273 research outputs found
Attributing northern high-latitude precipitation change over the period 1966β2005 to human influence
Using an optimal fingerprinting method and improved observations, we compare observed and CMIP5 model simulated annual, cold season and warm season (semi-annual) precipitation over northern high-latitude (north of 50A degrees N) land over 1966-2005. We find that the multi-model simulated responses to the effect of anthropogenic forcing or the effect of anthropogenic and natural forcing combined are consistent with observed changes. We also find that the influence of anthropogenic forcing may be separately detected from that of natural forcings, though the effect of natural forcing cannot be robustly detected. This study confirms our early finding that anthropogenic influence in high-latitude precipitation is detectable. However, in contrast with the previous study, the evidence now indicates that the models do not underestimated observed changes. The difference in the latter aspect is most likely due to improvement in the spatial-temporal coverage of the data used in this study, as well as the details of data processing procedures.111911Ysciescopu
Evolutionarily Optimized Electromagnetic Sensor Measurements for Robust Surgical Navigation
Β© 2001-2012 IEEE. Miniaturized electromagnetic sensors are increasingly introduced to navigate surgical instruments to anatomical targets during minimally invasive procedures, such as endoscopic surgery. These sensors are usually attached at the distal tips of surgical instruments to track their three-dimensional motion represented by the position and orientation in six degrees of freedom. Unfortunately, these sensors suffer from inaccurate measurements and jitter errors due to the patient movement (e.g., respiratory motion) and magnetic field distortion. This paper proposes an evolutionary computing strategy to optimize the sensor measurements and improve the tracking accuracy of surgical navigation. We modified two evolutionary computation algorithms and proposed adaptive particle swarm optimization (APSO) and observation-boosted differential evolution (OBDE) to enhance the navigation accuracy. The experimental results demonstrate that our modified algorithms to evolutionarily optimize electromagnetic sensor measurements can critically reduce the tracking error from 4.8 to 2.9 mm. In particular, OBDE outperforms APSO for electromagnetic endoscopic navigation
Surface modification, strengthening effect and electrochemical comparative study of Zn-Al2O3-CeO3 and Zn-TiO2-CeO3 coating on mild steel
Surface enhancement of engineering materials is
necessary for preventing service failure and corrosion attacks
industrially. The surface modification, strengthening effect
and electrochemical comparative study of Zn-Al2O3-CeO3
and Zn-TiO2-CeO3 coating on mild steel was investigated.
Deposition was performed to obtain a better surface adherent
coating using the electrodeposition technique. Co-deposition
of mild steel resulted into surface modification attributes to
the complex alloys that were developed. Films of mild steel
were electrodeposited on zinc electrodes using the chloride
bath solutions. The effect of deposition potentials was systematically
studied using a focus ion beam scanning electron
microscope (FIB-SEM) and an atomic force microscope
(AFM) to observe the surface morphology, topography and
the surface adherent properties of the coatings. The elemental
composition and the phases evolved in composite coatings were measured by means of the energy dispersed
spectrometer (EDS). The microhardness measurements and
corrosion behaviours of the deposits were investigated.
Weight loss measurement was conducted on the plated samples
to observe the rate of corrosion and it was observed that
there was severe corrosion on the controlled sample in comparison
to the plated samples and that Zn-TiO2-CeO3
resisted more corrosion attacks
Hf-based high-k materials for Si nanocrystal floating gate memories
Pure and Si-rich HfO2 layers fabricated by radio frequency sputtering were utilized as alternative tunnel oxide layers for high-k/Si-nanocrystals-SiO2/SiO2 memory structures. The effect of Si incorporation on the properties of Hf-based tunnel layer was investigated. The Si-rich SiO2 active layers were used as charge storage layers, and their properties were studied versus deposition conditions and annealing treatment. The capacitance-voltage measurements were performed to study the charge trapping characteristics of these structures. It was shown that with specific deposition conditions and annealing treatment, a large memory window of about 6.8 V is achievable at a sweeping voltage of Β± 6 V, indicating the utility of these stack structures for low-operating-voltage nonvolatile memory devices
Molecular Prognostic Prediction for Locally Advanced Nasopharyngeal Carcinoma by Support Vector Machine Integrated Approach
BACKGROUND:Accurate prognostication of locally advanced nasopharyngeal carcinoma (NPC) will benefit patients for tailored therapy. Here, we addressed this issue by developing a mathematical algorithm based on support vector machine (SVM) through integrating the expression levels of multi-biomarkers. METHODOLOGY/PRINCIPAL FINDINGS:Ninety-seven locally advanced NPC patients in a randomized controlled trial (RCT), consisting of 48 cases serving as training set and 49 cases as testing set of SVM models, with 5-year follow-up were studied. We designed SVM models by selecting the variables from 38 tissue molecular biomarkers, which represent 6 tumorigenesis signaling pathways, and 3 EBV-related serological biomarkers. We designed 3 SVM models to refine prognosis of NPC with 5-year follow-up. The SVM1 displayed highly predictive sensitivity (sensitivity, specificity were 88.0% and 81.9%, respectively) by integrating the expression of 7 molecular biomarkers. The SVM2 model showed highly predictive specificity (sensitivity, specificity were 84.0% and 94.5%, respectively) by grouping the expression level of 12 molecular biomarkers and 3 EBV-related serological biomarkers. The SVM3 model, constructed by combination SVM1 with SVM2, displayed a high predictive capacity (sensitivity, specificity were 88.0% and 90.3%, respectively). We found that 3 SVM models had strong power in classification of prognosis. Moreover, Cox multivariate regression analysis confirmed these 3 SVM models were all the significant independent prognostic model for overall survival in testing set and overall patients. CONCLUSIONS/SIGNIFICANCE:Our SVM prognostic models designed in the RCT displayed strong power in refining patient prognosis for locally advanced NPC, potentially directing future target therapy against the related signaling pathways
CurrentβVoltage Characteristics in Individual Polypyrrole Nanotube, Poly(3,4-ethylenedioxythiophene) Nanowire, Polyaniline Nanotube, and CdS Nanorope
In this paper, we focus on currentβvoltage (IβV) characteristics in several kinds of quasi-one-dimensional (quasi-1D) nanofibers to investigate their electronic transport properties covering a wide temperature range from 300 down to 2 K. Since the complex structures composed of ordered conductive regions in series with disordered barriers in conducting polymer nanotubes/wires and CdS nanowires, all measured nonlinearIβVcharacteristics show temperature and field-dependent features and are well fitted to the extended fluctuation-induced tunneling and thermal excitation model (Kaiser expression). However, we find that there are surprisingly similar deviations emerged between theIβVdata and fitting curves at the low bias voltages and low temperatures, which can be possibly ascribed to the electronβelectron interaction in such quasi-1D systems with inhomogeneous nanostructures
Observation of a ppb mass threshoud enhancement in \psi^\prime\to\pi^+\pi^-J/\psi(J/\psi\to\gamma p\bar{p}) decay
The decay channel
is studied using a sample of events collected
by the BESIII experiment at BEPCII. A strong enhancement at threshold is
observed in the invariant mass spectrum. The enhancement can be fit
with an -wave Breit-Wigner resonance function with a resulting peak mass of
and a
narrow width that is at the 90% confidence level.
These results are consistent with published BESII results. These mass and width
values do not match with those of any known meson resonance.Comment: 5 pages, 3 figures, submitted to Chinese Physics
Exosome-Related Multi-Pass Transmembrane Protein TSAP6 Is a Target of Rhomboid Protease RHBDD1-Induced Proteolysis
We have previously reported that rhomboid domain containing 1 (RHBDD1), a mammalian rhomboid protease highly expressed in the testis, can cleave the Bcl-2 protein Bik. In this study, we identified a multi-pass transmembrane protein, tumor suppressor activated pathway-6 (TSAP6) as a potential substrate of RHBDD1. RHBDD1 was found to induce the proteolysis of TSAP6 in a dose- and activity-dependent manner. The cleavage of TSAP6 was not restricted to its glycosylated form and occurred in three different regions. In addition, mass spectrometry and mutagenesis analyses both indicated that the major cleavage site laid in the C-terminal of the third transmembrane domain of TSAP6. A somatic cell knock-in approach was used to genetically inactivate the endogenous RHBDD1 in HCT116 and RKO colon cancer cells. Exosome secretion was significantly elevated when RHBDD1 was inactivated in the two cells lines. The increased exosome secretion was verfied through the detection of certain exosomal components, including Tsg101, Tf-R, FasL and Trail. In addition, the elevation of exosome secretion by RHBDD1 inactivation was reduced when TSAP6 was knocked down, indicating that the role of RHBDD1 in regulating exosomal trafficking is very likely to be TSAP6-dependent. We found that the increase in FasL and Trail increased exosome-induced apoptosis in Jurkat cells. Taken together, our findings suggest that RHBDD1 is involved in the regulation of a nonclassical exosomal secretion pathway through the restriction of TSAP6
Identification of key genes for carcinogenic pathways associated with colorectal adenoma-to-carcinoma progression
Colorectal adenomas form a biologically and clinically distinct intermediate stage in development of colorectal cancer (CRC) from normal colon epithelium. Only 5% of adenomas progress into adenocarcinomas, indicating that malignant transformation requires other biological alterations than those involved in adenoma formation. The present study aimed to explore which cancer-related biological processes are affected during colorectal adenoma-to-carcinoma progression and to identify key genes within these pathways that can serve as tumor markers for malignant transformation. The activity of 12 cancer-related biological processes was compared between 37 colorectal adenomas and 31 adenocarcinomas, using the pathway analysis tool Gene Set Enrichment Analysis. Expression of six gene sets was significantly increased in CRCs compared to adenomas, representing chromosomal instability, proliferation, differentiation, invasion, stroma activation, and angiogenesis. In addition, 18 key genes were identified for these processes based on their significantly increased expression levels. For AURKA and PDGFRB, increased mRNA expression levels were verified at the protein level by immunohistochemical analysis of a series of adenomas and CRCs. This study revealed cancer-related biological processes whose activities are increased during malignant transformation and identified key genes which may be used as tumor markers to improve molecular characterization of colorectal tumors
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