensitivity. The practical utility of the immunoassay was also successfully verified by correctly determining the levels of both total and specific IgE in real human serum samples with high precision and reproducibility. The present H-Pt NP-based immunoassay system would serve as a platform for rapid, robust, and convenient analysis of IgE, and can be extended to the construction of diagnostic systems for a variety of clinically important target molecules.11Ysciescopu
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